Limited Feedforward Waveform Design for OFDM Dual-Functional Radar-Communications

We consider the problem of time-frequency waveform design for an OFDM dual-functional radar-communications (DFRC) system that communicates with receiver while simultaneously estimating target parameters using backscattered signals. In particular, goal is to achieve a favorable performance trade-off between radar and communications by optimizing subcarrier powers in region interest. First, we focus on radar-optimal minimize Cramér-Rao bound (CRB) delay-Doppler estimation subject integrated side-lobe level (ISL) constraint ambiguity domain. Next, investigate DFRC optimize rate under similarity constraint. Unlike traditional systems which ignore feedforward overhead conveying transmit control information, assume existence low-rate channel transceiver receiver. Relying covariance matrix linear minimum mean-squared-error (LMMSE) estimates input symbols, derive novel metric as function both forwarded propose joint signaling optimization (JWCSO) strategy leverages sparsity rank-one structure waveforms within alternating maximization framework. Simulation results show proposed JWCSO approach provides significant gains over conventional feedforward-agnostic achieves near-optimal performance, reaching boundary CRB-capacity only limited information.