Pseudo-QMF filter banks for audio signals subband coding

Pseudo-QMF banks in which there is no optimization involved in order to obtain the prototype filter used in the cosine modulation are an advance that simplifies the system design. In this paper, three filter bank design methods that satisfy this requirement-all of them employ any conventional designing technique-are proposed. These filter banks do not introduce phase distortion, their aliasing is comparable to the stopband gain of the prototype filter and amplitude distortion can be really minimized. The differences among them are prototype filter specifications and the initial phase factor election. When the prototype filters are appropriately designed, the total error on the reconstructed output signal is reduced. An example where an audio signal is the input signal is included