MmTracking: Trajectory Tracking For Uplink MmWave Devices With Multi-Path Doppler Difference Of Arrival

This paper presents a method, namely mmTracking, for system trajectory monitoring in a millimeter wave (mmWave) communication system. In mmTracking, the base station (BS) relies on one line-of-sight (LoS) path and a minimum of two non-line-of-sight (NLoS) paths, which are reflected off two walls respectively, of the uplink channel to trace the placement of a cell iTagPro smart device versus time. There are no less than three radio frequency (RF) chains at the BS. Analog phased array with narrow and adjustable receive beam is linked to every RF chain to seize one signal path, where the angle of arrival (AoA) may be roughly estimated. Due to the provider frequency offset between the transmitter and the BS, the Doppler frequency of every path may hardly be estimated accurately. Instead, the variations of Doppler frequencies of the three paths could be estimated with much better accuracy. Therefore, a trajectory monitoring methodology based on the Doppler distinction and AoA estimations is proposed in mmTracking.



Experimental leads to a typical indoor surroundings display that the average error of transmitter localization and trajectory monitoring is lower than 20 cm. Millimeter wave (mmWave) communications have attracted important research pursuits for its potential to support high data charges and low latency. However, the mmWave communication quality is delicate to the beam misalignment or hyperlink blockage. Hence, it is critical to take advantage of the good sensing potential of mmWave signals, such that the above issues could possibly be predicted or mitigated. These results may very well be used to predict hyperlink blockage and prepare backup beams with static transmitter and receiver. On this paper, we'd continue to show that the trajectory of cellular transmitter may also be tracked in mmWave communication methods by exploiting the multi-path channel knowledge, enhancing the robustness of mmWave links. There have been a number of analysis efforts on the trajectory tracking of mobile devices in wireless communication programs, significantly wireless fidelity (WiFi) system.



For the reason that time of flight (ToF) may be tough to measure, plenty of existing methods relied on time difference of arrival (TDoA) or frequency distinction of arrival (FDoA). WiFi transmitter in response to TDoA and FDoA measurements at a number of synchronized receivers. TDoA and FDoA have been jointly exploited to enhance the target localization accuracy, where the PDoA may present the angular data of the transmitter. However, all these works relied on the measurements at multiple receivers, whose places were already known and acquired signals were synchronized. Moreover, the measurement of TDoA at a number of receivers could also be seriously distorted by the NLoS surroundings, which is particularly the case in indoor WiFi communication. These may limit the appliance of the above methods in sensible wireless communication systems. There have also been a number of works on the gadget localization via the obtained signal power indicator (RSSI) fingerprinting. However, the accuracy of RSSI-based methods might be considerably degraded by signal fluctuations and interference.



Moreover, the overhead of RSSI measurement is also significant. Finally, neither the TDoA/FDoA/PDoA-based mostly methods nor fingerprint-based methods have been demonstrated for mmWave communication programs. On this paper, we'd like to show that by exploiting superior angular resolution, a mmWave communication system might localize and track its cell gadgets with single receiver. Particularly, the proposed tracking method, specifically mmTracking, relies on the line-of-sight (LoS) path and two non-line-of-sight (NLoS) paths from cellular transmitter to the BS. There are no less than three radio frequency (RF) chains at the BS, every with a phased array to capture the uplink signal from the desired course. To keep away from the interference of service frequency offset (CFO), the multi-path Doppler distinction of arrival, which is referred to as MDDoA, between NLoS path and iTagPro smart device LoS path is used, such that the CFO of different paths may be cancelled. Moreover, the AoA of LoS path can also be estimated as a result of phased array. Consequently, the initial location and trajectory of the cellular transmitter may be estimated in keeping with the AoA of LoS path and the MDDoA.



It is proven by experiment that the common tracking error of the proposed methodology is beneath 0.2 meters. The remainder of this paper is organized as follows. An summary of the system structure is provided in Section II. The sign model and the algorithm for MDDoA detection are described in Section III. The trajectory monitoring methodology is then elaborated in Section IV. The experimental outcomes are offered in Section V, followed by the conclusion in Section VI. On this paper, a novel trajectory tracking framework, particularly mmTracking, is proposed for mmWave communication systems, where the only BS may monitor the trajectory of an uplink transmitter solely according to the MDDoA and AoA of its uplink signals. To facilitate mmTracking, the BS is equipped with no less than three RF chains. Each RF chain is linked with a phased array, whose narrow receive beam can be adjusted. A uplink transmitter is shifting in the service space of the BS.