HQMF: Halfband quadrature mirror filters

In this paper, a Halfband FIR implementation of the widely used Quadrature Mirror Filter (QMF) approach is described. In the first part of the paper, the Half-band Quadrature Mirror Filter (HQMF) concept is introduced. In the second part of the paper the HQMF implementation, assuming a tree structure approach, is discussed. In the last part of the paper, figures of merit of the HQMF design are discussed in terms of processing savings compared to the QMF approach. It is shown that the number of multiplications required for sub-band splitting is almost halved through this concept.