Disclosure of Invention
The application provides a data packet detection method and a receiver, which can reduce error detection of data packets, realize synchronization of UWB equipment and improve robustness of damage, noise and interference of the receiver.
In order to achieve the above object, the embodiments of the present application provide the following solutions:
In a first aspect, a method of packet detection is provided, the method being executable by a first communication device. The first communication means may be a receiving end of the communication ends or a functional unit of the receiving end. Taking the communication two ends including the first device and the second device, where the first device is a receiving end, and the second device is a transmitting end as an example, the first communication device may be a unit, a functional module, and the like inside the first device. For example, the first communication means may be a chip provided in the first device, or the first communication means may be other means for realizing the functions of the first device. For convenience of description, the method for detecting a data packet provided in the first aspect will be described below by taking the first communication device as a receiver itself as an example.
The data packet detection method comprises the following steps: the receiver receives a data packet from the transmitter, the data packet corresponding to a first sequence, the first sequence comprising a first preamble sequence; the receiver carries out cross-correlation calculation on N subsequences decomposed by the first sequence and the second preamble sequence respectively to obtain N cross-correlation results, wherein the initial position of the first preamble sequence is positioned in one subsequence in the N subsequences, and N is a positive integer; subsequently, the receiver performs autocorrelation calculation on the N subsequences to obtain N-1 autocorrelation results, and detects the starting position of the data packet according to the N-1 autocorrelation results, the N cross-correlation results and a threshold set, wherein the threshold set comprises a frequency offset threshold, and the frequency offset threshold is used for indicating the influence degree of frequency offset on the autocorrelation results and/or the cross-correlation results.
In the method, the threshold set comprises a frequency offset threshold, and the influence degree of the frequency offset on the autocorrelation result and/or the cross-correlation result can be considered to measure whether the autocorrelation result and the cross-correlation result are accurate or not. Therefore, the receiver determines whether the data packet comprises the first preamble or not according to the N-1 autocorrelation results, the N cross correlation results and the threshold set, or the initial position of the detected data packet is more accurate, and error detection of the data packet can be reduced.
In one implementation, the frequency offset includes a carrier frequency offset (carrier frequency offset, CFO) and/or a sampling frequency offset (sampling frequency offset, SFO).
In one implementation, the set of metrics further includes at least one of: an autocorrelation threshold and a cross-correlation threshold. Wherein the autocorrelation threshold is used to determine whether or not to auto-correlate between the first preamble sequence and the second preamble sequence. The cross-correlation threshold is used to determine whether a cross-correlation between the first preamble sequence and the second preamble sequence is occurring.
The embodiment of the application does not limit the dimension of detecting the starting position of the data packet, for example, the starting position of the data packet can be detected by combining the autocorrelation threshold and the cross-correlation threshold, so that the method is more accurate.
In one implementation, detecting a start position of a data packet based on N-1 autocorrelation results and N cross-correlation results and a set of thresholds includes: and determining the correlation degree between N-1 autocorrelation results and N cross-correlation results and frequency offset respectively, and detecting the starting position of the data packet according to the autocorrelation threshold, the cross-correlation threshold, the frequency offset threshold, the N-1 autocorrelation results, the N cross-correlation results and the correlation degree.
In one implementation manner, the initial position of the data packet is a position corresponding to the first autocorrelation result and the first cross correlation result; wherein, the correlation degree between the first autocorrelation result and the frequency offset is higher than the frequency offset threshold, and the first autocorrelation result is higher than the autocorrelation threshold; the correlation between the first cross-correlation result and the frequency offset is above a frequency offset threshold and the first cross-correlation result is below a cross-correlation threshold.
The method comprehensively determines the starting position of the data packet based on the autocorrelation result, the cross-correlation result and the influence degree of the frequency offset on the autocorrelation result and the cross-correlation result, and can improve the robustness of the damage to the receiver and the multi-user interference, thereby being suitable for the receiving of a noisy environment.
