针对通信系统干扰抑制问题,提出一种基于最低误码率准则的多级软判决均衡器.通过调节各级均衡器的拒绝门限,可使多级软判决均衡器在计算复杂度与误码率之间取得折衷.仿真表明:对于扩展的二元相移键控信号,在相对强的调频信号和调幅信号联合干扰下,基于最低误码率准则的多级软判决均衡器能表现出良好的性能,并且大大减少了计算复杂度.此外,还发现多个非线性均衡器的组合在降低计算复杂度的同时还可获得比单个均衡器更低的误码率.
A multistage soft decision equalizer based on minimum bit error rate is proposed for interference suppression in communications. Bit error rate and computational complexity can be compromised by controlling rejection threshold of each stage. Simulation results show that when extended binary phase shifting keying signals are contaminated by the mix of relatively strong interference signals of amplitude modulation and frequency modulation, multistage soft decision equalizers based on minimum bit error rate can provide very low bit error rate, and the computational complexity is greatly reduced. Furthermore, it is found that by combining different nonlinear equalizers, performance superior to single equalizers can be obtained.