一种基于大数逻辑判决和信道响应的HARQ算法

为了克服无线信道时变和多径衰落对信号传输的影响，全球微波互联接入(WiMAX)系统采用混合自动重传请求(HARQ)技术以提高数据传输的可靠性，确保服务质量。传统的非合并HARQ算法处理比较简单，内存需求较少，但是重传次数多，系统吞吐量低；合并译码HARQ算法能够有效减少重传次数，提高系统吞吐量，但是运算复杂度和内存需求较大。针对已有算法存在的不足，提出了一种基于大数逻辑判决(MLD)和信道冲激响应功率(CSI)的HARQ合并译码算法—MLD-CSI。该算法综合运用择多判决法则和择优选择法则，在接收端对多次重传的接收信号进行合并译码。分析和仿真结果表明，在时变和多径信道环境下，所提算法与MRC合并算法相比，几乎不损失系统的误码率和吞吐量性能，且运算复杂度和内存需求显著降低，非常适用于实际系统。 

A Novel HARQ Algorithm Based on Majority Logic Decision Principle and Channel Response

In order to overcome the wireless mobile channel time-varying and multi-path fading effects on signal transmission, the technology of Hybrid Automatic Repeat Request(HARQ) in Worldwide Interoperability for Microwave Access (WiMAX) system can improve the reliability of data transmission, thereby ensuring the quality of service. The conventional HARQ algorithm without combining requires little mount of memory and has low complexity, but is poor in the bit error rate(BER) and throughput performance; The HARQ algorithm with combining decoding can improve the BER and throughput performance, but requires more mount of memory and increases the computing complexity. For the sake of conquering the two shortages above, this paper proposes a novel combining HARQ scheme named MLD-CSI based on majority logic decision principle and channel impulse response power, which integrates majority logical decision principle with optimality decision principle to combine the transmitted packets before decoding at the receiver. Computer simulations under the time-varying and multi-path fading environment show the performances of the proposed algorithm which align well with the analysis, by contrast with the MRC HARQ algorithm, the proposed algorithm requires less mount of memory and has lower complexity when reserving good performance. Therefore, the proposed algorithm is an efficient and feasible scheme for practical systems.