CN103780345A - System and method for multi-buffering non-constant-speed code transmission of real-time service in intensive communication - Google Patents

Abstract

The invention discloses a system and method for multi-buffering non-constant-speed code transmission of real-time service in intensive communication. The system comprises a coding terminal, at least two communication links and a decoding terminal, wherein the coding terminal sequentially conducts LT code coding on a plurality of information groups formed by dividing a video streaming so that a plurality of groups of multi-buffing LT codes can be obtained, and the obtained multi-buffering LT codes are sent by the coding terminal; the decoding terminal conducts LT code decoding on all the groups of multiple-buffering LT codes which are received accumulatively, so that corresponding information groups are obtained, and corresponding decoding buffering zones are emptied; when one communication link breaks down, other communication links are adopted to conduct data transmission through switching or other communication links and the communication link which breaks down are selected to conduct data communication at the same time. According to the system for multi-buffering non-constant-speed code transmission of the real-time service in intensive communication, when feedback links are not ideal in intensive communication, for example, the delay of one feedback link is long or the upstream link and the downstream link do not correspond to each other, real-time data can be transmitted efficiently and reliably; due to the feature of the non-constant speed codes, switching between the communication links is smoother.

Description

Many bufferings non-constant speed code transmission system and the method for real time business in intensive communication

Technical field

The present invention relates to wireless communication technology field, relate in particular to many bufferings non-constant speed code transmission system and the method for real time business in a kind of intensive communication.

Background technology

Mobile communication is the important foundation framework of information-intensive society, and development wideband wireless mobile communication is the basic strategy demand of China.Meanwhile, along with greatly abundant in information-intensive society chinesization life of China people, and smart mobile phone, flat board, notebook computer is universal, and mobile data services amount is almost exponential type magnanimity and increases.On the other hand, along with the quickening of Urbanization in China, urban population densification degree is constantly upgraded, and due to the restriction of land resource, the development of modern city is extended and is turned to three-dimensional extension by plane, this also makes mobile subscriber's quantity in unit are with floor and Terrain Elevation linear growth, show unprecedented densification trend, thereby the spectrum efficiency in unit are has proposed very big challenge to mobile communication.Therefore become the development trend of following metropolis cordless communication network towards mobile subscriber's the intensive overlay network of 3 D stereoization.

Under the wireless network environment of the intensive covering of 3 D stereoization, mobile multimedia application will constantly increase, and this will have higher requirement as real-time video transmission quality to wireless real-time data service.But, in domestic and foreign literature and patent, mostly only consider non-constant speed code Design and research under ideal feedback channel, so, need a kind of system of real-time service transmission of effective opposing feedback channel imperfection badly.

Summary of the invention

One of technical problem to be solved by this invention is the non-constant speed code of the many bufferings transmission system that real time business in a kind of intensive communication need to be provided, and it can effectively resist the imperfection of feedback channel.A kind of non-constant speed decoding transmission method of many bufferings of real time business is also provided in addition.

In order to solve the problems of the technologies described above, the invention provides the non-constant speed code of the many bufferings transmission system of real time business in a kind of intensive communication, comprise: coding side, it is provided with multiple encoding buffers, utilize some information groups that multiple encoding buffers are divided video flowing to carry out successively LT code coding and obtain the many bufferings of many groups LT codes, the obtained LT code that cushions each group is sent successively, and in conjunction with the information group in its corresponding encoding buffer of decoding feedback information updating; Transmission medium, comprises at least two communication links, for the many bufferings of the each group of real-time Transmission LT code; Decoding end, it is provided with multiple decoding buffer zones, thereby utilize each decoding buffer zone to carry out the decoding of LT code and obtain corresponding information group the LT code that cushions every group wherein totally receiving more, the decoding feedback information that transmission cushions LT code about this group more feeds back to described coding side, and empty corresponding decoding buffer zone, wherein, in the time that a communication link goes wrong, switch to other communication links and carry out transfer of data, or select other communication links and this communication link to carry out transfer of data simultaneously.

In one embodiment, described communication link communicates by the reliable transport protocol towards non-link, wherein, the erasure channel of the described reliable transport protocol towards non-link based on UDP bag and CRC check formation and the Code And Decode method that cushions LT code obtain more.

