CN102684824B - A kind of data transmission method and system - Google Patents
A kind of data transmission method and system Download PDFInfo
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- CN102684824B CN102684824B CN201110064665.5A CN201110064665A CN102684824B CN 102684824 B CN102684824 B CN 102684824B CN 201110064665 A CN201110064665 A CN 201110064665A CN 102684824 B CN102684824 B CN 102684824B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
- H04L1/0041—Arrangements at the transmitter end
- H04L1/0043—Realisations of complexity reduction techniques, e.g. use of look-up tables
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M13/00—Coding, decoding or code conversion, for error detection or error correction; Coding theory basic assumptions; Coding bounds; Error probability evaluation methods; Channel models; Simulation or testing of codes
- H03M13/37—Decoding methods or techniques, not specific to the particular type of coding provided for in groups H03M13/03 - H03M13/35
- H03M13/3761—Decoding methods or techniques, not specific to the particular type of coding provided for in groups H03M13/03 - H03M13/35 using code combining, i.e. using combining of codeword portions which may have been transmitted separately, e.g. Digital Fountain codes, Raptor codes or Luby Transform [LT] codes
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Abstract
The invention discloses a kind of data transmission method and system, comprising: first user is to the packet after control station transmission fountain codes coding; Second user is to the packet of control station transmission after fountain codes coding; Control station carries out network code to the packet that first user and the second user are sent; Control station sends to first user and the second user by after the packet fountain codes coding after described network code; By the program, effectively can overcome the problem of error propagation, improve the accuracy of transceiving data, reduce the decoding overheads of data in transmitting procedure, reduce encoding and decoding complexity.
Description
Technical field
The invention belongs to the communications field, more specifically, relate to the data transmission method in a kind of wireless communication system and system.
Background technology
In general, in cordless communication network, the resource of similar transmitting energy and so on always can be subject to certain restrictions, if will, by information transmission to each node, need to increase transmitting energy, make information reach receiving node with higher signal to noise ratio, but also can produce between very strong node simultaneously and disturb.On the other hand, if channel is along with time variations, as the movement of channel fading or node, also can have an impact to Signal reception.In addition, now a lot of cordless communication network agreements, only for point-to-point connection, does not make full use of the broadcast characteristic in wireless transmission; Find in information-theoretical research, by suitable coding and decoding scheme, network can save physical resource, but current most encoding scheme complexity is too high.Network code is a concept more widely, everyly receive multiple signal at via node, to process and the form broadcasted away can be called network code, therefore the way of realization of network code can have a variety of, network code make use of the broadcast characteristic of wireless channel, also use the information encoding-decoding Theories and methods that practicality is higher simultaneously, make great progress technically.
Traditional network always will avoid signal to send at same time slot, otherwise can form interference, possibly cannot correctly receive.As shown in Figure 1, the figure shows the mode of legacy network, make S1 and S3 represent the information that node N1 and node N3 sends respectively, first N1 sends S1 to N2, and N2 sends S1 to N3; Then N3 sends S3 to N2, N2 and sends S3 to N1 again, altogether needs 4 time slots to complete information exchange.
Fig. 2 is the mode adopting network code, and as shown in the figure, first first time slot N1 send S1 to N2, and after second time slot N3 transmission S3 to N2, N2 receive S1 and S3, coding generates
wherein
represent and do bit-level XOR to two signal frame S1 and S3, the 3rd time slot N2 sends S2 to N1 and N3, and after N1 and N3 receives S2, extract the signal required for self respectively, N1 node passes through
obtain S3, N3 node to pass through
obtain S1, this scheme needs 3 time slots altogether, compares with traditional transmission mode, and throughput has the improvement of 25%.
The prerequisite that a certain specific coding can realize transmitting in actual channel is the statistical property that transmit leg and reciever all need to know channel, and this hypothesis is invalid under many circumstances, transfer of data such as on internet, because the situation of channel is along with time variations, also just mean that packet loss is not constant.
