基于频率响应屏蔽的窄过渡带信道化接收机

Digital channelized receiver with narrow transition band based on FRM filter

针对信道数目增加和过渡带要求过窄带来的原型滤波器设计复杂度过高的问题,提出了一种新的窄过渡带信道化滤波器组设计方法。利用频率响应屏蔽技术(FRM),对原型半带滤波器进行插值得到窄过渡带,对原型屏蔽滤波器进行频谱搬移生成上、下支路屏蔽滤波器,对上、下支路合并得到窄过渡带滤波器,利用滤波器调制、多相滤波和相邻频带合并得到窄过渡带的滤波器组。最后通过Matlab进行8信道的设计实例验证了此结构的有效性。

To overcome the complexity in prototype filter design induced by the increase in the number of channels and the requirement of narrow transition band, a new design method of channel filter banks with narrow transition zone is proposed. Using Frequency Response Masking （FRM） techniques, the prototype half-band filter is interpolated to obtain a narrow transition band. First, the prototype masking filter is shifted in spectrum to generate masking filters for upper and lower branches. Then, the narrow transition band filter is obtained by synthesizing the upper and lower branches. Finally, the filter banks with narrow transition band are attained by filter modulation, poly-phase filtering and combination of adjacent bands. A 8-channel design examples with Matlab demonstrate effectiveness of the proposed method.