Background technology
WLAN is as the user is extensively paid close attention to from the system that the LAN cable that line method is arranged frees.According to WLAN, big many parts of the cable in the working space (as office) can omit, so that communication terminal (as personal computer PC) can relatively easily move.In recent years, thisly needed remarkable increase, and the speed that is accompanied by Wireless LAN system increases and the price reduction.Especially, recently, studied personal area network (PAN) has been used to set up small-scale wireless network between a plurality of electronic installations that are in around the individual environment, so that carry out information communication.For example, utilized the frequency band of the mandate that does not need power department to stipulate different wireless communication systems and radio communication device, such as 2.4-GHz frequency band, 5-GHz frequency band etc.
Example about the standard specification of wireless network comprises IEEE (institute of electrical and electronic engineers) 802.11 (for example referring to non-patent document 1), HiperLAN/2 (for example referring tonon-patent document 2 and non-patent document 3), IEEE802.15.3 and Bluetooth communication.About the IEEE802.11 standard, extension standards (such as IEEE802.11a, for example referring tonon-patent document 4, IEEE802.11b and IEEE802.11g) can be utilized according to the wireless communications method and the different of frequency band of using.
Utilize wireless communication system, form the multibus environment, wherein receive a plurality of reflected waves and postpone the combination of ripple at DRS, DRS also receives the ground wave from data transfer station side.Owing to multibus produces delay distortion (or frequency selection phasing), in communication process, produce error.This causes a problem, promptly produces because the intersymbol interference that delay distortion causes.
The major measure of opposing delay distortion comprises the multicarrier transfer approach, by OFDM modulation representative.Utilize OFDM (OFDM) method, the frequency setting of each carrier wave must make that each carrier wave is mutually orthogonal in a sign field.When the information of transmission, to go here and there-also conversion for the information of each symbol period serial transfer, this symbol period is slower than rate of information throughout.The dateout of a plurality of conversions is assigned to each carrier wave, thinks each carrier wave execution amplitude and phase modulated.By carrying out the anti-FFT about a plurality of carrier waves, data transaction becomes the time shaft signal, keeps the quadrature and the transmission of each carrier wave simultaneously.When the information of reception, carry out inverse operation, promptly the time shaft conversion of signals is become the frequency axis signal, so that carry out with respect to demodulation about the modulator approach of each carrier wave by carrying out FFT, carry out also-go here and there conversion then, so that reproduce the raw information that transmits with serial signal.The OFDM modulator approach has been used as the standard criterion as the WLAN among the IEEE802.11a/g.
Also have, another problem of wireless communication system is the linear spectral that the data by extremely continuous 0-1 form.For example, under the situation of using the OFDM modulator approach, structure consists of a plurality of subcarriers, and the difference between average power and the peak power is very big, and the power bracket that causes transmitting side and receiver side lacks.For this reason, on drive access, carry out scrambling usually for pseudo-random data.
Usually, transmitting side, scrambling is carried out by calculating the xor operation that transmits between data and the pseudo-random bit, and its output is used as the transmission data.On the other hand,, carry out descrambling, can extract the transmission data thus by the data of calculating reception and the xor operation between the pseudo-random bit at receiver side.At this moment, transmitting side must have identical pseudo-random bit generator and have identical initial value with receiver side.
The example that is used to carry out the wireless communication system of scrambling comprises IEEE802.11a, and it is the technical standard of WLAN.In Figure 32, shown the example of the structure of radio communication device, it is used for IEEE802.11a.This radio communication device is for example carried out about the voice communication corresponding to another radio communication device (not shown) of IEEE802.11a.After this, with 32 explanations of doing about wireless communication operation with reference to the accompanying drawings.
At first, the operation of signal flow explanation about transfer system will be followed.Under the situation of the data communication that is connected to computer, be imported into data I/O processing unit 102 such as the data-signal of audio frequency, this signal is converted into suitable digit data sequence.
Then, this data sequence is input to and transmits data processing unit 110.If need, this transmission data processing unit 110 receives the communication control data that will be sent to the radio communication device (not shown) from control unit 104, and this radio communication device is as the opposing party of radio communication.Transmit then data processing unit 110 control data that receives is carried out suitable multiplexing, form and output frame and structure of time slot so that transmit in radio zone.
Subsequently, CRC (cyclic redundancy check (CRC)) adder 112 will be used for being increased to the transmission data in the redundancy of receiver side detection error, and in addition, encryption device 114 will transmit data and encrypt and export.
Then, (back explanation) will transmit data and carry out scrambling scrambler 116 according to predetermined algorithm, so that form pseudo random sequence.Also have, data head (header) generator 117 generates PHY (physical layer) data head.After this, encoder 118 carries out convolutional encoding with the transmission data of PHY data head and scrambling, and is interweaved by interleaver 120.According to this interleaving treatment, the bit sequence of coding is according to specific regular recast arrangement, so as the receiver side burst error can promptly deinterleave by carrying out anti-operation (back explanation) be converted into random error.
After this, modulator 122 will transmit data map to signaling point and export in-phase component (I component) and quadrature component (Q component) in the delivery time.Comprehensive IFFT unit 124 carries out anti-FFT with output signal, carries out the OFDM modulation thus.
After this, the whole ripple unit 126 of time waveform provides guard time by increasing the cycle prefix, and dateout is carried out the window wing (window wing) processing so that the rising and the decline of level and smooth OFDM modulation symbol.
Then, digital to analog converter 128 will transmit data and be transformed into analog waveform from digital waveform, and RF conveyer 130 will transmit data and carry out filtering, utilizes I component and Q component to carry out Vector Modulation, frequency inverted to the control of suitable transmission channel, delivering power, amplification etc.
The RF conveyer 130 upwards transmission signal of conversion is imported into antenna 134 through antenna diplexer 132, sends out as electromagnetic wave from antenna 134 at last.This transmits the opposing party (not shown) reception of signal by radio communication.
Notice that antenna diplexer 134 is used for separately transmitting signal and received signal, use a duplexer in TDD method and the FDD/TDMA method, duplexer is used in the additive method usually.At this moment, we we can say, have used duplexer, and this is because the example here is the IEEE802.11a of TDD method.
Below, describe operation in detail about receiving system.Here we say,radio communication device 100 receives the transmission signal that is produced by another radio communication device (as the opposing party's (not shown) of radio communication, carrying out the identical processing of transfer system among the above-mentioned IEEE802.11a).
Transmission signal from radio communication the opposing party receives as electromagnetic wave at antenna 134.This signal comes out from the intrinsic transmission Signal Separation of antenna diplexer 132, is input to RF receiver 140 afterwards.RF receiver 140 amplifies received signal, and the attenuation of non-needed frequency composition is selected the channel that needs, frequency inverted, the control of received signal amplitude level, vector detection process (so that separating I component and Q component), bandwidth constraints etc., the I component of received signal and Q component are extracted out like this.
Analog to digital converter 142 is with the received signal converting digital waveform of the analog waveform of RF receiver 140 downward conversions.Afterwards, synchronous circuit 144 will receive data and carry out frame synchronization, correction of frequency errors etc.At this moment, under search can be communicated by letter immediately after power connection another communication party and analogue, the detection of synchronizing signal or initial synchronisation utilizes synchronous circuit 144 to carry out.Proposed multiple scheme about initial synchronisation, frame synchronization, correction of frequency errors etc., but this is not directly related with essence of the present invention, so this specification is not further described.
Subsequently, the whole ripple unit 146 of time waveform will receive data and make whole ripple of time, so that remove by increasing the guard time that the cycle prefix provides, comprehensive afterwards FFT unit 148 will receive data and carry out FFT to carry out the OFDM demodulation.
Afterwards, equalizer 150 utilizes the estimation of drive access and estimated result to carry out balanced.In some cases, the information of equalizer 150 input synchronous circuits 144 utilizes this information to estimate drive access etc.Note for equalizer proposes multiple setting, but these are not directly related with essence of the present invention, so this specification is not further described.
The output of equalizer 150 is input to demodulator 152, and is made signaling point and determine to receive the position estimated value with output.Afterwards, receive data and be input to deinterleaver 154,, be used for rearranging the bit sequence of coding to deinterleave according to ad hoc rules.Afterwards, decoder 156 is carried out the decoding of the self-correcting code that transmits side.
Then, the reception data that descrambler 158 will be decoded are carried out descrambling, and this process is to transmit the inverse transformation of the scrambling of side execution.Have, data head withdrawal device 157 is from the reception data pick-up PHY data head of decoding again.In addition,decryption device 160 deciphering transmits the enciphered data of sides, the reception data of the CRC of CRC check unit 162 outputs having removed afterwards and about receiving the CRC check result of data block.
Then, determining that the CRC check result who receives data block does not have under the situation of error, reception data processing unit 164 removes will be at the frame structure and the structure of time slot of radio zone transmission.Under the data communication situation of (for example being connected with computer), data I/O processing unit 102 becomes data-signal and output receiving data transaction subsequently.
Comprise under the situation of the communication control data of sending from the opposing party's (not shown) of radio communication in the reception data, extract these parts and be input to control unit 104 through receivingsystem control line 106 by receiving data processing unit 164.Afterwards, control unit 104 is explained control data of receiving and the operation control of carrying out each unit within theradio communication device 100 according to the instruction that receives.
Each unit of transfer system is connected to control unit 104 through transfer system control line 108.Correspondingly, control unit 104 can be carried out the various operation controls and the condition monitoring of transfer system through transfersystem control line 108, such as the ON/OFF control of transfer system, operation control and condition monitoring, the accurate adjustment of delivery time, coding method and the correction of signaling point mapping method, the control that retransmits etc. of RF conveyer 130.
Have, each unit of receiving system is connected to control unit 104 through receivingsystem control line 106 again.Correspondingly, control unit 104 can be carried out the operation control and the monitoring of various receiving systems through receivingsystem control line 106, as the correction of accurate adjustment, coding/decoding method and the signaling point mapping method of the operation control of the ON/OFF control of receiving system, RF receiver 140 and condition monitoring, time of reception, the control that retransmits etc.
Figure 33 shows the structure of the scrambler 116 in the transfer system that is arranged at radio communication device 100.Illustrated scrambler 116 is made of 7 grades of shift registers, wherein X1Be lowest order, X7Be highest order, every value is with X2-X7Order be displaced to adjacent more high-order.For highest order X7, calculate X4And X7The xor operation of output, the result is input to lowest order X1This result and input data intercropping xor operation simultaneously, this result as scrambling after data output.
Figure 33 has shown that the data that are different from 0000000 (being complete 0) are used for X1-X7This is because complete 0 data can not be used as scrambler.In other words, the aggregate of operable bit sequence is 27-1=127 can use any number wherein.The scrambling mode that the scrambling process takes place can change by revising scrambling initial value.
Figure 34 shows the structure of the descrambler 158 in the receiving system that is arranged at radio communication device 100.Illustrated descrambler has the structure that is entirely identical to the scrambler shown in Figure 24, its storage from the initial value that transmits side and provide to X1-X7, and the xor operation of the input data of the initial value of calculating storage and reception, carry out descrambling thus.
Figure 35 shows the form of the ofdm signal of IEEE802.11a regulation.As shown in the figure, preamble at first is transmitted, and the SIGNAL field transmits with an OFDM symbol afterwards, transmits the DATA field again.
The PHY data head of IEEE802.11a comprise on the MSB side of above-mentioned SIGNAL field, DATA field by 16 services of forming (service) field.Figure 36 has shown the structure of PHY data head in detail.As shown in the figure, the SIGNAL field comprise modulator approach, 4 RATE information determining from the code rate of self-correcting code, 1 reservation position, indication transferdata packets length 14 LENGTH information, be used to detect the bit error of SIGNAL field PARITY information, be used to stop 6 TAIL position of convolution (convolution) sign indicating number.Here, the PARITY position is provided with to such an extent that make the quantity that is included in " 1 " in the bit sequence that is made of RATE information, reservation position, LENGTH information and PARITY position become even number.
After the SIGNAL field, 16 service field and then, in these 16,7 transmission that are used for scrambling initial value (i.e. notice) of MSB side, this is identical with the initial value that is provided for the receiver side descrambling.In passing, the residue of reservation service field is 9.
