Bit error probability analysis for TCM in slow fading channels

Bit error probability evaluation of trellis-coded modulation (TCM) over fading channels is rather complicated, and the analytical results are limited to loose upper bounds leaving the system designer with the only option of simulation. Cavers and Ho (see IEEE Trans. Commun., vol.40, no.1, p.74-83, 1992) have derived an exact analytical expression for pairwise error-event probability. In this paper, using a different approach, the authors give an alternative method to compute the exact pairwise error event probability of TCM schemes in Rayleigh or Rician fading channels with perfect side information. For example, for a particular TCM scheme, they find the asymptotic difference between the exact and the upper bound of the pairwise error event probability to be 2.68 dB. As it turns out, for Rayleigh fading, the exact pairwise error probability can be calculated in closed-form. For the case of Rician fading, however, a closed-form expression is apparently impossible to obtain. It is observed that an accurate estimate of the bit error probability can be obtained by evaluating a sufficient number of pairwise error-event probabilities. Hence, this approach is a computationally feasible alternative to the simulation.<<ETX>>