In one embodiment, described coding side further comprises: division unit, it is for being divided into video flowing the information group of several equal lengths, and each information group is sorted successively and forms a coding queue, the information group of front setting quantity is put into each encoding buffer successively, wherein, the information group number of described setting quantity is identical with the number of encoding buffer, and each information group is divided into K LT packet equal in length; LT code coding unit, it carries out LT code coding to K LT packet in the coding current encoding buffer pointed of pointer and obtains p encoded packets, and p the encoded packets that transmission obtains successively, then, the next encoding buffer of the pointed of encoding, if last encoding buffer of present encoding pointed, first encoding buffer of the pointed of encoding, wherein, the number p of encoded packets is less than the number K of LT packet; Judging unit, it is in LT code cataloged procedure, for judging whether to receive the decoding feedback information from described decoding end, if receive described decoding feedback information, put into the encoding buffer corresponding with described decoding feedback information by not putting into first group of information group encoding buffer and that be arranged in coding queue head of the queue, continue the encoding buffer of the current sensing of coding pointer to carry out LT code coding otherwise return to LT code coding unit.

In one embodiment, described decoding end further comprises: receiving element, and it, puts it in corresponding decoding buffer zone according to the encoding buffer information of obtaining from the header packet information of this encoded packets in the time receiving encoded packets; LT code decoding unit, when the sum of the encoded packets that its accumulative total in certain decoding buffer zone receives is greater than K, encoded packets in this decoding buffer zone is carried out to the decoding of LT code, if successfully decoded, the information group decoding being obtained is put into the tail of the queue of decoding queue and is sent decoding feedback information to described coding side, otherwise p the encoded packets that corresponding encoding buffer sends continued to receive in this decoding buffer zone, and whole encoded packets of its accumulative total reception are carried out to the decoding of LT code, until successfully decoded.

According to a further aspect in the invention, the non-constant speed decoding transmission method of many bufferings of real time business in a kind of intensive communication is also provided, comprise: coding step, multiple encoding buffers are set, utilize some information groups that multiple encoding buffers are divided video flowing to carry out successively LT code coding and obtain the many bufferings of many groups LT codes, the obtained LT code that cushions each group is sent successively, and in conjunction with the information group in its corresponding encoding buffer of decoding feedback information updating; Transmitting step, by the many bufferings of the each group of communication link real-time Transmission LT code; Decoding step, multiple decoding buffer zones are set, thereby utilize each decoding buffer zone to carry out the decoding of LT code and obtain corresponding information group the LT code that cushions every group wherein totally receiving more, the decoding feedback information that transmission cushions LT code about this group more feeds back to described coding side, and empty corresponding decoding buffer zone, wherein, described communication link is at least two, in the time that a communication link goes wrong, switch to other communication links and carry out transfer of data, or select other communication links and this communication link to carry out transfer of data simultaneously.

In one embodiment, in described transmitting step, the reliable transport protocol of described communication link based on towards non-link communicates, wherein, the erasure channel of the described reliable transport protocol towards non-link based on UDP bag and CRC check formation and the Code And Decode method that cushions LT code obtain more.

In one embodiment, in described coding step, further comprise: step 710, video flowing is divided into the information group of several equal lengths, and each information group is sorted successively and forms a coding queue, the information group of front setting quantity is put into each encoding buffer successively, wherein, the information group number of described setting quantity is identical with the number of encoding buffer, and each information group is divided into K LT packet equal in length; Step 720, K LT packet in the coding current encoding buffer pointed of pointer carried out to LT code coding and obtain p encoded packets, and p the encoded packets that transmission obtains successively, then, the next encoding buffer of the pointed of encoding, if last encoding buffer of present encoding pointed, first encoding buffer of the pointed of encoding, wherein, the number p of encoded packets is less than the number K of LT packet; Step 730, in LT code cataloged procedure, judge whether to receive the decoding feedback information from described decoding end, if receive described decoding feedback information, put into the encoding buffer corresponding with described decoding feedback information by not putting into first group of information group buffering area and that be arranged in coding queue head of the queue, continue the encoding buffer of the current sensing of coding pointer to carry out LT code coding otherwise return to step 720.

