Asymptotic Performance Analysis of GSVD-NOMA Systems with a Large-Scale Antenna Array

TL;DR

This paper analyzes the asymptotic performance of a GSVD-NOMA scheme in large-scale MIMO downlink systems, deriving distributional limits and extending the approach to multi-user scenarios with hybrid access.

Contribution

It introduces a novel GSVD-NOMA transmission protocol, characterizes its asymptotic distributional properties, and extends it to multi-user systems with a hybrid multiple access strategy.

Findings

Derived the limiting distribution of generalized singular values for large antenna arrays.

Calculated the asymptotic average data rates for the proposed scheme.

Validated the analytical results with numerical simulations.

Abstract

This paper considers a multiple-input multiple-output (MIMO) downlink communication scenario with one base station and two users, where each user is equipped with m antennas and the base station is equipped with n antennas. To efficiently exploit the spectrum resources, we propose a transmission protocol which combines generalized singular value decomposition (GSVD) and non-orthogonal multiple access (NOMA). The average data rates achieved by the two users are adopted as performance metrics for evaluation of the proposed GSVD-NOMA scheme. In particular, we first characterize the limiting distribution of the squared generalized singular values of the two users' channel matrices for the asymptotic case where the numbers of transmit and receive antennas approach infinity. Then, we calculate the normalized average individual rates of the users in the considered asymptotic regime. Furthermore, we extend the proposed GSVD-NOMA scheme to the MIMO downlink communication scenario with more than two users by using a hybrid multiple access (MA) approach, where the base station first divides the users into different groups, then the proposed GSVD-NOMA scheme is implemented within each group, and different groups are allocated with orthogonal bandwidth resources. Finally, numerical results are provided to validate the effectiveness of the proposed GSVD-NOMA protocol, and the accuracy of the developed analytical results.