Relaying in the mode of network code adopts the coding of what form, and how preventing decode error from continuing in relay to propagate, is that former research does not deeply relate to.Relaying can take the method for directly merging to the information received on the one hand, is certain to like this cause error propagation; On the other hand, such as adopt common error correcting code, if relaying can not be correctly decoded, also need transmission to feed back to transmitting terminal requirement to retransmit, so for how reducing the decoding overheads of data in transmitting procedure, reduce encoding and decoding complexity, become current problem in the urgent need to address in Radio Transmission Technology.
Summary of the invention
For solving the problems of the technologies described above, on the mode basis of network code, the invention provides data transmission method in a kind of wireless communication system, fully effectively can reduce the decoding overheads of data in transmitting procedure, reduce encoding and decoding complexity.
Technical scheme of the present invention is:
First user is to the packet of control station transmission after fountain codes coding;
Second user is to the packet of control station transmission after fountain codes coding;
Control station carries out network code to the packet that first user and the second user are sent;
Control station sends to first user and the second user by after the packet fountain codes coding after described network code.
On the other hand, the invention provides the data transmission system in a kind of wireless communication system, it comprises:
With the first user sending packet after fountain codes coding to control station;
With the second user sending packet after fountain codes coding to control station;
The packet sent first user and the second user carries out the control station of network code, wherein, has the network encoding apparatus for carrying out network code to the packet sent from first user and the second user in control station;
In described first user, the second user and control station, all include fountain codes code device.
By above technical scheme, effectively can overcome the problem of error propagation, improve the accuracy of transceiving data, reduce the decoding overheads of data in transmitting procedure, reduce encoding and decoding complexity.
Accompanying drawing explanation
Accompanying drawing described herein is used to provide a further understanding of the present invention, forms a part of the present invention, and schematic description and description of the present invention, for explaining the present invention, does not form inappropriate limitation of the present invention.In the accompanying drawings:
Fig. 1 illustrates the mode of legacy network;
Fig. 2 illustrates the mode adopting network code;
Fig. 3 illustrates the cataloged procedure of Raptor code;
Fig. 4 illustrates the data transmission method flow chart of the embodiment of the present invention.
Embodiment
In order to make technical problem to be solved by this invention, technical scheme and beneficial effect clearly, understand, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.
As shown in Figure 4, the data transmission method that the embodiment of the present invention provides comprises:
First user is to the packet of control station transmission after fountain codes coding;
Second user is to the packet of control station transmission after fountain codes coding;
Control station carries out network code to the packet that first user and the second user are sent;
Control station sends to first user and the second user by after the packet fountain codes coding after described network code.
Fountain codes wherein belongs to no-rate codes (Rateless codes), and Raptor code belongs to the one in fountain codes.No-rate codes (Rateless codes) is different from block encoding and every K bit is compiled as pre-set certain bit number, no-rate codes (Rateless codes) compiles as infinite many bit streams transmit, when receiving terminal receive abundant bit number (determining according to the situation of channel) can decode time, inform that transmitting terminal stops sending, if decode unsuccessfully, then continue decoding until successfully decoded by more bit number again.No-rate codes has two distinguishing features: do not rely on channel conditions and low decoding complex degree.
Fountain codes is a kind of linear block codes of variable bit rate, and namely transmitting terminal can generate the encoded packets of any amount by original packet, as long as and receiving terminal receives enough coded data packet, probability that just can be very high successfully translates raw data packets.Compared with other error-correcting code technique, the channel conditions of fountain codes technology energy Adaptive change and lower encoding and decoding complexity etc., therefore, have huge advantage at application scenarioss such as Reliable Multicast Transport, multi-source download and data storages.
LT (Luby Transform) code is one of fountain codes that the earliest can be practical, and its adopts healthy and strong orphan's distribution (Robust Soliton Distribution; RSD) degree as code distributes, and realizes code check variable, but its encoding and decoding complexity can not reach design object.Raptor code is again improve on the basis of LT code, so still belong to fountain codes, it is by carrying out precoding to incoming symbol, then adopt one weaken RSD distribution LT code encode, thus, realize expense very little time, reach transmitting.
