Research On UAV Positioning And Tracking Based On Beamforming Technology

With the booming of the UAV industry,especially after the participation of major e-commerce giants,the market size has increased exponentially,which makes the research on UAV positioning technology is of great practical significance and market value.This thesis mainly studies the positioning and tracking of UAV based on multi-antenna technology.Firstly,this paper investigates the background of the UAV market,antenna array for DOA estimation,antenna array and joint estimation,introduces the basic principle of smart antenna and existing wireless positioning in detail,and states the influence factors and evaluation criteria of positioning.Finally,the details of the main contributions of this article are explained as follows:(1)Proposing a joint estimation algorithm for two-dimensional DOA and time delay.Basing on the special structure of the new L-shaped antenna,the whole problem is transformed into two sub-problems: One for joint estimation of 1D DOA and time delay;Another for 2D angle estimation and angle matching algorithm.Problem 1 can be processed by a conventional algorithm.Problem 2 can be processed by a self-matching 2D DOA estimation algorithm based on cross-correlation matrix in a new L-shaped antenna by improving the ccm-ESPRIT algorithm,which not only reduces the false matching rate but also effectively avoids small angle sensitive issues,and the computational efficiency has also improved.Finally,a simulation demonstration was carried out;(2)Presenting a 3D positioning algorithm for UAV based on single base station.First,the multipath decoherence is studied,and the proposed algorithm above is further optimized by combining WSMF.Then,the fast and effective 2D DOA estimation of the target under multipath is realized,with the precise ranging of TOF finally realized the UAV Positioning.Although,the algorithm proposed has estimation accuracy equivalent to the existing algorithm,it greatly saved computational overhead.Finally,a simulation demonstration was carried out;(3)Raising a tracking strategy based on single base station.The angular division of the full airspace by beamforming is performed.Set the active set and candidate set,and design the hierarchical codebook to perform spectral peak search on the search domain.Relying on the first-level confirmation,the second-level fine method greatly saves the scanning time and improves the positioning accuracy.This thesis also aims at interval period problem of the scanning involved in the tracking process,and draws on the congestion control theory in the TCP protocol to make a progressive update mechanism for the search domain interval period,which perfectly balances the positioning complexity and the loss probability.