Joint Channel Estimation, Interference Cancellation, and Data Detection for Ambient Backscatter Communications

This paper deals with the problem of joint channel estimation, interference suppression, and data detection for ambient backscatter communications, where a small device modulates its information by reflecting the radio-frequency signals emitted by a legacy orthogonal frequency-division multiplexing access point (AP). In particular, we study the case when the intended recipient of the backscatter information is integrated into the AP. The proposed technique, which relies on the space alternating generalized expectation maximization algorithm, detects the backscatter symbols iteratively, while the channel parameters are updated in parallel, leading to a receiver that also incorporates interference cancellation capabilities. Its performance is evaluated through Monte Carlo simulations.