The SIGNAL field is transmitted by BPSK R1/2, and the Eb/No that wherein needs is minimum in the modulating mode of IEEE802.11a regulation.Utilize OFDM to send to transmit by BPSK R1/2 data carrier and the situation of 48 subcarriers under, 24 of SIGNAL field equal 48 (subcarrier) * 1/2 (code rate)=24, and transmit with an OFDM symbol.This SIGNAL field is not carried out scrambling.
After this follow-up data field is transmitted under scrambled state, and this scrambling is to carry out with the modulating mode that the RATE field in the SIGNAL field is indicated.
To illustrate in greater detail the processing of the scrambling initial value that transmits side below, the processing of the descrambling initial value of receiver side.Scrambling and descrambling are (for example referring to the patent documents 1) realized by combination shift register and XOR circuit according to the generator multinomial of expression pseudo-random number sequence.
Figure 37 has shown the peripheral structure that transmits side scrambler 116 in detail.Transmitting data after encryption device 114 is encrypted, transmitting the EXOR116b of data in scrambler 116 by the XOR that calculates the scrambling mode that the method that transmits data and illustrate later produces and carry out scrambling.Its output is carried out error correction code at encoder 118.
Beginning is during scrambling, and scrambling mode generator 116a receives the notice from the scrambling initial value when producing scrambling mode of control unit 104.The scrambling initial value of notice is arranged in the register of the scrambling body that is made of shift register, as shown in figure 33, when for the value in each clock shift register, produces a scrambling mode.
Especially, about 7 of the service field of the head end that is arranged on the DATA field that is used to transmit scrambling mode, in 7 ' " 0 " data were transfused in the moment of encryption device 114 output, 7 of the service field XORs by the scrambling mode that calculates these data and will produce from scrambling initial value produce, for each position is provided with this scrambling initial value.
But the input data are complete " 0 ", so 7 scrambling initial value with setting of the output of EXOR116b are identical.Receiving the receiver side of these data, 7 of this field can be as the initial value of descrambling.
Figure 38 has shown the peripheral structure of the descrambler 158 of receiver side in detail.Receive data after decoder 156 has carried out the error correction decoding, the EXOR158b in descrambler 158 comes descrambling to receive data by calculating the XOR that receives data and descrambling pattern, and this descrambling pattern produces with the method that the back will illustrate.Its output is indecryption device 160 deciphering.
During the beginning descrambling, 7 of MSB side of service field of head end that are arranged at the DATA field of reception are extracted as the descrambling initial value, and be set in the register of the descrambling body that constitutes by shift register, as shown in figure 34, produce a descrambling pattern for the value in each clock shift register.
So, utilize IEEE802.11a, by using the service field in the PHY data head part (not scrambling) to construct 7 of scrambling initial value so that transmit, therefore identical scrambling initial value and descrambling initial value can be shared between transmitting and receiving, thus correct execution scrambling and descrambling.But the method that is used to utilize data division to transmit scrambling initial value is equal in the data division storage and is different from the data of the actual user data that will transmit of user and the method that transmits, so transmission efficiency worsened by this difference, and this is not desirable.
Have again, utilize the transformat of IEEE802.11a, be used to transmit the OFDM symbol use BPSK modulation of SIGNAL field, the S/N that wherein needs is very low, code rate=1/2, but the DATA field that comprises scrambling initial value then can be higher than the modulator approach of above-mentioned S/N with the S/N of needs to be transmitted, and code rate is higher than above-mentioned speed, therefore is easy to generate bit error.
Have again,, utilize convolution code to carry out error correction in physical layer for SIGNAL field and whole data.For the coding/decoding method of convolution code, having known has the Viterbi coding/decoding method.
On the other hand,, also be difficult to complete correction error, therefore detect under the situation of uncorrected error, need request to transmit and stress new transmission in the receiving equipment side even adopt so anti-error measure.Increase the number of repetition that retransfers and to influence communication speed.For example, when the fluidisation of (as QoS, service quality) such as execution motion image datas is communicated by letter, keep communication bandwidth and guarantee that stable speed just becomes very difficult.Therefore, in order to handle qos feature, for MAC (medium access control) sublayer data, promptly the PSDU of data can consider to carry out correction processing as media access control sublayer.Block code (for example Reed-Solomon product code) can be used for such error correction.
But even to the error correction of media access control sublayer execution corresponding to QoS, can not normally carry out synchronously between scrambling and the descrambling under the countermeasures of the situation do not carry out to(for) service, receiver side is descrambling PSDU normally.Can not normally carry out under the situation of descrambling, transmit side and will be requested the data that retransfer,, can not obtain this effect even carry out error correction corresponding to QoS.As mentioned above, can consider to guarantee transmission, cause error probably so should serve than SIGNAL with modulating mode with high level error tolerance about this service.
As the method that prevents owing to the deterioration of the transmission efficiency of notifying scrambling initial value to produce, proposed a kind of with reference to MAC Address and the technology (for example referring to patent document 2) of using its part as scrambling initial value.In the case, do not need to utilize data division to transmit scrambling initial value.
But, utilize this method, MAC Address itself can not be by scrambling, and this causes a problem aspect hidden.Have again, MAC Address itself can not be meaned by scrambling if MAC Address transmit during " 0 " and " 1 " in the data form the distribution of biasing, it just can not convert random bit sequences to, so still has the possibility of the linear composition of generation in the frequency spectrum in this district.
In addition, utilize IEEE802.11a, the MAC data head that comprises PHY data head, MAC Address etc. is clearly separated, adopting above-mentioned scrambling Notification Method under the situation of such wireless communication system, except MAC Address DATA partly is described, another part of MAC Address is used for PHY data head part, and this has caused redundancy.
International standard ISO/IEC8802-11:1999 (E) ANSI/IEEE Std802.11,1999 editions, part 11: WLAN medium access control (MAC) and physical layer (PHY) standard
Etsi standard ETSI TS 101761-1V1.3.1 broadband radio accesses network (BRAN); HIPERLAN 2 types; Data link control (DLC) layer; Part 1: master data transmitting function
ETSI TS 101 761-2V1.3.1 broadband radio accesses network (BRAN); HIPERLAN 2 types; Data link control (DLC) layer; Part 2: radio link control (RLC) sublayer
Embodiment
After this, will describe embodiments of the invention with reference to the accompanying drawings in detail.
Fig. 1 schematically illustrates the total of communication system according to an embodiment of the invention.Utilize the example among this figure, thecommunicator 21 that is connected to network 30 is wireless connections with thecommunicator 11 that is connected to messaging device 12.Communicator 21 is used as an access point (AP), and controls the connection of another communicator to network 30.Communicator 11 is intended to for example be connected to network 30 by communicating by letter withcommunicator 21 asterminal.Communicator 11 can with for example be connected as personal computer ofmessaging device 12 etc.The WLAN (local area network (LAN)) thatcommunicator 21,communicator 11 andnetwork 30 form as another network.
After this, will the structure ofcommunicator 11 be described.Communicator 11 andcommunicator 21 have essentially identical internal structure, though the function difference.
A. the structure of radio communication device and operation
Fig. 2 has schematically shown the functional structure of conveyer according to an embodiment of the invention.
Under the situation of data communication (for example being connected to a computer), data-signal is imported into I/O processing unit 502, and converts suitable digit data sequence to.
Then, this transmits data sequence to transmit data processing unit 510 inputs, if desired, receive the communication control data that will be sent to from control unit 504 as the radio communication device of radio communication the opposing party (not shown), communication control data suitably carry out multiplexing after, formation and output frame and structure of time slot are so that transmit in radio zone.
Then, CRC adder 512 is added the redundancy of the error that is used to detect receiver side to these transmissions data, and 514 pairs of encryption devices should transmit data encryption and export.
Then, scrambler 516 carries out scrambling according to pre-defined algorithm to these transmission data so that form pseudo-random data.Have, datahead generating unit 517 produces the PHY data head again.Scrambler 516 utilizes the part position of the PHY data head of data head generatingunit 517 generations to generate scrambling initial value, but it specifies and will make in the back.
Note utilizing the IEEE.802.11a standard generator multinomial below having stipulated:
S(x)=x7+x4+1
Then, encoder 518 will transmit data and make PHY data head and convolutional encoding, and then interleaver 520 will transmit data and interweave.According to this interleaving treatment, the bit sequence of coding is rearranged according to pre-defined rule, therefore at receiver side, promptly deinterleaves by carrying out inverse operation, and sudden error can convert random error to.
Then, the signaling point when modulator 522 will transmit data map to transmission, and output in-phase component (I component) and quadrature component (Q component).The OFDM modulation is carried out in compound IFFT unit 524, and anti-FFT is carried out in its output.
Then, time waveform shaping unit 526 provides guard time by adding the cycle prefix, and will transmit data and carry out the window wing (window wing) processing so that the rising and the decay of level and smooth OFDM modulation symbol.
Then, DA transducer 528 will transmit data and convert analog waveform to from digital waveform, and RF conveyer 530 transmits data filtering, utilize I component and Q component to carry out Vector Modulation, frequency inverted to the control of suitable transmitted frequency passage, delivering power, amplification etc.
The RF conveyer 530 upwards transmission signal of conversion is imported into antenna 534 through antenna diplexer 532, sends out as electromagnetic wave from antenna 534 at last.This transmits signal and is received by radio communication the opposing party (not shown).
Notice that antenna diplexer 534 is used for separately transmitting signal and received signal, use antenna switcher in TDD method and the FDD/TDMA method, duplexer is used in other method usually.Below we consider to use antenna switcher because the IEEE802.11a that has used the TDD method is as an example.
Each unit of transfer system is connected to control unit 504 through transfer system control line 508.Thus, control unit 504 can be carried out regularly accurate adjustment of the operation control of the various operations control of this transfer system and monitoring (such as the ON/OFF control of transfer system), RF conveyer 530 and condition monitoring, transmission, correction or the correction of signaling point mapping method, the control that retransmits etc. of coding method through transfersystem control line 508.
Have, Fig. 3 shows the functional structure of receiver according to an embodiment of the invention again.
Transmission signal from radio communication the opposing party receives as electromagnetic wave at antenna 634.This signal is input to RF receiver 640 then from the transmission Signal Separation ofantenna diplexer 632 self.RF receiver 640 amplifies received signal, and the attenuation of non-needed frequency composition is selected the channel that needs, frequency inverted, the control of received signal amplitude level, vector detection process (being used for separately I component and Q component), bandwidth constraints etc. are so the I component of received signal and Q component are extracted out.
The received signal that AD converter 642 is changed RF receiver 640 downwards converts digital waveform to from analog waveform.Then, synchronous circuit 644 will receive data and carry out frame synchronization, correction of frequency errors etc.Below when follow closely turn on the power switch or similar operations after under the search the opposing party's that can communicate by letter the situation, utilize synchronous circuit 644 to carry out the detection of synchronizing signals or initial synchronisation.Proposed multiple setting about initial synchronisation, frame synchronization, correction of frequency errors etc., but these and essence of the present invention do not have direct relation, so no longer explain in this specification.
Then, time waveform shaping unit 646 carries out the time waveform shaping so that remove by adding the guard time that the cycle prefix provides with receiving data, and comprehensive afterwards FFT unit 648 will receive data and carry out FFT so that carry out the OFDM modulation.
Then, equalizer 650 utilizes the estimation and the estimation result that transmit passage to carry out equilibrium.In some cases, equalizer 650 is imported the information of synchronous circuits 644 and is utilized this data-evaluation to transmit passage etc.Note having proposed multiple setting as equalizer, but these and essence of the present invention do not have direct relation, so no longer explain in this specification.
The output of equalizer 650 is input to demodulator 652, and makes signaling point and determine to receive a position estimated value so that export.Afterwards, receive data and be input to deinterleaver 654, rearrange the bit sequence of coding to deinterleave according to ad hoc rules.Decoder 656 is carried out the decoding of the self-correcting code that transmits side afterwards.
