Joint Receiver Design for Integrated Sensing and Communications: Is SIC Optimal?

In this letter, we investigate the joint receiver design for integrated sensing and communication (ISAC) systems, where the communication signal and the target echo signal are simultaneously received and processed to achieve a balanced performance between both functionalities. In particular, we proposed two design schemes to solve the joint sensing and communication problem of receive signal processing. The first is based on maximum likelihood (ML) detection and successive interference cancellation (SIC), and the other formulates a minimum mean squared error (MMSE) estimator for target estimation. We show that with the structural information of the communication signal taken into account, the second approach outperforms the SIC method. Numerical results are provided to validate the effectiveness of the proposed optimal designs.