Waveform Design for MIMO-OFDM Based Dual-functional Radar and Communication Systems

Dual-functional radar-communications (DFRC) technique has attracted substantial attention. The radiation power of radar system is usually very high, and it is usually not afforded by the communication receiver. To solve this problem, this paper proposes a waveform design scheme for the DFRC system based on multiple-input and multiple-output (MIMO) and orthogonal frequency division multiplexing (OFDM) techniques. In the proposed scheme, a convex optimization problem is firstly formulated to derive the optimal covariance matrix of the transmit signals. Based on the optimal covariance matrix, a subcarrier and power allocation scheme is proposed to meet the power requirement of the DFRC system. Simulation results show that compared with the traditional OFDM based DFRC scheme, the proposed scheme can achieve almost the same target detection performance, and a much higher achievable data rate. Meanwhile, the proposed scheme can guarantee that the power radiated in the communication direction satisfies the communication power requirement.