A Decision-Feedback Channel Estimation Receiver for Independent Nonidentical Rayleigh Fading Channels

We derive a decision-feedback channel estimation receiver for independent and non-identically distributed (i.n.d.) Rayleigh fading channels. The receiver has memory to store signals received over the past several symbol intervals, and then use them to adaptively estimate instantaneous channel gains. The receiver adapts its decision rule based on estimates of the varying channel gains, and hence it is partially coherent. We also obtain the bit error rate (BER) of the channel estimation receiver for binary phase-shift keying (BPSK) and quadrature phase-shift keying (QPSK) modulations. The BER results are obtained in simple forms which explicitly show the effects of system parameters on the BER. In addition, our results are applicable to the cases where all the branches have arbitrary fade rates.