MULTIPLE-MODE DIGITAL MODULATION USING A SINGLE SQUARE-ROOT NYQUIST PULSE-SHAPING TRANSMIT FILTER

摘要

In a method of digital communication where the transmitter includes apulse-shaping filter and the receiver includes a plurality of correspondingmatchedfilters, the pulse shaping filter is approximated to match a plurality offilters of thereceiver for reducing the number of transmit shaping filters. The filtercomprises asquare-root raised cosine (SRRC) filter where the SRRC filter amplitude/phaseresponse is approximated using a typical Parks-McClellan (remez) algorithm fordesigning linear phase FIR filters which, for a given set of input parameters,outputsa transmit filter coefficient set for the SRRC filter. The input parameters totheParks-McClellan algorithm are chosen by iteration such that pass-band ripple,3-dB point,and stop-band attenuation of the transmit filter meet or exceed specificationrequirements while the resulting transmit-receive filter pair ISI is minimizedacross aplurality of matched filter specifications.