In one embodiment, in described decoding step, further comprise: step 810, in the time receiving encoded packets, according to the encoding buffer information of obtaining from the header packet information of this encoded packets, puts it in corresponding decoding buffer zone; Step 820, when the sum of the encoded packets receiving in certain decoding buffer zone is greater than K, encoded packets in this decoding buffer zone is carried out to the decoding of LT code, if successfully decoded, the information group decoding being obtained is put into the tail of the queue of decoding queue and is sent decoding feedback information to described coding side, otherwise this decoding buffer zone continues to receive p the encoded packets that corresponding encoding buffer sends, and whole encoded packets that it is received carry out the decoding of LT code, until successfully decoded.

In one embodiment, the transmission rate of described many buffering LT codes is:

$R_r=\frac{l\·K\·P_m}{{\mathrm{\Σ}}_i^l(s_i\·p\·t_c+t_{\mathrm{di}})}$

Wherein, l is total information group number, and K is the number of LT packet equal in length in each information group, P _mfor LT data package size, s _ithe group number of the many buffering LT codes that receive for i information group successfully decoded is front, p is the encoded packets number that each information group generates, t _cthe transmission time of cushioning LT code corresponding to transmission data link one group more, t _diit is the arrival decoding end required time of feedback information after i information group decoding.

In one embodiment, meeting max{t _di< pmt _cunder-1 prerequisite, the efficiency of transmission of described many buffering LT codes is:

$\mathrm{\&eta;}=\frac{R_r}{R}=\frac{K}{\mathrm{pE}\left(s\right)}$

Wherein, the number that m is described encoding buffer, R is transmission data link actual transmission speed, the expectation of the group number of many buffering LT codes that E (s) receives for successfully decoded is front.

Compared with prior art, one or more embodiment of the present invention can have the following advantages by tool:

The non-constant speed code transmission system of many bufferings of the present invention is carried out the encoding and decoding of data based on non-constant speed code, and comprises that at least two communication links transmit information, and this has guaranteed the continuity of transfer of data in the time that real-time fault appears in link; Owing to having adopted encoding buffer and decoding buffer zone, the non-constant speed code of many bufferings of the present invention has better overcome non-permanent digital time-delay characteristics, therefore when native system can in intensive communication, feedback link time delay be larger or uplink downlink when peer feedback link is not undesirable, real time data is carried out to high efficient and reliable transmission, and switching between communication link is more smooth.

Other features and advantages of the present invention will be set forth in the following description, and, partly from specification, become apparent, or understand by implementing the present invention.Object of the present invention and other advantages can be realized and be obtained by specifically noted structure in specification, claims and accompanying drawing.

Accompanying drawing explanation

Accompanying drawing is used to provide a further understanding of the present invention, and forms a part for specification,, is not construed as limiting the invention jointly for explaining the present invention with embodiments of the invention.In the accompanying drawings:

Fig. 1 is the block diagram of the non-constant speed code of the many bufferings transmission system of real time business in intensive according to an embodiment of the invention communication;

Fig. 2 is the flow chart of the coding method based on many buffering LT codes of one example according to the present invention;

Fig. 3 is the flow chart of the coding/decoding method based on many buffering LT codes of one example according to the present invention;

Fig. 4 is that the efficiency of transmission of the non-constant speed code of the many bufferings transmission system of real time business in the intensive communication of one example according to the present invention has in time delay situation and the comparison diagram of the efficiency of transmission of other system at feedback link;

Fig. 5 is the frame diagram of the non-constant speed code of the many bufferings transmission system of real time business in the intensive communication of one example according to the present invention.

Embodiment

For making the object, technical solutions and advantages of the present invention clearer, below in conjunction with accompanying drawing, the present invention is described in further detail.

Fig. 1 is the block diagram of the non-constant speed code of the many bufferings transmission system (hereinafter to be referred as the non-constant speed code transmission system of many bufferings) of real time business in intensive according to an embodiment of the invention communication, Fig. 5 is the frame diagram of the non-constant speed code of the many bufferings transmission system of one example according to the present invention, below take transmitting video files as example, and to describe by reference to the accompanying drawings native system in detail be how to carry out transfer of data.

The non-constant speed code transmission system of many bufferings mainly comprises coding side 10, transmission medium 20 and decoding end 30 as can be seen from Figure 1.

