S + N energy selection combining for BPSK signaling in rayleigh fading channels

A signal-plus-noise (S + N) energy selection combining (S +N-ESC) scheme and a weighted S +N-ESC scheme for binary phase shift keying (BPSK) signaling are studied. The S + N-ESC selects the branch with the maximum S + N energy for detection. The advantage of the S+N-ESC and the weighted S+N-ESC is that they require no explicit channel estimation for diversity branch selection. The bit error rate (BER) performances of the S + N-ESC and the weighted S + N-ESC are analyzed for BPSK signaling in independent and nonidentically distributed (i.n.d.) Rayleigh fading channels. We show that the average error rate performance of the S+N-ESC is the same as classical signalto-noise ratio selection combining (SNR-SC), which requires the estimation of fading amplitudes for branch selection, in independent and identically distributed (i.i.d.) Rayleigh fading channels. We also show that the weighted S + N-ESC has the same BER performance as the classical SNR-SC for i.n.d. Rayleigh fading channels.