Extension of the ERDMOSM1 and ERDMOSM2 Reduced Group Delay Finite Impulse Response (FIR) in Digital Filtering

Abstract

AbstractThe conventional digital filters may not be suitable in such DSP applications where distortion-less responses are desired along with the minimum group-delayed output. The conventional Finite Impulse Response (FIR) filters give the distortion-less output but it has an objectionable group-delay response. The Infinite Impulse Response (IIR) filters can be used to minimize the group delay but due to its recursive nature, it introduces distortion in response. In this paper, a novel modified overlap-save method-based FIR filter is proposed that improves the group delay. To design such filters, we first make the impulse response causal, and then causal impulse responses are shifted by (N-1)/2 unit for odd order impulse response and N/2 for even order impulse response. Further, we have proposed a novel algorithm for the removal of undesired samples from the convolution result. The final output response shows significant improvement in group delay over the existing techniques.KeywordsGroup delayFIR filterIIR filterEnhance Reduce delay modified over-lap save Method (ERDMOSM)