Optimal Thresholds for Differential Energy Detection of Ambient Backscatter Communication

With wide application of RFID, backscatter communication has become a focus in academy and industry. Specially, ambient backscatter communication has attracted much attention due to its low energy consumption and low cost. In this paper, we study the signal detection of the ambient backscatter communication system and focus on the differential energy detection method. Specifically, we use the off-the-shelf differential encoding model to eliminate the necessity of channel state information (CSI). Differential energy detection method and ML detector are applied as well to make the detecting results more precise and to obtain better performance. Based on them, we improve the approximate threshold and propose optimal thresholds decision algorithm of signal detection, which is proved feasible and efficient. Corresponding BER expressions are derived to estimate the performance of the algorithm. Simulation results are then provided to corroborate the theoretical studies. It can be shown from the results that using two optimal thresholds will improve the performance of the system to some extent, it will also be more tolerant to longer transmitting distance, especially when the channel status are not good.