CN101615986A - A kind of data transmission method, device and communication system - Google Patents

Abstract

The embodiment of the invention discloses a kind of data transmission method, comprising: transmission block is divided at least one group, and each group comprises at least one encoding block; For each group is added cyclic redundancy CRC check position; Send the group behind the described interpolation CRC check position.Simultaneously, the embodiment of the invention discloses a kind of data transmission device and communication system, retransmit the group of check errors correspondence, significantly reduced the data re-transmission amount, obtain bigger throughput gain simultaneously based on grouping thought.

Description

A kind of data transmission method, device and communication system

Technical field

The present invention relates to the communications field, specifically, relate to a kind of data transmission method, data transmission device and communication system.

Background technology

Generally be to be that unit transmits and storage in the Communications And Computer field, and transmission channel have damage in general with the Frame that " 0 " " 1 " is formed.Be the correctness of check reception data, present method is to add the correctness check information in transmit data frames, and this method is called cyclic redundancy check (CRC) (Cyclic Redundancy Check), is called for short CRC check.

In the 802.16e agreement, a burst burst is when bit number is greater than 4800 bits after adding CRC check bit and filling bit padding bit, when coding, can be divided into a plurality of encoding blocks and independent coding, before modulation, encoding block is linked in sequence according to cutting apart, see Fig. 1.

If in the one or more decode encoded blocks mistakes of receiving terminal, make a mistake in the CRC check demonstration transmission block, receiving terminal is by retransmitting (Automatic Repeat Request automatically, ARQ) request resends data, transmitting terminal is received the whole transmission block of ARQ request retransmission, and retransmission processes as shown in Figure 2.

If any the decode encoded blocks mistake in the transmission block all shows as whole transmission block decoding error during re-transmission, can't judge which encoding block makes a mistake, need retransmit whole transmission block during re-transmission, cause the decline of the wasting of resources and throughput performance.

Summary of the invention

The embodiment of the invention proposes a kind of new data transmission method, Apparatus and system based on the deficiency of mentioning in the prior art.

A kind of data transmission method comprises:

Transmission block is divided at least one group, and each group comprises at least one encoding block;

For each group is added a cyclic redundancy CRC check position;

Send the group behind the described interpolation CRC check position.

Correspondingly, the embodiment of the invention provides a kind of data transmission device, comprising:

Segmentation module is used for transmission block is divided at least one group, and each group comprises at least one encoding block;

Pretreatment module, each group that is used for described segmentation module is divided into is added the CRC check position;

Data transmission blocks is used to send the pretreated data of described pretreatment module.

In addition, the embodiment of the invention also provides a kind of communication system, comprises transmitter, communicate by letter with receiver, wherein:

Described transmitter is used for transmission block is divided at least one group, and each group comprises at least one encoding block, adds the CRC check position for described each group, and coding, preliminary treatment also send.

The embodiment of the invention is formed an encoding block group with some encoding blocks, each encoding block group adds CRC, when one or more coded block transmission mistake, only need to retransmit the group of makeing mistakes and need not retransmit whole transmission block, significantly reduced data re-transmission amount and feedback overhead.

Description of drawings

Fig. 1 is CRC addition manner schematic diagram in existing 802.16 agreements;

Fig. 2 is retransmission processes schematic diagram in existing 802.16 agreements;

Fig. 3 is the segmentation method schematic diagram one of the embodiment of the invention;

Fig. 4 is the segmentation method schematic diagram two of the embodiment of the invention;

Fig. 5 is the data transmission device structured flowchart of the embodiment of the invention.

Embodiment

Below in conjunction with drawings and Examples, the specific embodiment of the present invention is described in further detail:

The embodiment of the invention provides a kind of data transmission method, and transmission block comprises at least one group, and each group comprises at least one encoding block; Add a cyclic redundancy CRC check position for each group, send described through the group behind the interpolation CRC check position.

As shown in Figure 3, transmission block is divided into a plurality of encoding blocks (Code Blcok), some encoding blocks are formed a group (group).The group number that one of them transmission block comprises is more than or equal to 1, and the encoding block number that each group comprises is more than or equal to 1.Each group adds a CRC.

Also transmission block can be divided into a plurality of groups in addition, every group is added the CRC check position, again each component is become one or more encoding blocks.As shown in Figure 4.

Each encoding block length comprises following several situation in the said method: not the encoding block number on the same group identical/difference, not the encoding block length on the same group identical/difference.

