Data Fusion for Ground TargetTracking in GSM NetworksVom Fachbereich Elektrotechnik und Informatik derUniversit¨at Siegenzur Erlangung des akademischen GradesDoktor der Ingenieurwissenschaften(Dr.-Ing.)genehmigte DissertationvonM.E. Miao Zhang1. Gutachter: Prof. Dr.-Ing. habil. O. Loffeld2. Gutachter: Prof. Dr. rer. nat. C. RulandVorsitzender: Prof. Dr. H. BessaiTag der mundlic¨ hen Prufung:¨ 7.12.2010AcknowledgmentsI would like to take this opportunity to express my sincere gratitude to allthe people who have supported and encouraged me during my Ph.D. study.My first thank goes to Prof. Dr.-Ing. habil. Otmar Loffeld for supervisingme in this thesis work. He encouraged me to pursue my ideas and supportedme with valuable discussions. His comprehensive knowledge and experiencein estimation theory was very insightful for me. I am specially gratefulto Dr.-Ing. Stefan Knedlik, the team leader of my research group. Fromhim I learned how to write academic documents and how to present mywork. He supported me to attend a variety of conferences in my field topresent my work and discuss with professional people. Moreover, he alsohelped me a lot in applying for scholarships. His suggestions of not only thework but also the other matters are very useful. I also want to thank Prof.Dr. rer. nat. Christoph Ruland, an expert in communication, for being mysecond supervisor. The discussion with him helped me in understanding thecommunication field.