Optimal power allocation and energy efficiency of AF OSTBC-MIMO systems

This paper adresses the optimization of power allocation and the energy efficiency (EE) of Orthogonal Space Time Block Code (OSTBC) in Multiple Input Multiple Output (MIMO) networks with amplify-and-forward (AF) relaying. Indeed, an optimization scheme is proposed that targeted the maximization of the end-to-end (e2e) Signal to Noise Ratio (SNR) with optimal power allocation. Furthermore, an algorithm is suggested for energy-efficient power allocation by minimizing the total energy consumption under the constraints of guaranteeing a quality of service given an e2e SNR to be above a certain threshold and maintaining the total consumed energies under the available energy budget. Thus, the proposed algorithm aims to minimize a cost function defined by a weighted sum of source and relay energies. The effect of increasing the number of antennas at nodes on respectively the BER and the average EE of the system, is also a contribution of this work. The efficiency of the proposed schemes is verified by simulation results.