Coding side 10 is for file waiting for transmission is converted to video flowing, and coding method based on non-constant speed code is encoded to obtained video flowing.Such as, can, by obtaining video file such as shooting harvester (such as video camera), and by calling LibVLC built-in function, obtained video file be carried out to VLC video streaming coding, thereby obtain video stream file.

Specifically, in coding side 10, be provided with multiple encoding buffers, utilize some information groups that multiple encoding buffers are divided video flowing to carry out successively LT code coding and obtain the many bufferings of many groups LT codes, the obtained LT code that cushions each group is sent successively, and in conjunction with the information group in its corresponding encoding buffer of decoding feedback information updating.Many buffering LT codes in the present embodiment are a kind of improved non-constant speed code.Here said decoding feedback information is ACK feedback packet.

Coding side 10 further comprises: division unit 11, LT code coding unit 12 and judging unit 13.Wherein, division unit 11 is for being divided into video flowing the information group of several equal lengths, and each information group is sorted successively and forms a coding queue, the information group of front setting quantity is put into each encoding buffer successively, wherein, the information group number of setting quantity is identical with the number of encoding buffer, and each information group is divided into K LT packet equal in length.

For LT code coding unit 12, it carries out LT code coding to K LT packet in the coding current encoding buffer pointed of pointer and obtains p encoded packets, and p the encoded packets that transmission obtains successively, then, the next encoding buffer of the pointed of encoding, if last encoding buffer of present encoding pointed, first encoding buffer of the pointed of encoding, wherein the number p of encoded packets is less than the number K of LT packet.

13 of judging units judge whether to receive the decoding feedback information from decoding end 10 in LT code cataloged procedure, if receive this decoding feedback information, put into the encoding buffer corresponding with this decoding feedback information by not putting into first group of information group encoding buffer and that be arranged in coding queue head of the queue, continue the encoding buffer of the current sensing of coding pointer to carry out LT code coding otherwise return to LT code coding unit 12.

For transmission medium 20, it is for the video flowing after real-time Transmission coding, and at least comprises two communication links.This makes in the time that a communication link goes wrong, and switches to other communication links and carries out transfer of data, or select other communication links and this communication link to carry out transfer of data simultaneously.Such as, if LTE link due to the increasing of intensive user, makes the total time delay of data increase, can change transmission direction, take WLAN link transmission, due to importance such as non-constant speed encoded packets, link switching has higher fluency.

Please refer to Fig. 5, in the example of Fig. 5, transmission medium 20 comprises two links, LTE link and the WLAN link with relay station.Preferably, communication link communicates by the reliable transport protocol towards non-link, wherein, should be towards reliable transport protocol of non-link the erasure channel based on UDP bag and CRC check formation and the Code And Decode method that cushions LT code more obtain.In the erasure channel being formed by UDP bag and CRC check, adopt the error control method of many buffering LT codes only need to spend a small amount of computing cost, just can assurance system realize transmission reliably, and there is under the effect of udp protocol efficient communication and non-constant speed encoding channel rate adaptation coupling, high bit-error communication environment the little and reciprocity stream attribute of encoded packets of feedback channel pressure, therefore, this reliable transport protocol towards non-link can use in multilink situation.

In decoding end 30, be provided with multiple decoding buffer zones, thereby utilize each decoding buffer zone to carry out the decoding of LT code and obtain corresponding information group the LT code that cushions every group wherein totally receiving more, the decoding feedback information that transmission cushions LT code about this group more feeds back to coding side 10, and empties corresponding decoding buffer zone.Such as, decoding end 30 receives the video stream file of many buffering LT code forms from LTE user side and/or WIFI by Ethernet, it is decoded, and in real time by decoded file transfer to VLC player, to complete real-time broadcasting demonstration.At this, the number of choosing decoding buffer zone can be greater than the number of encoding buffer, to increase the tolerance to delay of feedback information.

In detail, decoding end 30 further comprises: receiving element 31 and LT code decoding unit 32.Wherein, receiving element 31, in the time receiving encoded packets, according to the encoding buffer information of obtaining from the header packet information of this encoded packets, puts it in corresponding decoding buffer zone.For LT code decoding unit 32, when the sum of its encoded packets receiving in certain decoding buffer zone is greater than K, encoded packets in this decoding buffer zone is carried out to the decoding of LT code, if successfully decoded, the information group decoding being obtained is put into the tail of the queue of decoding queue, and empty this decoding buffer zone, in addition, also send decoding feedback information to coding side 10, otherwise p the encoded packets that corresponding encoding buffer sends continued to receive in this decoding buffer zone, and whole encoded packets that it is received carry out the decoding of LT code, until successfully decoded.

