Power Scaling of Uplink Massive MIMO Systems With ArbitraryRank Channel Means
Abstract
This paper investigates the uplink achievable rates of massive multipleinput multipleoutput (MIMO) antenna systems in Ricean fading channels, using maximalratio combining (MRC) and zeroforcing (ZF) receivers, assuming perfect and imperfect channel state information (CSI). In contrast to previous relevant works, the fast fading MIMO channel matrix is assumed to have an arbitraryrank deterministic component as well as a Rayleighdistributed random component. We derive tractable expressions for the achievable uplink rate in the largeantenna limit, along with approximating results that hold for any finite number of antennas. Based on these analytical results, we obtain the scaling law that the users' transmit power should satisfy, while maintaining a desirable quality of service. In particular, it is found that regardless of the Ricean $K$factor, in the case of perfect CSI, the approximations converge to the same constant value as the exact results, as the number of base station antennas, $M$, grows large, while the transmit power of each user can be scaled down proportionally to $1/M$. If CSI is estimated with uncertainty, the same result holds true but only when the Ricean $K$factor is nonzero. Otherwise, if the channel experiences Rayleigh fading, we can only cut the transmit power of each user proportionally to $1/\sqrt M$. In addition, we show that with an increasing Ricean $K$factor, the uplink rates will converge to fixed values for both MRC and ZF receivers.
 Publication:

IEEE Journal of Selected Topics in Signal Processing
 Pub Date:
 October 2014
 DOI:
 10.1109/JSTSP.2014.2324534
 arXiv:
 arXiv:1405.6952
 Bibcode:
 2014ISTSP...8..966Z
 Keywords:

 Computer Science  Information Theory
 EPrint:
 doi:10.1109/JSTSP.2014.2324534