OFDM-DFRC Waveform Design Based on Mutual Information in Presence of Doppler

This paper extends the design of a mutual information (MI)-optimal orthogonal frequency-division multiplexing (OFDM) waveform for dual-function radar-communication (DFRC) systems to scenarios with multiple blocks (or sweeps) and narrowband Doppler. The waveform is intended to refine the estimation of a pre-detected range-extended target using prior knowledge of its second-order statistics while transmitting information. As a first result, the target’s estimation performance and the MI-based objective function prove to be Doppler-independent. In addition, the waveform design reduces to that previously described for a single block without Doppler, provided a well-designed cyclic prefix is appended to the OFDM waveform. In that case, an efficient implementation is described for the radar receiver. Numerical results illustrate the benefits of the optimized waveform compared to an equal-power allocation and show that small errors in Doppler at pre-detection can be tolerated.