In one implementation, the method further comprises: and (3) performing (M-1) dimensional linear interpolation processing on the autocorrelation threshold, the autocorrelation threshold and the frequency offset threshold, wherein M is an integer greater than 3. In this way, the loss of detection performance can be reduced.
In one implementation, the set of thresholds further includes: a combination of at least two of an autocorrelation threshold, a cross-correlation threshold, and a frequency offset threshold. Thus, the accuracy of data packet detection can be improved.
In a second aspect, a communication device is provided, which may be a receiver or a chip arranged in the receiver. For convenience of description, the communication device itself is taken as an example of the receiver.
A receiver, comprising: a transceiver, a correlation calculator, and a processor. Wherein the transceiver is configured to receive a data packet from the transmitter, the data packet corresponding to a first sequence, the first sequence comprising a first preamble sequence. The correlation calculator is used for carrying out cross-correlation calculation on N subsequences decomposed by the first sequence and a local second preamble sequence to obtain N cross-correlation results, and carrying out autocorrelation calculation on the N subsequences to obtain N-1 autocorrelation results, wherein the initial position of the first preamble sequence is positioned in one subsequence in the N subsequences, and N is a positive integer. The processor is configured to detect a start position of the data packet according to the N-1 autocorrelation results and the N cross-correlation results and a set of thresholds, wherein the set of thresholds includes a frequency offset threshold for indicating a degree of influence of the frequency offset on the autocorrelation results and/or the cross-correlation results.
In one implementation, the receiver further comprises: and the demultiplexer is used for decomposing the data packet received by the transceiver into N paths and respectively outputting the N paths to the related calculator, wherein one path corresponds to one sub-sequence.
In one implementation, the frequency offset includes a CFO and/or an SFO.
In one implementation, the set of metrics further includes at least one of: an autocorrelation threshold and a cross-correlation threshold. Wherein the autocorrelation threshold is used to determine whether or not to auto-correlate between the first preamble sequence and the second preamble sequence. The cross-correlation threshold is used to determine whether a cross-correlation between the first preamble sequence and the second preamble sequence is occurring.
In one implementation, a processor is specifically configured to: determining the correlation degree between N-1 autocorrelation results and N cross correlation results and frequency offset respectively; and detecting the starting position of the data packet according to the autocorrelation threshold, the cross-correlation threshold, the frequency offset threshold, the N-1 autocorrelation results, the N cross-correlation results and the correlation degree.
In one implementation manner, the initial position of the data packet is a position corresponding to the first autocorrelation result and the first cross correlation result; wherein, the correlation degree between the first autocorrelation result and the frequency offset is higher than the frequency offset threshold, and the first autocorrelation result is higher than the autocorrelation threshold; the correlation between the first cross-correlation result and the frequency offset is above a frequency offset threshold and the first cross-correlation result is below a cross-correlation threshold.
In one implementation, the processor is configured to perform (M-1) dimensional linear interpolation on the autocorrelation threshold, and the frequency offset threshold, where M is an integer greater than 3.
In one implementation, the set of thresholds further includes: a combination of at least two of an autocorrelation threshold, a cross-correlation threshold, and a frequency offset threshold.
In a third aspect, a communication device is provided, the communication device comprising functional modules for performing the method of the first aspect. For example, the communication device: including a processing unit (sometimes also referred to as a processing module or processor) and/or a transceiver unit (sometimes also referred to as a transceiver module or transceiver). These units (modules) may perform the corresponding functions in the method examples of the first aspect described above, see in particular the detailed description of the method examples, which are not described here in detail.
The communication device may be the receiver in the first aspect, or may be a chip or a chip system in the receiver. Optionally, the communication device further comprises a memory. The memory is used for storing computer programs or instructions or data, the processing unit is coupled with the memory and the transceiver unit, and when the processing unit reads the computer programs or instructions or data, the communication device executes the method executed by the receiver in the method embodiment.
In a fourth aspect, the present application provides a computer readable storage medium storing a computer program which, when executed, implements the method of the first aspect described above.