Although LT code function admirable, but do not reach the dreamboat of encoding and decoding complexity yet, namely the operand that generating each coded identification needs is a constant irrelevant with incoming symbol length, and the operand that decoding success needs is a linear function about incoming symbol length.
Raptor code applies the feature of the feature of LT code and the decoding algorithm of LDPC (Low-Density ParityCheck) code dexterously, the two is organically combined, devises a kind of concatenated coding.Greatly reduce the complexity of decoding like this.The encoding and decoding complexity of Raptor code is o (kln (1/ ε)), and wherein k is incoming symbol length, and ε is decoding overheads.Visible, the encoding and decoding complexity of Raptor code is a linear function about incoming symbol length k.
The cataloged procedure of Raptor code as shown in Figure 3, is made up of precoding process and LT code cataloged procedure.Precoding process, by k incoming symbol, is converted to the individual intermediate symbols of k ' by traditional correcting and eleting codes such as LDPC, then individual for k ' intermediate symbols is carried out secondary coding as the incoming symbol of LT code, thus obtains the coded identification of Raptor code.
The decoding of Raptor code equally in two steps, translates intermediate symbols and translates source incoming symbol.
The first step, due to the incoming symbol that intermediate symbols is as LT coding, generation coded identification, so according to the character of LT code, the individual intermediate symbols of k ' is translated if want, receiving terminal needs the number of symbols received to be larger than k ', then can translate the individual intermediate symbols of k ' by the coding/decoding method of LT code.
Second step, recycles the decoding character of traditional correcting and eleting codes, and individual for k ' intermediate symbols decoding is reverted to k source incoming symbol.So far, decode procedure terminates.
As far as possible the design object of Raptor code reduces decoding overheads, makes it level off to zero, reduce encoding and decoding complexity simultaneously as far as possible.Ideally, the constant that the operand of each coded identification of generation becomes irrelevant with incoming symbol length should be made, and the operand of decoding is a linear function about incoming symbol length.Although common Raptor code can reach this two design objects, require that incoming symbol very grows (code length is generally more than 10,000 bits); And in systems in practice, incoming symbol code length is all shorter, code length is in a few kilobit.
The fountain codes of transmitting terminal and receiving terminal can adopt the no-rate codes such as LT code and Raptor code, reaches independent of channel and the characteristic reducing decoding complex degree.Wherein, Raptor code is compared LT code and is had better performance.
Adopt the degree of the LT code in the method redesign Raptor code of new differential evolution and LDPC code to distribute, can decoding overheads be reduced, and make the operand generating each coded identification be the constant irrelevant with incoming symbol length.
The coding and decoding of Raptor code is LT code and LDPC code independently process, and therefore when designing, the design of Raptor code can regard the independent optimization of LT code and LDPC code as.The object of LDPC code is issued to minimum bit-error rate at high code check, and LT code is then be issued to LDPC code error correction scope in the prerequisite of minimum decoding overheads.
Embodiment one
User A adopts Raptor code to send N1 >=K packet to base station (or relaying), and wherein K is the number of raw data packets, and N1 is the number of data packets after Raptor code coding of actual transmission; When after the correct decoding K raw data packets of base station, base station sends ACK acknowledge message to user A; After user A receives the ACK message sent base station, stop sending packet.
User B adopts Raptor code to send N2 >=K packet to base station or relaying, and wherein K is the number of raw data packets, and N2 is the number of data packets after Raptor code coding of actual transmission; When after the correct decoding K raw data packets of base station, base station sends ACK acknowledge message to user B; After user B receives the ACK message sent base station, stop sending packet;
Network code is carried out to the raw data packets that user A and user B sends in base station (or relaying), the information that two users send can be carried out XOR, obtain new K network code packet; Base station adopts Raptor code to send N3 >=K packet to user A and user B, and wherein K is the number of network code packet, and N3 is the number of data packets after Raptor code coding of actual transmission.
After user A and user B receives packet, first detect and obtain the information after merging, recycling its own signal carries out xor operation respectively to received signal, correctly solve desired signal, then ACK acknowledge message is sent to base station, after base station receives the ACK message of two users, stop sending packet.
