Research On The Key Technologies Of Ultra Wideband Wireless Security Detection System

UWB technology has high signal gain,fast processing speed,strong anti-jamming ability and other advantages.It can realize high precision target positioning and real-time imaging.So this technology has aroused widespread concern in the field of wireless security detection.With the widening detection range,increasing complexity of detection objects and increasing precision of detection,the performances of UWB wireless security detection system,such as measurement accuracy,real-time processing capability and environmental adaptability,need to be further improved.To solve the problems above,this paper improves the existing methods,enhances the system's environmental adaptability,and achieves better detection results in the actual scene.The main contributions of this article are as follows:1.Aimed at the shortcomings of the positioning part in the existing UWB wireless security detection system,such as single application environment,low security and limited physical measurement,an improved real-time 3D UWB localization method for moving targets is proposed.This method optimizes the three-dimensional localization algorithm based on TDOA and achieves high positioning accuracy with a small number of detectors.Adaptive TOA time delay estimation method is designed,which can meet different requirements of environment and design.this method compromises system complexity and positioning accuracy,achieves real-time positioning in a short time and has strong environmental adaptability.2.Aiming at the deterioration of the imaging part in the existing UWB wireless security detection system in the case of the irregularity of the incident surface,an improved method of generating and reconstructing the microwave hologram is proposed.Aiming at generating the microwave hologram,The three-stage propagation structure is constructed by solving the incident point,and the influence of the unevenness of the incident surface is evaluated by the construction of the three-stage propagation structure.Finally,the phase-screen estimation is used to estimate changes of amplitude and phase when the incident wave passes through the rugged incident plane.In order to reconstruct the hologram of the hologram,the phase compensation method and the hierarchical reconstruction method are used to obtain the microwave image,the calculation amount is small and the imaging accuracy is high.3.Combined with the method proposed in this paper,the UWB wireless security detection system is designed and implemented.The standard deviation of positioning is less than 1 meter in a large cube room with side length of 150 meters,it has a very high positioning accuracy.This system can also adapt to the uneven incident surface,overcome the shortcomings of existing algorithms,and achieve goodimaging results.As the results show,the system has good real-time performance,high positioning and imaging precision,and strong practical value and application prospect.