基于LDPC码的不等差错保护方法及性能仿真

Method and Performance Simulation Based on Unequal Error Protection of LDPC Codes

为了提高卫星通信在受到外界干扰、信道带宽资源受限时信道的利用率和信息的传输质量,提出一种基于LDPC码的信源信道联合编码方法。通过对DVB-S2标准中码长为16200bit、码率为1/2的LDPC码进行打孔,构造速率兼容LDPC码,简化了硬件设计的复杂度。利用不同速率的LDPC码对经SPIHT算法压缩后的码流按重要程度不同进行不等差错保护。实验表明,方法可以有效保护重要数据,提高卫星通信中图像的传输质量。

The available channel bandwidth of satellite communication is limited when the outside interference is serious. In order to improve the satellite communication channel utilization and information transmission quality, we propose a joint sourcechannel coding method based on LDPC codes. We select DVB-S2 LDPC code with 16200bits length and 1/2 rate as the mother code. To simplify the complex hardware design, we obtain the rate-compatible LDPC codes by puncturing the mother code. The bit stream compressed by SPIHT algorithm is protected by using the unequal error protection method via applying different rate LDPC codes. Simulation results show that the program can effectively protect the important data, and improves the image transmission quality.