Joint Power Allocation and Beamforming for NonOrthogonal Multiple Access (NOMA) in 5G MillimeterWave Communications
Abstract
In this paper we explore nonorthogonal multiple access (NOMA) in millimeterwave (mmWave) communications (mmWaveNOMA). In particular, we consider a typical problem, i.e., maximization of the sum rate of a 2user mmWaveNOMA system. In this problem, we need to find the beamforming vector to steer towards the two users simultaneously subject to an analog beamforming structure, while allocating appropriate power to them. As the problem is nonconvex and may not be converted to a convex problem with simple manipulations, we propose a suboptimal solution to this problem. The basic idea is to decompose the original joint beamforming and power allocation problem into two subproblems which are relatively easy to solve: one is a power and beam gain allocation problem, and the other is a beamforming problem under a constantmodulus constraint. Extension of the proposed solution from 2user mmWaveNOMA to moreuser mmWaveNOMA is also discussed. Extensive performance evaluations are conducted to verify the rational of the proposed solution, and the results also show that the proposed suboptimal solution achieve closetobound sumrate performance, which is significantly better than that of timedivision multiple access (TDMA).
 Publication:

arXiv eprints
 Pub Date:
 November 2017
 arXiv:
 arXiv:1711.01380
 Bibcode:
 2017arXiv171101380X
 Keywords:

 Computer Science  Information Theory
 EPrint:
 14pages, Submitted to TWC