Diversity and decision-feedback equalization in cellular mobile radio with cochannel interference

This paper presents the performance analysis of quadrature amplitude modulation (QAM) using decision-feedback equalization (DFE) over a cellular radio channel with frequency-selective fading and cochannel interference (CCI). With infinite taps the decision-feedback equalizer has been shown to be superior to linear equalizer in reducing both the intersymbol interference (ISI) and CCI. However, only equalizers with a few taps can be realized in the practical receiver design. In contrast to the noise-limited case, our simulation results reveal that the DFE can not outperform the linear equalizer (LE) using the same finite taps when CCI dominates the overall system performance. The modulation and statistical characteristics of CCI are considered. Our analysis also includes the effects of antenna diversity combining techniques. We employ Gaussian quadrature rules (GQR) to assess the error probability efficiently.