Impact of Nodes Mobility and Imperfect SIC on the Outage Performance of Multi-Tag Ambient Backscatter Systems Over Nakagami- <i>m</i> Fading Channels

This paper investigates the joint impact of nodes mobility and imperfect successive interference cancellation (SIC) on the performance of a multi-tag ambient backscatter communication (AmBC) system over Nakagami-mfading channels. Specifically, the system comprises a mobile ambient RF source,Kenergy harvesting enabled mobile passive tags, and a moving reader. All wireless links are subject to time-selective fading, modeled using a first-order autoregressive process. To enhance the performance, a tag selection policy is employed to select the best tag amongKcandidates, while the reader utilizes both perfect SIC (pSIC) and imperfect SIC (ipSIC) techniques. Under this realistic setting, we derive closed-form analytical expressions for the outage probability (OP) and ergodic capacity in both pSIC and ipSIC scenarios. Furthermore, we present asymptotic OP analyses in the high signal-to-noise ratio (SNR) regime to extract key insights into the system’s diversity order. We also present the system throughput analysis under both pSIC and ipSIC cases. Several practical scenarios are also examined, including static nodes configuration and large time-varying errors, to characterize their effects on the system performance. We also analyze the influence of various system and channel parameters, nodes mobility, and the SIC control parameter on the system performance. Finally, simulation results are provided to validate the accuracy of the derived analytical expressions.