Dual-functional Cellular and Radar Transmission: Beyond Coexistence

We propose waveform design for a dual-functional multi-input-multi-output (MIMO) system, which carries out both radar target detection and multi-user communications using a single hardware platform. By enforcing both a constant modulus (CM) constraint and a similarity constraint with respect to referenced radar signals, we aim to minimize the downlink multiuser interference. Unlike conventional approaches which obtain suboptimal solutions to the generally NP-hard CM optimization problems involved, we propose a branch-and-bound method to efficiently find the global minimizer of the problem. Simulations show that the proposed algorithm significantly outperforms the state-of-art by achieving a favorable trade-off between radar and communication performance.