Accurate BER analysis of bandlimited DS-CDMA system with EGC and SC diversity over Nakagami fading channels

Accurate average bit error rate analysis of diversity receivers for asynchronous bandlimited binary DS-CDMA systems operating over Nakagami-m fading channels is studied. Predetection equal gain combining (EGC) and selection combining (SC) are considered. The fading is assumed to be flat and slow, and random spreading sequences are considered. The spectrum raised cosine (SRC) and Beaulieu-Tan-Damen (BTD) pulse shapes are employed. The improved Gaussian approximation for multiple access interference is employed with characteristic function and Fourier series methods for the performance analysis. Our results are valid for arbitrary diversity order and arbitrary Nakagami fading parameter and the computational complexity does not grow with the diversity order. The new Beaulieu-Tan-Damen pulse outperforms the spectrum raised-cosine pulse in all situations examined.