Joint antenna diversity and combined DFE/decoding of trellis coded modulation on frequency-selective fading mobile radio channels

A Monte Carlo simulation study of a combined FDMA/TDMA slow frequency-hopping trellis coded adaptive receiver for multipath Rayleigh fading channels is presented. The receiver structure, first proposed by Proakis (1989) and then developed by Ralf Mehlan and Heinrich Meyr (1992) for use on HF fading channels, comprises decision feedback equalizer (DFE), block deinterleaver and TCM decoder in one unit. Antenna diversity is considered leading to a joint diversity and combined equalization/decoding scheme. Furthermore, cyclic slow frequency hopping is used to attain intrinsic frequency diversity to perform a near ideal channel interleaving with a short processing delay. In order to asses the performance of this scheme Monte-Carlo simulations of the system have been carried out where the dynamic behavior of the mobile radio channel has been simulated by means of a selective equal-energy two-ray Rayleigh model, with a variable delay, τ, between the two rays. Bit error rate (BER) is obtained as a function of signal-to-noise ratio (SNR) and with τ, Doppler spread, number of frequencies in the frequency-hopping pattern, number of DFE coefficients and TDMA frame length as parameters