PERFORMANCES OF 16QAM WITH FADING COMPENSATION AND POSTDETECTION DIVERSITY RECEPTION IN SATELLITE MOBILE CHANNELS

This paper studies the effects of N-branch postdetection selection div ersity reception, where N=1, 2, 3 or 4, incorporated with fading compe nsation on a digital satellite mobile system. The digital satellite mo bile system transmits a pilot-symbol-aided 16-ary quadrature-amplitude modulated (PSA-16QAM) signal over the Rician channels. A selection me thod that makes use of the pilot symbols to select one of the N branch es in the diversity reception system for signal detection, and a novel PSA technique that makes use of both the pilot symbols and data symbo ls for fading compensation, are proposed, Computer simulation tests ar e used to assess the effects of the proposed techniques on bit-error r ate performances (BER) of the PSA-16QAM system in the presence of addi tive white Gaussian noise (AWGN) or co-channel interference (CCI) in t he Rician faded channels. When frequency diversity is used, PSA-16QAM with 2-branch and 4-branch diversity reception occupies about the same bandwidths as quaternary phase-shift-keying (QPSK) without using dive rsity and with 2-branch diversity, respectively, yet achieving the sam e capacity. Thus, simulation tests on the BER performances of a QPSK s ystem without diversity and with 2-branch diversity are also carried o ut and the results are used to determine the preferred system arrangem ents. (C) 1997 John Wiley & Sons, Ltd.