Design of M-Channel Uniform Linear-Phase Filter Banks with Partial Cosine Modulation

In this paper, a method of partial cosine modulation isproposed to maintain the Linear-phase (LP) property of M-channeluniform filter banks. We design the lowpass analysis filter separately,getting the highpass by shifting it by pi, and obtain the bandpass viacosine modulation of a prototype filter, justifying the name "partialcosine modulation". For the elimination of significant aliasingdistortion, a necessary and sufficient condition is derived. With theproposed design criteria, the problem of uniform LP bank design becomesthat of designing only two filters, one prototype and the lowpassfilter, leading to a less design effort. By employing theParks-McClellan algorithm, a global optimum solution in the minimaxsense can be obtained. In addition, the proposed method is applicableto filter banks with arbitrary number of channels and offers moreflexible in choosing the filter length.