低密度奇偶校验码的性能分析与水下通信验证

在ADSP-BF561上实现了低密度奇偶校验码的编码算法。为解决编码复杂度高的问题,将校验矩阵变换后存入数据空间。为节省存储空间,采用压缩算法,并提出相应的编码算法,没有增加复杂度。对不同码率的低密度奇偶校验码在不同信道中的性能进行仿真分析。将不同码率的低密度奇偶校验码应用于水声通信系统进行浅海试验,结果表明低密度奇偶校验码能提高通信系统的鲁棒性,码率越低性能越好。当解码前符号信噪比在7～8dB时,可达到近似无误码的通信性能。

Performance analysis of Low-Density Parity-Check codes and verification in underwater communication

The encoding algorithm of Low-Density Parity-Check(LDPC) codes is implemented in ADSP-BF561.To solve the problem of high encoding complexity,the transformed check matrix need to be stored in the data space of DSP.Compression scheme is exploited to save memory,and the proposed encoding algorithm related to the compressed check matrix does not increase complexity.The paper simulates and analyses the performance of different code rates of LDPC codes over different channels.The test results in the shallow sea show that LDPC codes can dynamically improve the robustness of underwater communication system.Moreover,LDPC codes with lower code rate can obtain better performance.Approximately error-free communication performance can be achieved when signal-to-noise ratio per symbol before decoding reaches 7～8 dB.