Efficient packet detection for D2D power-saving communications over mobile wireless cellular networks

Device-to-device (D2D) communication is an emerging technique that can reduce device transmission power and enhance cellular capacity, which allows direct communication between two mobile devices. Amount of small packets may exchange between devices in burst mode transmission with the constraint of low overhead and low complexity for energy efficient processing. One of the major challenges for outband D2D communications is packet-based synchronization. Due to channel fading or path loss, the received signal-to-noise ratio (SNR) is time-varying with a wide range, resulting in selection of an appropriate threshold for well balancing both missed detection probability (MDP) and false alarm probability (FAP) inconveniently. We propose an efficient packet detection scheme with easily threshold setting based on WiFi interface. By employing a novel normalized factor as a denominator in autocorrelation based timing metric, both theoretical analysis and the conducted simulation results show that the gap between MDP and FAP is enlarged, facilitating threshold selection for a wide range of SNR in additive white Gaussian noise (AWGN) channel. More importantly, the threshold setting in multi-path Rayleigh fading channels can be determined according to the AWGN case straightforwardly.