Joint Radar and Communications System with Channel Uncertainty

In this paper, we consider an in-band joint radar and communications (JRAC) system to increase spectrum efficiency. One of the possible approaches to this system is to utilize spectrum sensing with energy detection at the radar system to sense for the absence of communication signal from the base station. With this information, the JRAC system can mitigate the interference of radar to the operation of the base station. Thus, we propose a spectrum-sensing-aided JRAC system, evaluated under two performance metrics the radar mutual information (MI) and communication data rate (CDR). Through simulations, this paper will derive optimal conditions to achieve the greatest performance for both MI and CDR, under the trade-off performance of the two systems.