Estimating the target DOA, range and velocity using subspace methods in a MIMO OFDM DFRC system

Abstract

Dual-function Radar communication (DFRC) systems implement Radar detection and communication using the same hardware simultaneously. Significant attention has been paid to a multiple-input multiple-output DFRC system based on orthogonal frequency division multiplexing (OFDM). So far, the directions of arrival of the targets have been well estimated using subspace methods. In this paper, the ranges and/or velocities are estimated using the subspace methods. To this end, the Radar waveform must be based on the data symbols that are replicated over a few sub-carriers and/or during a few OFDM symbols. To avoid data replication, the target ranges and velocities can be estimated based on a least-squares (LS) or total LS method. After giving a few practical considerations, simulation results show that the proposed approaches outperform the existing ones based on the Fourier transform and/or Lasso algorithm. The performance of the proposed approaches is compared with the Cramer–Rao bound. Moreover, we show how the performance of the DFRC system (in terms of the accuracy of the estimated target parameters and data rate) evolves when modifying the system parameters, such as the number of sub-carriers and the number of OFDM symbols.