基于LDPC码的HARQ系统仿真

摘要

In order to transport data efficiently and reliably without reducing the transmission rate of data, minimize the bit error rate and improve the system throughput, LDPC (Low-Density Parity-Check Code) are used as forward error correction code in HARQ (Hybrid Automatic Repeat Request) system, and it combined with ARQ (Automatic Repeat Request) technology. The ARQ scheme chooses SR-ARQ, namely selective request ARQ, it will choose the error data block to retransmission, and using type-I HARQ pattern to do request controlling. The model is built and system is designed on simulink. Combined Matlab modulation, the throughput of code with different length and different code rate is analyzed, and the results are shown by using ARQ scheme and without it, the results indicate that the system with ARQ scheme has better performance on throughput.%为有效和可靠地传输数据,在不降低数据传输速率的条件下,最大限度地减小误码率,提高系统吞吐量,利用Matlab和Simulink平台共同仿真了混合自动重传请求HARQ (Hybrid Automatic Repeat Request)系统.该系统使用低密度奇偶校验码LDPC (Low-Density Parity-Check Code)作为前向纠错码FEC( Forward Error Correction),采用SR-ARQ (Automatic Repeat Request)机制,即选择重传机制,对出错的数据分组进行重传,通过type-Ⅰ型HARQ方式进行重传控制,完成了混合自动重传请求系统的构建和模型设计.同时结合编程仿真分析了不同码长、不同码率的码字在利用重传控制机制前后系统的吞吐量差别.仿真结果表明,使用重传控制机制后的系统吞吐量性能有所提高.