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Improved Design and SOVA Algorithm for Serial Concatenated Convolutional Code 被引量:2
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作者 万蕾 匡镜明 《Journal of Beijing Institute of Technology》 EI CAS 2001年第2期180-185,共6页
To improve the performance of the short interleaved serial concatenated convolutional code(SCCC) with low decoding iterative times, the structure of Log MAP algorithm is introduced into the conventional SOVA decoder... To improve the performance of the short interleaved serial concatenated convolutional code(SCCC) with low decoding iterative times, the structure of Log MAP algorithm is introduced into the conventional SOVA decoder to improve its performance at short interleaving delay. The combination of Log MAP and SOVA avoids updating the matrices of the maximum path, and also makes a contribution to the requirement of short delay. The simulation results of several SCCCs show that the improved decoder can obtain satisfied performance with short frame interleaver and it is suitable to the high bit rate low delay communication systems. 展开更多
关键词 serial concatenated convolutional code Turbo code iterative decoder WCDMA
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Blind reconstruction of convolutional code based on segmented Walsh-Hadamard transform 被引量:9
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作者 Fenghua Wang Hui Xie Zhitao Huang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第5期748-754,共7页
Walsh-Hadamard transform (WriT) can solve linear error equations on Field F2, and the method can be used to recover the parameters of convolutional code. However, solving the equations with many unknowns needs enorm... Walsh-Hadamard transform (WriT) can solve linear error equations on Field F2, and the method can be used to recover the parameters of convolutional code. However, solving the equations with many unknowns needs enormous computer memory which limits the application of WriT. In order to solve this problem, a method based on segmented WriT is proposed in this paper. The coefficient vector of high dimension is reshaped and two vectors of lower dimension are obtained. Then the WriT is operated and the requirement for computer memory is much reduced. The code rate and the constraint length of convolutional code are detected from the Walsh spectrum. And the check vector is recovered from the peak position. The validity of the method is verified by the simulation result, and the performance is proved to be optimal. 展开更多
关键词 convolutional code blind reconstruction Walsh-Hadamard transform (WriT) tinear error equation.
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Construction of Regular Rate-Compatible LDPC Convolutional Codes 被引量:1
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作者 Liwei Mu Chulong Liang +1 位作者 Zhiyong Liu Daru Pan 《China Communications》 SCIE CSCD 2016年第8期97-102,共6页
In this paper, we propose a new method to derive a family of regular rate-compatible low-density parity-check(RC-LDPC) convolutional codes from RC-LDPC block codes. In the RC-LDPC convolutional family, each extended... In this paper, we propose a new method to derive a family of regular rate-compatible low-density parity-check(RC-LDPC) convolutional codes from RC-LDPC block codes. In the RC-LDPC convolutional family, each extended sub-matrix of each extended code is obtained by choosing specified elements from two fixed matrices HE1K and HE1K, which are derived by modifying the extended matrices HE1 and HE2 of a systematic RC-LDPC block code. The proposed method which is based on graph extension simplifies the design, and prevent the defects caused by the puncturing method. It can be used to generate both regular and irregular RC-LDPC convolutional codes. All resulted codes in the family are systematic which simplify the encoder structure and have maximum encoding memories which ensure the property. Simulation results show the family collectively offer a steady improvement in performance with code compatibility over binary-input additive white Gaussian noise channel(BI-AWGNC). 展开更多
关键词 binary-input additive white Gaussian noise channel(BI-AWGNC) extended matrices rate-compatible low-density parity-check(RC-LDPC) convolutional codes
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NEW METHOD TO RECOVER INTERNET PACKET LOSSES USING(2,1,m)SYSTEMATIC CONVOLUTIONAL CODES
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作者 Peng Bo Wei Gang(Institute of Electron. Eng. and Control, South China University of Technology,Guangzhou 510640) 《Journal of Electronics(China)》 2002年第2期199-203,共5页
A new method to recover packet losses using (2,1,m) convolutional codes is proposed. The erasure correcting decoding algorithm and the decoding determinant theorem is presented. It is also proved that the codes with o... A new method to recover packet losses using (2,1,m) convolutional codes is proposed. The erasure correcting decoding algorithm and the decoding determinant theorem is presented. It is also proved that the codes with optimal distance profile have also optimal delay characteristic. Simulation results show that the proposed method can recover the packet losses more elliciently than RS codes over different decoding delay conditions and thus suits for different packet network delav conditions. 展开更多
