BER of PSAM 16-QAM with channel estimation error and MRC diversity

M-ary quadrature amplitude modulation (M-QAM) achieves high spectral efficiency in additive white Gaussian noise (AWGN) and fading channels. In practical wireless systems, the signal fading can severely degrade the receiver performance if the accurate channel amplitude and phase information is not available to the receiver. The bit error rate (BER) performance of maximal ratio combining (MRC) M-QAM with pilot symbol assisted modulation (PSAM) channel estimation in static and Rayleigh fading channels is derived. The effects of noise and estimator decorrelation on the received BER are examined. The high sensitivity of diversity systems to channel estimation error is investigated and quantified.