In a fifth aspect, there is provided a computer program product comprising: computer program code which, when run, causes the method of the first aspect described above to be performed.
Detailed Description
In the embodiment of the application, the existence of the data packet is detected based on the influence of the frequency shift on the autocorrelation and the cross correlation, so that the robustness of the damage, the noise and the interference of the receiver can be improved, and the error detection of the data packet can be reduced. For example, based on the cross-correlation detection index and the frequency offset detection index, the effect of CFO induced phase rotation may be reduced, enabling spreading/summing over multiple symbols to increase SNR. Sinusoidal interference or interference from other superimposed preambles of the transmitter may be reduced or reduced based on the autocorrelation detection index and the frequency shift detection index.
The embodiment of the application can be applied to wireless local area network systems such as internet of things (internet of things, ioT) networks or internet of vehicles (V2X). Of course, the embodiments of the present application may also be applicable to other possible communication systems, such as a long term evolution (long term evolution, LTE) system, a fifth generation (5 g) communication system, and a sixth generation (6th generation,6G) communication system in the future, etc.
The communication system comprises a transmitting end and a receiving end. The transmitting end can be a network device or a terminal device. When the transmitting end is a network device, the receiving end may be a terminal device. When the transmitting end is a terminal device, the receiving end may be a network device or a terminal device. When the transmitting end is network equipment, the receiving end is terminal equipment. The architecture of the communication system can be seen in fig. 1, where fig. 1 is an example in which the transmitting end is a network device and the receiving end is a terminal device.
The network device may be a means deployed in a radio access network (radio access network, RAN) to provide wireless communication functionality for the terminal device, e.g., may be a base station, various forms of control nodes (e.g., network controllers, radio controllers (e.g., radio controllers in a cloud radio access network (cloud radio access network, CRAN) scenario)), etc. In systems employing different radio access technologies, the names of base station capable devices may vary. For example, the LTE system may be referred to as an evolved NodeB (eNB or eNodeB), and the 5G system may be referred to as a next generation base station node (next generation node basestation, gNB), which is not limited by the specific name of the base station. The network device may also be a network device in a future evolved public land mobile network (publicland mobile network, PLMN), etc.
A terminal device may be a device that provides voice or data connectivity to a user, and may also be referred to as a User Equipment (UE), a mobile station (mobile station), a subscriber unit (subscriber unit), a station (station), etc. For example, the terminal device may be a cellular phone (cellularphone), a Personal Digital Assistant (PDA), a wireless modem (modem), a handheld device (handheld), a laptop (laptop computer), a cordless phone (cordless phone), a tablet (pad), a smart phone (smart phone), a customer premises equipment (customer premise equipment, CPE), a sensor with network access function, etc. With the development of wireless communication technology, devices that can access to a communication system, communicate with a network side of the communication system, or communicate with other objects through the communication system may be terminal devices in the embodiments of the present application, such as terminal devices and automobiles in intelligent transportation, home devices in intelligent homes, meter reading devices in smart grids, voltage monitoring devices, environment monitoring devices, video monitoring devices in intelligent security networks, cash registers, and so on.
The UWB technology can realize high-precision ranging and positioning at the centimeter level due to the characteristics of low power consumption, high time resolution and the like, and is widely applied. UWB technology does not require the use of carriers in conventional communication systems, but rather transmits data by transceiving extremely narrow pulses having nanoseconds or less, and thus, synchronization of transceiving devices is critical in UWB technology. The synchronization of the transmitting and receiving apparatuses is understood to mean that the data packet at the transmitting end is transmitted in the form of a pulse signal, and the receiving end determines from which of the plurality of received pulse signals the data packet to be received by the receiving end is started. Synchronization of the transceiver device may also be understood as determining the start position of the data packet by the receiving end or detecting the data packet by the receiving end.
