Towards Dual-functional Radar-Communication Systems: Optimal Waveform Design

TL;DR

This paper develops optimal waveform design strategies for dual-functional MIMO radar-communication systems, balancing radar detection and communication performance with efficient algorithms and theoretical guarantees.

Contribution

It introduces globally optimal solutions for beampattern design, a flexible weighted optimization framework, and a branch-and-bound algorithm for constant modulus waveforms, advancing dual-functional RadCom system design.

Findings

Closed-form solutions for omnidirectional and directional beampatterns.

A low-complexity algorithm for trade-off optimization.

Globally optimal constant modulus waveform design with complexity analysis.

Abstract

We focus on a dual-functional multi-input-multi-output (MIMO) radar-communication (RadCom) system, where a single transmitter communicates with downlink cellular users and detects radar targets simultaneously. Several design criteria are considered for minimizing the downlink multi-user interference. First, we consider both the omnidirectional and directional beampattern design problems, where the closed-form globally optimal solutions are obtained. Based on these waveforms, we further consider a weighted optimization to enable a flexible trade-off between radar and communications performance and introduce a low-complexity algorithm. The computational costs of the above three designs are shown to be similar to the conventional zero-forcing (ZF) precoding. Moreover, to address the more practical constant modulus waveform design problem, we propose a branch-and-bound algorithm that obtains a globally optimal solution and derive its worst-case complexity as a function of the maximum iteration number. Finally, we assess the effectiveness of the proposed waveform design approaches by numerical results.