Base station and two users can adopt the optimization degree distribution of following steps generation Raptor code to encode.
Start at the cataloged procedure of Raptor code, information source produces K packet, first needs the encoder entering LDPC code, therefore needs the degree of known LDPC code to distribute.The degree distribution of this LDPC code can produce in accordance with the following steps.
The production method of the degree distribution of LDPC code performs in accordance with the following steps:
(1) initial value arranging search depth is 0, and the maximum of search depth is G; Error rate threshold value is δ, then stochastic generation M degree distribution Γ
1(x), Γ
2(x), L Γ
mx (), wherein needs the most goodness searched for be distributed as Γ
best(x).
(2) the degree distribution generated in step (1) is substituted into optimization aim, make after N iterative decoding process, the error rate of fountain codes is minimum.Obtain the value ber of target function after N iteration
1, ber
2, L, ber
m, wherein ber_best is the minimum value in the middle of target function value after iteration, now record corresponding degree distribution Γ
best(x), and the value of search depth is increased by 1.If now the optimum error rate is higher than the error rate threshold value preset, i.e. ber_best > ber_th, enter step (3);
(3) for degree distribution Γ
ix () (1≤i≤M), stochastic generation scope is the integer that [1, M] 4 are different, by controlling the amplitude adjustment degree distribution of differential variation.Four random integers such as produced are respectively as r
i1, r
i2, r
i3, r
i4.Make amplitude controlling elements F=0.5, degree distribution can be expressed as
(4) repeat step (2), when the error rate is not higher than the error rate threshold value preset, search procedure terminates, and the record optimum error rate at this moment and most goodness distribute.
Obtain most goodness distribution Γ
bestafter (x)=[λ (x) ρ (x)], the packet of generation is carried out LDPC coding, then carry out the coding of LT code.Equally, cataloged procedure needs the degree of known LT code to distribute.
The production method of the degree distribution of LT code performs in accordance with the following steps:
(1) according to input information packet number K ', arrange and initially spend distribution, the distribution of this degree is the function of the code check R of packets of information number K ' and coding.
(2) produce the individual degree distribution of M ' at random, can Ω be expressed as
1(d), Ω
2(d), L, Ω
m '(d).The degree distribution generated in step (1) is substituted into optimization aim, and make after the secondary iterative decoding process of N ', the error rate is minimum.Such as obtain the value ber of target function after the secondary iteration of N '
1, ber
2, L, ber
m ', and make optimal objective function value ber_best be minimum value in the middle of target function value after iteration, i.e. ber_best=min (ber_best, ber
1, ber
2, L, ber
m '), record corresponding degree distribution Ω
best' (x), and the value of search depth is increased by 1.
(3) stochastic generation scope is at [1, M '] 4 different integer r
i1, r
i2, r
i3, r
i4, by controlling the amplitude adjustment degree distribution of differential variation, order
can from the Ω obtained
ix () calculates error rate ber
(i).
(4) if the error rate calculated is higher than the minimum value of target error rate, then step (2) is repeated, until target error rate remains unchanged or lower than the minimum value of target error rate, then stop search.The corresponding degree of record is distributed as the distribution of desired degree.
The degree distribution of LDPC code and LT code can be obtained by searching algorithm above, and then the coding of Raptor code can be carried out.
Embodiment two
User A adopts Raptor code to send N1 >=K packet to base station (or relaying), and wherein K is the number of raw data packets, and N1 is the number of data packets after Raptor code coding of actual transmission; When after the correct decoding K raw data packets of base station, base station sends ACK acknowledge message to user A; After user A receives the ACK message sent base station, stop sending packet.
User B adopts Raptor code to send N2 >=K packet to base station or relaying, and wherein K is the number of raw data packets, and N2 is the number of data packets after Raptor code coding of actual transmission; When after the correct decoding K raw data packets of base station, base station sends ACK acknowledge message to user B; After user B receives the ACK message sent base station, stop sending packet;
Network code is carried out to the raw data packets that user A and user B sends in base station (or relaying), can the modulation system of more high-order be adopted to do the information that two users send and merge, obtain new K network code packet; Base station adopts Raptor code to send N3 >=K packet to user A and user B, and wherein K is the number of network code packet, and N3 is the number of data packets after Raptor code coding of actual transmission.