Then, the reception data that descrambler 658 will be decoded are carried out descrambling, and this is the inverse transformation that transmits the scrambling of side execution.Have, datahead withdrawal device 657 is from the reception data pick-up PHY data head of decoding again.Descrambler 658 can utilize the part of PHY data head to produce the scrambling initial value identical with conveyer, but will explain it in the back.Note utilizing the IEEE802.11a standard, with the circuit of scrambler same type as descrambler.
In addition, the encryptions that 660 pairs of decryption devices transmit side are decrypted, the reception data of the CRC of CRC check unit 662 outputs having removed afterwards and about receiving the CRC check result of data block.
Then, do not have under the situation of error, receive data processing unit 664 and remove and be used for the frame structure and the structure of time slot that transmit in radio zone in the CRC check result who determine to receive data block.Under the situation of data communication (for example being connected to computer), data I/O processing unit 602 will receive data transaction and become data-signal and output afterwards.
Comprise under the situation from the communication control data of radio communication the opposing party (not shown) that this part extracts and is input to control unit 604 through receivingsystem control line 606 by receiving data processing unit 664 receiving data.Control unit 604 is explained the control data that receives afterwards, carries out the operation control of each unit in theradio communication device 600 according to the instruction that receives.
Each unit of receiving system is connected to control unit 104 through receiving system control line 106.Therefore, control unit 104 can be carried out the operation control of the multiple operation control of receiving systems and monitoring (as the ON/OFF control of receiving system), RF receiver 140 and condition monitoring, the correction of reception accurate adjustment, coding/decoding method and signaling point mapping method regularly, the control that retransmits etc. through receivingsystem control line 106.
The invention is characterized in a kind of method, this method is transmitting shared scrambling initial value between side and the receiver side.Describe the scrambling of transmission side and the processing of descrambling initial value in detail below with reference to Fig. 4, wherein Fig. 4 has shown the structure that transmits side scrambler 516 peripheries.
The data that are used to produce the data head that is made of the parameter that is used to control physical layer (for example code rate) are input todata head generator 517 from control unit 504.The data head information that encoder 518 will produce is here carried out error correction code.Generated through after the data head information of error correction code, carried out the transmission data of error correction code and utilized method described as follows to be linked to encoder 518.
That is to say that it is encrypted at encryption device 514 to transmit data, the EXOR516b in scrambler 516 comes scrambling by calculating the xor operation that transmits data and scrambling mode afterwards, and scrambling mode utilizes the method that illustrates later to generate.Encoder 518 carries out error correction code has been made error correction code with generation transmission data with output.
On the other hand,data head generator 517 produces data head information based on the data that are used to produce data head from control unit 504 input, and outputs to encoder 518 and scrambler 516.Scrambling initial value generator 516c is included in the scrambler 516, and it utilizes one of multiple technologies of illustrating later to produce scrambling initial value from data head information.The scrambling initial value that is produced is input to scrambling mode generator 516a.In fact, scrambling mode generator 516a also is the scrambler that is made of shift register shown in Figure 37, and scrambling initial value is set in this register, is each clock, produces a scrambling mode by the value in the shift register sequentially.
Here, in order to be easy to explanation, shown an example, make and be used to produce the data of data head in case be input todata head generator 517 from control unit 504, data head information produces atdata head generator 517, and be input to encoder 518 and scrambling generator 516c, but essence of the present invention is not limited thereto.For example, can be provided with like this, be that scrambling initial value generating unit 516c directly receives the data that are used to produce data head from control unit 504, and utilize the processing identical to produce data head information, then from data head information generation scrambling initial value withdata head generator 517 based on these data.
Have, Fig. 5 shows the structure of descrambler 658 peripheries of receiver side again.Decoder 656 will receive data to carry out after the error correction decoding, and the EXOR658b in descrambler 658 comes descrambling to receive data by calculating the xor operation that receives between data and the descrambling pattern, and this descrambling pattern utilizes the method that illustrates later to produce.Its output is in decryption device 660 deciphering.Before the beginning descrambling, carry out such as following operation to produce the descrambling initial value.
That is to say, decoder 656 will receive the data head information of the not scrambling of data to carry out after the error correction decoding, the parameter that is used to control physical layer is come out from the data head information extraction at datahead withdrawal device 657, is input to the descrambling initial value generator 658c in the descrambler 658 simultaneously.Here, descrambling initial value generator 658c utilizes one of multiple technologies of illustrating later to produce the descrambling initial value from the data head information of input.The descrambling initial value that produces is input to descrambling mode generator 658a.In fact, descrambling mode generator 658a also is the descrambler that is made of as shown in figure 38 shift register, and this descrambling initial value is set in this register, is each clock, produces a descrambling pattern by the value in the shift register sequentially.
Fig. 6 shows scrambler internal structure according to an embodiment of the invention.The essential structure as scrambler shown in the figure, scrambler 220 comprise twoshift registers 224 and 225, twoXOR circuit 226 and 227.Shift register 224 and 225 one 7 bit shift register of common formation and preservation are as the internal state of scrambler.Utilizeshift register 224 and 225, the fourth stage (X4) output and the 7th grade of (X7) output be input to XOR circuit 226.Have again, treat that the signal of scrambling is input to one of input port of XOR circuit 227.Under the situation of common scrambler, be provided to another input port ofXOR circuit 227 and scrambling is carried out in the input port ofshift register 224 by output withXOR circuit 226.
Utilize this scrambler 220, can be provided with like this, promptly wherein provide aselector 223 between the input of one of the output ofXOR circuit 226, input port ofXOR circuit 227 andshift register 224, one of output of the delivery outlet ofXOR circuit 226 andshift register 222 is connected to the input of one of input port ofXOR circuit 227 and shift register 224.Here,shift register 224 is used to preserve the initial value ofshift register 224 and 225.For example,Yu Ding 7 signals 620 can be used as this initial value.This is because signal 620 transmits (for example BPSK ofcode rate 1/2) with the modulating mode with high level error tolerance, therefore may realize free from error reception at receiving equipment.Especially, under the situation of utilizing data length than low 7 623, wish that more being assumed to each packet sets different value.
Control unit 221 provides timing controlled to selector 223.Control unit 221switches selectors 223, so in the moment through the scrambler initialization 651 of the service 650 ofXOR circuit 227, the output ofshift register 222 is provided to the input of one of input port ofXOR circuit 227 and shift register 224.Like this, be kept at the initial value that shiftregister 222 interior values are set to shiftregister 224 and 225.Have, scrambler initialization 651 is 7 " 0 " again, so be kept at values in theshift register 222 fromXOR circuit 227 outputs, and does not do any change, and this is by the character decision of XOR circuit.Then, through after theXOR circuit 227,control unit 221switches selectors 223 in scrambler initialization 651, makes the output ofXOR circuit 226 be provided to the input of one of input port ofXOR circuit 227 andshift register 224.
Have again,control unit 221 is set sign 211 with reference to initial value, show at initial value setting sign 211 under the situation of the initial value setting of not carrying out scrambler 220,control unit 221 is not carried out the timing controlled synchronous with above-mentioned scrambler initialization 651, andcontrol selector 223 makes the output ofXOR circuit 226 always be provided to the input of one of input port ofXOR circuit 227 and shift register 224.In the case, the value that is kept inXOR circuit 226 and 227 is not done any change as scrambler initial value, and in the moment of scrambler initialization 651 throughXOR circuit 227, this scrambler initial value is not done any change fromXOR circuit 227 outputs.
Therefore, even selected atselector 223 under the situation of any state, scrambler initial value all in the moment output of scrambler initialization 651 throughXOR circuit 227, can not run counter to original IEEE802.11a standard and operate so be appreciated that this.
Fig. 7 shows the structure of descrambler according to an embodiment of theinvention.Descrambler 270 shown in the figure comprises as scrambler 220: twoshift registers 274 and 275 and twoXOR circuit 276 and 277, and as the basic structure ofdescrambler.Shift register 274 and one 7 bit shift register of 275 common formations are preserved the internal state as descrambler.Utilizeshift register 274 and 275, the fourth stage (X4) output and the 7th grade of (X7) output be input to XOR circuit 276.Have again, treat that the signal of descrambling is input to one of input port of XOR circuit 277.In addition,descrambler 270 comprises a selector 273.Under the situation of common descrambler, in the moment of the signal that is equivalent to scrambling initialization 651 throughXOR circuit 277, make the signal for the treatment of descrambling be provided to the input of one of input port ofXOR circuit 277 andshift register 274 by switchingselector 273, switchingselector 223 makes the output ofXOR circuit 276 be provided to one of input port ofXOR circuit 277 and carries out descrambling with the input ofshift register 274.
Utilize thisdescrambler 270,shift register 272 is provided, its output is connected to the input of selector 273.Here,shift register 272 is used to preserve the initial value ofshift register 274 and 275.For example,, can use 7 predetermined signals 620, but need between transfer equipment and receiving equipment, to determine in advance that the position of which position is as initial value for these initial values.
The timing controlled that providescontrol unit 271 arrives selector 273.Control unit 271switches selectors 273 makes that the output ofshift register 272 is provided to the input of one of input port ofXOR circuit 277 andshift register 274 in the moment of the signal that is equivalent to serve 650 scrambler initialization 651 through XOR circuit 277.So, be kept at the initial value that shiftregister 272 interior values are set atshift register 274 and 275.Afterwards, through after theXOR circuit 277,control unit 271switches selectors 223 makes the output ofXOR circuit 276 be provided to the input of one of input port ofXOR circuit 277 andshift register 274 at the signal that is equivalent to serve 650 scrambler initialization 651.
Have again, obtain not carry out under the situation of the information of setting initial value to descrambler atcontrol unit 221,control unit 221 does not select to be kept at the value in theshift register 272, and switchingselector 273, make that in the moment of the signal that is equivalent to scrambler initialization 651 signal for the treatment of descrambling is provided to the input of one of input port ofXOR circuit 277 andshift register 274 through XOR circuit 277.For not carrying out the information of setting initial value to descrambler, for example can use the parity check bit 624 of signal 620.That is to say, be set at initial value under the situation of scrambler of transfer equipment, when data head generatingunit 210 generates parity check bits 624,, make odd bits be used for parity check bit 624 by inserting even bit.So, promptly determine whether to carry out to descrambler and set initial value by checking that at receiving equipment this parity check bit 624 can determine whether to have set initial value to scrambler.
Like this, the tentation data of signal 620 that has the high level error tolerance by use even be equivalent to the signal generation error of scrambler initialization 651, also can normally be carried out descrambling as the initial value of descrambler.
Notice that Figure 4 and 5 emphasize the operation of scrambler and the operation of descrambler, these contents are features of the present invention.In order to simplify accompanying drawing, omitted connection control line and the ON/OFF control regularly between control unit and each unit, as shown in Figures 2 and 3.
Like this,, obtain scrambling initial value and descrambling initial value, therefore need in transmitting frame, not be provided for notifying the field of scrambling initial value, improved data-transmission efficiency thus based on data head information according to the present invention.Moreover the total data part after the data head information can be it is hereby ensured the disguise of data division by scrambling, can also avoid the skewness of " 0 " " 1 " in the data.
Below with reference to the traffic operation of description of drawings according to the embodiment of the invention.
Fig. 8 has shown that with flow chart transfer equipment according to an embodiment of the invention carries out the process of scrambling.
At first, aftercommunication control unit 300 receives mac frame, utilize baseband processing unit 200, datahead generating unit 210 produces a PLCP data head (step S911).
Setting sign 211 indications at initial value sets to scrambler under the situation of initial value (step S912), according to the even parity position of IEEE802.11a standard generation signal 620, so that be set to parity check bit 624 (step S913).Afterwards, being kept at values in theshift register 224 and 225 in the scrambler 220 does not do any change and handles (step S917) as internal state (step S914) to carry out scrambling.
On the other hand, setting sign 211 indications at initial value should set to scrambler under the situation of initial value (step S912), produce the odd parity position of signal 620, perhaps produce the even parity position and be inverted and be worth parity check bit 624 (step S915) to set this.Afterwards, the value that is kept in theshift register 222 is set to theshift register 224 and 225 (step S916) of preserving the internal state in the scrambler 220 as initial value, handles (step S917) to carry out scrambling.
