Uplink detection and BER performance for wireless communication systems with ambient backscatter and multiple receiving antennas

Ambient backscatter is a new communication technology that utilizes ambient radio frequency signals to enable battery-free devices to communicate with each other. In this paper, we study the problem of signal detection and bit error rate (BER) performance for this novel communication system that utilizes ambient backscatter and multiple receiving antennas. Specifically, we first build up the theoretical system model and then propose a maximum likelihood detection method. We also obtain the optimal closed-form detection threshold and the corresponding BER expression. It is found that increasing the number of the receiving antennas can bring about larger BER gains at low SNR, while little gains in high SNR. Finally, simulation results are provided to corroborate our theoretical analysis.