CN101765147A - Method and device for transmitting data packet under high-speed transmission environment - Google Patents

Abstract

The invention discloses a method for transmitting data packets under a high-speed transmission environment. The method comprises that the preset same data packet is transmitted for N times in N TTI, wherein the interval between two adjacent times of transmission is k times of TTI, the N is any positive integer more than one and the k is any integer more than or equal to zero; a transmitting end retransmits a data packet to be sent according to the scheduling signaling or the feedback NACK information and in accordance with the transmission times and the transmission interval set in the step a; and a receiving terminal determines ACK/NACK information to be fed back according to N times of combined detection of the sent data packet. The invention additionally discloses a device for transmitting data under the high-speed transmission environment. By adopting the invention, the self-adapting performance of links is guaranteed, the method and the device are suitable for the high-speed transmission environment and the transmission efficiency is improved.

Description

Data pack transmission method under a kind of high-speed transmission environment and device

Technical field

The present invention relates to data transmission technology, data pack transmission method and device under particularly a kind of high-speed transmission environment.

Background technology

Along with the continuous development of the communication technology, the application scenarios of wireless communication system is more and more wider.Not only can support higher rate, abundant type of service, and higher requirement is also proposed on application scenarios.Under the environment of high-speed mobile, guarantee proper communication such as requiring.At present, the design object of LTE system is to keep communicating to connect under up to 500 kilometers speed per hours.

Under high velocity environment, wireless channel conditions changes violent, and coherence time is very little, and from the time promptly, blanking time, very short channel was just lost correlation.

Link adaptation techniques is one of basic fundamental that improves systematic function.The basic thought of link level adaptive technique is that adaptive conditioning signal transmission parameters utilizes current channel circumstance to improve systematic function fully.The basic transmission parameter that can regulate comprises modulation system, coded system, transmitting power and channel width etc., and AMC (adaptive modulation coding) is the most basic link adaptation techniques.If can accurately predict the channel condition when transmit next time, select suitable transmission parameter then can guarantee to reach or approaching best efficiency of transmission.For becoming channel slowly, communication system can be predicted the channel condition of next transmission time according to current channel condition, because channel variation is slow, the channel condition of next transmission time has extremely strong correlation with present channel.So prediction can reach suitable precision, link adaptation techniques can obtain extraordinary performance.For high-speed mobile environment, because channel variation is violent, front and back channel relevancy constantly is very weak, predicts that according to current time next channel transmitted condition is very inaccurate.And the AMC technology is very responsive to channel condition, so the general method that adopts is that long CQI is carried out smoothing processing, to obtain the estimation of large scale decline, adopt quite conservative MCS to select, only can be in the acquisition small part link circuit self-adapting gain under certain probability.Therefore, the gain of AMC is very little under the high velocity environment.

In general, can utilize transmit diversity technique or HARQ to retransmit the error that reduces prediction.HARQ is a kind of link adaptation techniques, and it can adapt to the continually varying channel condition automatically.Different with AMC is that HARQ is insensitive to measuring mistake and measuring time delay, these two kinds of link adaptation techniques of HARQ and AMC are used in combination obtain more satisfactory effect, be AMC based on channel measurement result determination data transmission rate roughly, HARQ is finely tuning message transmission rate according to the Real-time Channel condition on this basis.HARQ is by will passing wrong data re-transmission, obtaining diversity gain by merging.The shortcoming of HARQ is must determine whether according to the signaling (ACK/NACK) of feedback to retransmit, and it is very big that this causes controlling signaling consumption, and time-delay is big.Too much re-transmission is unaccommodated.

Summary of the invention

In view of this, the invention provides data transmission method and device under a kind of high-speed transmission environment, can guarantee the performance of link circuit self-adapting, be adapted to high-speed mobile environment, improve efficiency of transmission.

For achieving the above object, the present invention adopts following technical scheme:

Data transmission method for uplink under a kind of high-speed transmission environment, preset same data packet transmit N time in N TTI, and the time interval between adjacent twice transmission is k times of TTI, wherein, N is the positive integer greater than 1, and k is the integer more than or equal to 0, and this method also comprises:

A, transmitting terminal receive information NACK according to the mistake of schedule information or receiving terminal feedback, repeat transmission with sending packet according to the number of transmissions that sets and Transmission Time Interval;

B, transmitting terminal receive receiving terminal according to the determined correct/error reception of the joint detection results of N transmission of described transmission packet information A CK/NACK.

