CSI-Based NOMA for integrated sensing and communication

Integrated sensing and communication (ISAC) is a key enabler of beyond fifth-generation networks and a multitude of futuristic applications. However, the coexistence, scheduling and spectrum scarcity issues due to additional sensing signals are valid concerns. A communicating device requiring sensing can use its communication signal for sensing. However, a non-communicating device requiring sensing will need to transmit additional sensing signals, increasing traffic in the network. Thus, in this letter, a novel ISAC with iterative channel estimation (ISAC-ICE) method is proposed to provide spectral efficiency while maintaining sensing and communication performance. The proposed method attains this by enabling the multi-channel estimation from received non-orthogonal communication and sensing signals for uplink transmission. The simulation results and complexity analysis demonstrate that the proposed method enables non-orthogonal multiple accessing (NOMA) of ISAC with a linearithmic complexity.