Frequency domain overlapped modulated filter banks

Abstract

The structure of paraunitary modulated filter bank with power complementary prototype filter and arbitrary unitary modulation matrix is derived. By replacing the unitary modulation matrix of the analysis filter bank with left invertible matrix, one obtains biorthogonal modulated filter bank with power complementary linear phase lowpass prototype filter. Moreover, undersampled frequency domain overlapped filter bank can be constructed by designing modulation matrix with larger number of channels than decimation and the proposed structure allows arbitrary number of frequency channels to be overlapped. Unfolding technique is introduced to design frequency domain overlapped M band modulated filter bank. Application in quadrature modulation system is discussed.