After user A and user B receives packet, start to attempt decoding.First after utilizing its own signal correctly to solve desired signal respectively, then send ACK acknowledge message to base station, after base station receives the ACK message of two users, stop sending packet.
Base station and two users can adopt the optimization degree distribution of following steps generation Raptor code to encode.
Start at the cataloged procedure of Raptor code, information source produces the packet of K, first needs the encoder entering LDPC code, therefore needs the degree of known LDPC code to distribute.The degree distribution of this LDPC code can produce in accordance with the following steps.
The production method of the degree distribution of LDPC code performs in accordance with the following steps:
(1) initial value arranging search depth is 0, and the maximum of search depth is G; Error rate threshold value is δ, then stochastic generation M degree distribution Γ
1(x), Γ
2(x), L Γ
mx (), wherein needs the most goodness searched for be distributed as Γ
best(x).
(2) the degree distribution generated in step (1) is substituted into optimization aim, make after N iterative decoding process, the error rate of fountain codes is minimum.Obtain the value ber of target function after N iteration
1, ber
2, L, ber
m, wherein ber_best is the minimum value in the middle of target function value after iteration, now record corresponding degree distribution Γ
best(x), and the value of search depth is increased by 1.If now the optimum error rate is not higher than the error rate threshold value preset, i.e. ber_best≤ber_th, search terminates, and the record optimum error rate at this moment and most goodness distribute.
Obtain most goodness distribution Γ
bestx ()=[λ (x) ρ (x)], carries out LDPC coding and obtains the sequence that data length is, then carry out the coding of LT code by the information sequence of generation.Equally, cataloged procedure needs the degree of known LT code to distribute.
The production method of the degree distribution of LT code performs in accordance with the following steps:
(1) according to the number K ' of input packets of information, arrange and initially spend distribution, the distribution of this degree is the function of the code check R of packet number K ' and coding.
(2) produce the individual degree distribution of M ' at random, can Ω be expressed as
1(d), Ω
2(d), L, Ω
m '(d).The degree distribution generated in step (1) is substituted into optimization aim, and make after the secondary iterative decoding process of N ', the error rate is minimum.Such as obtain the value ber of target function after the secondary iteration of N '
1, ber
2, L, ber
m ', and make optimal objective function value ber_best be minimum value in the middle of target function value after iteration, i.e. ber_best=min (ber_best, ber
1, ber
2, L, ber
m '), record corresponding degree distribution Ω
best' (x).If now the optimum error rate is not higher than the error rate threshold value preset, i.e. ber_best≤ber_th, search terminates, and the record optimum error rate at this moment and most goodness distribute.
The degree distribution of LDPC code and LT code can be obtained by searching algorithm above, and then the coding of Raptor code can be carried out.
Embodiment three
User A adopts fountain codes to send N1 >=K packet to base station (or relaying), and wherein K is the number of raw data packets, and N1 is the number of data packets after fountain codes coding of actual transmission; When after the correct decoding K raw data packets of base station, base station sends ACK acknowledge message to user A; After user A receives the ACK message sent base station, stop sending packet.
User B adopts fountain codes to send N2 >=K packet to base station or relaying, and wherein K is the number of raw data packets, and N2 is the number of data packets after fountain codes coding of actual transmission; When after the correct decoding K raw data packets of base station, base station sends ACK acknowledge message to user B; After user B receives the ACK message sent base station, stop sending packet;
Network code is carried out to the raw data packets that user A and user B sends in base station (or relaying), the information that two users send can be carried out XOR, obtain new K network code packet; Base station adopts fountain codes to send N3 >=K packet to user A and user B, and wherein K is the number of network code packet, and N3 is the number of data packets after fountain codes coding of actual transmission.
After user A and user B receives packet, first detect and obtain the information after merging, recycling its own signal carries out xor operation respectively to received signal, correctly solve desired signal, then ACK acknowledge message is sent to base station, after base station receives the ACK message of two users, stop sending packet.
