Joint Target Estimation, Channel Estimation, and Symbol Detection for ISAC Systems

Interference mitigation for integrated sensing and communication (ISAC) is important for guaranteeing both communication and sensing performances. To suppress the interference between the downlink sensing and the uplink communication, it is necessary to judiciously design the receiver at the base station (BS). In this paper, we develop an ISAC receiver design by formulating a joint target estimation, channel estimation, and symbol detection (JEED) problem based on the maximum a posteriori (MAP) criterion, which turns out to be a mixed-integer problem. To solve this difficult problem, we develop an alternating direction method of multipliers (ADMM)-based algorithm, which has fast convergence and only involves closed-form expression calculations in each iteration. Simulation results show that our proposed algorithm can achieve excellent performances in terms of communication bit error rate (BER) and target sensing accuracy.