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 a pulse-shaping filter and the receiver includes a plurality of corresponding matched filters, the pulse shaping filter is approximated to match a plurality of filters of the receiver for reducing the number of transmit shaping filters. The filter comprises a square-root raised cosine (SRRC) filter where the SRRC filter amplitude/phase response is approximated using a typical Parks-McClellan (remez) algorithm for designing linear phase FIR filters which, for a given set of input parameters, outputs a transmit filter coefficient set for the SRRC filter. The input parameters to the Parks-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 specification requirements while the resulting transmit-receive filter pair ISI is minimized across a plurality of matched filter specifications.