Preferably, corresponding different time delays are provided with different described N values and described k value with performance requirement or corresponding different application scenarios;

Repeat to be transmitted as according to the number of transmissions that sets described in the step a: determine corresponding N value and k value according to current time delay and performance requirement or application scenarios, and repeat to transmit according to definite N value and k value.

Preferably, in described N the transmission, the time interval k between the different TTI transmission is set to identical or different.

Preferably, further comprise among the step a: when the transmission packet repeated to transmit according to the number of transmissions that sets, each TTI data carried by data was the different coding redundancy versions of same packet.

Preferably, the schedule information among the step a is dispatch or the configuration of periodicity in advance.

Preferably, the coding redundancy version of each TTI carrying data in N the initial transmission of the described transmission packet that carries out after the receiving scheduling information, with receive behind the nack message N time repeat to transmit in the redundancy versions and the order of each TTI carrying data be identical or different.

Preferably, this method further comprises: the performance requirement of joint-detection according to N transmission is determined code modulation mode MCS.

Preferably, in the multiple-input and multiple-output mimo system, this method further comprises: identical MIMO transmission mode is adopted in N transmission of described transmission packet.

Preferably, be in the time division multiplexing TDD system at duplex mode, described N transmission and time interval k are provided with according to current uplink and downlink timeslot ratio.

Preferably, described TTI granularity is subframe or time slot.

Data receive method under a kind of high-speed transmission environment comprises:

Preserve the number of transmissions N and the Transmission Time Interval k of the same packet of transmitting terminal setting in advance;

Repeat data packets for transmission N time according to the number of transmissions N that preserves and Transmission Time Interval k receiving end/sending end, and carry out joint-detection, determine that according to joint detection results the ACK/NACK feedback information is to transmitting terminal.

Data sending device under a kind of high-speed transmission environment comprises:

Memory cell is used to preserve the number of transmissions N of same packet and the time interval k between adjacent two transmission, and wherein, N is the positive integer greater than 1, and k is the positive integer more than or equal to 0;

Transmission unit is used for after receiving dispatch, repeats transmission with sending packet according to the number of transmissions of preserving in the described memory cell and Transmission Time Interval;

Receiving element is used to receive the ACK/NACK information that receiving terminal is determined according to the joint detection results of N transmission of described transmission packet.

Preferably, when described device was arranged in mimo system, described transmission unit when being further used for sending the transmission of packet after receiving dispatch, adopted identical MIMO transmission mode to described N transmission.

Data sink under a kind of high-speed transmission environment comprises memory cell, interface unit and joint-detection unit;

Described memory cell is used to preserve the number of transmissions N and the Transmission Time Interval k of the same packet that transmitting terminal is provided with;

Described interface unit is used for the number of transmissions N and the Transmission Time Interval k that preserve according to memory cell, and transmission and reception apparatus repeats data packets for transmission N time, and is transmitted to described joint-detection unit; Receive the ACK/NACK information that described joint-detection unit produces, and feed back to transmitting terminal;

Described joint-detection unit is used to receive N the repetition data packets for transmission that described interface unit is transmitted, and carries out joint-detection, produces ACK/NACK information according to joint detection results, and sends to described interface unit.

As seen from the above technical solution, among the present invention, preset same data packet repeats to transmit N time in N TTI, and the time interval between adjacent twice transmission be k times of TTI, wherein, N is the positive integer greater than 1, k is the integer more than or equal to 0; The initial transmission of one packet can be by dispatch or periodicity configure trigger in advance; Transmitting terminal repeats transmission with sending packet according to the number of transmissions that sets in advance and Transmission Time Interval according to the instruction of scheduler; Receiving terminal is received in N TTI and repeats data packets for transmission, detect, transmission result according to N TTI determines ACK/NACK information, if promptly joint-detection N time to retransmit the result be mistake then feedback error reception information (NACK), otherwise feed back correct reception information (ACK).By the way, the present invention repeats this packet repeatedly to transmit when sending data packet transmission, and transmission intercal can be greater than 1, promptly discontinuous transmission, thus the time diversity that obtains under the different channels condition gains; Simultaneously, in repeating repeatedly to transmit, merge according to all transmission results and to handle back feeding back ACK/nack message, and can be when intermediate conveyor feeding back ACK/nack message.When the advantage of this programme is to select Modulation and Coding Scheme MCS in link adaptation scheme, can repeat to determine, utilize time diversity, improve the accuracy of MCS according to N time; With the HARQ transfer ratio of common single TTI because general k value be less positive integer under high-speed case, thus the time of N re-transmission be far smaller than N time common HARQ re-transmission; And can greatly reduce the shared signaling consumption of ACK/NACK information.To sum up, the present invention can improve the performance of link circuit self-adapting, is adapted to high-speed mobile environment, improves efficiency of transmission.