Synchronization of the transceiving equipment is mainly achieved by a specific synchronization symbol in the data packet. The specific synchronization symbol is also referred to as a pilot symbol, a synchronization sequence, a preamble structure, a preamble sequence, or a preamble sequence. For purposes of this description, a particular synchronization symbol is hereinafter referred to as a synchronization preamble sequence. The synchronization preamble sequence is typically a ternary sequence consisting of three values { -1,0,1 }. The receiving device and the transmitting device are time synchronized if the synchronization preamble sequence transmitted by the transmitting device is aligned with a preamble sequence local to the receiving device (also simply referred to as a local preamble sequence). Alignment of two preamble sequences refers to the fact that the correlation coefficients of the two preamble sequences are large. And performing correlation calculation on the synchronous preamble sequence and the local preamble sequence, wherein the obtained correlation peak value is higher, so that the receiving device and the transmitting device are time-synchronized. If the correlation peak value obtained by the receiving device performing correlation calculation on the local preamble sequence and the synchronous preamble sequence received from the transmitting device is low, the receiving device and the transmitting device are time-unsynchronized.
To reduce interference between devices, different transmitting devices typically employ different synchronization preamble sequences. If the cross-correlation between the synchronization preamble sequence employed by the target transmitting apparatus and the synchronization preamble sequence employed by the interfering transmitting apparatus is small, the target receiving apparatus can suppress the interference by performing a correlation operation of the received signal and the synchronization preamble sequence employed by the target transmitting apparatus. Therefore, the reliability of detection can be ensured by utilizing the good autocorrelation characteristic of the preamble and the good cross-correlation characteristic between different preamble sequences.
However, since UWB is susceptible to phase rotation caused by carrier frequency offset (carrier frequency offset, CFO, abbreviated as frequency offset), conventional cross-correlation computation between preamble sequences cannot be spread or summed over symbols, and thus cannot increase signal-to-noise ratio (signalto noise ratio, SNR). The autocorrelation calculation between conventional preamble sequences is also susceptible to sinusoidal interference or additional superimposed preambles from other transmitters, resulting in lower accuracy of the autocorrelation calculation results, i.e., in erroneous detection of the start position of the data packet.
Aiming at the technical problems, the scheme of the embodiment of the application is provided. In the embodiment of the application, the detection of the data packet is realized from more dimensions. For example, in the embodiment of the application, the influence of CFO and/or SFO on the autocorrelation calculation or the cross correlation calculation among the preamble sequences is considered, and the detection of the data packet can be performed based on the CFO and/or the SFO, so that the accuracy of the detection of the data packet is improved, and the error detection of the starting position of the data packet is reduced.
The following describes the scheme provided by the embodiment of the application with reference to the accompanying drawings.
Referring to fig. 2, a flowchart of a packet detection method according to an embodiment of the present application is shown. Fig. 2 illustrates the method from the perspective of the receiver and transmitter interactions. The receiver may be a network device and the transmitter may be a terminal device. As shown in fig. 2, the flow of the packet detection method includes the following steps.
S201, the transmitter transmits the data packet to the receiver.
The data packet is carried by the first sequence, so to speak, the data packet corresponds to the first sequence. The data packet may include a first preamble sequence for time synchronization of the receiver and the transmitter in addition to data information transmitted by the transmitter to the receiver. The first preamble sequence may be used by the receiver to determine the start position of the data packet, or the first preamble sequence may be used by the receiver to detect the presence of the data packet; or whether a data packet is present by detecting whether the first preamble sequence is present. Detecting the data packet is essentially detecting whether the first preamble sequence is present.
S202, the receiver carries out cross-correlation calculation on N sub-sequences decomposed by the first sequence and the second preamble to obtain a cross-correlation result, wherein N is a positive integer.
The specific location of the first preamble in the data packet is not known to the receiver. For this purpose, the receiver may divide the data packet into multiple paths, for example, N paths, by a demultiplexer. Samples may be collected for each path, obtaining N subsequences. The first preamble sequence may be located in one or more of the sub-sequences, or the start position of the first preamble sequence is located in one of the N sub-sequences.
