PERFORMANCE COMPARISON FOR EFFICIENT DIGITAL DECIMATOR FILTER STRUCTURES

Abstract

In many practical applications of DSP, there is a problem of changing the sampling rate of a signal, either increasing it or decreasing it by some amount. For example, Telecommunication system transmits and receives different types of signals (e.g. fax, speech, video, etc), so there is a requirement to process the various signals at the different rates with corresponding bandwidth of the signals. The process of converting a signal from a given rate to a different rate is called as “sampling rate conversion” and the systems that employ multiple sampling rates in the processing of digital signals are called as “Multirate DSP systems”. ”. Digital audio engineering is an area that has benefited significantly from Multirate techniques. For example, they are used in the compact disc player to simplify the D/A conversion processes, while at the same time maintaining the quality of the reproduced sound. This project is based on to design and development of highly efficient Multirate digital filter structures for filtration of noisy signal in which the high sampling rate is decreased to the desired lower sampling rate. Digital filters such as IIR filter, FIR filter and CIC filter is designed and taking their performance in case of magnitude response, step response, impulse response, pole-zero plot, filter coefficients, storage requirements, hardware requirements, number of stages and simulated waveforms for same input specifications. Finally compare them and discuss the advantages and limitations of these filters. These filter structures designed in the Simulink model in Matlab 2012a environment.