Joint Radar and Multicast-Unicast Communication: A NOMA Aided Framework

TL;DR

This paper introduces a NOMA-based joint radar and communication framework that efficiently shares spectrum for radar detection and multicast-unicast data transmission, optimizing beamformers for enhanced performance.

Contribution

It proposes a novel NOMA-aided dual-functional radar-communication system with a joint beamforming optimization and a penalty-based algorithm for improved spectrum sharing.

Findings

Significant performance gains over benchmark schemes.

Effective beamformer optimization for rate and radar accuracy.

Successful integration of radar and communication functions in spectrum.

Abstract

The novel concept of non-orthogonal multiple access (NOMA) aided joint radar and multicast-unicast communication (Rad-MU-Com) is investigated. Employing the same spectrum resource, a multi-input-multi-output (MIMO) dual-functional radar-communication (DFRC) base station detects the radar-centric user (R-user), while transmitting mixed multicast-unicast messages both to the R-user and to the communication-centric user (C-user). In particular, the multicast information is intended for both the R- and C-users, whereas the unicast information is only intended for the C-user. More explicitly, NOMA is employed to facilitate this double spectrum sharing, where the multicast and unicast signals are superimposed in the power domain and the superimposed communication signals are also exploited as radar probing waveforms. A beamformer-based NOMA-aided joint Rad-MU-Com framework is proposed for the system having a single R-user and a single C-user. Based on this framework, the unicast rate maximization problem is formulated by optimizing the beamformers employed, while satisfying the rate requirement of multicast and the predefined accuracy of the radar beam pattern. The resultant non-convex optimization problem is solved by a penalty-based iterative algorithm to find a high-quality near-optimal solution. Finally, our numerical results reveal that significant performance gains can be achieved by the proposed scheme over the benchmark schemes.