Exploitation of Symmetrical Non-Convexity for Symbol-Level DFRC Signal Design

Constructive interference exploited by symbol-level (SL) signal processing is a promising solution for addressing the inherent interference problem in dual-functional radar-communication (DFRC) signal designs. This paper considers an SL-DFRC signal design problem which maximizes the radar performance under communication performance constraints. We exploit the symmetrical non-convexity property of the communication-independent radar sensing metric to develop low- complexity yet efficient algorithms. We first propose a radar-to- DFRC (R2DFRC) algorithm that relies on the non-convexity of the radar sensing metric to find a set of radar-only solutions. Based on these solutions, we further exploit the symmetrical property of the radar sensing metric to efficiently design the DFRC signal. Since the radar sensing metric is independent of the communication channel and data symbols, the set of radar-only solutions can be constructed offline, therefore reducing the computational complexity. We then develop an accelerated R2DFRC algorithm that further reduces the complexity. Finally, we demonstrate the superiority of the proposed algorithms compared to existing methods in terms of both radar sensing and communication performance as well as computational complexity.

I. Introduction

Dual-functional radar communication (DFRC) [1]–[3], also often referred to as integrated sensing and communication (ISAC), is an emerging technology envisioned as a critical component of future wireless networks, e.g., 6G networks. DFRC enables both radar sensing and communication function-alities while sharing the same spectrum and transmit waveform. Therefore, DFRC can substantially improve spectral efficiency and reduce system cost and power consumption.