Embodiment four
User A adopts LT code to send N1 >=K packet to base station (or relaying), and wherein K is the number of raw data packets, and N1 is the number of data packets after LT code coding of actual transmission; When after the correct decoding K raw data packets of base station, base station sends ACK acknowledge message to user A; After user A receives the ACK message sent base station, stop sending packet.
User B adopts LT code to send N2 >=K packet to base station or relaying, and wherein K is the number of raw data packets, and N2 is the number of data packets after LT code coding of actual transmission; When after the correct decoding K raw data packets of base station, base station sends ACK acknowledge message to user B; After user B receives the ACK message sent base station, stop sending packet;
Network code is carried out to the raw data packets that user A and user B sends in base station (or relaying), the information that two users send can be carried out XOR, obtain new K network code packet; Base station adopts LT code to send N3 >=K packet to user A and user B, and wherein K is the number of network code packet, and N3 is the number of data packets after LT code coding of actual transmission.
After user A and user B receives packet, first detect and obtain the information after merging, recycling its own signal carries out xor operation respectively to received signal, correctly solve desired signal, then ACK acknowledge message is sent to base station, after base station receives the ACK message of two users, stop sending packet.
Base station and two users can adopt the optimization degree distribution of following steps generation LT code to encode.
(1) according to the length K of input packet, arrange and initially spend distribution;
(2) random generation M degree distribution, is expressed as Ω
1(d), Ω
2(d), L, Ω
md (), described initial degree distribution is substituted into optimization aim, and make after several times iterative decoding process, the error rate is minimum, obtains the error rate ber of target function after several times iteration
1, ber
2, L, ber
m, and make the error rate ber_best of optimal objective function be minimum value in the target function error rate after iteration, record corresponding degree distribution Ω
best(x);
(3) stochastic generation scope is at [1, M] 4 different integer r
i1, r
i2, r
i3, r
i4, obtain Ω by the amplitude adjustment degree distribution controlling differential variation
i(x), and calculate corresponding error rate ber
i, wherein
f is the real constant of amplitude being used for controlling differential variation;
(4) if the error rate ber calculated
ilower than the error rate ber_best of target function, then change the error rate ber_best=ber of target function
iwith degree distribution Ω
best(x)=Ω
i(x), and repeat (3); If the error rate calculated is not less than the error rate of target function, then repeat (2); Until the error rate of target function remains unchanged or equals 0 in successive ignition, then stop search, record spends distribution accordingly.
The degree distribution of LT code can be obtained by searching algorithm above, and then the coding of LT code can be carried out.
In addition, present invention also offers a kind of data transmission system, comprising:
With the first user sending packet after fountain codes coding to control station;
With the second user sending packet after fountain codes coding to control station;
The packet sent first user and the second user carries out the control station of network code, wherein, has the network encoding apparatus for carrying out network code to the packet sent from first user and the second user in control station;
In described first user, the second user and control station, all include fountain codes code device.
Described fountain codes code device can but be not limited to Raptor code encoding device.
Above-mentioned explanation illustrate and describes comparatively preferred embodiment of the present invention, but as previously mentioned, be to be understood that the present invention is not limited to the form disclosed by this paper, should not regard the eliminating to other embodiments as, and can be used for other combinations various, amendment and environment, and can in invention contemplated scope described herein, changed by the technology of above-mentioned instruction or association area or knowledge.And the change that those skilled in the art carry out and change do not depart from the spirit and scope of the present invention, then all should in the protection range of claims of the present invention.
Claims (13)
1. a data transmission method, is characterized in that, comprising:
First user is to the packet of control station transmission after fountain codes coding;
Second user is to the packet of control station transmission after fountain codes coding;
Control station carries out network code to the packet that first user and the second user are sent;
Control station sends to first user and the second user by after the packet fountain codes coding after described network code.
