The Optimum Design of Multistage Multirate FIR Filter for Audio Signal Sampling Rate Conversion via a Genetic Algorithm Approach

In audio signal processing, there are three major sampling rates, 32 KHz, 44.1 KHz, and 48 KHz used in the audio signal processing. It is important to employ multirate signal processing techniques to remove imaging and/or aliasing in modern digital signal processing system with different input-output sampling rate. The application of equivalent multistage multirate sampling rate technologies can reduce the total storage requirement (TSR) and the number of multiplications per second (MPS), respectively. The choice of number of stages and the design of the order of FIR filters are the parameters to be determined. A two-phase algorithm combining the genetic algorithm and integer adjustment for parameter combination approach is proposed to determine these parameters. With different sampling rate conversions, several design examples are illustrated in this paper.