Performance Analysis of Integrated Sensing and Communication by Non-Orthogonal Multiplexing

We investigate the performance of integrated sensing and communication systems in the manner of non-orthogonal multiplexing (NOM-ISAC), which is more resource-efficient compared to reserving orthogonal time or frequency resources for sensing and communications signals. By considering the scenario of sensing-aided channel estimation in the downlink ISAC system, we give the information rates for communication signals and sensing echoes from an information-theoretic perspective. Consequently, a general expression of the joint rate regions under the power allocation condition is derived for sensing target and multiple communication user scenarios. We further investigate the performance bounds for non-ideal channel estimation in sensing-assisted communication. Experimental results show the performance region that NOM-ISAC can be achieved in accordance with the theory.