2. data transmission method according to claim 1, it is characterized in that, described first user to control station transmission fountain codes coding after packet after, before described control station carries out network code to the packet that first user and the second user are sent, control station decoding is from the packet of first user, control station sends ACK acknowledge message to first user, and first user, after receiving the ACK acknowledge message sent from control station, stops sending packet to control station.
3. data transmission method according to claim 1, it is characterized in that, described second user to control station transmission fountain codes coding after packet after, before described control station carries out network code to the packet that first user and the second user are sent, control station decoding is from the packet of the second user, control station sends ACK acknowledge message to the second user, and the second user, after receiving the ACK acknowledge message sent from control station, stops sending packet to control station.
4. data transmission method according to claim 1, is characterized in that, it is carry out binary system XOR between first user and the packet of the second user that described control station carries out network code to the packet that first user and the second user are sent.
5. the data transmission method according to claim 1 or 4, is characterized in that, described fountain codes is Raptor code.
6. data transmission method according to claim 5, is characterized in that, comprises by the method for fountain codes coding:
K raw data packets is sent into LDPC encoder, and the degree according to LDPC code distributes, and obtains the packet after k' coding;
K' packet after described LDPC code coding is put into the encoder of LT code, the degree according to LT code distributes, and generates the packet after N number of coding.
7. data transmission method according to claim 6, is characterized in that, the degree distributed acquisition process of described LDPC code comprises:
(1) the initial value S=0 of search depth is set, the maximum G of search depth; Error rate threshold value ber_th=δ, stochastic generation M degree distribution, is expressed as Γ
1(x), Γ
2(x) ... Γ
mx (), wherein, needs the most goodness distribution table of search to show for Γ
best(x);
(2) the degree distribution generated is substituted into optimization aim, make after several times iterative decoding, the error rate obtaining target function after several times iteration is ber
1, ber
2..., ber
mand make the error rate ber_best of optimal objective function be minimum value in the target function error rate after iteration, the value of search depth S is increased by 1, if the optimum error rate is not higher than the error rate threshold delta preset, i.e. ber_best≤δ, then the process of search degree distribution terminates, and the record optimum error rate now and most goodness distribute; Otherwise, enter (3);
(3) for degree distribution Γ
ix () (1≤i≤M), stochastic generation scope is the integer r that [1, M] 4 are different
i1, r
i2, r
i3, r
i4, obtain Γ by the amplitude adjustment degree distribution controlling differential variation
i(x), and calculate corresponding error rate ber
i, wherein
F is the real constant of amplitude being used for controlling differential variation;
(4) repeat (2), until search depth reaches maximum, or the optimum error rate is not higher than the error rate threshold delta preset, then the process of search degree distribution terminates; The record optimum error rate now and most goodness distribute.
8. data transmission method according to claim 6, is characterized in that, the degree distributed acquisition process of described LT code comprises:
(1) according to the number k' of input packet, arrange and initially spend distribution;
(2) random generation M degree distribution, is expressed as Ω
1(d), Ω
2(d) ..., Ω
md (), described initial degree distribution is substituted into optimization aim, and make after several times iterative decoding process, the error rate is minimum, obtains the error rate ber of target function after several times iteration
1, ber
2..., ber
m, and make the error rate ber_best of optimal objective function be minimum value in the target function error rate after iteration, record corresponding degree distribution Ω
best(x);
(3) stochastic generation scope is at [1, M] 4 different integer r
i1, r
i2, r
i3, r
i4, obtain Ω by the amplitude adjustment degree distribution controlling differential variation
i(x), and calculate corresponding error rate ber
i, wherein
F is the real constant of amplitude being used for controlling differential variation;
(4) if the error rate ber calculated
ilower than the error rate ber_best of target function, then change the error rate ber_best=ber of target function
iwith degree distribution Ω
best(x)=Ω
i(x), and repeat (3); If the error rate calculated is not less than the error rate of target function, then repeat (2); Until the error rate of target function remains unchanged or equals 0 in successive ignition, then stop search, record spends distribution accordingly.
9. data transmission method according to claim 1, is characterized in that, described control station comprises base station and/or relay station.