If the cross-correlation coefficient between a sub-sequence and the second preamble sequence is small, it is considered that the sub-sequence can be used to detect the first preamble sequence; if the cross correlation coefficient between a sub-sequence and the second preamble sequence is large, the sub-sequence may be considered as not being available for detecting the first preamble sequence. Thus, for each sub-sequence, the receiver may perform a cross-correlation calculation on each sub-sequence with the locally stored second preamble sequence to obtain N cross-correlation results.
S203, the receiver carries out autocorrelation calculation on the N subsequences to obtain N-1 autocorrelation results.
The approximate position of the first preamble, e.g., the frame number of the frame in which the first preamble sequence is located, may be determined based on the results of the cross-correlation calculation of the N sub-sequences with the second preamble sequence. Thus, autocorrelation calculations can be performed on a preceding sub-sequence and a following sub-sequence of the N sub-sequences to determine a finer granularity position of the first preamble sequence. The receiver may perform autocorrelation calculations on the previous sub-sequence and the next sub-sequence in sequence to obtain N-1 autocorrelation results. The first preamble sequence exists in a plurality of subsequences having a large autocorrelation.
S204, the receiver detects the initial position of the data packet according to the N-1 autocorrelation results and the N cross correlation results and the threshold set.
The set of thresholds may include an autocorrelation threshold and a cross-correlation threshold, the autocorrelation threshold being operable to determine whether or not to auto-correlate between the first preamble sequence and the second preamble sequence; the cross-correlation threshold may be used to determine whether a cross-correlation between the first preamble sequence and the second preamble sequence is occurring. The autocorrelation threshold and the cross-correlation threshold may determine which of the corresponding N subsequences of the N-1 autocorrelation results and the N cross-correlation results includes the first preamble sequence. For example, if the autocorrelation result is above the autocorrelation threshold and the cross-correlation result is below the cross-correlation threshold for a certain sub-sequence, then the probability that the sub-sequence includes the first preamble sequence is greater.
It is considered that the cross correlation calculation and the autocorrelation calculation between the preamble sequences are susceptible to CFO and/or SFO induced phase rotation, that is, the frequency offset may affect the autocorrelation calculation result and the cross correlation result, resulting in erroneous detection of the start position of the data packet/first preamble sequence.
For this reason, in the embodiment of the present application, the degree of influence of the frequency offset on the autocorrelation result and/or the cross-correlation result is taken as a parameter for measuring whether the autocorrelation result and the cross-correlation result are accurate. For example, the set of thresholds may further comprise a frequency offset threshold for indicating the extent to which the frequency offset affects the auto-correlation result and/or the cross-correlation result. In this way, the receiver determines whether the data packet includes the first preamble according to the N-1 autocorrelation results, the N cross correlation results, and the threshold set, or it is more accurate to detect the start position of the data packet.
Each threshold may be understood as a detection index, and accordingly, the autocorrelation threshold may be replaced by an autocorrelation detection index, the cross-correlation threshold may be replaced by a cross-correlation detection index, and the frequency offset threshold may be replaced by a frequency offset detection index. From this point of view, the set of thresholds may also be replaced by a set of detection indicators. For example, the set of detection indicators may include an autocorrelation detection indicator, a cross-correlation detection indicator, and a frequency offset detection indicator.
In an alternative implementation, the set of thresholds may further comprise a combination of at least two of an autocorrelation threshold, a cross-correlation threshold, and a frequency offset threshold. Or the set of detection indicators may further comprise a combination of at least two of an autocorrelation detection indicator, a cross-correlation detection indicator and a frequency offset detection indicator. Each group of combinations can be regarded as a new detection index. For example, the set of detection indicators may also include an autocorrelation detection indicator, a cross-correlation detection indicator, a frequency offset detection indicator, and a combination of the autocorrelation detection indicator and the frequency offset detection indicator.
The receiver may determine the correlation between each autocorrelation result and each cross-correlation result and the frequency offset, and detect the starting position of the data packet based on the autocorrelation threshold, the cross-correlation threshold, and the frequency offset threshold and the autocorrelation result, the cross-correlation result, and the correlation.
