CCI mitigation using interference whitening in bandlimited micro-cellular BPSK systems

Cochannel interference mitigation in bandwidth efficient BPSK systems operating in slow, flat fading micro-cellular environments is considered. The desired and interfering users undergo Nakagami-m and Rayleigh fading, respectively. A whitening matched filter and fractionally spaced linear minimum mean square error equalizer are employed in the receiver. While whitening maximizes the signal-to-noise plus interference ratio, the whitening matched filter introduces intersymbol interference in the decision statistic. A minimum mean square error equalizer is used to combat the intersymbol interference. Important observations regarding the performance of the proposed receiver structure are made. The performance with Beaulieu-Tan-Damen pulse shaping is always better than with spectrum raised-cosine pulse shaping. The performance is considerably better than the conventional matched filter receiver under a variety of fading conditions for the desired user. The performance gain decreases with the severity of the fading of the desired user. When the co-channel interference is synchronous, the performance can approach the optimum single user performance by appropriately choosing the tap spacing and length of the equalizer.