摘要
空间光通信技术是传输高速语音图像等数据信息的重要手段,为了解决星地激光通信系统中大气湍流效应的影响问题,提出一种低译码复杂度的多进制低密度奇偶校验(LDPC)码结合脉冲位置调制(PPM)的传输方案。所构造的多进制LDPC码不仅具有准循环特性,在硬件上易于用移位寄存器实现,且可以根据PPM的调制阶数灵活构造多进制LDPC码,优化系统级联结构。仿真结果表明,在弱湍流信道下此类码具较好的误码性能和较低的错误平层。在SER=10-6时,相比于基于GF(29)的RS(511,305)码,码率为0.88的多进制LDPC码约有4.75 d B的净编码增益。
Free space optical communication technology is an important solution for high rate voice, image and data transmission. For the purpose of solving the atmospheric turbulence effects in the satellite-to-ground laser communication system, we propose a concatenated scheme to combine Pulse- Position-Modulation （PPM） with non-binary Low-Density-Parity-Check （LDPC） codes, which have low decoding complexity. Codes constructed in this paper not only have the characteristic of quasi cyclic, easily to use shift registers to implement in hardware, but flexibly adjusted according to the order of PPM, optimizing the concatenated architecture. The simulation results show that, the constructed codes perform well over weak atmospheric turbulence channel and have low error floor. Compared with RS （511,305） codes over GF（29）, non-binary LDPC codes with rate 0.88 have approximately 4.75dB performance improvement at SER=10-6.
出处
《电子设计工程》
2017年第5期88-91,共4页
Electronic Design Engineering