Adopt each encoding block length same approach as follows during grouping:

If the transmission block size is B, transmission block is divided into N _CblockIndividual encoding block, packet count are N _Group, the CRC check bit number that each group is added is N _CRC, the encoding block number in each encoding block group is identical, the coded block size unanimity, and the bit number that then can obtain on average each encoding block is about:

$N=\frac{B+N_{\mathrm{group}}\·N_{\mathrm{CRC}}}{N_{\mathrm{Cblock}}}$

N may according to the restriction of encoder, add filling bit for a decimal non-integer, is example with the CTC encoder, obtains actual coded block size and is:

N _b=ceil (N)+paddingbit=8*M, M is an integer

Wherein, ceil represents to round up, N _bIt is 8 integral multiple.

Automatically retransmit in (HARQ) channel mixing, if one or more encoding block group decoding error, then based on group feeding back ACK/NACK, transmitting terminal only need retransmit the group that makes a mistake at receiving terminal.

Similarly, packet count is N _Group, the CRC check bit number that each group is added is N _CRC, the encoding block number in each encoding block group can be inequality, and coded block size is inconsistent, and the size of each encoding block is decided with actual conditions.

In grouping, can adopt packet count not wait principle.As shown in table 1 below, different transport block length adopt different groupings can obtain different gains, can adopt the method for different grouping number to obtain the most rational gain according to different transmission block sizes when then dividing into groups, and can make following grouping scheme in advance:

??TB ??size(bit)	??1～ ??4800	??4801～ ??9600	??9601～ ??14400	??14401～ ??19200	??19201～ ??24000	??24001～ ??28800	??28801～ ??33600	??33601～ ??38400	??38401～ ??43200	??43201～4 ??8000
											??groups	??1	??2	??3	??3	??3	??3	??3	??4	??4	??4

The different scheme of the different transport block length packet count of table 1

For example, if the length of transmission block is 20000bit, then transmission block is divided into 3 groups; If the length of transmission block is 40000bit, then transmission block is divided into 4 groups.

Owing to the probability of repeatedly re-transmission is less relatively, retransmits gain mainly from re-transmission for the first time, so can only consider to transmit for the first time analyze throughput of the present invention with situation about retransmitting for the first time.

The error probability of supposing transport block transmission is P _e, transmission block is divided into N _CblockIndividual encoding block, the length of each encoding block are N _bTransmission block is divided into N _GroupIndividual group, there is N the CRC check position that each group is added _CRCIndividual check bit then has in each group $N_{\mathrm{cpg}}=\frac{N_{\mathrm{Cblock}}}{N_{\mathrm{group}}}$ Individual encoding block has N _{B_group}=N _bN _CpgIndividual bit.

Then the error probability of each group is: $P_{e\_\mathrm{group}}=1-{(1-P_e)}^{\frac{1}{N_{\mathrm{group}}}}$

For the grouping scheme in the existing 802.16e agreement, once transmission and once retransmitting, on each resource units correct information transmitted number is: $\frac{N_{b\_\mathrm{group}}\·N_{\mathrm{group}}-N_{\mathrm{CRC}}}{(N_{b\_\mathrm{group}}\·N_{\mathrm{group}})\·(1+P_e)}.$

During the embodiment of the invention was once transmitted and once retransmitted, correct information transmitted number was on each resource units: $\frac{N_{b\_\mathrm{group}}\·N_{\mathrm{group}}-N_{\mathrm{CRC}}\·N_{\mathrm{group}}}{(N_{b\_\mathrm{group}}\·N_{\mathrm{group}})\·(1+P_{\text{e\_group}})}$

The throughput gain that is obtained with respect to the grouping scheme in the existing 802.16e agreement is:

$r=\frac{\frac{N_{b\_\mathrm{group}}\·N_{\mathrm{group}}-N_{\mathrm{CRC}}\·N_{\mathrm{group}}}{(N_{b\_\mathrm{group}}\·N_{\mathrm{group}})\·(1+P_{e\_\mathrm{group}})}}{\frac{N_{b\_\mathrm{group}}\·N_{\mathrm{group}}-N_{\mathrm{CRC}}}{(N_{b\_\mathrm{group}}\·N_{\mathrm{group}})\·(1+P_e)}}-1=\frac{N_{b\_\mathrm{group}}\·N_{\mathrm{group}}-N_{\mathrm{CRC}}\·N_{\mathrm{group}}}{N_{b\_\mathrm{group}}\·N_{\mathrm{group}}-N_{\mathrm{CRC}}}\·\frac{1+P_e}{1+P_{e\_\mathrm{group}}}-1.$

The concrete assignment of following formula is obtained following table:

??N b_group·N group	??r(％)for2 ??groups	??r(％)for3 ??groups	??r(％)for4 ??groups
				??4800	??4.1049	??\	??\
??9600	??4.3685	??5.7975	??\
				??14400	??4.456	??5.9754	??6.6759
??19200	??4.4997	??6.0643	??6.8103
				??24000	??4.526	??6.1176	??6.8909
??28800	??4.5434	??6.1531	??6.9446
				??33600	??4.5559	??6.1785	??6.983
??38400	??4.5653	??6.1975	??7.0117

??43200	??4.5725	??6.2123	??7.0341
				??48000	??4.5784	??6.2241	??7.052

The gain that the different transport block length of table 2 adopt the different grouping scheme to obtain

As can be seen from the above table, the group technology of the embodiment of the invention, throughput performance is improved, and packet count can be decided to be 2,3 or 4 groups according to different coded block size, can increase under the little situation in complexity to obtain higher gain.