Description of drawings

Fig. 1 is the overview flow chart of the data transmission method under the high speed transmission environment of the present invention.

Fig. 2 is the relative position relation and the schematic diagram that carry out N transmission and re-transmission (Re-transmission) of the inventive method in whole transmitting terminal transmission data procedures.

Fig. 3 is the overall construction drawing of the data sending device under the high speed transmission environment of the present invention.

Fig. 4 is the overall construction drawing of the data sink under the high speed transmission environment of the present invention.

Fig. 5 is the application schematic diagram of the inventive method in the LTE TDD system.

Fig. 6 is the application schematic diagram of time slot for TTI granularity in the inventive method in the LTE TDD system.

Embodiment

For making purpose of the present invention, technological means and advantage clearer, the present invention is described in further details below in conjunction with accompanying drawing.

In the LTE system, the up technical scheme that has adopted the up covering of raising of a kind of TTI of being referred to as bundling.By data being wrapped in 4 continuous TTI transmission, the transmission quality when improving the uplink UE power limited improves up covering.If TTI bundling is applied to high velocity environment, because the time diversity effect of a plurality of TTI, raising transmission performance that can be to a certain degree.But because the difference of TTIbundling conceptual design target, the TTI that repeats to transmit is a continuous dispensing, and the time diversity gain of acquisition is very little, and to retransmit 4 times be in order to improve link budget 3dB, for how utilizing the time diversity parameter also to optimize inadequately.

Basic thought of the present invention is: with reference to TTI bundling and HARQ scheme packet is repeated transmission, thereby realize the time diversity gain, called after TTI repeats transmission plan (TRS, TTIrepetition scheme) here.

Fig. 1 is the overview flow chart of the data transmission method under the high speed transmission environment of the present invention, and as shown in Figure 1, this method comprises:

Step 101, preset same data packet repeats to transmit N time in N TTI, and the time interval between adjacent twice transmission be k times of TTI, wherein, N is the positive integer greater than 1, k is the integer more than or equal to 0.

The time interval among the present invention between twice transmission refers to: the TTI number of being separated by between twice transmission.

Same packet is set in this step repeats to transmit N time, thereby realize the time diversity gain.Simultaneously, the time interval of adjacent twice transmission was provided with during this N time repeated to transmit, and was k times of TTI.

When carrying out the transmission of certain packet, can this packet of transmission primaries in the TTI.Therefore in this step, when same packet being set repeating to transmit N time, need utilize N TTI to carry out described N time and transmit.Particularly, repeat to transmit and can transmit in a continuous N TTI for N time of same packet, at this moment k gets 0; Perhaps, this N time is repeated transmission also can be to finish in discrete N TTI, and at this moment k gets corresponding positive integer.

Simultaneously, in the TDD system, because the configuration of uplink and downlink timeslot ratio may be different, therefore when carrying out being provided with of the time interval between the number of transmissions and adjacent twice transmission in this step, need determine the time interval between concrete the number of transmissions and adjacent twice transmission according to current uplink and downlink timeslot ratio.Promptly for downlink transfer, the time interval between the number of transmissions of setting and adjacent twice transmission should guarantee that all N time transmission all carry out in the downlink business frame; For uplink, the time interval between the number of transmissions of setting and adjacent twice transmission should guarantee that all N time transmission all carry out in the uplink service frame.