Fig. 9 utilizes flow chart to show according to the descrambling process in the receiving equipment of the embodiment of the invention.
At first, after 260 decodings of convolutional code decoder device received packet, data headanalytic unit 280 was analyzed PLCP data head (step S921).Afterwards, data headanalytic unit 280 checks whether the parity check bit 624 in the signal 620 is the even parity position (step S922) of satisfying the IEEE802.11a standard.
At step S922, determining under the situation of parity check bit 624 for the even parity position of satisfying the IEEE802.11a standard,control unit 271switches selector 273, make that in the moment of the signal that is equivalent to scrambler initialization 651 signal for the treatment of descrambling is provided to the input of one of input port ofXOR circuit 277 andshift register 274 as the initial value (step S924) that meets this standard through XOR circuit 277.Afterwards, the signal that is equivalent to scrambler initialization 651 is through after theXOR circuit 277,control unit 271switches selectors 223, makes the output ofXOR circuit 276 be provided to the input of one of input port ofXOR circuit 277 andshift register 274, and carries out descrambling (step S927).
On the other hand, at step S922, at definite parity check bit 624 is under the situation of odd parity position,control unit 271switches selector 273, make that in the moment of the signal that is equivalent to scrambler initialization 651 output ofshift register 272 is provided to the input of one of input port ofXOR circuit 277 andshift register 274 to set initial value (step S926) through XOR circuit 277.Afterwards, through after theXOR circuit 277,control unit 271 switchingselectors 223 make the output ofXOR circuit 276 be provided to the input of one of input port ofXOR circuit 277 andshift register 274 and carry out descrambling (step S927) at the signal that is equivalent to scrambler initialization 651.Note, at this moment, under the situation of subsequent treatment, preferably the odd parity position is changed into the even parity position in this stage with reference to parity check bit 624.
Like this according to the present invention, the part of signal 620 that has the high level error tolerance by utilization is as the initial value of the internal state of scrambler 220, can realize having between the scrambler 220 of high level error tolerance and thedescrambler 270 synchronously.Have again, by setting and the operation that is sent to scrambler 220, the initial value of thedescrambler 270 of selective reception equipment rightly of carrying out initial value in the part that is included in signal 620.
The operation that destroys the standard rule is not carried out in attention according to the communication system of present embodiment.Be equivalent to moment of the signal of scrambler initialization 651 in transmission, transmission will be set at the initial value of the internal state of descrambler, guarantees thus to operate according to standard.Have again, receive this signal, receive packet, therefore other any problem can not take place because odd parity only is dropped even be different from communication party's communicator.
Below, the example of the correction of one embodiment of the present of invention is described with reference to the accompanying drawings.
Figure 10 has shown the first correction example of one embodiment of the present of invention.Revise example about first shown in the figure, twotypes descrambler 270 and the 290 parallel outlet sides that are provided at convolutionalcode decoder device 260 in the receivingequipment.Descrambler 270 is a descrambler as shown in Figure 6, and it makes and can utilizeshift register 272 to set initial value.On the other hand,descrambler 290 is traditional descrambler as shown in figure 11.
The basic structure of descrambler shown in Figure 11 is identical with descrambler shown in Figure 5, promptly comprises twoshift registers 294 and 295, twoXOR circuit 296 and 297.Control unit 291 switches selectors 293, makes in the moment of the signal that is equivalent to scrambler initialization 651 throughXOR circuit 277, and the signal for the treatment of descrambling is provided to the input of one of input port ofXOR circuit 297 and shift register 294.Afterwards, through after theXOR circuit 297,control unit 291 switches selectors 293 at the signal that is equivalent to scrambler initialization 651, makes the output ofXOR circuit 296 be provided to the input of one of input port ofXOR circuit 297 andshift register 294.
In Figure 10, whether each field thaterror determining unit 305 is analyzed the output ofdescrambler 270 and 290 satisfies the scope of regulation and stipulation.For example, example shown in Figure 35 is 16 service field after the SIGNAL field of PHY data head, in these 16, is used to transmit scrambling initial value from 7 of MSB side, and 9 of all the other of back are as keeping the position, and regulation is made as complete 0 in standard at present.Therefore, the descrambling result must become complete 0.Correspondingly, it is 0 entirely that the output of descrambler indicates these to keep the position, and this is confirmed as reasonably exporting the result.
Have again,, suppose the validity of determining its content according to the calibration capability ofblock code decoder 320, but can utilizeerror determining unit 305 before proofreading and correct, to determine about PSDU.For example, as shown in figure 12, the MAC data head is added to mac frame, and the latter is the content of PSDU, and each field of MAC data head comprises predetermined data.For example, various types of control informations are included in theframe control 710 of head end of MAC data head, the version of theprotocol version 711 indication MAC agreements that its head end is two.The rule thatprotocol version 711 is formulated is, sets two " 0 " value, and other value keeps gives use in the future.Correspondingly, comprise under the situation that is different from two " 0 " values, can determine that this does not satisfy the scope of standard defined at protocol version.Note,, can be provided with like this, promptly wherein utilize the block code processing signal afterwards ofdecoder 320 to determine about utilizing definite method of the PSDU that mentions here.
Similarly, also abouttype 712, keeping two " 1 " is to use in the future, therefore comprises under the situation of two " 1 " in thistype 712, can determine that this does not satisfy the scope of standard defined.Have, about thesubtype 713 of back, the bit pattern of reservation exists according to the combination withtype 712 again.
Correspondingly, be set underdescrambler 270 and 290 one of any situations at the initial value that is different from scrambler 220, each field that might descrambling output all can not satisfy the scope of standard defined.Error determining unit 305 signs depart from the section of the scope of standard defined, and control selector 303 makes the output that does not depart from scope ofdescrambler 270 and 290 be provided to data block decoder 320.Notice that delaycell 307 and 309 is used for preserving the output ofdescrambler 270 and 290 during definite process oferror determining unit 305, and can utilize realizations such as a delay line, shift register.
For example, be not set at initial value under the situation of scrambler 220 of transfer equipment side, the output that it is contemplated thatdescrambler 290 becomes correct, and the output ofdescrambler 270 becomes incorrect.This is that the possibility that therefore can imagine the scope that departs from the standard defined is high because wait to utilize the data sequence of different initial value descramblings can regard as almost at random.Have, be set at initial value under the situation of scrambler 220 of transfer equipment side, if error does not take place, identical initial value also is set to descrambler 270 and descrambler 290.But the signal that is equivalent to scrambler initialization 651 is relatively low to the tolerance of error, might wait that the initial value that is set to descrambler 290 comprises an error.In this case, the output ofdescrambler 270 becomes correct, and the output ofdescrambler 290 becomes incorrect.Correspondingly,error determining unit 305 is carried out control, so that select the output ofdescrambler 270.
So, revise in the example first, can select initial value by definite process in the receiving equipment side, and do not need by the parallel part that the number of winning the confidence 620 is provided as thedescrambler 270 of initial value with get the signal that is equivalent to scrambler initialization 651descrambler 290 as initial value, utilize parity check bit 624 untill further notices about setting the information of initial value, do not need also to determine whether each field of the output ofdescrambler 270 anddescrambler 290 satisfies the scope of standard defined.
Figure 13 has shown the second correction example of embodiments of the invention.Shown in the figure second revises in the example, thedescrambler 270 parallel outlet sides that are provided at the convolutionalcode decoder device 260 of receiving equipment of two same types.620 fens other parts of these descrambler No. of winning theconfidence 270 are as initial value, but it is different as initial value whom is got.For example, if in advance in the position of transmitting the fixed two kinds of fetch bits of side mark, depend on the value of radio wave state on any one when transmitting as initial value, twodescrambler 270 are set to such an extent that get two types the value of bit position respectively as the initial value at receiving equipment place, carry out descrambling then.
Error determining unit 305 is as the first correction example, and whether each field of analyzing the output of twodescrambler 270 satisfies the scope of standard defined.Twodescrambler 270 are carried out the descrambling of different initial values respectively, so its output is different.Correspondingly, arbitrary output of twodescrambler 270 all becomes correct, and another output becomes incorrect, thuserror determining unit 305 to carry out control so that select according to standard be the output ofcorrect descrambler 270.
So, in this second correction example, twodescrambler 270 are provided side by side, they respectively the value of the not coordination position of the number of winning the confidence 620 as initial value, and whether the output of determining its each field satisfies the scope of standard defined, can select bit position based on definite result of transfer equipment side thus, can select initial value, and not utilize parity check bit 624 untill further notices about setting the information of initial value based on definite result of receiving equipment side.
The method of B, generation scrambling initial value and descrambling initial value
Below, with the method for explanation generation scrambling initial value and descrambling initial value, this is a feature of the present invention.In this explanation, physical layer data header as shown in figure 14 is as data head information.This is equivalent to remove the remainder that service field obtains from the physical layer data header of IEEE802.11a shown in Figure 35.Have, each of scrambling initial value and descrambling initial value all is to constitute by 7 again.
The generation scrambling initial value that illustrates later and arbitrary method of descrambling initial value all generate scrambling initial value and descrambling initial value based on the physical layer data header.Correspondingly, all as shown in figure 35 be used to notify the service field of scrambling initial value to become not needed.Therefore the user can use 16 of service field of data division, can improve data-transmission efficiency thus.Have, this makes whole data division by scrambling again.But essence of the present invention is not limited to structure shown in Figure 5.
Themethod 1 of B-1, generation scrambling initial value and descrambling initial value
Figure 15 has shown first method that generates scrambling initial value and descrambling initial value based on the physical layer data header.
The method is utilized the SIGNAL field of not scrambling, extracts 7 from the precalculated position of SIGNAL field, is set to scrambler as scrambling initial value, then scrambled data and sending out.In example shown in Figure 15, in the SIGNAL field, from 7 of MSB to the 7 bit extractions of LENGTH field, as scrambling initial value.
Have, after the SIGNAL field of the not scrambling of decoding,receiver side extracts 7 from the precalculated position of respective field at first in the same manner, is set to descrambler as the descrambling initial value, begins the descrambling of DATA part then again.In example shown in Figure 15, in the SIGNAL field, from 7 of MSB to the 7 bit extractions of LENGTH field and as scrambling initial value.
Themethod 2 of B-2, generation scrambling initial value and descrambling initial value
Utilizing saidmethod 1 to produce under the situation of scrambling initial value, unless determine to extract 7 method modestly from the physical layer data header, might these 7 be 0 entirely just, this depends on data content.Even complete 0 it also is used as original data sequence output and without scrambling as scrambling initial value, so this is inappropriate to scrambling initial value, must avoid.
Correspondingly, in the physical layer data header, exist under the situation about guaranteeing not, can consider such method for complete 0 field, wherein conveyer and receiver the two all meet agreement, make the relevant bits field be included in 7 that constitute scrambling initial value.
For example, utilize IEEE802.11a, the RATE field (referring to Figure 14) as the position of indication modulating mode is provided in the physical layer data header, and stipulated the method for description RATE field as shown in table 1.
[table 1]
According to table 1,, can guarantee also that the RATE field is constant to help 0 even between transmitting and receiving, selected specific transfer rate.Correspondingly, if used the bit allocation method identical with the RATE field, value or a fixing value of obtaining by whole values of mixing RATE field (4) and other field are used as scrambling and descrambling initial value, can guarantee thus that scrambling and descrambling initial value are constant to help 0.
Figure 16 has shown second method that generates scrambling and descrambling initial value based on the physical layer data header.In example as shown in the figure, 4 RATE field of SIGNAL field and 3 of beginning from the MSB of LENGTH field are extracted respectively, and the position of these extractions is connected the value that obtains as scrambling initial value and descrambling initial value.According to such initial value, at least 4 of beginning of this MSB of 7 can not become entirely 0 certainly, it is hereby ensured the operation of scrambler.
