Performance of MRC and EGC antenna diversity reception for M-QAM over Ricean fading environment with PSAM and LMMSE channel estimation

In this paper, the average bit error rate (BER) performance of square M-level quadrature-amplitude modulation (M-QAM) with imperfect channel estimation via LMMSE under Gaussian-error model is addressed with maximal-ratio combining (MRC) and equal-gain combining (EGC) schemes. The channels are modelled as frequency-flat Ricean fading corrupted by additive white Gaussian noise (AWGN). Average output SNR after combining and average BERs of MRC and EGC antenna diversity combining schemes are analyzed via Monte-Carlo simulations versus different key system parameters such as average received bit SNR per antenna, number of antennas L, Ricean K-factor and normalized channel estimation correlation coefficient ? to reveal the actual diversity gain in terms of power efficiency with these combining schemes under realistic LMMSE-based channel estimation scenarios for pilot-symbol aided modulation (PSAM).