In a specific implementation, a detection region may be established, where the detection region has the same dimensions as the number of elements included in the detection index set. Taking the example that the detection index set includes an autocorrelation detection index, a cross correlation detection index, and a frequency offset detection index. The detection area may be a three-dimensional detection area. As shown in fig. 3, a schematic diagram of the detection area is shown. Wherein the X axis corresponds to an autocorrelation detection index/autocorrelation threshold; the Y axis corresponds to the cross-correlation detection index/cross-correlation threshold; the Z-axis corresponds to the frequency offset detection index. In fig. 3, the autocorrelation detection index, and the frequency offset detection index are normalized as examples, and the value ranges correspond to [0,1].
Wherein the X-axis, Y-axis, and Z-axis may set a threshold for determining whether the first preamble sequence is present, the threshold being above indicating the presence of the first preamble sequence (i.e., the presence of a data packet) and the threshold being below indicating the absence of the first preamble sequence (i.e., the absence of a data packet). The threshold may be configured by an external register to obtain optimal packet detection performance to adapt to the characteristics of the receiver analog front end. It will be appreciated that the XY plane (i.e. z=0) can see conventional packet detection with only auto-correlation detection index and cross-correlation detection index, separated stepwise into two planes by an auto-correlation threshold and a cross-correlation threshold.
Positions within the detection region that correspond to high autocorrelation thresholds, cross-correlation thresholds, and frequency offset thresholds are indicative of the presence of the first preamble sequence. The detection surface may be configured in discrete steps as shown in fig. 3, or the discrete steps may be removed as a single plane. The detection region corresponds to a combination of the autocorrelation detection index and the cross correlation detection index and the frequency offset detection index having a value high enough to indicate the presence of a data packet. Correspondingly, the initial position of the data packet is the position corresponding to the first autocorrelation result and the first cross correlation result. Wherein, the correlation degree between the first autocorrelation result and the frequency offset is higher than the frequency offset threshold, and the first autocorrelation result is higher than the autocorrelation threshold; the correlation of the first cross-correlation result with the frequency offset is above a frequency offset threshold and the first cross-correlation result is below a cross-correlation threshold. That is, the start position of the packet satisfies the following condition: the correlation degree between the autocorrelation result and the frequency offset is higher than the frequency offset threshold and higher than the autocorrelation threshold; the correlation of the cross-correlation result with the frequency offset is above the frequency offset threshold and below the cross-correlation threshold. Alternatively, the sub-sequence corresponding to the cross-correlation result having the frequency offset with the frequency offset higher than the frequency offset threshold and higher than the auto-correlation threshold is determined as the sub-sequence including the first preamble sequence.
The detection of data packets may be performed in a very "harsh" environment. Accordingly, the autocorrelation detection index may be used to indicate the presence of self-similar "energy" of the received noisy preamble. The cross-correlation detection indicator may be used to indicate the presence of a received noise preamble sequence. The more self-similarity energy that is observed (i.e., the higher the autocorrelation detection index), the higher the "known similarity" with the second preamble sequence must be (i.e., the higher the autocorrelation detection index must be), marking a "packet detect" event that indicates the presence of a packet. The frequency offset detection index may be used to increase robustness to receiver impairments. For example, the frequency offset detection index may improve robustness to multi-user interference by measuring the phase rotation difference of the auto-correlation and cross-correlation based metrics.
The effect of CFO induced phase rotation can be reduced based on the cross-correlation detection index and the frequency offset detection index, enabling spreading/summing over multiple symbols to increase SNR. Sinusoidal interference or interference from other superimposed preambles of the transmitter may be reduced or reduced based on the autocorrelation detection index and the frequency shift detection index. Therefore, in the embodiment of the application, the influence of the frequency offset on the autocorrelation and the cross correlation is quantized, so that the multi-user interference can be resisted. The multiple users include UWB preambles that are transmitted simultaneously.
