Design of M-Channel Uniform Linear-Phase Filter Banks with Partial Cosine Modulation ∗
Wei Zhong, Shi Guangming, Xuemei Xie, Xuyang Chen · 2009
In this paper, a method of partial cosine modulation is proposed to maintain the Linear-phase (LP) property of M-channel uniform filter banks. We design the lowpass analysis filter separately, getting the highpass by shifting it by π, and obtain the bandpass via cosine modulation of a prototype filter, justifying the name par- tial cosine modulation. For the elimination of significant aliasing distortion, a necessary and sufficient condition is derived. With the proposed design criteria, the problem of uniform LP bank design becomes that of designing only two filters, one prototype and the lowpass filter, leading to a less design effort. By employing the Parks-McClellan algorithm, a global optimum solution in the minimax sense can be obtained. In addition, the proposed method is ap- plicable to filter banks with arbitrary number of channels and offers more flexible in choosing the filter length.