Trade-Off for Terahertz Beam Squint Enabled ISAC System

In this paper, we investigate a wideband terahertz massive multiple-input multiple-output (MIMO) integrated sensing and communications (ISAC) system, where the beam squint effect is considered, and develop a three-dimensional (3D) beamforming strategy based on the two-tier true-time-delay (TTD) architecture to maximize the achievable rate under the sensing coverage and resolution constraints. We reconstruct the optimization problem through the controllable 3D beam squint method and then derive the optimal configuration for the TTD and phase shifter parameters, facilitating the trade-off between the achievable rate and sensing coverage with adequate sensing resolution. Numerical simulations are conducted to verify the effectiveness of the proposed beamforming method and demonstrate the performance trade-off between the communication and sensing processes.