Adaptive Modulation and Diversity Combining Based on Output-Threshold MRC

In this paper, we propose a combined adaptive modulation transmission and output-threshold MRC diversity reception scheme for high spectral and power efficient wireless transceiver design. The modulation constellation size and the number of combined diversity paths are jointly determined based on the fading channel conditions and the required error rate performance. We derive the statistics of the resulting output signal-to-noise ratio (SNR) and then use it to analyze the proposed system in terms of performance, complexity, and spectral efficiency. Some selected numerical examples are finally presented to illustrate the mathematical formulism