高阶调制通用恒模盲均衡算法

摘要

High data rate communication over limited bandwidth or multi-path channels suffers severe distortion due to the Inter-Symbol Interference (ISI). Constant Modulus blind equalization Algorithms (CMA) are widely used for mitigating this phenomenon. But for higher-order no constant amplitude modulations, CMA works less effective for its large residual error. A simple modified error function which is suitable for variable constellation is proposed for better convergence performance. The new algorithm is well verified by theoretic analysis and numerical simulations, and the theoretic analysis and simulations show that the new algorithm's residual error is much less than the origin algorithms' in MQAM and MAPSK modulation systems and the new algorithm is suitable for applications under these conditions.%在无线通信高速数据传输中,限带效应及多径信道带来的码间干扰(ISI)严重影响接收信号的质量.目前广泛采用恒模盲均衡算法(CMA)消除ISI,但是对于高阶非恒定幅度调制信号,CMA算法收敛后的稳态误差很大,收敛效果较差.该文在改进原CMA算法误差更新函数的基础上,提出了一种新的均衡算法.新算法有效地降低了高阶调制下均衡器的稳态偏差并能适应各种调制体制.理论分析和数值仿真给出,新算法在MQAM以及MAPSK调制下都较原CMA算法性能有较大的提升,适合应用在高阶调制体制的通信系统中.