Performance Analysis for Ambient Backscatter Communications With Hybrid Long-Short Packets

This paper studies the perfermance of an ambient backscatter communication (AmBackCom) network with hybrid long and short packets, where long packets are used for the cellular transmission while multiple Internet-of-Things (IoT) nodes take turns to backscatter short packets via backscatter communication (BackCom). Considering the energy causality constraint of each IoT node and the joint decoding error between BackCom and the cellular transmission, we derive the closed-form expressions of the block error rate (BLER) for each IoT node’s BackCom, as well as the upper and lower bounds of the outage probability for the cellular transmission. Simulation results verify the correctness of the derived expressions and show the impacts of key parameters on the BLER of BackCom and the outage performance of the cellular transmission. Specifically, there exists an optimal power reflection coefficient that minimizes the average BLER of all the IoT nodes and the average BLER decreases with the short-packet blocklength until it reaches a certain value. Besides, the outage probability of the cellular transmission is well bounded by the derived upper and lower bounds, which become tighter when the long-packet data bits increase.