From another viewpoint, the invention allows for the non-constant speed decoding transmission method of a kind of many bufferings, below in conjunction with the non-constant speed code transmission system of above-mentioned many bufferings, the method is elaborated.

First, coding side 10 arranges multiple encoding buffers, utilize some information groups that multiple encoding buffers are divided video flowing to carry out successively LT code coding and obtain the many bufferings of many groups LT codes, the obtained LT code that cushions each group is sent successively, and in conjunction with the information group in its corresponding encoding buffer of decoding feedback information updating.

Fig. 2 is the flow chart of the coding method based on many bufferings LT codes according to an embodiment of the invention, with reference to figure 2, describes coding side 10 below in detail as video flowing is encoded.

As shown in step S210, first division unit 11 is divided into video flowing the information group of some equal lengths, and each information group is sorted successively and forms a coding queue, wherein, the information group of front setting quantity is put into each encoding buffer successively, wherein, the information group number of setting quantity is identical with the number of encoding buffer, and each information group is divided into K LT packet equal in length.In step S220, LT code coding unit 12 carries out LT code coding to K LT packet in the coding current encoding buffer pointed of pointer and obtains p encoded packets, and p the encoded packets that transmission obtains successively, then, the next encoding buffer of the pointed of encoding, if last encoding buffer of present encoding pointed, first encoding buffer of the pointed of encoding, wherein the number p of encoded packets is less than the number K of LT packet.

In detail, one group of information is divided into the isometric LT packet that K length is P bit, then selects at random d packet to make step-by-step XOR as a LT encoded packets, be appreciated that such packet and encoded packets have syntople.Wherein, d is that the coding number of degrees are stochastic variables, and in engineering, this stochastic variable adopts robust radian to distribute:

$\mathrm{\&rho;}\left(d\right)=\frac{\mathrm{\&mu;}\left(d\right)+v\left(d\right)}{{\mathrm{\&Sigma;}}_d(\mathrm{\&mu;}\left(d\right)+v\left(d\right))},d=\mathrm{1,2},...,K$

Wherein: $\mathrm{\&mu;}\left(d\right)=\left\{\begin{array}{cc}\frac{1}{K},& d=1\\ \frac{1}{d(d-1)},& d\&GreaterEqual;2\end{array}\right.,$ $\left(d\right)=\left\{\begin{array}{cc}\frac{S}{\mathrm{Kd}},& d<\frac{K}{S}\\ \frac{S}{K}\ln \left(\frac{S}{\mathrm{\&delta;}}\right),& d=\frac{K}{S}\\ 0,& d>\frac{K}{S}\end{array}\right.,$ $S=\mathrm{\&lambda;}\ln \left(\frac{K}{\mathrm{\&delta;}}\right)\sqrt{K},$ The parameter that δ and λ degree of being distribute, δ represents when receiving

the maximum error probability of decoding, λ is satisfied $\frac{1}{K}\frac{\sqrt{K}}{\ln \left(\frac{K}{\mathrm{\&delta;}}\right)}<\mathrm{\&lambda;}<\frac{1}{2}\frac{\sqrt{K}}{\ln \left(\frac{K}{\mathrm{\&delta;}}\right)}$ Positive parameter.

As shown in step S230, judging unit 13 judges whether to receive the decoding feedback information from decoding end 30 in LT code cataloged procedure, if receive this decoding feedback information, put into the encoding buffer corresponding with this decoding feedback information by not putting into first group of information group buffering area and that be arranged in coding queue head of the queue, continue the coding buffering of the current sensing of coding pointer to carry out LT code coding otherwise return to step S220.Such as, if receive the ACK feedback packet from certain decoding buffer zone, first group of information group not putting into buffering area and be arranged in coding queue head of the queue put into this decoding and cushioned corresponding coding buffering.

