On the Energy-Spectral Efficiency Trade-off of the MRC Receiver in Massive MIMO Systems with Transceiver Power Consumption

الأصل · EN

We consider the uplink of a multiuser massive MIMO system wherein a base station (BS) having M antennas communicates coherently with K single antenna user terminals (UTs). We study the energy efficiency of this system while taking the transceiver power consumption at the UTs and the BS into consideration. For a given spectral efficiency R and fixed transceiver power consumption parameters, we propose and analyze the problem of maximizing the energy efficiency as a function of (M,K). For the maximum ratio combining (MRC) detector at the BS we show that with increasing R, (M,K) can be adaptively increased in such a way that the energy efficiency converges to a positive constant as R → ∞ ((M,K) is increased in such a way that a constant per-user spectral efficiency R/K is maintained). This is in contrast to the fixed (M,K) scenario where the energy efficiency is known to converge to zero as R → ∞. We also observe that for large R, the optimal (M,K) maximizing the energy efficiency is such that, the total power consumed by the power amplifiers (PA) in all the K UTs is a small fraction of the total system power consumption.