Joint Subcarrier Assignment and Power Allocation for OFDM-Based Integrated Sensing and Communication

In this letter, we consider both detection performance and estimation performance, proposing a joint sub-carrier assignment and power allocation (JSAPA) algorithm for orthogonal frequency division multiplexing (OFDM)-based integrated sensing and communication (ISAC) systems. By jointly optimizing the OFDM subcarrier assignment, the sensing power allocation, and the communication power allocation, we aim to maximize the communication data rate of the ISAC system, subject to the constraints of the peak-to-sidelobe ratio of the ambiguity function, the Cramér-Rao lower bound of delay estimation, and the power budget of the ISAC base station. Due to the non-convexity of the optimization problem, we decompose the original problem into two subproblems, which can separate the subcarrier assignment from the power allocation and eliminate the binary nonconvex constraint. Sparse-encouraging log-sum function approximation and majorization-minimization methods are used to solve the subproblems. Simulation results show that by providing great design flexibility, the proposed JSAPA algorithm can effectively improve the communication performance subject to the sensing performance as well as other constraints.