Can complete the many buffering LT code codings to video stream file in coding side 10 by above step, by the many bufferings of the each group of the communication link real-time Transmission in transmission medium 20 LT code.Wherein, communication link is at least two, in the time that a communication link goes wrong, switches to other communication links and carries out transfer of data, or select other communication links and this communication link to carry out transfer of data simultaneously.As mentioned above, the reliable transport protocol of the communication link in the present embodiment based on towards non-link communicates, the erasure channel of this agreement based on UDP bag and CRC check formation and cushion the Code And Decode method of LT code more.It should be noted that, if decoding buffer zone does not all receive the coded p the obtaining encoded packets of corresponding information group, such as receiving only p-2 encoded packets, now, decoding end 30 does not send and requires it to resend the request of this p encoded packets to coding side 10.

Finally, decoding end 30 also arranges multiple decoding buffer zones, the LT code that cushions every group that utilizes that each decoding buffer zone receives accumulative total carries out LT code decoding and obtains corresponding information group more, the decoding feedback information that transmission cushions LT code about this group more feeds back to coding side 10, and empties corresponding encoding buffer.

Fig. 3 is the flow chart of the coding/decoding method based on many bufferings LT codes according to an embodiment of the invention, with reference to figure 3, describes coding side 30 below in detail as video flowing is decoded.In step S310, first receiving element 31 in the time receiving encoded packets, according to the encoding buffer information of obtaining from the header packet information of this encoded packets, puts it in corresponding decoding buffer zone.Then, in step S320, when the sum of the encoded packets receiving in certain decoding buffer zone is greater than K, LT code decoding unit 32 carries out the decoding of LT code to the encoded packets in this decoding buffer zone, if successfully decoded, the information group decoding being obtained is put into the tail of the queue of decoding queue, and empty this decoding buffer zone, also send decoding feedback information to coding side 10, otherwise p the encoded packets that corresponding encoding buffer sends continued to receive in this decoding buffer zone, and whole encoded packets that it is received carry out the decoding of LT code, until successfully decoded.

Particularly, the encoded packets that the coding degree information degree of finding carrying according to packet header is 1 is as decode node, because decode node is that its unique data is in abutting connection with copying completely of wrapping, so can recover this corresponding contiguous data bag according to coded message.Simultaneously, by all with it the packet of recovery in abutting connection with encoded packets step-by-step XOR and make the degree of these encoded packets subtract 1, and continue the encoded packets that searching degree is 1, if found, repeat operation above until all K packet all recovers, be successfully decoded, if do not found, return and decode unsuccessfully, wait for that receiving more (p of next group) bag decodes again.

Be appreciated that and apply in the present embodiment the complementary link of relaying and cushion LT code more, reduce the impact that brings to LT coding efficiency because of the time delay of feeding back ACK packets of information, improve the efficiency of transmission of traditional LT code, reliable and stable data transport service is finally provided.

In addition, many buffering LT codes of the present embodiment have better transmission rate than common LT code.Calculate the transmission rate of many buffering LT codes by following formula:

$R_r=\frac{l\&CenterDot;K\&CenterDot;P_m}{{\mathrm{\&Sigma;}}_i^l(s_i\&CenterDot;p\&CenterDot;t_c+t_{\mathrm{di}})}$

Wherein, l is total information group number, and K is the number of LT packet equal in length in each information group, P _mfor LT data package size, s _ithe group number of the many buffering LT codes that receive for i information group successfully decoded is front, p is the encoded packets number that each information group generates, t _cthe transmission time of cushioning LT code corresponding to transmission data link one group more, t _diit is the arrival decoding end required time of feedback information after i information group decoding.

And, meeting max{t _di< pmt _cunder-1 prerequisite, cushion the efficiency of transmission of LT code transmission more:

$\mathrm{\&eta;}=\frac{R_r}{R}=\frac{K}{\mathrm{pE}\left(s\right)}$

Wherein, the number that m is encoding buffer, R is transmission data link actual transmission speed, the expectation of the group number of many buffering LT codes that E (s) receives for successfully decoded is front.

Fig. 4 is that the efficiency of transmission of the non-constant speed code of the many bufferings transmission system of one example according to the present invention has in time delay situation and the comparison diagram of the efficiency of transmission of other system at feedback link.As can be seen from Figure 4 many buffering LT codes feedback link have time delay different channels (such as, ideal communication channel, awgn channel and fading channel) in efficiency of transmission all higher than traditional LT code.

