An incremental redundancy hybrid automatic repeat- request （IR-HARQ）scheme based on irregular repeat-accumulate （IRA）codes is proposed. The design of rate compatible punctured IRA codes suitable for an IR-HARQ sch...An incremental redundancy hybrid automatic repeat- request （IR-HARQ）scheme based on irregular repeat-accumulate （IRA）codes is proposed. The design of rate compatible punctured IRA codes suitable for an IR-HARQ scheme is well formulated and efficiently solved by a linear-programming method, along with a one-dimensional approach for density evolution. Compared to IR-HARQ schemes based on turbo codes, simulation shows that the proposed IR-HARQ schemes based on IRA codes may achieve almost the same performance at a block size of 1 024, but better throughput at a block size of 4 096. The advantages of the proposed scheme in implementation, including decoding complexity and parallelism, make it more attractive in practice than the IR-HARQ schemes based on both turbo and LDPC codes.展开更多
The non-binary(NB) Irregular Repeat Accumulate(IRA) codes, as a subclass of NB LDPC codes, potentially have an excellent error-correcting performance. They are also known to provide linear complexity of encoding, but ...The non-binary(NB) Irregular Repeat Accumulate(IRA) codes, as a subclass of NB LDPC codes, potentially have an excellent error-correcting performance. They are also known to provide linear complexity of encoding, but the basic encoding method with the serial rate-1 accumulator significantly limits the encoder throughput. Then the objective of the research presented in this paper is to develop an encoding method pro- viding significantly increased throughput of an NB-IRA encoder altogether with a flexible code construction methods for the structured(S-NB-IRA) codes eligible for the proposed encoding method. For this purpose, we reformulate the classic encoding algorithm to fit into the partial parallel encoder architecture. We propose the S-NB-IRA encoder block diagram and show that its estimated throughput is proportional to the submatrix size of the parity check matrix, which guarantees a wide complexity- throughput tradeoff. Then, in order to facilitate the S-NB-IRA coding systems design, we present a computer search algorithm for the construction of good S-NB-IRA codes. The algorithm aims at optimizing the code graph topology along with selecting an appropriate non-binary elements in the parity check matrix. Numerical results show that the constructed S-NB-IRA codes significantly outperform the binary IRA and S-IRA codes, while their performance is similar to the best unstructured NB-LDPC codes.展开更多
为了避免交织器产生的时延,通过改进的渐进边增长(PEG)算法和循环中国剩余定理构造了一种不规则重复累积(IRA)码。与常规的IRA码相比,提出的码字具有半随机半结构化形式,不需要设计交织器,且码长选择更加灵活。仿真结果显示,在码率为1/...为了避免交织器产生的时延,通过改进的渐进边增长(PEG)算法和循环中国剩余定理构造了一种不规则重复累积(IRA)码。与常规的IRA码相比,提出的码字具有半随机半结构化形式,不需要设计交织器,且码长选择更加灵活。仿真结果显示,在码率为1/2的条件下,当误码率为10-6时,构造的IRA(1 000,500)码与PEG-IRA(1 000,500)码和基于剩余类数对的IRA(1 000,500)码相比,在对应的相同条件下分别取得了0.2 d B和0.1 d B左右的净编码增益提升;且在码率为3/4时,所构造的IRA(16 200,11 880)码比相同码长和码率的DVB-S2标准LDPC码净编码增益提高了约0.1 d B左右。展开更多
针对协作中继网络中目的端接收来自不同源节点发送的多个信息副本的合并方式,提出了联合非规则重复累积码与网络编码的改进译码算法.首先对各链路的调制信息进行软解调处理,并根据中继处网络编码的异或信息和直达链路中原信息的函数对...针对协作中继网络中目的端接收来自不同源节点发送的多个信息副本的合并方式,提出了联合非规则重复累积码与网络编码的改进译码算法.首先对各链路的调制信息进行软解调处理,并根据中继处网络编码的异或信息和直达链路中原信息的函数对应关系,提取出协作节点发送到目的端的信息副本;然后更新非规则重复累积码在译码过程中直达链路与协作链路下的两个信息副本的软解调信息,构造出新的译码判决方法,进而推导了16QAM软解调对数似然比值的简化方法;最后分析了系统的中断概率及频谱效率.仿真结果表明,该译码算法在QPSK、16QAM两种调制方式下均能获得较低的误比特率,且采用对数似然比值的简化方法,能在0.3 d B性能损失代价下降低系统的译码难度.展开更多
