Power Allocation for Coexisting Multicarrier Radar and Communication Systems in Cluttered Environments

TL;DR

This paper develops power allocation strategies for coexisting multicarrier radar and communication systems in cluttered environments, optimizing radar SINR while respecting communication constraints.

Contribution

It introduces a novel joint and unilateral power optimization framework using quadratic transform and sequential convex programming techniques.

Findings

Joint design improves radar SINR significantly.

Unilateral design effectively supports secondary radar operation.

Proposed methods outperform subcarrier allocation approaches.

Abstract

In this paper, power allocation is examined for the coexistence of a radar and a communication system that employ multicarrier waveforms. We propose two designs for the considered spectrum sharing problem by maximizing the output signal-to-interference-plus-noise ratio (SINR) at the radar receiver while maintaining certain communication throughput and power constraints. The first is a joint design where the subchannel powers of both the radar and communication systems are jointly optimized. Since the resulting problem is highly nonconvex, we introduce a reformulation by combining the power variables of both systems into a single stacked variable, which allows us to bypass a conventional computationally intensive alternating optimization procedure. The resulting problem is then solved via a quadratic transform method along with a sequential convex programming (SCP) technique. The second is a unilateral design which optimizes the radar transmission power with fixed communication power. The unilateral design is suitable for cases where the communication system pre-exists while the radar occasionally joins the channel as a secondary user. The problem is solved by a Taylor expansion based iterative SCP procedure. Numerical results are presented to demonstrate the effectiveness of the proposed joint and unilateral designs in comparison with a subcarrier allocation based method.