Nhan Thanh Nguyen, Dr. Nir Shlezinger

In wideband integrated sensing and communications (ISAC) systems, conventional designs optimize dual-functional waveforms over the entire bandwidth. This approach significantly restricts beamforming flexibility and degrades communications performance under strict radar sensing constraints. This webinar presents a novel subcarrier allocation strategy to enhance the communications–sensing performance tradeoff in ISAC. The proposed method selectively assigns a subset of subcarriers for radar sensing while enabling communication across the full bandwidth. This ensures dedicated subcarriers for communications without radar interference, while maintaining sensing accuracy. To realize this idea, we formulate a sum rate maximization problem and propose a three-step solution with efficient initialization methods to reduce computational complexity and improve convergence. Our simulation results show that the proposed scheme achieves a 70% improvement in sum rate while maintaining the same radar beampattern accuracy and requiring fewer RF chains compared to conventional wideband ISAC designs.