Interference whitening receivers for CCI mitigation in micro-cellular BPSK systems
Kathiravetpillai Sivanesan, Norman C. Beaulieu · 2005
Cochannel interference and fading are the dominant impairments in micro-cellular wireless communication systems. Cochannel interference mitigation for BPSK systems in slow, flat fading micro-cellular environments is considered. Nonreturn-to- zero (rectangular) pulse shaping is considerd to allow analytical solutions. Slow Rayleigh faded cochannel interference is Gaus- sian distributed after the demodulation. Thus, a receiver struc- ture which maximizes the instantaneous signal-to-noise plus inter- ference ratio, minimizes the average bit error rate. A whitening matched filter receiver is used instead of a conventional matched filter. While whitening maximizes the signal-to-noise plus inter- ference ratio, it introduces intersymbol interference in the deci- sion statistic. A fractionally spaced minimum mean square error equalizer is employed to combat the intersymbol interference. The performance of the proposed receiver structure closely approaches the optimum single user performance when appropriately chosen tap lengths and tap spacings are employed. An optimal decorre- lating receiver structure that bases its decision on observation over one symbol duration is also proposed. I. INTRODUCTION