Accurate error probability estimate using moment method for decision-feedback equalization in digital cellular mobile radio with optimum diversity combining

This research provides fast and accurate performance analysis for optimum diversity combining and decision feedback equalization with quadrature amplitude modulation over frequency-selective fading channels. Many authors have studied the upper bound performance for such a diversity receiver, but the accurate performance has not been evaluated completely. In our analysis, the accurate error rate for the fading signal is obtained by using the moment method for each individual run in the quasi-analytical Monte-Carlo simulation. In this approach, simulation techniques are first used to evaluate the residual ISI in an equalized pulse response, and then moments of this ISI are calculated using a very fast and accurate recursive method of computation. Based on these moments, we use the series expansion to obtain the error rate of the system. Finally, we show that by using the moment method, the error rate estimation can be improved approximately by an order of 10 in average error rate and 4-5 in outage probability compared to the results obtained by the upper bound approach