一种 QAM星座点优化方法及性能分析

QAM Constellation Point Optimization and Its Performance Analysis

正交幅度调制(Quadrature Amplitude Modulation,QAM)是目前无线通信中大量应用的调制技术,其位于4个角的星座点易受链路的影响而导致较高误码率。提出了一种QAM星座点整形优化方法,并对整形优化后的QAM星座点性能进行了计算机仿真分析。以标准星座点为初始值,通过遗传算法逐步迭代,搜索出抗削峰的星座点,从而降低解调误码。仿真结果表明,相比标准QAM,整形优化后的星座点峰均比降低1 dB@1E-6,且在OBO=3.5 dB时有大约0.3 dB@SER=1E-3的解调增益提升。

QAM(Quadrature Amplitude Modulation)is a commonly used modulation technique in current wireless communications,and its constellation points located at the four corners are susceptible to high BERs due to the influence of the link.This paper proposes a QAM constellation point shaping optimization method,and carries out a computer simulation analysis of the performance of the shaping-optimized QAM constellation points.It takes the standard constellation points as initial values and searches for clipping-resistant constellation points by iterating step by step through a genetic algorithm to reduce demodulation BERs.Simulation results indicate that compared to standard QAM,the shaping-optimized constellation point PAR is reduced by 1 dB@1E-6 and won approximately 0.3 dB@SER=1E-3 demodulation gain improvement when OBO=3.5 dB.