Closed-form expressions for the SEP of QAM diversity combining in uncertain channels

We present closed-form expressions for the symbol error probability (SEP) of diversity combining receivers operating under Rayleigh fading. Only an imperfect, training-based estimate of the individual, possibly correlated fading branches shall be available at the receiver. While most of the previous papers on this topic have dealt with PSK schemes only, we address the more complicated problem of finding SEP expressions for general multi-amplitude ASK and QAM constellations. Both one-and two-dimensional constellations are considered and virtually no restrictions are made regarding the covariance matrices of channel and noise