采用FRM的窄过渡带奇型排列结构改进方法

为了解决数字信道化中窄过渡带滤波器组计算复杂度较高的问题，提出了一种采用频率响应屏蔽（FRM）的窄过渡带奇型排列非最大抽取滤波器组高效结构。在设计该结构的原型滤波器时，首先通过对原型滤波器进行插值得到FRM上支路的滤波器，然后将信号延时与插值后的滤波器相减得到位于下支路的互补滤波器，再利用屏蔽滤波器对插值产生的多余镜像进行屏蔽，最终得到所设计的FRM滤波器。对该改进结构进行了MATLAB仿真，仿真结果验证了该改进结构的正确性。与多相滤波器组结构相比，采用该结构可节省约80%的乘法器资源。由于该改进结构中将抽取提前，降低了系统采样率的限制条件，可以直接应用于高速采样系统中。

An improved approach for odd-arrangement structure with narrow transition band based on FRM

In order to solve the problem of high computation complexity of narrow transition band filter bank,an odd-arrangement non-maximally decimated efficient structure with narrow transition band filter bank based on frequency response masking(FRM)is proposed.Firstly,when the prototype filter of this structure is designed,the FRM filter of the upper arm is obtained through the interpolated prototype filter.Secondly,the complementary filter of the lower arm is obtained by the delay signal subtracted from the interpolated prototype filter.Then the masking filter is used to shield the mirror caused by the interpolated filter.Finally,the desired FRM filter is obtained.The improved structure is simulated by MATLAB,and the simulation results verify the correctness of this improved structure.This efficient structure saves 80% of the multiplier resources compared with the polyphase filter bank architecture.Because the decimation module is located at the front of this im-proved structure,the limited condition of the sampling rate of the system is reduced and it can be directly used in the high-speed sampling system.