LDPC联合PPM的调制解调方法  

Modulation and Demodulation Method of LDPC Combined with PPM

作　　者：赵柏山[1] 宋丰仕 ZHAO BaiShan;SONG FengShi(School of Information Science and Engineering, Shenyang University of Technology, Shenyang 110870, China)

机构地区：[1]沈阳工业大学信息科学与工程学院,沈阳110870

出　　处：《微处理机》2019年第1期16-19,共4页Microprocessors

摘　　要：在开放式大气激光通信系统中,大气中噪声的存在严重影响激光通信质量。为了改善通信质量,降低开放式大气激光通信的误码率,提出了一种改进的激光通信方法。该方法将低密度奇偶校验码与脉冲位置调制和软解调相联合,应用于开放式大气激光通信系统中。低密度奇偶校验码能提高编码效率,提升纠错能力。脉冲位置调制能降低激光发射平均功率,保证通信质量。软解调可以充分利用信道信息,进行有效解码。仿真给出了不同循环校验码长和不同循环校验迭代次数条件下的通信性能曲线,验证了该方法在明显降低误码率上的有效性。In the open atmosphere laser communication system, the existence of atmospheric noise seriously affects the quality of laser communication. In order to improve the communication quality and reduce the error rate of open atmosphere laser communication, an improved laser communication method is proposed. The method combines the low density parity check code with pulse position modulation and soft demodulation, so as to apply to an open atmospheric laser communication system. Low density parity check codes can improve coding efficiency and error correction capability. Pulse position modulation can reduce the average power of laser emission and ensure communication quality. Soft demodulation can make full use of channel information for effective decoding. Simulation shows the communication performance curves under different cyclic check codes lengths and different cyclic check iteration times,and verifies the effectiveness of this method in significantly reducing the bit error rate.

关 键 词：脉冲位置调制 低密度奇偶校验码 软解调 

分 类 号：TN929.12[电子电信—通信与信息系统]