Energy-Efficient Power Allocation And Performance Estimation For MIMO-MRC Systems

Adaptive power allocation problem where it minimizes the energy-per-good bit (EPG) of a system employing a multiple-input multiple-output maximum ratio combining (MIMO-MRC) scheme is formulated. Closed-form results are obtained for the optimum transmit power and minimum EPG as a function of the number of antennas employed and the quality of the channel. The cumulative distribution function (CDF) of the minimum EPG in closed form is obtained to assess the performance of the solution in a statistically varying channel. The energyefficiency trade-off between enhanced diversity and the increased circuit power consumption of multiple antennas is explored. In particular, EPG CDF in a numerical example is used to find the most energy-efficient number of antennas for a given probability of outage. Both Rayleigh and Rician MIMO fading channels are considered. Keywords-Energy minimization, MIMO, beamforming, MIMO MRC, fading channels, adaptive power allocation. Introduction.