Ambiguity removal technique for user position determination in nongeostationary satellite communications systems
✍ Scribed by Hiroyasu Ishikawa; Hideyuki Shinonaga; Hideo Kobayashi
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 383 KB
- Volume
- 83
- Category
- Article
- ISSN
- 8756-6621
No coin nor oath required. For personal study only.
✦ Synopsis
Presently, much research has been carried out on systems providing satellite communication service based on portable terminals using nongeostationary satellites with multispot beam configurations such as ICO and Iridium. In these systems, it is necessary to detect the user terminal position accurately so that the terminal access, hand-over between the spot beams, and hand-over between the satellites are carried out efficiently. As a user position determination method by one nongeostationary satellite, the method computing the position by using the propagation delay time between the satellite and the user and the Doppler shift is a representative one. In the conventional method, the ambiguity of the estimated position in the position detection becomes a problem. In this paper, a method is proposed to eliminate ambiguity of the estimated position that becomes a problem in the position detection with a nongeostationary satellite. In addition, the area with ambiguity problem, evaluation of the time rate, and the effect of the moving speed and direction on the ambiguity elimination success probability are evaluated by computer simulation. It is shown that the proposed method can sufficiently be used in a real system.