Joint Optimal Number of RF chains and Power Allocation for Downlink Massive MIMO Systems

摘要

This paper investigates the downlink of massive multiple-inputmultiple-output (MIMO) systems that include a single cell Base Station (BS)equipped with large number of antennas serving multiple users. As the number ofRF chains is getting large, the system model considered in this paper assumes anon negligible circuit power consumption. Hence, the aim of this work is tofind the optimal balance between the power consumed by the RF chains and thetransmitted power. First, assuming an equal power allocation among users, theoptimal number of RF chains to be activated is analytically found. Then, for agiven number of RF chains we derive analytically the optimal power allocationamong users. Based on these analysis, we propose an iterative algorithm thatcomputes jointly the optimal number of RF chains and the optimal powerallocation vector. Simulations validate the analytical results and show thehigh performance provided by the proposed algorithm.