In sum, the non-constant speed code of the many bufferings transmission system of the present embodiment is carried out the encoding and decoding of data based on non-constant speed code, and comprise that at least two communication links transmit information, this has guaranteed the continuity of transfer of data in the time that real-time fault appears in link; Owing to having adopted encoding buffer and decoding buffer zone, the non-constant speed code of many bufferings of the present invention has better overcome non-permanent digital time-delay characteristics, therefore when native system can in intensive communication, feedback link time delay be larger or uplink downlink when peer feedback link is not undesirable, real time data is carried out to high efficient and reliable transmission, and switching between communication link is more smooth.

The above; be only specific embodiment of the invention case, protection scope of the present invention is not limited to this, is anyly familiar with those skilled in the art in technical specification of the present invention; to modification of the present invention or replacement, all should be within protection scope of the present invention.

Claims (10)

1. the non-constant speed code of a many bufferings transmission system for real time business in intensive communication, comprising:

Coding side, it is provided with multiple encoding buffers, utilize some information groups that multiple encoding buffers are divided video flowing to carry out successively LT code coding and obtain the many bufferings of many groups LT codes, the obtained LT code that cushions each group is sent successively, and in conjunction with the information group in its corresponding encoding buffer of decoding feedback information updating;

Transmission medium, comprises at least two communication links, for the many bufferings of the each group of real-time Transmission LT code;

Decoding end, it is provided with multiple decoding buffer zones, thereby utilize each decoding buffer zone to carry out the decoding of LT code and obtain corresponding information group the LT code that cushions every group wherein totally receiving more, the decoding feedback information that transmission cushions LT code about this group more feeds back to described coding side, and empty corresponding decoding buffer zone

Wherein, in the time that a communication link goes wrong, switch to other communication links and carry out transfer of data, or select other communication links and this communication link to carry out transfer of data simultaneously.

2. the non-constant speed code transmission system of many bufferings according to claim 1, it is characterized in that, described communication link communicates by the reliable transport protocol towards non-link, wherein, the erasure channel of the described reliable transport protocol towards non-link based on UDP bag and CRC check formation and the Code And Decode method that cushions LT code obtain more.

3. the non-constant speed code transmission system of many bufferings according to claim 2, is characterized in that, described coding side further comprises:

Division unit, it is for being divided into video flowing the information group of several equal lengths, and each information group is sorted successively and forms a coding queue, the information group of front setting quantity is put into each encoding buffer successively, wherein, the information group number of described setting quantity is identical with the number of encoding buffer, and each information group is divided into K LT packet equal in length;

LT code coding unit, it carries out LT code coding to K LT packet in the coding current encoding buffer pointed of pointer and obtains p encoded packets, and p the encoded packets that transmission obtains successively, then, the next encoding buffer of the pointed of encoding, if last encoding buffer of present encoding pointed, first encoding buffer of the pointed of encoding, wherein, the number p of encoded packets is less than the number K of LT packet;

Judging unit, it is in LT code cataloged procedure, for judging whether to receive the decoding feedback information from described decoding end, if receive described decoding feedback information, put into the encoding buffer corresponding with described decoding feedback information by not putting into first group of information group encoding buffer and that be arranged in coding queue head of the queue, continue the encoding buffer of the current sensing of coding pointer to carry out LT code coding otherwise return to LT code coding unit.

4. the non-constant speed code transmission system of many bufferings according to claim 3, is characterized in that, described decoding end further comprises:

Receiving element, it, puts it in corresponding decoding buffer zone according to the encoding buffer information of obtaining from the header packet information of this encoded packets in the time receiving encoded packets;

LT code decoding unit, when the sum of the encoded packets that its accumulative total in certain decoding buffer zone receives is greater than K, encoded packets in this decoding buffer zone is carried out to the decoding of LT code, if successfully decoded, the information group decoding being obtained is put into the tail of the queue of decoding queue and is sent decoding feedback information to described coding side, otherwise p the encoded packets that corresponding encoding buffer sends continued to receive in this decoding buffer zone, and whole encoded packets of its accumulative total reception are carried out to the decoding of LT code, until successfully decoded.

