A Study Of Mobile Location Technology In Wireless Cellular Communication Systems

With the rapid development of the communication technology in recent years, especially the wireless cellular mobile communication technology, the mobile users have been increased very rapidly. For example in China there were about thirteen million users in 1997 but there were already two hundreds and fifty million users in 2003. The key factor of driving the mobile communication technology is the communication quality and the new service. So the wireless cellular mobile communication not only affords the traditional speech communication service but also the new service. The wireless location service is one of the important new services. The USA Federal Communications Commission (FCC) issued the "Enchance-911" (E-911) in July 1996. The main purpose was to provide the forwarding arrangement with the public safety agency. It requires all of the mobile network company implement the whole Mobile Station (MS) location service with prescriptive position precision and probability. The FCC update E-911 in October 2001,It requires the mobile network company implement location service with more position precision and probability in 12,31,2005. The E-911 accelerates the mobile terminal location technology development. After several years, all kinds of location technique have been proposed to achieve the demands of the E-911 in the limited time. Including the location promises additional services, it will improve the fraud detection, traffic management and the Intelligent Transportation Systems (ITS). It will also provide the Advanced Traveler Information Services (ATMS), and allow system operators to maximize profits and encourage usage behaviors by offering different rates depending on whether the phone is used at home, so many governments and companies devote much manpower and material resources to research and trial-manufacture of the wireless cellular location system.This dissertation presents some methods based on the research of the wireless location in the cellular communication system of the author. The main works are as follows:The dissertation gives a discussion and generalization all kinds of location methods fundamental principle then compares these methods performance, realizable complexity and applied circumstance. The dissertation proposes a kind of location method based on the Time Difference of Arrive (TDOA), through analyzing the location of CDMA communication system technology. At the same time, the thesis analyses the performance of the method and gets the parameter precision of the TDOA is the key factor of the influence location performance. The dissertation proposes a detection algorithm of the Time of Arrive (TOA) in the wireless fading channel. This algorithm achieves robust detection in the low Signal Noise Ratio (SNR). It is easy to getting the high precision TDOA by estimating the TOA.The dissertation proves the location by the TDOA is the unbiased estimation by analyzing the multi-path delay model in wireless communication. So it enhances the location precision by calculating the mean of many times measure. The algorithm is very useful to hold still MS and the low speed MS.To the simple method by using only many times measure to account mean isn't useful to location when the MS is moving. So the dissertation proposes a location and tracking algorithm that applies to the hold still MS too.Through discussing wireless channel path loss model and outfield testing experiment, the thesis proposes a location method using the receive signal power and develops a demo system based on the GSM communication system. Finally, it proposes the scheme by using the resource of the GSM communication network The dissertation is organized as three parts. The first part is the 2nd chapter, and it discusses all kinds of location methods and compares their performance. The second part is from the 3rd chapter to the 6th chapter, which discusses the location and tracking in the CDMA cellular communication system. The third part is the 7th chapter, and it discusses the location based...