Detections for Ambient Backscatter Communications Systems With Dynamic Sources

In this paper, signal detection in ambient backscatter communication (AmBC) with dynamic sources is investigated. Dynamic ambient radio frequency sources are the sources which transmit their signals randomly. The states of the dynamic source include the on-state and off-state. In the off-state, dynamic sources do not transmit any signal and the backscatter device cannot backscatter any signal accordingly. The received signals may contain only pure noises. Thus, it brings new challenges to the signal detection. We develop detection methods with/without truncating received signals for AmBC under both dynamic complex Gaussian source signals and dynamic M-ary phase-shift keying (M-PSK) source signals with on-off keying. To make detection simple and tractable for the dynamic M-PSK at the receiver, Manchester code is applied. Simulation results show it is necessary to truncate part of the signal in detections in the high signal-to-noise ratio region unless the received signals contain few pure noise samples, in order to reduce the bit-error-rate of backscatter signals.