基于delta-sigma调制的超高阶QAM概率整形算法

Design of Ultra-high order QAM probabilistic shaping algorithm based on delta-sigma modulation

摘要:

针对终端用户数量的急速增长,以及大容量、高速率的网络通信性能需求,研究了delta-sigma实现机理,可以将通信信号进行高阶量化；在功率受限的高斯信道中,分析了通过概率整形,将均匀分布的比特序列转换成高斯分布的序列符号,可以得到最优的输入分布序列；基于delta-sigma调制算法,在强度调制直接检测系统中实现了超高阶16384QAM的传输；在此基础之上利用概率整形技术,对超高阶QAM信号进行了整形,分别探究了不同信息熵下的传输性能；通过实验仿真结果可以说明,概率整形可以很好的适用于基于delta-sigma的超高阶通信,并有效提升通信传输效能。信息熵每降低1bit/symbol,系统接收性能大约提升0.5 dB。

关键词:强度调制;delta-sigma调制;概率整形;超高阶调制;信息熵

Abstract:

For sharp growth in the number of end-users, and large capacity, the delta-sigma implementation principle is studied, and the communication signal is quantized in high order. In a power constrained Gaussian channel, the optimal input distribution sequence can be obtained by probability shaping when the uniformly distributed bit sequence symbol of Gaussian distribution. High speed network communication performance requirements, the paper presents an ultra-high order 16384QAM probabilistic shaping transmission algorithm in the direct detection system of intensity modulation. On these basis, the ultra-high order QAM signal is reshaped by probabilistic shaping technology, and the transmission entropy is investigated respectively. The result of simulation can be explained that probabilistic shaping transmission algorithm is a suitable method applied to proving transmission performance of ultra-high level communication. And the performance of receive system is proved 0.5dB as the information reduced per 1bit/symbol.

Key words:Intensity modulation;Delta-sigma modulation;Shaping transmission;Ultra-high order modulation;Information entropy