Positioning Receiver Using Full-duplex Relay

With the development of the smart devices, location-based service information is becoming more and more important. The location information of the users is becoming a treasure for business. But the current wireless network positioning methods, mostly use the signals sent by the target subjects to locate them. This kind of techniques have been studied in the past decades. However, few researches focus on the receiver positioning,which is because it is very difficult to locate the the receiver when the only useful information is the signals transmitted by the transmitter. This greatly limits the development of positioning technology. To satisfy this positioning requirement, this paper proposes the receiver positioning, i.e., positioning receiver using full-dulpex amplify-and-forward relay as the first trail.The proposed receiver positioning techniques in this paper create a transmitter- relay- receiver link using characteristics of the full-duplex relay. Then, the received signal to noise ratio(SNR) at the receiver changes, which will trigger the closed loop power control(CLPC) between transmitter and receiver. This will further lead to the adjustment of the transmission power at the transmitter, and then satisfy the target SNR at the receiver. The adjustment of the transmission power contains the location information of the receiver,which can be detected by the relay. Based on the measurement of the relay, the full-duplex relay, i.e., the anchor, can estimate the location of the receiver.Firstly, in non-light-of-sight(NLOS) environment, this paper proposes two receiver positioning methods based on full-duplex relay, i.e., receiver positioning based on the channel gain estimation by the full-duplex relay, and receiver positioning based on timedifference-of-arrival(TDOA) estimation by the full-duplex relay. Then this paper analyzes the two proposed positioning methods, and the performance of them. Finally, the parameters of the two proposed methods are given by simulations.Secondly, in light-of-sight(LOS) environment, this paper proposes another receiver positioning technique based on full-duplex relay, where the transmission antenna is equipped with antenna arrays. Based on this, this paper proposes the receiver positioning method based on angle estimation by the full-duplex relay, which requires multiple anchors to alternately act as full-duplex relay. Then, in order to simplify the process of the receiver positioning, this paper proposes another method jointly considering angle estimation and TDOA estimation to locate the receiver. Finally, the parameters of the two proposed methods are given by simulations.Finally, this paper concludes the proposed receiver positioning techniques, and further discusses the future research works.