Joint Transmit Beamforming and Receive Filters Design for Coordinated Two-Cell Interfering Dual-Functional Radar-Communication Networks

Dual-functional radar-communication (DFRC) has been viewed as a promising component in future networks. The considered two-cell interfering DFRC network involves two multi-antenna base stations (BSs), and each BS serves multiple single-antenna users and receives echo signals to detect the target. An optimization framework for the joint transmit beamforming and receive filters design of a coordinated two-cell network is formulated. Specifically, we minimize the transmit power at two BSs subject to the signal-to-interference-and-noise ratio constraints. To solve the formulated non-convex optimization problem, an alternating optimization-based method is invoked. For the transmit beamforming design, a locally optimal successive inner convex approximation (SICA)-based method with fast convergence is firstly proposed. To further reduce the computational complexity, we also provide three zero-forcing (ZF)-based sub-optimal methods for practical consideration. For the receive filters design, a power iterations-based method is proposed. Simulation results validate the effectiveness of our proposed SICA-based locally optimal and ZF-based sub-optimal schemes.

I. Introduction

Modern radar systems which originated from the first half of the twentieth century have been deployed worldwide and occupy the sub-6 GHz band for weather observation and military security, etc [1]. On the other hand, a growing number of communication systems are working on the same band and are envisioned to achieve harmonious coexistence with radar in the forthcoming 6G. Therefore, the issue of radar and communication spectrum sharing (RCSS) [2] has attracted widespread interest from both industry and the research community. Lately, RCSS can be categorized into two main research directions, i.e., radar-communication coexistence (RCC) [3] and dual-functional radar-communication (DFRC) [4], [5]. In contrast to RCC which includes individual radar and communication systems, both remote sensing and wireless communication can be simultaneously performed in DFRC systems. More introductions and related works about RCSS and DFRC can be found in [2]–[5] and references therein.