A technique of demodulating a .pi./4-DQPSK composite carrier waveform using a non-coherent discriminator based receiver is presented. In particular, a means of recovering .pi./4-DQPSK modulated data symbols using a dual output discriminator in conjunction with a dual binary amplitude detection process...http://www.google.com/patents/US5526381?utm_source=gb-gplus-sharePatent US5526381 - Robust non-coherent detector for .pi./4-DQPSK signals
