Sum Rate Maximizing Multigroup Multicast Beamforming under Per-antenna Power Constraints

TL;DR

This paper develops a novel beamforming algorithm to maximize sum rate in multigroup multicast systems with per-antenna power constraints, demonstrating significant performance gains over heuristic methods.

Contribution

It introduces a detailed optimization solution for sum rate maximization under per-antenna power constraints in multigroup multicast systems, including practical channel models and array configurations.

Findings

Proposed algorithm outperforms heuristic solutions in sum rate.

Effective in Rayleigh fading and line-of-sight conditions.

Sensitivity analysis highlights impact of user angular separation.

Abstract

A multi-antenna transmitter that conveys independent sets of common data to distinct groups of users is herein considered, a model known as physical layer multicasting to multiple co-channel groups. In the recently proposed context of per-antenna power constrained multigroup multicasting, the present work focuses on a novel system design that aims at maximizing the total achievable throughput. Towards increasing the system sum rate, the available power resources need to be allocated to well conditioned groups of users. A detailed solution to tackle the elaborate sum rate maximization multigroup multicast problem under per-antenna power constraints is therefore derived. Numerical results are presented to quantify the gains of the proposed algorithm over heuristic solutions. Besides Rayleigh faded channels, the solution is also applied to uniform linear array transmitters operating in the far field, where line-ofsight conditions are realized. In this setting, a sensitivity analysis with respect to the angular separation of co-group users is included. Finally, a simple scenario providing important intuitions for the sum rate maximizing multigroup multicast solutions is elaborated.