Performance of quadrature amplitude modulation with nonlinear transmit amplifiers in Rayleigh fading

A method is presented to compensate for the performance degradation of a 16-QAM modulation scheme due to nonlinear distortion which does not resort to complicated processing and equalization. The symbol error probability performance of the proposed receiver is derived analytically and compared with the uncompensated demodulation technique. We consider a compensated diversity receiver for independent Rayleigh fading channels, where the average signal-to-noise ratios of the diversity branches are not necessarily equal. It is shown that the compensated technique is a viable approach for such non-constant envelope higher order modulation schemes.