Abstract
It is well known that M-channel filter banks, satisfying either the perfect-reconstruction (PR) or near-PR property, can be obtained by cosine modulation of a linear-phase prototype filter. In this work, we investigated the effects of choosing odd or even number of channels on the performance of both PR and near-PR and near-PR cosine-modulated filter banks (CMFBs). Given the same m, a performance degradation happens in the PR case with odd numbered M. Contrarily, the choice of even or odd M has little effects on the whole system quality for near-PR one. In addition, we made some comparisons between the constrained optimization and the Parks-McClellan algorithm with cosine roll-off characteristic in designing near-PR CMFBs. Detailed analyses and numerical comparisons show that the PR and near-PR systems have their individual characteristics in terms of M an m selection. Studies here can provide useful and practical guidelines for choosing right filter systems.
* Supported by National Natural Science Foundation of China (Grant No. 60372047) and Natural Science Foundation of Shaanxi Province, China (Grant No. 2005F18)
Notes
* Supported by National Natural Science Foundation of China (Grant No. 60372047) and Natural Science Foundation of Shaanxi Province, China (Grant No. 2005F18)