| Due to the sudden nature of natural disasters,it is difficult to prevent,so it is necessary to search and rescue the trapped people immediately after the disaster,and the positioning of the trapped people after the disaster is a necessary condition for post-disaster rescue.Most of the current positioning technologies are multi-base station positioning,which has high requirements on the location of base stations and the time synchronization between base stations.However,in a post-disaster environment,the deployment of multiple base stations and the time synchronization calibration between base stations will waste valuable time.The rescue time cannot meet the needs of rapid rescue.Therefore,it is necessary to study the single-base station positioning technology that does not require time synchronization to realize the positioning of trapped people as soon as possible.As the key technology of 5G system,large-scale antenna technology has better angle and delay measurement capabilities,making single-base station positioning possible,and providing a foundation for single-base station positioning technology in post-disaster environments.Based on large-scale antenna arrays,this paper studies a single base station positioning method for complex post-disaster environments.The main contents of this paper are as follows:1.Aiming at the large amount of calculation of the angle estimation algorithm in large-scale antenna arrays,an improved algorithm based on the Propagator Method(PM)is proposed.On the basis of ESPRIT algorithm,an improved algorithm is proposed.The algorithm directly constructs the rotation invariant matrix by the propagation operator,which avoids the eigenvalue decomposition of the covariance matrix of the received data,and does not need to search for the peak value of the spectral function,which reduces the computational complexity.When the sub-array is degenerated,the sub-array with overlapping parts is divided,and the noise is averaged during the calculation process,which improves the performance of the algorithm in the case of low signal-to-noise ratio.2.Aiming at the near-field effect caused by the increase of the size of the large-scale antenna array,a high-order cumulant parameter estimation algorithm based on the propagation operator is proposed,which can realize the parameter estimation in the near-field and can calculate the near-field at the same time.The angle of arrival of the signal from the source and the distance between the source and the antenna array.The method reduces the influence of noise on parameter estimation through high-order cumulants,and uses propagation operators to reduce computational complexity,which provides support for single-base station positioning technology in largescale antennas.3.Aiming at the positioning problem in the non-line-of-sight environment,a single base station positioning method based on the scatterer model is proposed.The method is based on the angle and time delay measurement of large-scale antennas for multipath signals,and a nonlinear optimization problem is constructed through the scatterer model.Single base station positioning in non-line-of-sight environment is achieved by measuring the angle and delay of multipath signals with largescale antennas. |