关键词 convolutional code: Packet loss Erasure correcting codes
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Blind recognition of k/n rate convolutional encoders from noisy observation 被引量:13
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作者 Li Huang Wengu Chen +1 位作者 Enhong Chen Hong Chen 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第2期235-243,共9页
Blind recognition of convolutional codes is not only essential for cognitive radio, but also for non-cooperative context. This paper is dedicated to the blind identification of rate k/n convolutional encoders in a noi... Blind recognition of convolutional codes is not only essential for cognitive radio, but also for non-cooperative context. This paper is dedicated to the blind identification of rate k/n convolutional encoders in a noisy context based on Walsh-Hadamard transformation and block matrix (WHT-BM). The proposed algorithm constructs a system of noisy linear equations and utilizes all its coefficients to recover parity check matrix. It is able to make use of fault-tolerant feature of WHT, thus providing more accurate results and achieving better error performance in high raw bit error rate (BER) regions. Moreover, it is more computationally efficient with the use of the block matrix (BM) method. © 2017 Beijing Institute of Aerospace Information. 展开更多
关键词 Cognitive radio CONVOLUTION convolutional codes Error correction Hadamard matrices Hadamard transforms Linear transformations Mathematical transformations Matrix algebra Signal encoding
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Blind recognition of punctured convolutional codes 被引量:18
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作者 LUPeizhong LIShen +1 位作者 ZOUYan LUOXiangyang 《Science in China(Series F)》 2005年第4期484-498,共15页
This paper presents an algorithm for blind recognition of punctured convo-lutional codes which is an important problem in adaptive modulation and coding. For a given finite sequence of convolutional code, the parity c... This paper presents an algorithm for blind recognition of punctured convo-lutional codes which is an important problem in adaptive modulation and coding. For a given finite sequence of convolutional code, the parity check matrix of the convolutional code is first computed by solving a linear system with adequate error tolerance. Then a minimal basic encoding matrix of the original convolutional code and its puncturing pattern are determined according to the known parity check matrix of the punctured convolutional code. 展开更多
关键词 blind recognition punctured convolutional code generator matrix puncturing pattern.
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Construction of Rate-Compatible(RC) Low-Density Parity-Check(LDPC) Convolutional Codes Based on RC-LDPC Block Codes 被引量:1
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作者 穆丽伟 韩国军 刘志勇 《Journal of Shanghai Jiaotong university(Science)》 EI 2016年第6期679-683,共5页
In this paper,a family of rate-compatible(RC) low-density parity-check(LDPC) convolutional codes can be obtained from RC-LDPC block codes by graph extension method.The resulted RC-LDPC convolutional codes,which are de... In this paper,a family of rate-compatible(RC) low-density parity-check(LDPC) convolutional codes can be obtained from RC-LDPC block codes by graph extension method.The resulted RC-LDPC convolutional codes,which are derived by permuting the matrices of the corresponding RC-LDPC block codes,are systematic and have maximum encoding memory.Simulation results show that the proposed RC-LDPC convolutional codes with belief propagation(BP) decoding collectively offer a steady improvement on performance compared with the block counterparts over the binary-input additive white Gaussian noise channels(BI-AWGNCs). 展开更多
关键词 rate-compatible(RC) low-density parity-check(LDPC) convolutional codes systematic maximum encoding memory belief propagation(BP) decoding
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Response compaction for system-on-a-chip based on advanced convolutional codes 被引量:1
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作者 HAN Yinhe LI Huawei +1 位作者 LI Xiaowei ANSHUMAN Chandra 《Science in China(Series F)》 2006年第2期262-272,共11页
This paper addresses the problem of test response compaction. In order to maximize compaction ratio, a single-output compactor based on a (n, n-1, m, 3) convolutional code is presented. When the proposed theorems ar... This paper addresses the problem of test response compaction. In order to maximize compaction ratio, a single-output compactor based on a (n, n-1, m, 3) convolutional code is presented. When the proposed theorems are satisfied, the compactor can avoid two and any odd erroneous bits cancellations, and handle one unknown bit (X bit). When the X bits in response are clustered, multiple-weight check matrix design algorithm can be used to reduce the effect of massive X bits. Some extended experimental results show that the proposed encoder has an acceptable-level X tolerant capacity and low error cancellations probability. 展开更多
关键词 SOC test response compaction convolutional code ALIASING X bits masking.
