Uplink performance of cellular massive MIMO with fractional power control: Asymptotic analysis

This paper addresses the spatial-average analysis of uplink signal to interference ratio (SIR) and throughput in massive MIMO networks with maximum ratio combining (MRC). The analysis incorporates the effects of fractional power control (FPC) and other cells interference (ICI) due to estimation error in channel state information (CSI). Based on an asymptotic approach, tractable expressions are presented for SIR-distributions and specific performance metrics (coverage probability and average rate) in poisson topology model. Moreover, the considered approach is applicable both to random and deterministic network topologies. The impacts of key network-features such as FPC, path-loss exponent and base station (BS) density are characterized. Numerical results validate the model and show that the coverage probability in lower 50th percentile can be maximized by adjusting FPC compensation-fraction between 0.2 and 0.5 depending on the system parameters. Also, for SIR threshold of 0 dB, allocating FPC of 0.25 for uplink transmit power can achieve approximately 6% improvement in coverage probability in cell edge area compared to constant-power policy and about 14% improvement compared to full channel-inversion policy. The provided approximation results can replace the need for lengthy-Monte-Carlo simulations in designing of large scale MIMO systems and quantify the trade-off between improved cell-edge SIR for low and moderate values of FPC.