Themethod 3 of B-3, generation scrambling initial value and descrambling initial value
Described as above-mentioned part B-2, scrambling initial value is complete 0 to be inappropriate, must avoid.But, can not guarantee to exist not become complete 0 field, this depends on the structure of physical layer data head part, can consider such situation, wherein can not use the method that generates scrambling initial value that will couple together from the position that the physical layer data head part extracts.About handling the method for this situation, can consider following Example.
That is to say, undernon-complete 0 the situation in position that extracts, transmit side andextract 7, utilize the position of extracting to carry out scrambling and handle as scrambling initial value from the precalculated position of SIGNAL part.On the other hand, just be under 0 the situation entirely at 7 that partly extract from SIGNAL, transmit the side utilization and do not carry out scrambling and handle for complete 0 one 7 specific scrambling initial value (for example " 0101111 ").
Similarly, at first the decode SIGNAL part of not scrambling ofreceiver side extracts 7 from the precalculated position, under 7 non-situations of complete 0 that extract, utilizesextract 7 to begin scramble process as the descrambling initial value.But at 7 that extract just be under complete 0 the situation, and receiver side is determined not utilized and do not carried out scrambling for complete 0 one 7 specific scrambling initial value (for example " 0101111 ") and handle, and utilizes this initial value execution scramble process.
Figure 17 has shown the third party's method that generates scrambling and descrambling initial value based on the physical layer data header.In example as shown in the figure, 7 of beginning of the MSB from the LENGTH field of SIGNAL field are extracted, under 7 non-situations of complete 0 that extract as scrambling initial value and descrambling initial value.On the other hand, 7 that begin to extract at the MSB from the LENGTH field just under complete 0 the situation, and " 0101111 " that provides in advance prevents thus that as scrambling initial value and descrambling initial value initial value from becoming complete 0.
Themethod 4 of R-4, generation scrambling initial value and descrambling initial value
Described as above-mentioned part B-2, complete 0 is inappropriate for scrambling initial value, must avoid, but can not guarantee to exist and can not become complete 0 field, this depends on the structure of physical layer data head part, can consider such situation, wherein can not use the method that generates scrambling initial value that to couple together from the position that the physical layer data head part extracts.About handling the method for this situation,, other method will be described about this part though can use the method shown in the above-mentioned part B-3.
That is to say, length in scrambling initial value is under the situation of n position (wherein n is a natural number), transmit side group and extract (n-k) position (wherein k is the natural number less than n) from physical layer data head part or its part in transmitting the shared rule of side and receiver side, insert the bit sequence that the bit sequence that transmits k position known between side and the receiver side arrives (n-k) position of extracting to transmit pattern known between side and the receiver side, generate scrambling initial value thus, utilize this scrambling initial value to carry out scrambling then and handle.Here, at least 1 bit sequence for logical one is used as the known k position of the bit sequence of (n-k) position that will be inserted into extraction, prevents that thus initial value from becoming complete 0.
Similarly, at first the decode SIGNAL part of not scrambling of receiver side, based on transmitting rule that side and receiver side know altogether transmission data pick-up (n-k) position from physical layer data head or its part, insert k bit sequence (making that at least 1 is logical one) in the bit sequence of (n-k) position of extracting to transmit the known pattern of side and receiver side, so generate the descrambling initial value, can recover receiving data sequence by descrambling so.
Here, as long as k is the natural number that satisfies 0<k<n, in principle can be for k give any value, if still for k has given a big value, be taken as the narrowed width of the value of scrambling initial value, this is bad.Correspondingly, complete 0 in order to ensure preventing that scrambling initial value from becoming, preferably bottom line is k=1.
Figure 18 has shown the cubic method that generates scrambling and descrambling initial value based on the physical layer data header.In example as shown in the figure, k=1.In the example shown in the figure, LENGTH field in the SIGNAL field from MSB begin only 6 be extracted, as scrambling initial value from 6 of LSB side, are fixed value " 1 " as all the other 1 of the MSB of scrambling initial value, prevent that thus scrambling initial value from becoming complete 0.
Under the situation of inserting such fixed bit, the position of fixedvalue 1 " 1 " does not need to be MSB, so arbitrary position of 7 of initial value can be used as fixed bit.That is to say that the two all should meet and inserts the agreement of fixed value " 1 " to same position at system design stage conveyer and receiver, therefore the insertion position of this position is not limited to illustrated position.
Themethod 5 of B-5, generation scrambling initial value and descrambling initial value
The method that generates scrambling initial value based on the bit pattern that extracts from the physical layer data header so far has been described, but can have considered to be different from the method for said method, wherein generated scrambling initial value and prevent complete 0 simultaneously based on the physical layer data header.
As an example, can consider a kind of method, wherein generate scrambling initial value based on the quantity that is included in the logical one in the physical layer data header.Figure 19 has shown the 5th method that generates scrambling initial value and descrambling initial value.Example shown in the figure has illustrated that reserved field is that 0,100 byte is transmitted by BPSK R1/2.
In the case, the RATE field becomes " 1101 ", and the LENGTH field becomes " 001001100000 ", and correspondingly, so far, the quantity of the logical one in the bit field is 6, and when carrying out even parity, the PARITY field is set at " 0 ".Therefore the quantity of the logical one of whole SIGNAL field is 6, and when withbinary 7 bit representations, this value becomes " 0000110 ".This value transmits side and sets the X of this value as scrambler and descrambler as scrambling initial value1-X7Initial value, as Figure 19 top explanation, and carry out scrambling.
Have, decode the at first in the same way SIGNAL part of not scrambling of receiver side is counted the quantity of logical one in the SIGNAL field after the decoding again, and uses by the value that obtains with binary this quantity of 7 bit representations as the descrambling initial value.In example shown in Figure 19, receiver side is set " 0000110 " as X1-X7Initial value, as describing in scrambler and the descrambler, and the beginning scramble process.
As the embodiment that shows in the accompanying drawing, under the situation of the position assignment of using RATE field and LENGTH field (as IEEE802.11a), the quantity of logical one is necessary for 1 or more, and this is very easily as scrambling initial value.
Incidentally, the physical layer data header of similar IEEE802.11a has been used in above-mentioned explanation supposition, and the quantity of logical one is not more than 24, is necessary for complete 0 TALL part even comprise.The width of the initial value of scrambler as an example used herein is 7, therefore can handle the quantity of the logical one of not misdelivered at most to 127.But, if the bit quantity of physical layer data header is 127 or more, and be under 7 the situation, to cause a problem at the width of scrambling initial value, promptly after the quantity of the logical one in having counted whole physical layer data header, bit width shortens.
This problem can utilize such method to solve, wherein in order to address this problem, under the situation of the logical one in counting physical layer data head, the quantity of logical one only with respect to 127 or still less the bit position of the predetermined quantity of value (transmitting side and receiver side determines jointly) count, rather than use entire portion, the value that obtains with the result of binary representation counting is as scrambling initial value, and perhaps after the number count of the logical one of entire portion, the number that obtains is by 27=128 remove (the 7th root is to be determined by the bit width of scrambling/descrambling initial value) here, remove then the result as scrambling initial value, these methods are also included within the flesh and blood of the present invention.
Themethod 6 of B-6, generation scrambling initial value and descrambling initial value
The method of describing in utilizing above-mentioned part B-5 generates under the situation of scrambling initial value, guarantee that by the definition of physical layer data header constant the helping under 0 the situation of the quantity of logical one can not cause problem, ifhelp 0, just may scrambling initial value become complete 0 but the quantity that can not guarantee logical one is constant.For this reason, will prevent complete 0 method by the rule that expansion generates scrambling initial value in this part explanation.
We have determined to count the quantity of the logical one in the physical layer data header, and for example under this quantity is not 0 situation, the value that obtains by the quantity withbinary system 7 these countings of bit representation is carried out scrambling then as scrambling initial value.But just be under 0 the situation, to utilize and carry out scrambling in the quantity of logical one for certain specific scrambling initial value (for example " 0101111 ") of complete 0.
Similarly, at first the decode physical layer data head part of not scrambling of receiver side, the quantity of the logical one in the counting physical layer data header, be not under 0 the situation in this quantity, get value with this quantity ofbinary 7 bit representations as the descrambling initial value, and the beginning scramble process, but just be under 0 the situation in this quantity, it is not utilize to carry out for complete 07 specific scrambling initial value (for example " 0101111 ") that receiver side is determined scrambling, and utilizes this initial value to carry out descrambling.
Figure 20 has shown thatanti-complete 0 rule of having utilized expansion generates the 6th method of scrambling and descrambling initial value based on the physical layer data header.In illustrated embodiment, the quantity of the logical one in the counting SIGNAL field is not under 0 the situation in this quantity, gets value that this quantity withbinary 7 bit representations obtains and carries out scrambling as scrambling initial value and handle.On the other hand, just be under 0 the situation, to utilize " 0101111 " that before provided to prevent that as scrambling initial value and descrambling initial value initial value from becoming complete 0 in the quantity of logical one.
Themethod 7 of B-7, generation scrambling initial value and descrambling initial value
Scrambling initial value is complete 0 to be inappropriate, should avoid, still depend on the structure of physical layer data head part, can consider such situation, wherein there is not a field, therefore can uses method as the generation scrambling initial value of top B-5 explanation for complete 0.Can use method conduct to prevent complete 0 method, but this part will illustrate other method such as forward part B-6 explanation.
That is to say, length in scrambling initial value is under the situation of n (wherein n is a natural number) position, the transmission side is by the quantity generation scrambling initial value of the logical one of the transmission data in counting physical layer data head or its part, and be inserted in this bit sequence to transmit the bit sequence that side and the known pattern of receiver side will transmit the known m position of side and receiver side, this bit sequence is to obtain by the quantity with binary system (n-m) (wherein m is the natural number less than n) this logical one of bit representation.Utilizing this scrambling initial value to carry out scrambling then handles.Here, the bit sequence that at least one position is a logical one prevents thus that as the m position of the bit sequence that is inserted into (n-m) position scrambling initial value from becoming complete 0.
Have again, receiver side is counted the quantity of the logical one in the transmission data in the physical layer data head that is included in reception or its part similarly, utilize the descrambling initial value to carry out scramble process, wherein this descrambling initial value is transmitting side and the known pattern of receiver side, and the known at least one position of side and receiver side obtain in the bit sequence that the quantity of the logical one of counting with binary (n-m) bit representation obtains for the bit sequence of the m position of logical one is inserted into by transmitting.So, can recover to receive data.
Here, as long as m can give any value for satisfying the natural number of 0<m<n to m on the principle.If but given an especially big value to m, be as the narrowed width of scrambling initial value, this is undesirable.Therefore, complete 0 in order to ensure preventing that scrambling initial value from becoming, preferably, the minimum m=1 that is limited to.
Figure 21 has shown the 7th method that generates scrambling initial value and descrambling initial value based on the physical layer data header.In illustrative example, m=1, the quantity of the logical one of physical layer data header is 6,6 of beginning from LSB as scrambling initial value in " 000110 " that obtains withbinary 6 bit representations are fixedvalue 1 as 1 of the remainder of the MSB of scrambling initial value.
Under the situation of inserting such fixed bit, the position of this fixed value " 1 " can be on arbitrary bit position of 7 initial value.That is to say that the two all should meet the agreement that fixed value " 1 " is inserted into same position at design phase conveyer and receiver, thus an insertion position, position be not limited to illustrated like that.
Themethod 8 of B-8, generation scrambling initial value and descrambling initial value
Scrambling initial value is complete 0 to be inappropriate, should avoid, but the structure that depends on the physical layer data head part, can consider such situation, wherein there is not a field, therefore can not uses the method (the same) that generates scrambling initial value based on the bit sequence that extracts from the physical layer data head part for complete 0.Anti-other method of problem here will be described in this section.
That is to say, be under the situation of n (n is a natural number) position in the length of scrambling initial value, transmits the quantity of the logical one that the transfer data packets in side counting physical layer data head or its part draws together, and (x is for less than 2 with transmitting the x that side and receiver side know altogethernNatural number) be added to the quantity of this counting, get bit sequence that the result with this addition of binary n bit representation obtains then as scrambling initial value, carry out the scrambling operation.
