Performance of PRMA schemes via fading channels

A packet reservation multiple access (PRMA) assisted microcellular cordless telecommunications (CT) system is investigated for office type environments. The objective speech quality is found as a function of channel signal-to-noise ratio (SNR) for transmissions over narrowband Rayleigh fading channels, parametrized with the number of PRMA users. A moderate-complexity 16-ary CT scheme comprising a 4-b/symbol 32-kb/s adaptive differential pulse code modulation (ADPCM) speech codec, a Reed-Solomon forward error correction (FEC) codec, and a diversity-assisted 16-level star quadrature amplitude modulation (16-StQAM) modem is proposed. The 264-kBd 20-slot PRMA scheme supports 36 users while maintaining virtually imperceptible speech degradation for channel SNRs in excess of about 25 dB and for mobile speeds above 2 mph.