PERFORMANCE ANALYSIS OF ASYMPTOTICALLY OPTIMAL NONCOHERENT DETECTION OF TRELLIS-CODED MULTI-AMPLITUDE MULTI-PHASE MODULATION SIGNALS IN GAUSSIAN-NOISE AND ISI CHANNELS

Performance upper bounds for noncoherent receivers employed in conjunction with single and multi-amplitude/-phase signals, transmitted over time dispersive and Gaussian noise channels are derived, Based upon a metric which has been previously derived by the authors, we present analytical expressions and computer generated results for the performance of asymptotically optimal noncoherent detection over such channels. As a typical application of the developed theoretical analysis, we consider wideband telecommunication systems, where time dispersion resulting in intersymbol interference (ISI) is one of the significant sources of system performance degradation, Numerical evaluation of the optimal noncoherent decoding algorithms, shows the proposed bounds to be an effective and efficient means of evaluating the performance of the noncoherent receivers under investigation, Using the derived bounds, performance evaluation results for modulation schemes such as pi/4-shift DQPSK (differential quadrature phase shift keying), 8- and 16-DQAM (differential quadrature amplitude modulation), at very low bit-error rates (BER), which would otherwise pose impractically high computational loads when using Monte-Carlo error counting techniques, are readily obtained, At BER >10(-4) evaluation results generated via computer simulation have verified the tightness of the bounds.