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Non-Intrusive Design of Self-Checking FSM Based on Convolutional Codes
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作者 李明 徐拾义 +3 位作者 万发雨 辜建伟 彭明明 姜竞赛 《Tsinghua Science and Technology》 SCIE EI CAS 2007年第S1期73-77,共5页
A non-intrusive design of self-checking finite state machines (FSMs) in VLSI circuits was investigated using convolutional codes. We propose a novel scheme which cannot only detect but also correct errors occurred in ... A non-intrusive design of self-checking finite state machines (FSMs) in VLSI circuits was investigated using convolutional codes. We propose a novel scheme which cannot only detect but also correct errors occurred in FSM states. The error state will be corrected and sent back to the FSM, so that the concurrent error in the current state is detected and corrected immediately. Moreover, we realize the IP core of the self-checking module by SMIC 0.25-μm CMOS technology and also simulate its function in FPGA. 展开更多
关键词 self-checking finite state machines (FSMs) convolutional codes error-detection
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Path Weight Complementary Convolutional Code for Type-Ⅱ Bit-Interleaved Coded Modulation Hybrid ARQ System
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作者 程宇新 张磊 +1 位作者 依那 项海格 《Tsinghua Science and Technology》 SCIE EI CAS 2007年第S1期240-245,共6页
Bit-interleaved coded modulation (BICM) is suitable to bandwidth-efficient communication systems. Hybrid automatic repeat request (HARQ) can provide more reliability to high-speed wireless data transmission. A new pat... Bit-interleaved coded modulation (BICM) is suitable to bandwidth-efficient communication systems. Hybrid automatic repeat request (HARQ) can provide more reliability to high-speed wireless data transmission. A new path weight complementary convolutional (PWCC) code used in the type-Ⅱ BICM-HARQ system is proposed. The PWCC code is composed of the original code and the complimentary code. The path in trellis with large hamming weight of the complimentary code is designed to compensate for the path in trellis with small hamming weight of the original code. Hence, both of the original code and the complimentary code can achieve the performance of the good code criterion of corresponding code rate. The throughput efficiency of the BICM-HARQ system wit PWCC code is higher than repeat code system, a little higher than puncture code system in low signal-to-noise ratio (SNR) values and much higher than puncture code system, the same as repeat code system in high SNR values. These results are confirmed by the simulation. 展开更多
关键词 bit-interleaved coded modulation type-II hybrid automatic repeat request path weight comple- mentary convolutional code throughput efficiency
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Performance of Convolutionally Coded Multicarrier DS-CDMA System
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作者 SONG Li-xin HUANG Tian-shu DU Guang-yu 《Semiconductor Photonics and Technology》 CAS 2005年第4期281-286,共6页
A new convolutionally coded direct sequence (DS) CDMA system is proposed. The outputs of a convolutional encoder modulate multiple band-limited DS-CDMA waveforms. The receiver detects and combines signals for the desi... A new convolutionally coded direct sequence (DS) CDMA system is proposed. The outputs of a convolutional encoder modulate multiple band-limited DS-CDMA waveforms. The receiver detects and combines signals for the desired user and feeds a soft-decision Viterbi decoder. The performance of this system is compared to that of a convolutionally coded single carrier DS CDMA system with a Rake receiver. At roughly equivalent receiver complexity, results will demonstrate superior performance of the coded multicarrier system. 展开更多
关键词 convolutional code Rayleigh fading Multicarrier CDMA Frequency diversity Narrow-band interference
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Semi-LDPC Convolutional Codes:Construction and Low-Latency Windowed List Decoding
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作者 Qianfan Wang Suihua Cai +1 位作者 Li Chen Xiao Ma 《Journal of Communications and Information Networks》 EI CSCD 2021年第4期411-419,共9页