基金The National High Technology Research and Develop-ment Program of China(863Program)(No.2006AA01Z263)the National Natural Science Foundation of China(No.60672081)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK2006502)the Open Research Fund of National Mobile Communications Research Laboratory of Southeast Uni-versity(No.2008N01)
文摘An incremental redundancy hybrid automatic repeat- request （IR-HARQ）scheme based on irregular repeat-accumulate （IRA）codes is proposed. The design of rate compatible punctured IRA codes suitable for an IR-HARQ scheme is well formulated and efficiently solved by a linear-programming method, along with a one-dimensional approach for density evolution. Compared to IR-HARQ schemes based on turbo codes, simulation shows that the proposed IR-HARQ schemes based on IRA codes may achieve almost the same performance at a block size of 1 024, but better throughput at a block size of 4 096. The advantages of the proposed scheme in implementation, including decoding complexity and parallelism, make it more attractive in practice than the IR-HARQ schemes based on both turbo and LDPC codes.
基金supported by the Polish Ministry of Science and Higher Education funding for statutory activities (decision no. 8686/E-367/S/2015 of 19 February 2015)
文摘The non-binary(NB) Irregular Repeat Accumulate(IRA) codes, as a subclass of NB LDPC codes, potentially have an excellent error-correcting performance. They are also known to provide linear complexity of encoding, but the basic encoding method with the serial rate-1 accumulator significantly limits the encoder throughput. Then the objective of the research presented in this paper is to develop an encoding method pro- viding significantly increased throughput of an NB-IRA encoder altogether with a flexible code construction methods for the structured(S-NB-IRA) codes eligible for the proposed encoding method. For this purpose, we reformulate the classic encoding algorithm to fit into the partial parallel encoder architecture. We propose the S-NB-IRA encoder block diagram and show that its estimated throughput is proportional to the submatrix size of the parity check matrix, which guarantees a wide complexity- throughput tradeoff. Then, in order to facilitate the S-NB-IRA coding systems design, we present a computer search algorithm for the construction of good S-NB-IRA codes. The algorithm aims at optimizing the code graph topology along with selecting an appropriate non-binary elements in the parity check matrix. Numerical results show that the constructed S-NB-IRA codes significantly outperform the binary IRA and S-IRA codes, while their performance is similar to the best unstructured NB-LDPC codes.
文摘为了避免交织器产生的时延,通过改进的渐进边增长(PEG)算法和循环中国剩余定理构造了一种不规则重复累积(IRA)码。与常规的IRA码相比,提出的码字具有半随机半结构化形式,不需要设计交织器,且码长选择更加灵活。仿真结果显示,在码率为1/2的条件下,当误码率为10-6时,构造的IRA(1 000,500)码与PEG-IRA(1 000,500)码和基于剩余类数对的IRA(1 000,500)码相比,在对应的相同条件下分别取得了0.2 d B和0.1 d B左右的净编码增益提升;且在码率为3/4时,所构造的IRA(16 200,11 880)码比相同码长和码率的DVB-S2标准LDPC码净编码增益提高了约0.1 d B左右。
文摘针对协作中继网络中目的端接收来自不同源节点发送的多个信息副本的合并方式,提出了联合非规则重复累积码与网络编码的改进译码算法.首先对各链路的调制信息进行软解调处理,并根据中继处网络编码的异或信息和直达链路中原信息的函数对应关系,提取出协作节点发送到目的端的信息副本;然后更新非规则重复累积码在译码过程中直达链路与协作链路下的两个信息副本的软解调信息,构造出新的译码判决方法,进而推导了16QAM软解调对数似然比值的简化方法;最后分析了系统的中断概率及频谱效率.仿真结果表明,该译码算法在QPSK、16QAM两种调制方式下均能获得较低的误比特率,且采用对数似然比值的简化方法,能在0.3 d B性能损失代价下降低系统的译码难度.