Have, receiver side is counted the quantity of the logical one that the transfer data packets in the physical layer data head of reception or its part draws together similarly again, and (x is for less than 2 with transmitting the x that side and receiver side know altogethernNatural number) be added to the quantity of this counting, get bit sequence that the result with this addition of binary n bit representation obtains then as the descrambling initial value, carry out descrambling operation.
Here, if the total bit of the transmission data in the physical layer data head is b0, the bit width of scrambling initial value and descrambling initial value is s, preferably, satisfies b0+x≤2sOtherwise scrambling initial value that may generate and descrambling initial value are owing to the carry (carryover) of numeral becomes complete 0.
In the case, not the quantity of counting logical one about whole positions of the transmission data in the physical layer data head, but count the quantity of logical one about its a part of b1 (position that will count of supposition transmit between side and the receiver side understand mutually), the determining of b1 should satisfy b1+x≤2sPerhaps, can utilize such method to handle above-mentioned situation, promptly about whole body counting after the quantity of logical one, x is added on it, the number that obtains is by 2sRemove, its result is as scrambling initial value.These methods of mentioning are also included within the scope of flesh and blood of the present invention.
Here, as long as x satisfies 0<x<2nNatural number, in principle can be for x gives any value, if but for x has given a big value, be taken as the narrowed width of the value of scrambling initial value, this is bad.Correspondingly, complete 0 in order to ensure preventing that scrambling initial value from becoming, preferably bottom line is x=1.
Figure 22 has shown all directions method that generates scrambling initial value and descrambling initial value based on the physical layer data header.In illustrative example, x=1, the quantity of the logical one of physical layer data header is 6, and this value is added " 1 " and is obtained " 0000111 " to obtain 7,7 withbinary 7 bit representations, and the latter is as scrambling initial value.
Have again, the quantity that receiver side can determine to be included in the logical one in the physical layer data header of reception in the same manner is 6, so this value is added " 1 " to obtain 7,7 represent withbinary 7 bit wides, obtain " 0000111 ", get " 0000111 " and recover to receive data as descrambling initial value execution descrambling.
Themethod 9 of B-9, generation scrambling initial value and descrambling initial value
In above-mentioned part B-5, scrambling initial value and descrambling initial value generate from the quantity of logical one, but on the contrary, exist the quantity of utilizing logical zero to generate the method for scrambling initial value and descrambling initial value.
Figure 23 has shown the 9th method that generates scrambling initial value and descrambling initial value based on the quantity of the logical zero in the physical layer data header.Illustrated that in illustrative example reserved field is a situation zero, that 100 bytes are transmitted by BPSK R1/2.
In the case, the RATE field becomes " 1101 ", and the LENGTH field becomes " 001001100000 ", so so far the quantity of the logical one in the bit field is 6, when carrying out even parity, the PARITY field is set at " 0 ".Correspondingly, the quantity of the logical zero of whole SIGNAL field is 18, if just become " 0010010 " withbinary system 7 bit representations, the latter is as scrambling initial value, and the conveyer side is set at x with this value1-x7Initial value (as what illustrate in the scrambler at the top of Figure 23 and the descrambler) and carry out the scrambling operation.
Have, decode the at first in the same manner SIGNAL part of not scrambling of receiver side is counted the quantity of logical zero in the SIGNAL field after the decoding again, and the value that use obtains this quantity withbinary 7 bit representations is as the descrambling initial value.In example shown in Figure 23, receiver side is set " 0010010 " as x1-x7Initial value (as illustrating in scrambler and the descrambler) and begin descrambling operation.
As the embodiment that shows among the figure, under the situation of the position assignment of using RATE field and LENGTH field (defining as IEEE802.11a), the quantity of logical one must be 1 or bigger, and this is easily as the scrambling initialization.
Incidentally, in the above description, supposing to use to be similar to the physical layer data header of IEEE802.11a, must be that the quantity of complete 0 TAIL partial logic " 0 " also is not more than 24 even comprise.Here the initial value width that is used as the scrambler of example is 7, therefore can handle the quantity of the logical zero of not misinformated at the most to 127.But, if the quantity of the position of physical layer data header is 127 or more, when the width of scrambling initial value is 7, can produce a problem, promptly after the quantity of the logical zero of having counted whole physical layer data header simply, bit width shortens.
This problem can solve like this, wherein when the logical zero in the counting physical layer data head, only about 127 or the quantity (transmitting side and receiver side defines jointly) of the bit position counting logical zero of still less predetermined number and do not count entire portion, the value that the result who counts with binary representation obtains is as scrambling initial value, perhaps after the quantity of the logical zero of having counted entire portion, the quantity that obtains is by 27=128 remove (the 7th is to be determined by the bit width of scrambling/descrambling initial value) here, remove the result as scrambling initial value, these methods are also included within the flesh and blood of the present invention.
Themethod 10 of B-10, generation scrambling initial value and descrambling initial value
When the method in utilizing above-mentioned part B-9 generates scrambling initial value, do not become complete 0 if can guarantee by the quantity of the logical zero of physical layer data header definition, can not have problems, complete 0, then might scrambling initial value become complete 0 but if the quantity that can not guarantee logical zero does not become.For this reason, will utilize the rule of the generation scrambling initial value of expansion to prevent complete 0 method in this part explanation.
We have determined to count the quantity of the logical zero in the physical layer data header, for example under this quantity is not 0 situation, the value that obtains with this quantity ofbinary system 7 bit representations is taken as scrambling initial value and carries out scrambling, but the quantity at logical zero just is 0 o'clock, utilizes to be different from complete 07 specific scrambling initial value (for example " 0101111 ") and to carry out scrambling and handle.
Similarly, at first the decode physical layer data head part of not scrambling of receiver side, the quantity of the logical zero in the counting physical layer data header, if this quantity is not 0, get the value that obtains with this quantity ofbinary system 7 bit representations as the descrambling initial value and carry out descrambling, but when this quantity just was 0, receiver side determined that scrambling is to utilize to be different from complete 07 specific scrambling initial value (for example " 0101111 ") and to carry out, and utilizes this initial value to carry out scramble process.
Figure 24 has shown and utilizes complete 0 the rule of preventing of expansion to generate the tenth method of scrambling initial value and descrambling initial value based on the physical layer data header.In illustrative example, the quantity of the logical zero of counting SIGNAL field when this quantity is not 0, is carried out the scrambling processing with the value that binary this quantity of 7 bit representations obtains as scrambling initial value.On the other hand, when this quantity just is complete 0 the time, utilize " 0101111 " that before provided to prevent that as scrambling initial value and descrambling initial value initial value from becoming complete 0.
Themethod 11 of B-11, generation scrambling initial value and descrambling initial value
Scrambling initial value is complete 0 to be inappropriate, should avoid, still depend on the structure of physical layer data head part, can consider such situation, can not guarantee wherein that the quantity of logical zero is constant andhelp 0, therefore can not use the method for the generation scrambling initial value that illustrates among the above-mentioned part B-9.The method of describing such as above-mentioned part B-10 can still also will illustrate anti-other method of problem here in this section as preventing complete 0 method.
That is to say, when the length of scrambling initial value is n (n is a natural number) position, transmit side and generate scrambling initial value by following mode, promptly count the quantity of the logical zero in the transmission data that are included in physical layer data head or its part, by obtaining a bit sequence, be inserted into aforementioned sequence to transmit the sequence that side and the known pattern of receiver side will transmit the known h position of side and receiver side with binary (n-h) (h for less than the natural number of n) this quantity of bit representation.Utilize this scrambling initially to know then and carry out the scrambling processing.Here, at least 1 bit sequence for logical zero is used as the h position of the bit sequence that is inserted into (n-h) position, can prevent that thus initial value from becoming complete 0.
Have again, receiver side is counted the quantity of the logical zero in the transmission data in the physical layer data head part that is included in reception or its part similarly, by obtaining a bit sequence with this quantity of binary (n-m) bit representation, to transmit known at least one of side and receiver side be that the m bit sequence of logical one is inserted into aforementioned sequence to transmit side and the known pattern of receiver side, the value that obtains is thus got and is made the descrambling initial value and carry out descrambling operation, so can recover to receive data.
Here, as long as h is the natural number that satisfies 0<h<n, in principle can be for h give any value, if still for h has given a big value, be taken as the narrowed width of the value of scrambling initial value, this is bad.Correspondingly, complete 0 in order to ensure preventing that scrambling initial value from becoming, preferably bottom line is h=1.
Figure 25 has shown the 11 method that generates scrambling initial value and descrambling initial value based on the physical layer data header.In the illustrated embodiment, h=1, the quantity of the logical zero of physical layer data header is 18, and " 010010 " that obtains with binary this value of 6 bit representations is as begin from theLSB side 6 of scrambling initial value, is fixedvalue 1 as of the MSB of scrambling initial value.
When inserting such busy hour fixed, the position of this fixed value of 1 " 1 " can be on any position of 7 initial value.That is to say that the two all should meet the agreement of fixed value " 1 " being inserted same position in the design phase conveyer and receiver, so this insertion position is not limited to illustrated position.
Themethod 12 of B-12, generation scrambling initial value and descrambling initial value
Scrambling initial value is complete 0 to be inappropriate, should avoid.But the structure that depends on the physical layer data head part can be considered such situation, can not guarantee that wherein the quantity of logical zero does not become 0, therefore can not use the method (the same) of the generation scrambling initial value that illustrates among the above-mentioned part B-9.In this part anti-other method of problem here will be described.
That is to say, be under the situation of n (n is a natural number) position in the length of scrambling initial value, transmits the quantity of the logical zero that the transfer data packets in side counting physical layer data head or its part draws together, and (y is for less than 2 to increase the y that transmits side and receiver side and know altogethernNatural number) to the quantity of this counting, get the bit sequence that obtains with this result of binary n bit representation and carry out scrambling as scrambling initial value and handle.
Have, receiver side is counted the quantity of the physical layer data head or the logical zero that the transfer data packets in its part is drawn together of reception similarly again, and (y is less than 2 to the y that increase transmission side and receiver side are known altogethernNatural number) to the quantity of this counting, get the bit sequence that obtains with this result of binary n bit representation and carry out scramble process, so can recover to receive data as the descrambling initial value.
Here, if whole quantity of the transmission data in physical layer data head or its part is b0, the bit width of scrambling initial value and descrambling initial value is s, preferably satisfies b0+y≤2sOtherwise scrambling initial value that might produce and descrambling initial value are because the carry (carryover) of numeral becomes complete 0.
In the case, do not count the quantity of the logical zero in whole positions of the transmission data in the physical layer data head, but count the quantity (position that will count of supposition transmit side and receiver side understand mutually) of logical zero among its a part of b1, the determining of b1 should satisfy b1+y<2sPerhaps, above-mentioned situation can utilize such method to handle, and wherein in whole positions of the transmission data in having counted the physical layer data head after the quantity of logical zero, the quantity of this counting is added y, and the gained result is by 2sRemove, remove the result as scrambling initial value.These methods of mentioning are also included within the scope of flesh and blood of the present invention.
Here, as long as y satisfies 0<y<2nNatural number, can give any value to y, if but give a big value to y, get the narrowed width of making scrambling initial value, this is preferably.Therefore complete 0 in order to ensure preventing that scrambling initial value from becoming, preferably, the minimum y=1 that is limited to.
Figure 26 shows the 12 method that generates scrambling initial value and descrambling initial value based on the physical layer data header.In the illustrative example, y=1, the quantity of the logical zero that comprises in the physical layer data header is 18, and this quantity is added to " 1 " and obtains 19,19 and obtain " 0010011 " withbinary system 7 bit representations, and it is as scrambling initial value.
Have again, the quantity that receiver side can determine to be included in the logical zero in the physical layer data header of reception in the same way is 18, obtain 19,19 and obtain " 0010011 " as the descrambling initial value so this quantity is added to " 1 ", can recover to receive data thus withbinary system 7 bit representations.
Themethod 13 of B-13, generation scrambling initial value and descrambling initial value
At above-mentioned part B-5, the method that generates scrambling initial value based on the quantity that is included in the logical one in the physical layer data header has been described.On the contrary, in above-mentioned part B-9, illustrated that the quantity of utilizing logical zero generates the method for scrambling/descrambling initial value.