It should be noted that, in the embodiment of the present application, the number of the detection indexes is not limited, and fig. 2 illustrates an example in which three detection indexes exist. In a possible implementation, there may be at least four detection indicators, such as an autocorrelation detection indicator and a frequency offset detection indicator, that can be used to measure the presence of other interferers or to measure spectral harmonics due to nonlinear distortion in the power amplifier to more accurately determine interference and reduce missed detection interference.
In one implementation, when the detection index is three detection indexes, bilinear interpolation based on the three detection indexes can be performed to reduce detection performance loss. For ease of understanding, please refer to fig. 4, which is another schematic diagram of the detection area. Fig. 4 is different from fig. 3 in that the autocorrelation detection index, and the frequency offset detection index are subjected to bilinear interpolation processing. Similarly, if there are M detection indicators, the detection area can be obtained by (M-1) dimensional linear interpolation for the M detection indicators.
In the embodiment of the application, the existence of the data packet is detected based on the influence of the frequency shift on the autocorrelation and the cross correlation, so that the robustness of the damage, the noise and the interference of the receiver can be improved, and the error detection of the data packet can be reduced. For example, based on the cross-correlation detection index and the frequency offset detection index, the effect of CFO induced phase rotation may be reduced, enabling spreading/summing over multiple symbols to increase SNR. Sinusoidal interference or interference from other superimposed preambles of the transmitter may be reduced or reduced based on the autocorrelation detection index and the frequency shift detection index. Therefore, in the embodiment of the application, the influence of the frequency offset on the autocorrelation and the cross correlation is quantized, so that the multi-user interference can be resisted. The multiple users include UWB preambles that are transmitted simultaneously.
Based on the same inventive concept, an embodiment of the present application provides a communication device, for example, a receiver, which may be adapted to perform the method of the embodiment shown in fig. 2. Referring to fig. 5, the receiver includes: a transceiver 510, a processor 520, and a correlation calculator 530.
Wherein, the transceiver 510 is configured to receive a data packet from a transmitter, where the data packet corresponds to a first sequence, and the first sequence includes a first preamble sequence. The correlation calculator 530 is configured to perform cross-correlation calculation on the N subsequences decomposed by the first sequence and the second preamble sequence, to obtain N cross-correlation results; performing autocorrelation calculation on the N subsequences to obtain N-1 autocorrelation results; the starting position of the first preamble sequence is located in one of N subsequences, wherein N is a positive integer. The processor 520 is configured to detect a start position of the data packet based on the N-1 autocorrelation results and the N cross-correlation results and a set of thresholds, where the set of thresholds includes a frequency offset threshold that is used to indicate a degree of influence of the frequency offset on the autocorrelation results and/or the cross-correlation results.
In one implementation, the communication apparatus further includes: and the demultiplexer is used for decomposing the data packet received by the receiver into N paths and respectively outputting the N paths to the related calculator, wherein one path corresponds to one sub-sequence.
In one implementation, the frequency offset includes a CFO and/or an SFO.
In one implementation, the set of thresholds further includes at least one of: an autocorrelation threshold and a cross-correlation threshold. Wherein the autocorrelation threshold is used to determine whether or not to auto-correlate between the first preamble sequence and the second preamble sequence. The cross-correlation threshold is used to determine whether a cross-correlation between the first preamble sequence and the second preamble sequence is occurring.
In one implementation, the processor 520 is specifically configured to: determining the correlation degree between N-1 autocorrelation results and N cross correlation results and frequency offset respectively; and detecting the starting position of the data packet according to the autocorrelation threshold, the cross-correlation threshold, the frequency offset threshold, the autocorrelation result, the cross-correlation result and the correlation degree.
In one implementation manner, the initial position of the data packet is a position corresponding to the first autocorrelation result and the first cross correlation result; wherein, the correlation degree between the first autocorrelation result and the frequency offset is higher than the frequency offset threshold, and the first autocorrelation result is higher than the autocorrelation threshold; the correlation between the first cross-correlation result and the frequency offset is above a frequency offset threshold and the first cross-correlation result is below a cross-correlation threshold.
