Based on the prototype filter for filtering the speech signal simulation

The filter can be eliminated from the received signal or weaken the noise to extract useful signals.The prototype filter is the basic of other filters.This paper,which based on Matlab,mainly studies the basic way to design prototype filter,and give an emphasis on the basic concepts of Butterworth filter and Chebyshev filter.Digital filter's design specifications come from analog prototype filter by frequency transform.Filtering and simulating the voice signal based on the prototype filter,and the method given by the frequency mapping method can be converted to the desired filter.