Performance Analysis of Adaptive L-QAM for Opportunistic Decode-and-Forward Relaying
In this paper, the authors investigate the performance of constant-power adaptive L-ary Quadrature Modulation (L-QAM) for an opportunistic Decode-and-Forward (DF) relaying scheme. Specifically, they adopt adaptive five-mode L-QAM with fixed and optimum switching and derive expressions for the error rate, outage probability and spectral efficiency over both independent and identical (i.i.d.) and independent and non-identical (i.n.d.) Rayleigh fading channels. Cooperative diversity is a powerful solution for extracting diversity advantages without the need for installation of multiple antennas at the terminals. In cooperative diversity, some neighboring nodes help the source node through relaying its signal to the destination.