In one implementation, the processor 520 is further configured to perform (M-1) dimensional linear interpolation on the autocorrelation threshold, and the frequency offset threshold, where M is an integer greater than 3.
In one implementation, the set of thresholds further includes: a combination of at least two of an autocorrelation threshold, a cross-correlation threshold, and a frequency offset threshold.
In one possible design, the communication device includes a baseband device and a radio frequency device, and the processor 520 includes the baseband device or the processor 520 is part of the baseband device. The transceiver 510 may be a radio frequency device.
The processor 510 is sometimes referred to as a processing module or processing unit, and the transceiver 510 is sometimes referred to as a transceiver module or transceiver unit. The transceiver 510 is capable of implementing a transmitting function and a receiving function, and may be referred to as a transmitting unit (sometimes also referred to as a transmitting module) when the transceiver 510 implements the transmitting function, and may be referred to as a receiving unit (sometimes also referred to as a receiving module) when the transceiver 510 implements the receiving function. The transmitting unit and the receiving unit may be the same functional unit, which is called a transceiver unit, and which can realize a transmitting function and a receiving function; or the transmitting unit and the receiving unit may be different functional units, and the transceiving unit is a generic term for these functional units. These units (modules) may perform the corresponding functions in the method examples of the first aspect or the second aspect, and are specifically referred to in the detailed description of the method examples, which are not described herein.
The communication device may be a chip or a chip system comprising a communication interface and a processor, optionally together with a memory. Wherein the memory is used for storing computer programs or instructions or data, and the processor is coupled with the memory and the communication interface. When the processor reads the computer program or instructions or data, the communication device is caused to perform the method performed by the receiver in the above-described method embodiments, for example, the communication device may be the receiver or a baseband chip and a radio frequency chip in the receiver. The communication interface may be an input-output interface and the processor may be a logic circuit. The input-output interface is used for inputting and/or outputting information. The input-output interface may be an interface circuit, an output circuit, an input circuit, a pin, or related circuitry, etc. The logic circuit is configured to perform the method described in the method embodiments above.
In a specific implementation process, the communication device may be a chip, the input circuit may be an input pin, the output circuit may be an output pin, and the logic circuit may be a transistor, a gate circuit, a flip-flop, various logic circuits, and the like. The input signal received by the input circuit may be received and input by, for example and without limitation, a receiver, the output signal may be output by, for example and without limitation, a transmitter and transmitted by a transmitter, and the input circuit and the output circuit may be the same circuit, which functions as the input circuit and the output circuit, respectively, at different times. The application does not limit the specific implementation modes of the input/output interface and the logic circuit.
Embodiments of the present application also provide a computer-readable storage medium including instructions that, when executed on a computer, cause the computer to perform the method performed by the receiver in the method shown in fig. 2.
The embodiment of the application also provides a computer program product, which comprises computer program code, and the computer program code, when executed, causes a computer to execute the method executed by a receiver in the method shown in fig. 2.
An embodiment of the present application provides a chip system, where the chip system includes a processor and may further include a memory, to implement the functions of the receiver in the method shown in fig. 2. The chip system may be formed of a chip or may include a chip and other discrete devices.
It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of the functional modules is illustrated, and in practical application, the above-described functional allocation may be performed by different functional modules according to needs, i.e. the internal structure of the apparatus is divided into different functional modules to perform all or part of the functions described above. The specific working processes of the above-described systems, devices and units may refer to the corresponding processes in the foregoing method embodiments, which are not described herein.
In the embodiments of the present invention, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the modules or units is merely a logical functional division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in the embodiment of the present invention may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied in essence or a part contributing to the prior art or all or part of the technical solution in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor (processor) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: universal serial bus flash disk (Universal Serial Bus FLASH DISK, USB), removable hard disk, read-Only Memory (ROM), random access Memory (Random Access Memory, RAM), magnetic or optical disk, and other various media in which program code may be stored.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the scope of the application. Thus, it is intended that the present application also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.