A new method for designing efficient linear phase recursive filters

In this paper we address the design of linear phase IIR filters for infinite length input sequences. We propose a new method that, although based on a conventional block processing noncausal two-pass scheme, does not involve overlapping of the blocks. Instead, we consider a pure state variable approach and obtain the best possible choice of the initial state to apply to the second stage for each block. This is the result of interpreting the problem from the point of view of the autocorrelation of the impulse response of one of the stages. The proposed scheme is more efficient than previous approaches, the reduction in number of operations achieving a maximum of <f>17%</f> in relation to other methods. Simulations show that the error at the output can be made arbitrarily small. [Copyright &y& Elsevier]