Generate a correction example of the method for scrambling/descrambling initial value according to these, transmit side and count the quantity of logical one and logical zero in the physical layer data header respectively, and obtain the absolute value of the difference of these two quantity, represent this absolute value with binary 7 (bit lengths that are equivalent to scrambling initial value and descrambling initial value), so generate scrambling initial value.
Similarly, at first the decode physical layer data head part of not scrambling of receiver side, counting is included in the logical one in the physical layer data header of reception and the quantity of logical zero respectively, also obtain the absolute value of the difference between these two quantity, with binary this absolute value of 7 bit representations, generate the descrambling initial value thus and begin scramble process then.
Themethod 14 of B-14, generation scrambling initial value and descrambling initial value
In above-mentioned part B-13, no problem under logical one that comprises in the physical layer data header and the unequal situation of the quantity of logical zero, but under the situation that these two values equate, it is complete 0 that scrambling initial value becomes, so scrambling is handled and can't be carried out.
In above-mentioned B-6 and B-10, illustrated that the method that generates scrambling initial value by expansion prevents complete 0 method, in this part, complete 0 the method for expanding based on same rule of preventing will be described also.
Transmit side and count the logical one that is included in the physical layer data header and the quantity of logical zero respectively, and obtain the absolute value of the difference of these two quantity.Be not that transmitting side can be by representing that with binary 7 (bit lengths that are equivalent to scrambling initial value) this absolute value generates scrambling initial value under 0 the situation at the absolute value of the difference of these two quantity.On the other hand, just be under 0 the situation at the absolute value of the difference of these two quantity, determine to transmit the side utilization and be different from predetermined 7 scrambling initial value (for example " 0101111 ") of complete 0 and carry out scrambling.
Similarly, at first the decode physical layer data head part of not scrambling of receiver side, counting is included in the logical one in the physical layer data head part and the quantity of logical zero respectively, also obtains the absolute value of the difference of these two quantity.Be not that receiver side is by representing that with binary 7 (bit lengths that are equivalent to the descrambling initial value) this absolute value generates the descrambling initial value under 0 the situation at the absolute value of the difference of these two quantity.On the other hand, just be 0 o'clock at the absolute value of the difference of these two quantity, the receiver side utilization is different from complete 0 predetermined descrambling initial value (for example " 0101111 ") beginning scramble process.
Themethod 15 of B-15, generation scrambling initial value and descrambling initial value
In above-mentioned B-7 and B-11, illustrated to prevent that scrambling initial value from becoming complete 0 other method, in this part, identical complete 0 the method that prevents will be described also.
That is to say, length in scrambling initial value is under the situation of n (n is a natural number) position, transmit side and count the logical one in the transmission data that are included in physical layer data head or its part and the quantity of logical zero respectively, obtain the absolute value of the difference of these two quantity.Transmit side to transmit side and the known pattern of receiver side, insert with this bit sequence that thoroughly deserves generation scrambling initial value of binary (n-i) (i is the natural number less than n) bit representation by the bit sequence that will transmit the known i position of side and receiver side, utilize this scrambling initial value to carry out scrambling then.Here, the bit sequence that at least one position is a logical one prevents thus that as the i position of the bit sequence that will be inserted into (n-i) position scrambling initial value from becoming complete 0.
Similarly, receiver side is counted the logical one that comprises in the transmission data in the physical layer data head of reception or its part and the quantity of logical zero respectively, and obtains the absolute value of the difference of these two quantity.Receiver side is to transmit side and the known pattern of receiver side, insert with this bit sequence that thoroughly deserves generation descrambling initial value of binary (n-i) (i is the natural number less than n) bit representation by the bit sequence that will transmit the known i position of side and receiver side, utilize this descrambling initial value to carry out descrambling then, so can recover to receive data.
Here,, can give any value to i as long as i is the natural number that satisfies 0<i<n, if but give a big value to i, get the narrowed width of making scrambling initial value, whether preferably this.Therefore complete 0 in order to ensure preventing that scrambling initial value from becoming, preferably, the minimum i=1 that is limited to.
Themethod 16 of B-16, generation scrambling initial value and descrambling initial value
In above-mentioned B-8 and B-12, illustrated to prevent that scrambling initial value from becoming complete 0 other method, in this part, identical complete 0 the method that prevents will be described also.
That is to say, length in scrambling initial value is under the situation of n (n is a natural number) position, transmit side and count the logical one in the transmission data that are included in physical layer data head or its part and the quantity of logical zero respectively, and obtain the absolute value of the difference of these two quantity.Transmitting side will transmit the z that side and receiver side know altogether (z will be less than 2nNatural number) be added to this absolute value, get bit sequence that this result with binary n bit representation obtains and carry out scrambling as scrambling initial value and handle.
Similarly, receiver side is counted physical layer data head or the logical one in the transmission data in its part and the quantity of logical zero that is included in reception respectively, and obtains the absolute value of the difference of these two quantity.Receiver side will transmit the z that side and receiver side know altogether, and (z is for less than 2nNatural number) be added to this absolute value, get the bit sequence that this result with binary n bit representation obtains and carry out scramble process, so can recover to receive data as the descrambling initial value.
Here, if whole quantity of the transmission data in the physical layer data head is b0, the bit width of scrambling initial value and descrambling initial value is s, preferably satisfies b0+z≤2sOtherwise scrambling initial value that might generate and descrambling initial value are because the carry (carryover) of numeral becomes complete 0.
In the case, not the quantity of counting logical one about whole positions of the transmission data in the physical layer data head, but count the quantity of logical one about its a part of b1 (position that will count of supposition transmit between side and the receiver side understand mutually), the determining of b1 should satisfy b1+z<2sPerhaps, can utilize such method to handle above-mentioned situation, promptly about whole body counting after the quantity of logical one, z is added on it, the number that obtains is by 2sRemove, its result is as scrambling initial value.These methods of mentioning are also included within the scope of flesh and blood of the present invention.
Here, as long as z satisfies 0<z<2nNatural number, in principle can be for z gives any value, if but for x has given a big value, be taken as the narrowed width of the value of scrambling initial value, this is bad.Correspondingly, complete 0 in order to ensure preventing that scrambling initial value from becoming, preferably, bottom line is z=1.
In the above-mentioned explanation, utilize the bit sequence that generates from the physical layer data header and do not do to change and be used as scrambling initial value and carry out scrambling, also utilize this initial value to make the descrambling initial value and carry out descrambling.But essence of the present invention is not limited thereto.Also comprise a kind of situation in the scope of flesh and blood of the present invention, produce superior effect of the present invention equally, wherein transmit the bit sequence that adnation becomes to become the scrambling initial value basis, carry out the position conversion of this bit sequence, make scrambling initial value with the bit sequence after the conversion.Receiver side generates the bit sequence as descrambling initial value basis, carries out the position conversion of this bit sequence, and is used as the descrambling initial value.
For example, in the embodiment shown in Figure 19, generate under the situation of scrambling initial value in quantity by the logical one in the counting physical layer data header, technical scope of the present invention even comprise such setting, if wherein the quantity of logical one is 6, obviously do not obtain " 0000110 " but " 1111001 " after the conversion of position as scrambling initial value with thisquantity 6 ofbinary 7 bit representations.
C, corresponding to the scrambling/descrambling that transmits frame format
So far understood the method that transmits scrambling initial value such as the not scrambling zone of physical layer data head of utilizing from the principle.But in actual wireless communication, can consider to transmit frame format like this, wherein in a radio frames, have the field of a plurality of not scramblings.In this part, explanation will scrambling/de-scrambling method according to the present invention be used for the method for various transmission frame formats.
Figure 27 has shown a structure example that transmits frame, wherein has the field of a plurality of not scramblings in a radio frames.In illustrated embodiment, one is transmitted frame and comprises a plurality of to (being made of physical layer quantity head part and data division) of a preamble (it is the head of this transmission frame) and back.The scrambling initial value of scrambling follow-up data part is wanted in each physical layer data head part storage, and physical layer data head part and one of data division formation are right.
When transmitting such transmission frame, the physical layer data head part is by scrambling, and follow-up data division utilizes scrambling initial value that the physical layer data head part of urgent front extracts by scrambling.Have, when receiving this transmission frame, the physical layer data head part of descrambling initial value scrambling never extracts, and utilizes the data division of this descrambling initial value descrambling immediately following the scrambling that will receive after the physical layer data head part again.
In example shown in Figure 27, one is transmitted right to physical layer data head part (PHY header) 2 and data division (DATA) 2 that frame comprises the physical layer data head part (PHY header) 1 of a preamble (Preamble), back and data division (DATA) 1.Notice that data division can be known burst.
During transmission, the information bit S1 that is stored in physical layer data head part (PHY header) 1 is as scrambling initial value, utilize this initial value scrambling immediately following the data division (DATA) 1 behindPHY 1, similarly, the information bit S2 that is stored in physical layer data head part (PHY header) 2 is as scrambling initial value, utilizes this initial value scrambling immediately following the data division (DATA) 2 behind PHY 2.Have again, during reception, after receiving the physical layer data head part (PHY header) 1 of not scrambling, extract information bit S1, utilize S1 to carry out descrambling immediately following the data division (DATA) 1 behindPHY 1 as the descrambling initial value, similarly, receive the physical layer data head part (PHY header) 2 of not scrambling after, extract information bit S2, utilize S2 to carry out descrambling as the descrambling initial value immediately following the data division (DATA) 2 behindPHY 2.
Have, Figure 28 has shown another structure example that transmits frame again, wherein has the field of a plurality of not scramblings in a radio frames.In illustrated embodiment, immediately following being scrambling unwanted signal (for example be used for the balanced training signal that transmits passage, carry out the data etc. of the broadcasting of peripheral station) afterwards in physical layer data head part (PHY header), the back is a data division (DATA) of wanting scrambling again.
Under the situation of such transmission frame format, during transmission, utilize the scrambling initial value that is stored in the physical layer data head part, data division is from head beginning scrambling.Have again, during reception, at first receive the physical layer data head part of not scrambling, extract the descrambling initial value, utilize this descrambling initial value carrying out descrambling immediately following the data division after scrambled signals not from it.
In the case, after the physical layer data head part transmits or receives, corresponding to the transmission or the reception of the signal section of scrambling should not postpone the starting position of scrambling or descrambling one predetermined periods.
Have, Figure 29 has shown a structure example that transmits frame again, and wherein two or more physical layer data head part comprise in a radio frames, are data division afterwards.In illustrated embodiment, the storage of each physical layer data head part is used for the scrambling initial value of the scrambling of follow-up transmission signal, when transmitting or receiving, whenever a physical layer data head through out-of-date, carry out scrambling and descrambling with the multistage.
That is to say that during transmission, the information bit S1 that is stored in the physical layer data head part (PHY header) 1 is used as scrambling initial value, follow-up signal, promptly physical layer data head part (PHYheader) 2 is by scrambling.Similarly, the information bit S2 that is stored in the physical layer data head part (PHY header) 2 is used as scrambling initial value, follow-up signal, and promptly data division (DATA) is by scrambling.
Have again, during reception, receive the physical layer data head part (PHY header) 1 of not scrambling after, extract information bit S1, utilize S1 to make the descrambling initial value and come, be i.e. physical layer data head part (PHY header) 2 descramblings follow-up signal.Below, extract information bit S2 from physical layer data head part (PHYheader) 2, utilize S2 to come descrambling to closely follow data division (DATA) 2 behindPHY 2 as the descrambling initial value.
Have, Figure 30 has shown a structure example that transmits frame again, and wherein the head at frame is a preorder, be a plurality of right afterwards, this each to constituting, as shown in Figure 27 by physical layer data head part and data division.Here, data division can be known burst.
In the example of Figure 27, utilize the scrambling/descrambling initial value that extracts from each physical layer data head part to come scrambling/descrambling immediately following thereafter each data division.That is to say, only carry out scrambling/descrambling a stage.
On the contrary, in the example of Figure 30, carry out two stage scrambling/descrambling.That is to say, in the example of Figure 29, utilize scrambling/descrambling of carrying out signal following closely from the initial value of each physical layer data head part extraction.
