A Novel ISaC Approach for Uplink NOMA System

This letter proposes an integrated sensing and communication (ISaC) solution in uplink non-orthogonal multiple access (NOMA) systems. Specifically, we present a signalling approach in which, to enforce mutual interference cancellation between the radar and communication signals, the radar symbols are alternately reversed in consecutive periods while the data symbols are phase-rotated. To realise this approach, we propose a receiver structure that combines elements of zero forcing (ZF) and maximum likelihood (ML) for pair-wise detection of the targets and data. Comparing the bit error rate (BER) performance, the achievable sum rate (ASR), and the accuracy of radar channel estimation (RCE), the results show that the proposed approach has superior performance regardless of the power of the radar signal due to the perfect elimination of mutual interference between the communication and radar systems.