Signal detection and BER analysis for RF-powered devices utilizing ambient backscatter

Devices that harvest power from radio-frequency (RF) signals are generally referred to as RF-powered devices. One emerging technology that enables RF-powered devices to communicate with others is ambient backscatter. In this paper, we study the problem of signal detection and analyse the uplink bit error rate (BER) performance for RF-powered devices utilizing ambient backscatter. Specifically, we build up a theoretical model for a communication system which consists of one reader and one tag. The tag employs ambient backscatter to communicate with the reader. Next we design an optimal detector which can minimize the BER and find the closed-form expression for the detection threshold. Noting that the optimal detector cannot result in equal BERs in detect “0” or “1”, therefore we design another detector that can achieve the same error probability in detecting “0” with that in detecting “1”. Moreover, we analyse the BER performance for both detectors. Finally, simulations are provided to corroborate the proposed studies.