A Unified Analysis for Coded DS-CDMA With Equal-Gain Chip Combining in the Downlink of OFDM Systems

This paper presents a novel unified analysis for the bit-error rate in the downlink of convolutionally coded and single-user detected MC-CDMA, MCDS-CDMA, TFL-CDMA, and OFDMA. Performance is analyzed under the assumption of Hadamard spreading codes, equal-gain chip combining, and a highly correlated frequency-selective Rayleigh-fading channel. Closed-form expressions are presented for the cumulative distribution function, probability density function, and moment generating function for the signal-to-noise-plus-interference ratio after despreading. The presented results assume error-free channel estimates, a perfectly synchronized receiver, and are found to agree reasonably well with simulation results.