Particularly, during transmission, get the information bit S1 that is stored in the physical layer data head part (PHY header) 1 and thereafter signal is carried out scrambling as scrambling initial value.In illustrative example, get S1 as scrambling initial value, data division (DATA) 1 and physical layer data head part (PHY header) 2 is similarly by scrambling.Here, when physical layer data head part (PHYheader) 2 occurred, information bit S2 extracted as new scrambling initial value from it, and then, getting S2 is data division (DATA) 2 as scrambling initial value scrambling signal thereafter.
Have again, during reception, receive the physical layer data head part (PHY header) 1 of not scrambling after, extract information bit S1 as the descrambling initial value, utilize this descrambling initial value to come to the follow-up signal descrambling.In illustrative example, get S1 as the descrambling initial value, data division (DATA) 1 and physical layer data head part (PHY header) 2 is by descrambling.Here, when physical layer data head part (PHY header) 2 occurred, information bit S2 extracted as new descrambling initial value from it, and then, getting S2 is data division (DATA) 2 as scrambling initial value scrambling signal thereafter.
In the case, after the new initial value of next physical layer data head part appearance when obtaining scrambling or descrambling, the initial value quilt when last scrambling that obtains of follow-up signal utilization or descrambling is scrambling or descrambling continuously.
Incidentally, studied MIMO (multiple-input and multiple-output) communication means recently, wherein space division multiplexing, promptly independently many mutually in logic transmission passages are by the conveyer side that a plurality of antenna equipments are housed and the two foundation of receiver-side.MIMO communication is the technology that realizes transmitting capacity extension, improves communication speed, and it uses space division multiplexing, and is therefore very superior on the frequency service efficiency.
Figure 31 has shown a structure example that transmits frame format, and it can be applicable to the MIMO communication means.In illustrative example, for transmitting the destination, data provide four MIMO passages, and four data of this supposition are carried out space division multiplexing and transmission.
As shown in the figure, in transmitting frame, preorder (Preamble) is the physical layer data head part (PHY header) 1 about whole relevant transmission frame afterwards, the back is with the physical layer data head part of utilizing space division multiplexing (PHY header) 2-5 that is useful on each MIMO passage, also with four data part (DATA) 2-5 that carry out space division multiplexing are arranged.Each data division can be given different transfer rates.For example, data division (DATA) 2-5 give 6mbps respectively, 6mbps, and 12mbps and 24mbps, so whole system realizes that the data of 48mbps transmit.
Illustrate that as above-mentioned according to the present invention, scrambling/descrambling initial value can be based on extracting from each physical layer data head part with the common rule of the opposing party that communicates by letter.
When transmitting this transmission frame, utilize the scrambling initial value that extracts from physical layer data head part (PHY header) 1, follow-up physical layer data head part (PHY header) 2 is by scrambling.
As shown in figure 31, for each MIMO passage provides physical layer data head part (PHYheader) 2-5, and utilize time division multiplexing sequentially to be transmitted.At this moment, physical layer data head part (PHY header) 3 utilizes the scrambling initial value that extracts from physical layer data head part (PHY header) 2 by scrambling, afterwards in the same manner, physical layer data head part (PHYheader) 4 utilizes the scrambling initial value that extracts from physical layer data head part (PHY header) 3 by scrambling, and physical layer data head part (PHY header) 5 utilizes the scrambling initial value that extracts from physical layer data head part (PHY header) 4 by scrambling.
Then, the scrambling initial value that extracts from corresponding physical layer data head part of the data division utilization on each passage of space division multiplexing is by scrambling.That is to say, the scrambling initial value that utilization is extracted from physical layer data head part (PHY header) 2, data division on the respective channel (DATA) 2 is by scrambling, the scrambling initial value that utilization is extracted from physical layer data head part (PHY header) 3, data division on the respective channel (DATA) 3 is by scrambling, the scrambling initial value that utilization is extracted from physical layer data head part (PHY header) 4, data division on the respective channel (DATA) 4 is by scrambling, the scrambling initial value that utilization is extracted from physical layer data head part (PHYheader) 5, (DATA) 5 of the data division on the respective channel is by scrambling.
On the other hand, during reception, the physical layer data head part of descrambling initial value scrambling never (PHY header) 1 extracts.
Then, utilize time division multiplexing sequentially to receive physical layer data head part (PHY header) 2-5 of each MIMO passage, but this moment, the descrambling initial value descrambling physical layer data head part (PHY header) 2 that utilization is extracted from physical layer data head part (PHYheader) 1, afterwards with the same manner, the descrambling initial value descrambling physical layer data head part (PHY header) 3 that utilization is extracted from physical layer data head part (PHY header) 2, utilization utilizes the descrambling initial value descrambling physical layer data head part (PHY header) 5 that extracts from physical layer data head part (PHY header) 4 from the descrambling initial value descrambling physical layer data head part (PHY header) 4 that physical layer data head part (PHY header) 3 extracts.
Then,, after each passage receives, utilize the descrambling initial value that extracts from corresponding physical layer data head part that the data division that receives is done scrambling and handle at the data division of space division multiplexing.That is to say, data division (DATA) 2 on the descrambling initial value descrambling respective channel that utilization is extracted from physical layer data head part (PHY header) 2, data division (DATA) 3 on the descrambling initial value descrambling respective channel that utilization is extracted from physical layer data head part (PHY header) 3, data division (DATA) 4 on the descrambling initial value descrambling respective channel that utilization is extracted from physical layer data head part (PHY header) 4 utilizes the data division (DATA) 5 on the descrambling initial value descrambling respective channel that extracts from physical layer data head part (PHY header) 5.
Attention has illustrated such example in present embodiment of the present invention, wherein want the packet of scrambling and its scrambling initial value to produce in same packet, but is not limited to want the packet of scrambling, also can use the value in another packet.For example, under the always identical situation of data length, be (to transmit) under the fixing situation of signal field such as AV, can consider in the transfer equipment side initial value of next packet that last 7 bit data (for example nybble of CRC) that can receive the packet of its confirmation of receipt signal (ACK) before transmission immediately will transmit as scrambling.In the case, in the receiving equipment side, last 7 initial values of the packet that its confirmation of receipt signal is returned before reception immediately as next packet that will receive of descrambling.
But, in the case, might transmit side and not receive the confirmation of receipt signal, utilize last initial value to transmit last packet, therefore effectively way is to utilize two descrambler shown in Figure 20 to prepare and select the initial value of two types.Have, in the case, if there are a plurality of terminals in an accessing points, also have a plurality of packets reply the confirmation of receipt signal, this is to make us nerve-racking complex situations, therefore originally is provided in the system of the corresponding accessing points of a terminal effective especially.
Note, this embodiment of the present invention has shown a realization example of the present invention, each of invention defined item in it and the following claim book has corresponding relation, but is not limited thereto, and can be used for various change conditions under the situation that does not break away from essence of the present invention.
For example, in theclaim 4 and 5, chromacoder is corresponding to scrambler 220, and its internal state is corresponding to the value that is kept inshift register 224 and 225.Have, for example the initial value setting device is corresponding to shiftregister 222 andselector 223 again.
In addition, for example, in theclaim 7, the data head generating means is corresponding to datahead generating unit 210.
In addition, for example, in theclaim 8 and 14, be included in parity signal in the physical layer data head corresponding to parity check bit 624.
In addition, for example, in theclaim 9, chromacoder is corresponding to scrambler 220, and its internal state is corresponding to the value that is kept inshift register 224 and 225.Have, for example, initial value is set indicating device and is set sign 211 corresponding to initial value again.Have, for example, the initial value setting device is corresponding to shiftregister 222 andselector 223 again.Also have, the data head generating means is corresponding to datahead generating unit 210.
In addition, for example, in theclaim 10, initial value register is corresponding to shift register 222.Have, for example first shift register is corresponding to shiftregister 224 again.Also have, for example second shift register is corresponding to shift register 225.Have, for example first calculator is corresponding toXOR circuit 226 again.Also have, for example, selector is corresponding to selector 223.Also have, for example, second calculator is corresponding to XOR circuit 227.Have, for example control device is corresponding to controlunit 221 again.
Have, for example, in theclaim 11, chromacoder is corresponding to descrambler 270 again, and its internal state is corresponding to shiftregister 274 and 275 values of preserving.Have, for example the initial value setting device is corresponding to shiftregister 272 andselector 273 again.Also have, for example, the signal of indication initialization timing is corresponding to scrambler initialization 651.
Moreover for example, in theclaim 12, chromacoder is corresponding to descrambler 270, and its internal state is corresponding to shiftregister 274 and 275 values of preserving.Have, for example the data head analytical equipment is corresponding to data headanalytic unit 280 again.Also have, for example, the initial value setting device is corresponding to shiftregister 272 andselector 273.
Moreover for example, in theclaim 15, initial value register is corresponding to shift register 272.Have, first shift register is corresponding to shiftregister 274 again.Have, for example second shift register is corresponding to shiftregister 275 again.Have, for example, first calculator is corresponding toXOR circuit 276 again.Also have, for example, second calculator is corresponding to XOR circuit 277.Also have, for example, control device is corresponding to controlunit 271.
Moreover for example, in theclaim 16, for example, descrambler is corresponding to descrambler 270 or 290.Have, for example, selector is corresponding to selector 303 again.Have, for example, error determines that device is corresponding to error determiningunit 305 again.
Have, in theclaim 3, for example, first chromacoder is corresponding to scrambler 220 again, and its internal state is corresponding to the value of preserving inshift register 224 and 225.Have, for example, initial value is set indicating device and is set Warning Mark 211 corresponding to initial value again.Have, for example, the first initial value setting device is corresponding to shiftregister 222 andselector 223 again.Have, for example the data head generating means is corresponding to datahead generating unit 210 again.Have, for example the secondary signal conversion equipment is corresponding to descrambler 270 again, and its internal state is corresponding to the value of preserving inshift register 274 and 275.Have, for example, the data head analytical equipment is corresponding to data headanalytic unit 280 again.Have, for example the second initial value setting device is corresponding to shiftregister 272 andselector 273 again.
Have, in claim 43 and 46, for example, the process of the physical layer data head of generation transfer data packets is corresponding to step S911 again.Have again, for example, set indicating device at initial value and show and an initial value should be set under the situation of internal state, be used to change parity signal in the physical layer data head process, set tentation data that the physical layer data head comprises as the process of the initial value of the internal state of scrambler corresponding to step S912, S915 and S916.Have again, for example be used for transfer data packets signal to be processed being scheduled to the process of arithmetical operation and output corresponding to step S917 according to the internal state of scrambler.
Have, in claim 44 and 47, for example, the process of analyzing the physical layer data head that receives packet is corresponding to step S921 again.Have again, for example, under the situation in normal value is set to the parity signal of physical layer data head, the data that are used to set the head of signal to be processed set under as the process of the initial value of the internal state of descrambler, in outlier is set to the parity signal of physical layer data head as the situation of initial value set information be different from signal to be processed be included in tentation data in the physical layer data head as the process of the initial value of the internal state of descrambler corresponding to step S922, S924 and S926.Have again, for example, be used for being scheduled to the process of arithmetical operation and output corresponding to step S927 according to the signal that the internal state of descrambler will be handled.
Note, the process that illustrates in the embodiments of the invention can be thought of as a kind of method that comprises these a series of processes, or can make computer carry out the program of these a series of processes or store the recording medium of this program.
As mentioned above, described the present invention in conjunction with the embodiments in detail.But those skilled in the art can make various changes and replacement to the present invention under the situation that does not break away from essence of the present invention obviously.
In this specification, embodiments of the invention are described based on IEEE802.11a as the standard criterion of Wireless LAN system, but essence of the present invention is not limited thereto, and the present invention can the same manner applies to scrambling/descrambling between needing to transmit and receive, other communication system of notice and shared scrambling initial value between transmitting and receiving.
In other words, the present invention is disclosed with the example form, the content property of should not be construed as limiting of this specification.In order to determine essence of the present invention, should be with reference to claims.