Multirate Digital Signal Processing

Summary

Processing a signal at more than one sampling rate is called multirate digital signal processing. This chapter presents downsampling and upsampling which are the two basic operations used, respectively, to reduce and increase the sampling rate in multirate digital signal processing. Convolution followed by downsampling is the basic step in the computation of the discrete wavelet transform (DWT). In addition to adders, multipliers, and delays, two more devices, decimators and interpolators, are used in implementing multirate digital signal processing systems. Multirate digital signal processing provides higher efficiency in signal processing applications. The chapter then describes the two‐channel filter bank, which is made of decimators, interpolators, and delays. It derives an efficient implementation of the filter bank, called the polyphase form. Filter banks are the basic implementation structures of the DWT. Polyphase filter structures provide an efficient implementation of sampling rate conversion systems.