Cut to the Chase: A Fast-Decoding Scheme for Symbiotic Backscatter Multi-User NOMA Systems

This paper proposes a fast-decoding scheme based on the successive interference cancellation (SIC) framework for symbiotic backscatter multi-user non-orthogonal multiple access (NOMA) systems, which aims to decode the desired primary NOMA signal and the backscatter signal for the end-users in an efficient manner. Under the proposed decoding framework, we derive the symbiotic constraints on the decoding thresholds and power allocation ratios to guarantee the minimum decoding times and a shorter decoding times than the conventional solutions, respectively. Moreover, we derive the corresponding successful fast-decoding probability at high transmit signal-to-noise ratio (SNR). By keeping the primary channel statistics or the decoding threshold for the backscatter signal sufficiently low, our results demonstrate that the decoding speed of the proposed decoding scheme is most certainly faster than the conventional ones.