BER of MFSK With Postdetection Switch-and-Stay Combining in Correlated Rayleigh and Rician Fading

The performance of
M
-ary frequency shift keying (MFSK) with dual-branch postdetection switch-and-stay combining (SSC) in correlated Rayleigh and Rician fading is studied. Closed-form expressions are derived for the average bit error rate (BER) of MFSK with postdetection SSC in correlated Rayleigh and Rician fading. Optimum switching thresholds that minimize the average BER are obtained. Extensive Monte Carlo simulations are presented to test the validity of the analytical results. The performance of MFSK with dual-branch postdetection SSC is compared to the performance of MFSK with dual-branch predetection SSC. The effects of correlation, fading parameter, fading power imbalance and switching threshold on the relative performance of the postdetection SSC compared to predetection SSC are examined.