The embodiment of the invention provides a kind of data transmission device based on above-mentioned grouping thought, as shown in Figure 5, comprising:

Segmentation module is used for transmission block is divided at least one group, and each group comprises at least one encoding block;

Pretreatment module, each group that is used for described segmentation module is divided into is added a CRC check position;

Data transmission blocks is used to send the pretreated data of described pretreatment module.

Further, described data transmission blocks can comprise retransmission module, when being used for data transmission fault, retransmits the group of makeing mistakes.

Need to prove that the preliminary treatment here can include but not limited to interweave, modulation treatment, precoding.

The embodiment of the invention also provides a kind of communication system based on above-mentioned grouping thought, comprises transmitter, communicate by letter with receiver, wherein:

Transmitter is used for transmission block is divided at least one group, and each group comprises at least one encoding block, is that described each group adds a CRC check position, coding, preliminary treatment and send that described preliminary treatment includes but not limited to interweave, modulation treatment, precoding.

Receiver is used for the data that receiver/transmitter sends, the checking data correctness, and instruct to transmitter according to group feeding back ACK or NACK.Instruction of each group feedback rather than instruction of each encoding block feedback.

When transmitter is received the NACK instruction according to every winding, retransmit the group of makeing mistakes; When receiving the ACK instruction, do not retransmit corresponding group of data.

The data transmission device of the embodiment of the invention is divided into a plurality of groups with the data to be transmitted piece, and each group comprises at least one data block, when the generation error of transmission need retransmit, retransmits the group of makeing mistakes rather than retransmits whole transmission block.

The embodiment of the invention is divided at least one group with transmission block, each group is added a CRC, when one or more coded block transmission mistake, only retransmits the group of makeing mistakes and need not retransmit whole transmission block, significantly reduce the data re-transmission amount, obtained bigger throughput gain simultaneously.

Module in the embodiment of the invention can be distributed in a device, also can be distributed in multiple arrangement.Above-mentioned module can be merged into a module, also can further split into a plurality of submodules.

It will be appreciated by those skilled in the art that accompanying drawing is the schematic diagram of a preferred embodiment, the module in the accompanying drawing might not be that enforcement the present invention is necessary.

The scheme of the content record of claim also is the protection range of the embodiment of the invention.

One of ordinary skill in the art will appreciate that all or part of processing in the foregoing description method is to instruct relevant hardware to finish by program, described program can be stored in a kind of computer-readable recording medium.

The explanation of above embodiment just is used for helping to understand method of the present invention and thought thereof; Simultaneously, for one of ordinary skill in the art, according to thought of the present invention, the part that all can change in specific embodiments and applications, in sum, this description should not be construed as limitation of the present invention.

Claims (9)

1, a kind of data transmission method is characterized in that, comprising:

Transmission block is divided at least one group, and each group comprises at least one encoding block;

For each group is added cyclic redundancy CRC check position;

Send the group behind the described interpolation CRC check position.

2, data transmission method according to claim 1 is characterized in that, the number of interior encoding block is not identical or different on the same group, and the length of each encoding block is identical or different.

3, data transmission method according to claim 1 is characterized in that, the group number that described transmission block is divided into is according to the preset amount of transmission block.

4, data transmission method according to claim 1 is characterized in that, during data transmission fault, retransmits the group of makeing mistakes.

5, a kind of data transmission device is characterized in that, comprising:

Segmentation module is used for transmission block is divided at least one group, and each group comprises at least one encoding block;

Pretreatment module, each group that is used for described segmentation module is divided into is added the CRC check position;

Data transmission blocks is used to send the group after described pretreatment module is added the CRC check position.

6, device according to claim 5 is characterized in that, described data transmission blocks further comprises: retransmission module when being used for data transmission fault, retransmits the group of makeing mistakes.

7, a kind of communication system comprises transmitter, communicates with receiver, it is characterized in that,

Described transmitter is used for transmission block is divided at least one group, and each group comprises at least one encoding block, for described each group is added CRC check position and transmission.

8, communication system according to claim 7 is characterized in that,

Described receiver is used for the data that receiver/transmitter sends, the correctness of the described data of verification, and correctly reply ACK or wrong responses NACK instructs to transmitter according to the group feedback.

9, communication system according to claim 8 is characterized in that, when described transmitter receives the NACK instruction, retransmits the group of makeing mistakes.

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