Detection with Uncertainty in Target Direction for Dual Functional Radar and Communication Systems

TL;DR

This paper proposes an iterative optimization method for dual functional radar and communication systems that effectively manages target direction uncertainty, maximizing SCNR while satisfying communication QoS constraints.

Contribution

It introduces a novel alternating optimization approach with penalty and Dinkelbach methods to handle nonconvex problems in uncertain target direction scenarios.

Findings

Algorithm converges within 3 iterations.

SCNR performance remains stable across different target directions.

Proposed method outperforms existing approaches in effectiveness.

Abstract

Dual functional radar and communication (DFRC) systems are a viable approach to extend the services of future communication systems. Most studies designing DFRC systems assume that the target direction is known. In our paper, we address a critical scenario where this information is not exactly known. For such a system, a signal-to-clutter-plus-noise ratio (SCNR) maximization problem is formulated. Quality-of-service constraints for communication users (CUs) are also incorporated as constraints on their received signal-to-interference-plus-noise ratios (SINRs). To tackle the nonconvexity, an iterative alternating optimization approach is developed where, at each iteration, the optimization is alternatively performed with respect to transmit and receive beamformers. Specifically, a penalty-based approach is used to obtain an efficient sub-optimal solution for the resulting subproblem with regard to transmit beamformers. Next, a globally optimal solution is obtained for receive beamformers with the help of the Dinkleback approach. The convergence of the proposed algorithm is also proved by proving the nondecreasing nature of the objective function with iterations. The numerical results illustrate the effectiveness of the proposed approach. Specifically, it is observed that the proposed algorithm converges within almost 3 iterations, and the SCNR performance is almost unchanged with the number of possible target directions.