This paper presents a new coding scheme called semi-low-density parity-check convolutional code(semi-LDPC-CC),whose parity-check matrix consists of both sparse and dense sub-matrices,a feature distinguished from the c... This paper presents a new coding scheme called semi-low-density parity-check convolutional code(semi-LDPC-CC),whose parity-check matrix consists of both sparse and dense sub-matrices,a feature distinguished from the conventional LDPC-CCs.We propose sliding-window list(SWL)decoding algorithms with a fixed window size of two,resulting in a low decoding latency but a competitive error-correcting performance.The performance can be predicted by upper bounds derived from the first event error probability and by genie-aided(GA)lower bounds estimated from the underlying LDPC block codes(LDPC-BCs),while the complexity can be reduced by truncating the list with a threshold on the difference between the soft metrics in the serial decoding implementation.Numerical results are presented to validate our analysis and demonstrate the performance advantage of the semi-LDPC-CCs over the conventional LDPC-CCs. 展开更多
关键词 low-density parity-check convolutional codes(LDPC-CCs) spatially coupled LDPC(SC-LDPC)codes sliding-window list(SWL)decoding
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Ensemble of High Performance Structured Binary Convolutional LDPC Codes with Moderate Rates 被引量:1
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作者 Liwei Mu 《China Communications》 SCIE CSCD 2020年第10期195-205,共11页
An algebraic construction methodology is proposed to design binary time-invariant convolutional low-density parity-check(LDPC)codes.Assisted by a proposed partial search algorithm,the polynomialform parity-check matri... An algebraic construction methodology is proposed to design binary time-invariant convolutional low-density parity-check(LDPC)codes.Assisted by a proposed partial search algorithm,the polynomialform parity-check matrix of the time-invariant convolutional LDPC code is derived by combining some special codewords of an(n,2,n−1)code.The achieved convolutional LDPC codes possess the characteristics of comparatively large girth and given syndrome former memory.The objective of our design is to enable the time-invariant convolutional LDPC codes the advantages of excellent error performance and fast encoding.In particular,the error performance of the proposed convolutional LDPC code with small constraint length is superior to most existing convolutional LDPC codes. 展开更多
关键词 algebraic construction (n 2 n−1)codes convolutional low-density parity-check(LDPC)codes fast encoding maximum achievable syndrome former memory large girth
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Joint Source-Channel Decoding of EVRC Speech Encoder Using Residual Redundancy
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作者 阿哈麦德 尤肖虎 高西奇 《Journal of Southeast University(English Edition)》 EI CAS 2002年第2期103-107,共5页
The enhanced variable rate codec (EVRC) is a standard for the 'Speech ServiceOption 3 for Wideband Spread Spectrum Digital System,' which has been employed in both IS-95cellular systems and ANSI J-STC-008 PCS ... The enhanced variable rate codec (EVRC) is a standard for the 'Speech ServiceOption 3 for Wideband Spread Spectrum Digital System,' which has been employed in both IS-95cellular systems and ANSI J-STC-008 PCS (personal communications systems). This paper concentrateson channel decoders that exploit the residual redundancy inherent in the enhanced variable ratecodec bitstream. This residual redundancy is quantified by modeling the parameters as first orderMarkov chains and computing the entropy rate based on the relative frequencies of transitions.Moreover, this residual redundancy can be exploited by an appropriately 'tuned' channel decoder toprovide substantial coding gain when compared with the decoders that do not exploit it. Channelcoding schemes include convolutional codes, and iteratively decoded parallel concatenatedconvolutional 'turbo' codes. 展开更多
关键词 residual redundancy convolutional codes turbo codes
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Integrated Joint Source-Channel Symbol-by-Symbol Decoding of Variable-Length Codes Using 3-D MAP Sequence Estimation 被引量:1
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作者 WU Jing CHEN Shuzhen 《Wuhan University Journal of Natural Sciences》 CAS 2007年第3期471-475,共5页
