| Along with the rapid development of the communication technology, the study of the cellular wireless location technology is constantly improved. Our country, as the burgeoning mobile market, owns the most users and the highest mobile operation earnings. The location services will be one of the most popular operations. Therefore, the development prospect of the location services will be extensive.In this thesis, some key technologies of cellular terrestrial mobile location technology are focused on. Three kinds of algorithms consist of parameters estimation, error mitigation and mobile position estimation are investigated in detail. At the same time, according to the characteristic of fixed geography entironment around the base station, the algorithms mentioned above are improved based on the prior position information. The main contents of this paper are as follows:1. In order to research the parameters estimation, scheme establishment and error analyzing om mobile location, the performance of existing representative algorithms are summarized, and the advantages and disadvantages of which are contrasted in general as well. The ascendencies of single station and network location schemes in different scenes are discussed in detail.2. A small angle distinguish algorithm based on the prior geography information is presented. The prior angle information (the angle between the base station and the barrier) is introduced to the MUSIC algorithm, in order to improve the distinguish performance of MUSIC algorithm under the small angle difference instance. The validity of the instance in which the angle difference is very small between the known and unknown angle has been proved from the theory and simulation.3. In order to reduce the complexity, a TOA estimation algorithm based on the Bayes Theory has been investigated. The TOA estimation has been divided into two parts, the coarse estimation and the refined estimation. The approach we present can get the path delays with better estimation accuracy and less complexity.4. A TOA/AOA single station GA algorithm based on the prior geography information has been investigated. The thesis focuses on the infection of fasle location results introduced by the non-line-of-sight. After combining the prior geography information and adaptive function, the problem with GA algorithm easy to get into the local best results has been solved effectively. The approach we present can locate the mobile with better accuracy.5. Aiming at the situation when several base sations can get the up-signal, the location means with delays show better performance than that with angles. Therefore, a MDS algorithm based on the TOA has been studied. The thesis focuses on the topological structure among the base stations and the mobile. Compared with the traditional MDS algorithms, the approach we present own better ability of processing the redundant information.6. NLOS error is the main factor which can badly affect location precision. A NLOS error mitigation algorithm based on the neural network and kalman filter is presented. First, the situations when NLOS error submits to different distribution have been simulated, and then the thesis make more tests in real environment. The validity of the approach we present has been proved from the simulation and true measurement.7. The thesis takes the WCDMA system for example, the test scheme based on the WCDMA location system has been designed, and the primary software code has been realized. According to the WCDMA location test system, the outfield experimentation work has been accomplished in different test scenes, in order to validate the performance of the algorithms presented in this thesis. |
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