Improving Concurrency for Cosine-modulated Filterbank Windowing

A novel method exploits the time-reversal of mirror symmetric pairs of polyphase components of a linearphase proto~pe jilter to obtain more than 25!Zo reduction in required MIPs to perform prototype windowing of either an analysis or synthesis cosine modulated jilterbank on a suitable architecture. The architecture required to obtain this MIPs reduction is only a minor modijlcation to many DSP architectures and is, in fact, available in the latest DSP designs. The proposed algorithm is particularly suited for large overlap factors, where the windowing computation dominates the required MIPs., one important example being thejilterbank used in kfPEG audio compression.