Most of multimedia schemes employ variable-length codes (VLCs) like Huffman code as core components in obtaining high compression rates. However VLC methods are very sensitive to channel noise. The goal of this pape... Most of multimedia schemes employ variable-length codes (VLCs) like Huffman code as core components in obtaining high compression rates. However VLC methods are very sensitive to channel noise. The goal of this paper is to salvage as many data from the damaged packets as possible for higher audiovisual quality. This paper proposes an integrated joint source-channel decoder (I-JSCD) at a symbol-level using three-dimensional (3-D) trellis representation for first-order Markov sources encoded with VLC source code and convolutional channel code. This method combines source code and channel code state-spaces and bit-lengths to construct a two-dimensional (2-D) state-space, and then develops a 3-D trellis and a maximum a-posterior (MAP) algorithm to estimate the source sequence symbol by symbol. Experiment results demonstrate that our method results in significant improvement in decoding performance, it can salvage at least half of (50%) data in any channel error rate, and can provide additional error resilience to VLC stream like image, audio, video stream over high error rate links. 展开更多
关键词 integrated joint source-channel decoding (I-JSCD) variable-length code (VLC) exp-Golomb code convolutional code maximum a-oosteriori (MAP)
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Soft Decoding Scheme of Convolution Code Combined with Huffman Coding
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作者 郭东亮 陈小蔷 吴乐南 《Journal of Southeast University(English Edition)》 EI CAS 2002年第3期208-211,共4页
This paper proposes a modification of the soft output Viterbi decoding algorithm (SOVA) which combines convolution code with Huffman coding. The idea is to extract the bit probability information from the Huffman codi... This paper proposes a modification of the soft output Viterbi decoding algorithm (SOVA) which combines convolution code with Huffman coding. The idea is to extract the bit probability information from the Huffman coding and use it to compute the a priori source information which can be used when the channel environment is bad. The suggested scheme does not require changes on the transmitter side. Compared with separate decoding systems, the gain in signal to noise ratio is about 0 5-1.0 dB with a limi... 展开更多
关键词 soft output Viterbi decoding a priori information Huffman coding convolution code
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Improved Adaptive Random Convolutional Network Coding Algorithm 被引量:2
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作者 Guo Wangmei Cai Ning Wang Xiao 《China Communications》 SCIE CSCD 2012年第11期63-69,共7页
To address the issue of field size in random network coding, we propose an Improved Adaptive Random Convolutional Network Coding (IARCNC) algorithm to considerably reduce the amount of occupied memory. The operation o... To address the issue of field size in random network coding, we propose an Improved Adaptive Random Convolutional Network Coding (IARCNC) algorithm to considerably reduce the amount of occupied memory. The operation of IARCNC is similar to that of Adaptive Random Convolutional Network Coding (ARCNC), with the coefficients of local encoding kernels chosen uniformly at random over a small finite field. The difference is that the length of the local encoding kernels at the nodes used by IARCNC is constrained by the depth; meanwhile, increases until all the related sink nodes can be decoded. This restriction can make the code length distribution more reasonable. Therefore, IARCNC retains the advantages of ARCNC, such as a small decoding delay and partial adaptation to an unknown topology without an early estimation of the field size. In addition, it has its own advantage, that is, a higher reduction in memory use. The simulation and the example show the effectiveness of the proposed algorithm. 展开更多
关键词 convolutional network coding adaptive network coding algorithm random coding
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Algebraic Approach to Random Convolutional Network Coding over Wireless Packet Networks
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作者 郭网媚 刘斌越 蒋馥蔚 《Transactions of Tianjin University》 EI CAS 2013年第4期307-312,共6页
