The design of low complexity two-channel lattice-structure perfect-reconstruction filter banks using genetic algorithms

This paper considers the design of reduced complexity 2 band QMF filter banks. In order to ensure perfect reconstruction, a lattice architecture has been adopted. Genetic algorithms are used to search for an optimal set of coefficients comprising simple sums of signed power of two terms. This allows the entire filter bank to be implemented using only additions and a single multiplicative scaling factor. Results are presented which show that the proposed method can be used to design filters with superior (in terms of minimax ripple) performance, compared to various infinite precision designs. Genetic algorithms can also be used to jointly optimise both performance and complexity in order to achieve an optimum performance/complexity trade off.