Synthesis and characterization of quadrature mirror filter banks

Abstract

Multirate signal processing techniques are widely used in many areas of modern engineering such as-Communication Engineering, Image Processing, Digital Audio and Multimedia. The main advantage of a multirate system is the substantial decrease of computational complexity, and consequently, the cost reduction. The computational efficiency of multirate algorithms is based on the ability to use simultaneously different sampling rates in the different parts of the system. The sampling rate alterations generate the unwanted effects through the system: spectral aliasing in the sampling rate decrease, and spectral images in the sampling rate increase. The multirate filtering makes the general concept of multirate signal processing applicable in practice. For multirate filters, finite impulse response (FIR) or infinite impulse response (IIR) transfer functions can be used for generating the overall system. The selection of the filter type depends on the criteria at hand. An FIR filter easily achieves a strictly linear-phase response, but requires a larger number of operations per output sample when compared with an equal magnitude response IIR filter. The linearphase FIR filter is an adequate choice when the waveform of the signal has to be preserved. An advantage of the multirate design approach is the ability of improving significantly the efficiency of FIR filters thus making them very desirable in practice. The multirate signal processing and multirate filtering have been attracted many researchers during the last several decades. The rapid development of the new algorithms and new design methods has been influenced by the advances in computer technology and software development. Although the existing literature on the subject is very large, the multirate signal processing is an open area of research. This study illustrates the examples of the applications of multirate filters and the design of multirate filter banks. First, a brief review of the properties of the two-channel analysis and synthesis filter banks.