Bit error rate analysis of hybrid selection/maximal-ratio diversity combining with channel estimation error

Hybrid selection/maximal-ratio combining (H-S/MRC) diversity is a very important diversity combining technique in wideband systems. It can be employed to reduce the complexity of RAKE receivers, which are needed to achieve acceptable performance on frequency selective fading channels. A method for calculating the bit error rate (BER) of H-S/MRC diversity systems with channel estimation error is introduced. It is applied to derive BER expressions for binary shift keying (BPSK), quadrature shift keying (QPSK) and M-ary quadrature amplitude modulation (M-QAM). Results for selection combining (SC) and MRC are also obtained as two special cases. The effects of the estimation errors on the system performances are studied in detail. The sensitivities of different modulation schemes to channel estimation errors are examined.