In addition, the setting of N value and k value will inevitably exert an influence to transmission performance, and for example, the N value is big more, and transmission reliability is good more, but propagation delay time is just big more; The correlated time of channel is short more, and the k value of relative set should be more little.Therefore, when carrying out being provided with of N value and k value, can different N values and k value be set, when transmitting, utilize the N value of current application scene or performance requirement correspondence and k value to transmit according to different application scenarioss and performance requirement.

Concrete, when the N value is provided with, time delay that can be corresponding different and performance requirement or corresponding different application scenarioss, different N values and k value are set, be that N value and k value need to consider on the one hand professional requirement to propagation delay time when being provided with, the requirement of taking into account system transmission performance on the other hand is provided with the balanced consideration in two aspects, perhaps is provided with according to application scenarios.

Step 102, transmitting terminal repeat transmission with sending packet according to the number of transmissions and the Transmission Time Interval thatstep 101 is provided with according to schedule information.

In the existing HARQ transmission, every biography one secondary data all needs to dispatch by dispatch.And among the present invention, utilize a schedule information to finish by disposable scheduling to the triggering of N time of packet transmission.Wherein, schedule information can be the signaling on the PDCCH.Particularly, after receiving schedule information, transmitting terminal is determined current transmission packet, and carries out N transmission of this transmission packet according to the number of transmissions N that is provided with in thestep 101 and Transmission Time Interval k in corresponding TTI.Wherein, schedule information can be dispatch or the configuration of periodicity in advance, be N the transmission that schedule information can trigger a packet, perhaps also can adopt the mechanism of similar continuous dispatching, a dispatch triggers a class packet of cyclical transmission, promptly after the transmitting terminal receiving scheduling signaling, to the transmission packet A (as voice packet) of cyclical transmission, in each transmission cycle, all carry out N N the transmission of setting in the TTI.

When transmitting, if only be provided with a kind of N value and k value in thestep 101, then N and the k according to this setting transmits; If corresponding different factors such as application scenarios are provided with a plurality of different N values and/or k value in thestep 101, then this step need be determined the N value and the k value of factor correspondence such as current application scene, and the transmission that sends packet according to this definite N value and k value.

Among the present invention, will send that packet receives schedule information and N time of carrying out transmitted and be called initial transmission.In this N time initial transmission, N the different coding redundancy versions that the TTI data carried by data can be same packet is to realize the HARQ gain.

Further, when transmitting terminal transmits, need carry out the selection of modulation coding mode (MCS) by the AMC technology, among the present invention, preferably, the joint detection results of transmitting based on N TTI when this MCS selects, rather than based on the transmission of each TTI, with the service quality (QoS) that guarantees that N TTI merges, promptly the overall performance according to N transmission requires to carry out the selection of MCS.

In addition, in mimo system, identical MIMO transmission mode is adopted in N the transmission that sends data.

Step 103, transmitting terminal receive receiving terminal according to the definite ACK/NACK information of joint detection results that sends packet N time.

Receiving terminal is when receiving the transmission data, utilize the received signal of N transmission to carry out joint-detection, and determine ACK/NACK information according to joint detection results, feed back to transmitting terminal again, and need not produce ACK/NACK information, thereby greatly reduce the shared signaling consumption of ACK/NACK information at each transmission result.Simultaneously, the joint-detection by N transmission result has realized the gain that HARQ and time diversity are brought.

After this step, after transmitting terminal receives nack message, also need to have sent the re-transmission of packet, particularly, this re-transmission mode can for:

Step 104 if receive nack message, then retransmits transmission to described transmission packet according to the number of transmissions and the Transmission Time Interval that are provided with in thestep 101 in N TTI, up to transmitting correct or reaching the maximum retransmission that sets in advance.

When transmitting terminal receives nack message, when the data that send in the determiningstep 102 are not correctly received, still repeat transmission according to N value that is provided with in thestep 101 and k value, correct up to transmission, promptly receive ACK information, perhaps reach the maximum retransmission that sets in advance.

