Performance of decorrelating receiver in multipath Rician fading channels

This paper focuses on the performance analysis of the decorrelating multipath combining receiver in multipath Rician faded CDMA channels. M-ary QAM scheme is employed to improve the spectral efficiency. Approximate expressions are first derived for the two performance indexes: the average symbol error rate (SER) and the average bit error rate (BER) when the receiver perfectly knows the channel information of the user of interest. To achieve desirable closed-form expressions of the SER and the BER, we exploit results in large system analysis and make assumptions of a high signal-to-interference ratio (SIR) and/or a small Rician K-factor. To measure the receiver performance in the practical scenario, we further derive expressions to approximate the average SER and BER with channel uncertainty. The pilot-symbol aided linear minimum mean-square channel estimator is considered to obtain an accurate channel estimate and to obtain an expression for the variance of the channel estimation error required for calculating the error rate. All analytical results are compared with simulation results.