Self-interference suppression techniques in integrated sensing and communication systems: an overview

Exponential increases have been observed in the number of wireless terminals, leading to highly congested spectrum resources and increasing mutual interference between terminals, which causes the corresponding performance to approach the theoretical limit. Integrated sensing and communication (ISAC) systems have gained popularity as a way to make the best use of the limited radio frequency (RF) spectrum that is currently accessible. Since ISAC systems reuse the same resources, such as frequency of operation, waveforms, and hardware, they present a number of design issues. Innovative strategies are required to ensure the optimal functioning of both subsystems. The primary aims of ISAC are potential hardware gains and platform synergies. Although ISAC improves communication and sensing capacity considerably, mutual interference between sensing and communication always limits the performance of the integrated system. As a result, interference cancellation appears to be an important avenue for ISAC, gaining increasing interest. This chapter highlights some key techniques proposed in the literature to overcome the self-interference issue in ISAC systems. Moreover, this chapter also highlights some possible future research directions that need attention in order to minimize the self-interference challenge in ISAC systems.