Generalized Rational Sampling Rate Conversion Polyphase FIR Filter

In this letter, we derived a mathematical expression that can help in developing a generalized rational sampling rate conversion polyphase finite impulse response filter, for all relatively prime values of the upsampling (L) and downsampling (M) factors. In contrast to the existing approaches, the proposed structure efficiently exploits the involved noncausality to eliminate input delay requirements. In addition, the minimization of output delay requirement is presented. A numerical example is also studied to validate the proposed structure. We further evaluate the performance of the proposed structure in terms of total delay requirements (D), multiplication complexity (M), and addition complexity (A). Compared to a similar recent approach, the proposed structure is found to be more efficient in terms of D for L < M and L > M. However, it has reduced computational complexity in terms of A than the existing approach for L < M and same for L > M, whereas both approaches have same M for L < M and L > M.