5. the non-constant speed decoding transmission method of many bufferings of real time business in intensive communication, comprising:

Coding step, multiple encoding buffers are set, utilize some information groups that multiple encoding buffers are divided video flowing to carry out successively LT code coding and obtain the many bufferings of many groups LT codes, the obtained LT code that cushions each group is sent successively, and in conjunction with the information group in its corresponding encoding buffer of decoding feedback information updating;

Transmitting step, by the many bufferings of the each group of communication link real-time Transmission LT code;

Decoding step, multiple decoding buffer zones are set, thereby utilize each decoding buffer zone to carry out the decoding of LT code and obtain corresponding information group the LT code that cushions every group wherein totally receiving more, the decoding feedback information that transmission cushions LT code about this group more feeds back to described coding side, and empty corresponding decoding buffer zone

Wherein, described communication link is at least two, in the time that a communication link goes wrong, switches to other communication links and carries out transfer of data, or select other communication links and this communication link to carry out transfer of data simultaneously.

6. the non-constant speed decoding transmission method of many bufferings according to claim 5, it is characterized in that, in described transmitting step, the reliable transport protocol of described communication link based on towards non-link communicates, wherein, the erasure channel of the described reliable transport protocol towards non-link based on UDP bag and CRC check formation and the Code And Decode method that cushions LT code obtain more.

7. the non-constant speed decoding transmission method of many bufferings according to claim 5, is characterized in that, in described coding step, further comprises:

Step 710, video flowing is divided into the information group of several equal lengths, and each information group is sorted successively and forms a coding queue, the information group of front setting quantity is put into each encoding buffer successively, wherein, the information group number of described setting quantity is identical with the number of encoding buffer, and each information group is divided into K LT packet equal in length;

Step 720, K LT packet in the coding current encoding buffer pointed of pointer carried out to LT code coding and obtain p encoded packets, and p the encoded packets that transmission obtains successively, then, the next encoding buffer of the pointed of encoding, if last encoding buffer of present encoding pointed, first encoding buffer of the pointed of encoding, wherein, the number p of encoded packets is less than the number K of LT packet;

Step 730, in LT code cataloged procedure, judge whether to receive the decoding feedback information from described decoding end, if receive described decoding feedback information, put into the encoding buffer corresponding with described decoding feedback information by not putting into first group of information group buffering area and that be arranged in coding queue head of the queue, continue the encoding buffer of the current sensing of coding pointer to carry out LT code coding otherwise return to step 720.

8. the non-constant speed decoding transmission method of many bufferings according to claim 7, is characterized in that, in described decoding step, further comprises:

Step 810, in the time receiving encoded packets, according to the encoding buffer information of obtaining from the header packet information of this encoded packets, puts it in corresponding decoding buffer zone;

Step 820, when the sum of the encoded packets receiving in certain decoding buffer zone is greater than K, encoded packets in this decoding buffer zone is carried out to the decoding of LT code, if successfully decoded, the information group decoding being obtained is put into the tail of the queue of decoding queue and is sent decoding feedback information to described coding side, otherwise this decoding buffer zone continues to receive p the encoded packets that corresponding encoding buffer sends, and whole encoded packets that it is received carry out the decoding of LT code, until successfully decoded.

9. according to the non-constant speed decoding transmission method of many bufferings described in claim 5-8 any one, it is characterized in that, the transmission rate of described many buffering LT codes is:

$R_r=\frac{l\&CenterDot;K\&CenterDot;P_m}{{\mathrm{\&Sigma;}}_i^l(s_i\&CenterDot;p\&CenterDot;t_c+t_{\mathrm{di}})}$

Wherein, l is total information group number, and K is the number of LT packet equal in length in each information group, P _mfor LT data package size, s _ithe group number of the many buffering LT codes that receive for i information group successfully decoded is front, p is the encoded packets number that each information group generates, t _cthe transmission time of cushioning LT code corresponding to transmission data link one group more, t _diit is the arrival decoding end required time of feedback information after i information group decoding.

10. the non-constant speed decoding transmission method of many bufferings according to claim 9, is characterized in that, is meeting max{t _di< pmt _cunder-1 prerequisite, the efficiency of transmission of described many buffering LT codes is:

$\mathrm{\&eta;}=\frac{R_r}{R}=\frac{K}{\mathrm{pE}\left(s\right)}$

Wherein, the number that m is described encoding buffer, R is transmission data link actual transmission speed, the expectation of the group number of many buffering LT codes that E (s) receives for successfully decoded is front.

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