Simulated performance of coded digital transmission in a multi-user indoor radio communications environment

Abstract

The performance of error correction codes in conjunction with different diversity methods is investigated in a simulated multi-user indoor radio communications environment in the presence of a single interferer. Bit-error curves are presented for soft-decision convolution coding and for trellis coding with simple diversity methods. The degradation in bit error rate caused by CCI (co-channel interference) on uncoded QPSK (quadrature phase-shift keying), convolutionally coded QPSK, and trellis-coded 8-PSK is presented. The results indicate that the given trellis codes (without interleaving) have poor performance in a Rayleigh fading medium; their performance is even worse in the presence of both fading and CCI. The performance of soft-decision convolutional coding was much better than that of trellis, but at the expense of increasing the channel bandwidth.