Interference whitening receivers for bandlimited DS-CDMA systems in Nakagami fading

A whitening matched filter receiver for multiple access interference suppression is considered for a bandlimited DS-CDMA system in Nakagami fading. The whitening matched filter, while maximizing the signal-to-noise-plus-interference ratio, introduces intersymbol interference in the decision statistic. A fractionally spaced linear MMSE equalizer is introduced to combat the intersymbol interference. The Beaulieu-Tan-Damen pulse and the conventional spectrum raised-cosine pulse are employed as chip pulse shapes. Asynchronous timing and slow flat fading are assumed. The precise BER expressions are derived using characteristic function and Fourier series methods.