When carrying out the re-transmission of packet, the redundancy versions (RV) when retransmitting for N time can be identical with the redundancy versions of N the initial transmission of carrying out in thestep 102 before, also can difference.For example, Fig. 2 for the inventive method in whole transmitting terminal transmission data procedures relative position relation and carry out N initial transmission and the schematic diagram of re-transmission (Re-transmission).As shown in Figure 2, at transmitting terminal, will carry out data after CRC check, coding and the RM encoding process as sending data.When carrying out data packet transmission, N=3,3 times the redundancy versions that adopts during initial transmission is respectively RV1, RV2 and RV3, when retransmitting, the redundancy versions that adopts when retransmitting for 3 times is identical with redundancy versions in 3 initial transmission before, also is respectively RV1, RV2 and RV3.In addition, the time interval of transmission is k1 betweensubframe 1, the subframe 2, and the time interval of transmission is k2 between subframe 2 and the subframe 3.In Fig. 2, k1=k2, in fact, as previously mentioned, the two can not wait yet.

If N the redundancy versions (RV) when retransmitting is different with the redundancy versions of N initial transmission before, then can bring further merging gain, but, the each transmission in needing to retransmit with each time at N initial transmission in advance, the corresponding setting also preserved corresponding redundancy versions.

So far, data transmission method for uplink flow process of the present invention finishes.

Corresponding with sending method, the data receive method among the present invention comprises:

Preserve the number of transmissions N and the Transmission Time Interval k of the same packet of transmitting terminal setting in advance;

Repeat data packets for transmission N time according to the number of transmissions N that preserves and Transmission Time Interval k receiving end/sending end, and carry out joint-detection, determine that according to joint detection results the ACK/NACK feedback information is to transmitting terminal.Thereby make transmitting terminal determine whether transmission is successful according to the ACK/NACK information of feedback.

The present invention also provides data sending device and the receiving system under a kind of high-speed transmission environment.Wherein the structure of dispensing device comprises as shown in Figure 3: memory cell, transmission unit and receiving element.

Wherein, the most basically, memory cell is used to preserve the number of transmissions N of same packet and the time interval k times TTI between adjacent two transmission, and wherein, N is the positive integer greater than 1, and k is the integer more than or equal to 0; Transmission unit is used for the ACK/NACK information of receiving scheduling information and receiving element, and after receiving schedule information or nack message, repeats transmission with sending packet according to the number of transmissions of preserving in the described memory cell and Transmission Time Interval; Receiving element is used to receive receiving terminal according to the determined ACK/NACK information of joint detection results that sends N transmission of packet.

If device shown in Figure 3 is arranged in mimo system, then transmission unit preferably, in the time of can being further used for sending the transmission of packet after receiving schedule information, adopts identical MIMO transmission mode to described N transmission.

With above-mentioned dispensing device correspondingly, the present invention also provides a kind of receiving system as shown in Figure 4.This receiving system comprises memory cell, interface unit and joint-detection unit.

Wherein, memory cell is used to preserve the number of transmissions N and the Transmission Time Interval k of the same packet that transmitting terminal is provided with.

Interface unit is used for the number of transmissions N and the Transmission Time Interval k that preserve according to memory cell, and transmission and reception apparatus repeats data packets for transmission N time, and is transmitted to the joint-detection unit; Receive the ACK/NACK information that the joint-detection unit produces, feed back to dispensing device.

The joint-detection unit is used for N the data packets for transmission that reception interface unit is transmitted, and carries out joint-detection, produces ACK/NACK information according to joint detection results, sends to interface unit.

The above-mentioned the specific embodiment of the present invention that is.By as seen above-mentioned, among the present invention, on the one hand data are being bound transmission on a plurality of TTI, and widening the time interval that repeats to transmit, thereby making full use of the time diversity gain with respect to TTI Bundling scheme, improve the system transmissions performance; On the other hand, in repeating repeatedly to transmit, merge processing back feeding back ACK/nack message according to all transmission results, and can be when intermediate conveyor feeding back ACK/nack message, can either improve adaptive performance by HARQ, greatly reduce the shared signaling consumption of ACK/NACK information again.

Fig. 5 is the application schematic diagram of the inventive method in the LTE TDD system.Wherein this TDD system adopts LTE frame structure type2, UL/DL=2/2+DwPTS, N=2, k=4.

In addition, carry out when transmission N time in N TTI, this TTI normally is unit with the subframe.But for the smaller packet of data volume, be further to save system resource, improve efficiency of transmission, preferably, TTI can time slot be that unit carries out, but to remain with the subframe be unit in the setting of k value.For example, among Fig. 6, TTI is time slot.