10. a data transmission system, comprising:
With the first user sending packet after fountain codes coding to control station;
With the second user sending packet after fountain codes coding to control station;
The packet sent first user and the second user carries out the control station of network code, wherein, has the network encoding apparatus for carrying out network code to the packet sent from first user and the second user in control station;
It is characterized in that, in described first user, the second user and control station, all include fountain codes code device.
11. data transmission systems according to claim 10, is characterized in that, described fountain codes code device is Raptor code encoding device.
12. 1 kinds of control stations, this control station is applied to the method described in claim 1-9 any one or the data transmission system described in claim 10 or 11, it is characterized in that, has fountain codes code device in described control station.
13. control stations according to claim 12, is characterized in that, described fountain codes code device is Raptor code encoding device.
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| CN201110064665.5A CN102684824B (en) | 2011-03-17 | 2011-03-17 | A kind of data transmission method and system |
| PCT/CN2011/076691 WO2012122758A1 (en) | 2011-03-17 | 2011-06-30 | Data transmission method and system, and control station |
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| US10129928B2 (en) * | 2012-12-14 | 2018-11-13 | Huawei Technologies Co., Ltd. | System and method for UE fountain relay based network |
| CN103973402B (en) * | 2013-02-06 | 2019-02-05 | 华为技术有限公司 | Data transmission method for uplink, method of reseptance and equipment |
| CN104219710B (en) * | 2013-05-31 | 2019-03-12 | 中兴通讯股份有限公司 | A kind of information transferring method, intermediate node and terminal |
| CN104219030B (en) * | 2013-05-31 | 2019-06-14 | 中兴通讯股份有限公司 | A kind of method and device of transmission network coded data |
| CN103346859B (en) * | 2013-06-06 | 2016-08-10 | 电子科技大学 | The encoding and decoding method of distributed unequal error protection LT code |
| EP2827503A1 (en) * | 2013-07-15 | 2015-01-21 | Alcatel Lucent | Rateless encoding |
| CN104782097A (en) * | 2013-10-22 | 2015-07-15 | 华为技术有限公司 | Method and device for calculating quantity of encoded data packets transmitted within broadcast system |
| CN103716134B (en) * | 2013-11-21 | 2016-08-24 | 浙江大学 | The coding method of cumulative fountain codes is spent under feedback condition |
| CN105634671A (en) * | 2015-12-23 | 2016-06-01 | 中国人民解放军军械工程学院 | Communication method based on fountain codes and physical layer network coding |
| EP3447943B1 (en) * | 2016-05-11 | 2021-04-07 | Huawei Technologies Co., Ltd. | Data transmission method, device and system |
| CN105897382A (en) * | 2016-06-08 | 2016-08-24 | 乐视控股（北京）有限公司 | Data synchronization method and device |
| CN108809487B (en) * | 2017-05-04 | 2022-07-22 | 华为技术有限公司 | Data transmission method, base station and terminal equipment |
| CN107565984B (en) * | 2017-08-14 | 2020-06-19 | 华南理工大学 | Raptor code optimized coding method with precoding as irregular code |
| CN109088701A (en) * | 2018-09-26 | 2018-12-25 | 北京理工大学 | A kind of LDPC code serial transmission method based on online fountain codes |
| CN110191248B (en) * | 2019-06-07 | 2020-09-29 | 天府新区西南交通大学研究院 | Feedback-based unmanned aerial vehicle image transmission method of Bats Code |
| CN112737729B (en) * | 2019-10-28 | 2022-04-19 | 哈尔滨工业大学（深圳） | Data transmission method and device, computer equipment and storage medium |
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| CN101695016A (en) * | 2009-10-22 | 2010-04-14 | 浙江大学 | Multi-user random access system based on rateless codes and coding and decoding method thereof |
| CN101820333A (en) * | 2010-04-16 | 2010-09-01 | 浙江大学 | Distribution type access transmission method of cognitive multi-user and multi-channel system based on rate-free code |
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| CN101820333A (en) * | 2010-04-16 | 2010-09-01 | 浙江大学 | Distribution type access transmission method of cognitive multi-user and multi-channel system based on rate-free code |
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