FMT系统的滤波器组优化设计

Optimization Design of Filter Bank for FMT System

传统滤波多音调制(FMT)系统的原型滤波器阻带衰减不够大,过渡带宽度衰减速度慢,导致系统性能较低。为此,提出一种基于FMT系统载波间干扰抑制的滤波器组优化设计方法。通过优化滤波器组中原型滤波器的通带截止频率、过渡带宽度和旁瓣峰值来提高FMT系统的子信道频谱约束性。仿真结果表明,采用该优化方法设计的原型滤波器具有较小的过渡带宽度和旁瓣峰值,对应的FMT系统具有更好的子信道频谱约束性和误码率性能。

The prototype filter band attenuation of traditional Filtered Multi-tone（ FMT） system is not large enough,the transition band width decays slowly,and it causes the system has low performance. In order to slove this proplem,an optimized design method of filter bank based on inter-carrier interference suppression of FMT system is proposed. The subchannel spectrum constraint is improved by optimizing the passband cutoff frequency,the bandwidth of the transition band and the peak of sidelobe of the prototype filter. Simulation results show that the prototype filter designed by this method has smaller transition band and sidelobe peak, and the corresponding FMT system has better subchannel spectrum constraint and bit error rate performance.