Being preferred embodiment of the present invention only below, is not to be used to limit protection scope of the present invention.Within the spirit and principles in the present invention all, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (14)

1. the data transmission method for uplink under the high-speed transmission environment is characterized in that preset same data packet is transmitted N time in N TTI, and the time interval between adjacent twice transmission is k times of TTI, and wherein, N is the positive integer greater than 1, k is the integer more than or equal to 0, and this method also comprises:

A, transmitting terminal receive information NACK according to the mistake of schedule information or receiving terminal feedback, repeat transmission with sending packet according to the number of transmissions that sets and Transmission Time Interval;

B, transmitting terminal receive receiving terminal according to the determined correct/error reception of the joint detection results of N transmission of described transmission packet information A CK/NACK.

2. method according to claim 1 is characterized in that, corresponding different time delays is provided with different described N values and described k value with performance requirement or corresponding different application scenarios;

Repeat to be transmitted as according to the number of transmissions that sets described in the step a: determine corresponding N value and k value according to current time delay and performance requirement or application scenarios, and repeat to transmit according to definite N value and k value.

3. method according to claim 1 and 2 is characterized in that, in described N the transmission, the time interval k between the different TTI transmission is set to identical or different.

4. method according to claim 1 is characterized in that, further comprises among the step a: when the transmission packet repeated to transmit according to the number of transmissions that sets, each TTI data carried by data was the different coding redundancy versions of same packet.

5. method according to claim 1 is characterized in that, the schedule information among the step a is dispatch or the configuration of periodicity in advance.

6. method according to claim 1, it is characterized in that, the coding redundancy version of each TTI carrying data in N the initial transmission of the described transmission packet that carries out after the receiving scheduling information, with receive behind the nack message N time repeat to transmit in the redundancy versions and the order of each TTI carrying data be identical or different.

7. method according to claim 1 is characterized in that, this method further comprises: the performance requirement of joint-detection according to N transmission is determined code modulation mode MCS.

8. method according to claim 1 is characterized in that, in the multiple-input and multiple-output mimo system, this method further comprises: identical MIMO transmission mode is adopted in N transmission of described transmission packet.

9. method according to claim 1 is characterized in that, is in the time division multiplexing TDD system at duplex mode, and described N transmission and time interval k are provided with according to current uplink and downlink timeslot ratio.

10. method according to claim 1 is characterized in that, described TTI granularity is subframe or time slot.

11. the data receive method under the high-speed transmission environment is characterized in that this method comprises:

Preserve the number of transmissions N and the Transmission Time Interval k of the same packet of transmitting terminal setting in advance;

Repeat data packets for transmission N time according to the number of transmissions N that preserves and Transmission Time Interval k receiving end/sending end, and carry out joint-detection, determine that according to joint detection results the ACK/NACK feedback information is to transmitting terminal.

12. the data sending device under the high-speed transmission environment is characterized in that this device comprises:

Memory cell is used to preserve the number of transmissions N of same packet and the time interval k between adjacent two transmission, and wherein, N is the positive integer greater than 1, and k is the integer more than or equal to 0;

Transmission unit is used for after receiving dispatch, repeats transmission with sending packet according to the number of transmissions of preserving in the described memory cell and Transmission Time Interval;

Receiving element is used to receive the ACK/NACK information that receiving terminal is determined according to the joint detection results of N transmission of described transmission packet.

13. device according to claim 12, it is characterized in that, when described device is arranged in mimo system, described transmission unit, when being further used for after receiving dispatch, sending the transmission of packet, identical MIMO transmission mode is adopted in described N transmission.

14. the data sink under the high-speed transmission environment is characterized in that this device comprises memory cell, interface unit and joint-detection unit;

Described memory cell is used to preserve the number of transmissions N and the Transmission Time Interval k of the same packet that transmitting terminal is provided with;

Described interface unit is used for the number of transmissions N and the Transmission Time Interval k that preserve according to memory cell, and transmission and reception apparatus repeats data packets for transmission N time, and is transmitted to described joint-detection unit; Receive the ACK/NACK information that described joint-detection unit produces, and feed back to transmitting terminal;

Described joint-detection unit is used to receive N the repetition data packets for transmission that described interface unit is transmitted, and carries out joint-detection, produces ACK/NACK information according to joint detection results, and sends to described interface unit.

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