To characterize the algebraic structure of wireless network coding, a hypergragh is utilized to model wireless packet networks from network layer. The algebraic description of random convolutional network coding is de... To characterize the algebraic structure of wireless network coding, a hypergragh is utilized to model wireless packet networks from network layer. The algebraic description of random convolutional network coding is deduced, and the coding condition is also presented. Analyses and simulations show that random convolutional coding is capacity-achieving with probability approaching 1. 展开更多
关键词 wireless network coding random convolutional network coding HYPERGRAPH capacity-achieving
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A multiple copyright identification watermarking algorithm based on code division multiple access
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作者 张帆 li Jie +1 位作者 Su Yuting Zhang Chuntian 《High Technology Letters》 EI CAS 2008年第4期377-383,共7页
A multiple watermarking algorithm is presented according to the multiple accessing technique of the code division multiple access (CDMA) system. Multiple watermarks are embedded into digital images in the wavelet tr... A multiple watermarking algorithm is presented according to the multiple accessing technique of the code division multiple access (CDMA) system. Multiple watermarks are embedded into digital images in the wavelet transform domain. Each of the watermarks is embedded and extracted independently without impacts to each other. Multiple watermarks are convolution encoded and block interleaved, and the orthogonal Gold sequences are used to spread spectrum of the copyright messages. CDMA encoded water-mark messages are embedded into the wavelet sub-bands excluding the wavelet HH1 sub-bands. The embedment amplitude is decided by Watson' s perceptual model of wavelet transform domain, and the embedmeut position in the selected wavelet sub-bands is decided randomly by a pseudo-random noise (PN) sequence. As a blind watermm'king algorithm, watermarks are extracted without original image. The watermarking capacity of proposed algorithm is also discussed. When two watermarks are embedded in an image at the same time, the capacity is larger than the capacity when a single watermark is embedded, and is smaller than the sum of the capacity of two separately embedded watermarks. Experimental results show that the proposed algorithm improves the detection bits error rate (BER) observably, and the multiple watermarks have a preferable robustness and invisibility. 展开更多
关键词 code division multiple access (CDMA) WATERMARKING convolutional coding
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Performance evaluation of multicast relay network using LDPC and convolutional channel codes along-with XOR network coding 被引量:3
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作者 Tariq Aziz Nasir Saleem Muhammad Iqba 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2012年第4期122-128,共7页
In this paper, we have compared the performance of joint network channel coding (JNCC) for multicast relay network using low density parity check (LDPC) codes and Convolutional codes as channel codes while exclusi... In this paper, we have compared the performance of joint network channel coding (JNCC) for multicast relay network using low density parity check (LDPC) codes and Convolutional codes as channel codes while exclusive or (XOR) network coding used at the intermediate relay nodes. Multicast relay transmission is a type of transmission scheme in which two fixed relay nodes contribute in the second hop of end-to-end transmission between base transceiver station (BTS) and a pair of mobile stations. We have considered one way and two way multicast scenarios to evaluate the bit error rate (BER) and throughput performance. It has been shown that when using XOR network coding at the intermediate relay nodes, the same transmission becomes possible in less time slots hence throughput performance can be improved. Moreover we have also discussed two possible scenarios in the proposed system model, in which both diversity and multiplexing gain has been considered. It is worth notifying that BER and throughput achieved for LDPC codes is better than Convolutional codes for all the schemes discussed. 展开更多
关键词 cooperative relaying network coding multicast relay networks LDPC codes convolutional codes
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