Power split optimization for joint communication and sensing in MIMO OFDM systems

This letter investigates joint sensing and communication (JSAC) in multi-antenna orthogonal frequency division multiplexing (OFDM) systems by optimizing the transmit power allocation between communication and sensing functions. We formulate an adaptive optimization problem to determine the power split that maximizes communication performance while satisfying a sensing accuracy constraint defined in terms of range error bound (REB), i.e., the square root of the Cramèr-Rao lower bound (CRLB) on the range estimate. To solve this, we propose a two-step approach: an offline design phase followed by an online refinement, leveraging a closed-form solution for adaptive power allocation. Numerical results demonstrate that the proposed method substantially enhances communication quality compared to fixed power splitting, without degrading sensing performance.