Coefficient decimation approach for realizing reconfigurable finite impulse response filters

Abstract

A new approach to implement computationally efficient reconfigurable finite impulse response (FIR) filter is presented in this paper. If the coefficients of an FIR filter are decimated by M, i.e., if every M <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> coefficient of the filter is kept unchanged and remaining coefficients are changed to zeros, a multi-band frequency response will be obtained. The resulting frequency responses will have centre frequencies at 2pik/M, where k is an integer ranging from 0 to M-1. If these multi-band frequency responses are selectively masked using inherently low complex wide transition-band masking filters, different low-pass, high-pass, bandpass, and bandstop filters can be obtained. If every M <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> coefficient is grouped together removing the zero coefficients in between, a decimated frequency response in comparison to the original frequency response is obtained. In this paper, we also show the design of a reconfigurable filter bank using the above approach.