Satellite Communications Network Based On The Channel Characteristics Of Resource Management And Routing Technology Research

The satellite mobile communication can realize the radio communication between the mobile terminals by using the satellite repeaters which act as relay. Among the satellite mobile communication systems, the LEO-MSS's (Low Earth Orbit Mobile Satellite Systems) possesses the wide development space due to their global seamless coverage, much shorter transmission delay, less power requirement for the user terminals and strong ability in anti-ruin. Moreover, they will play an important role in the future's Personal Communication Systems (PCS).Chapter 1 is the preface, which concisely introduces the development status of the satellite communication, then summarizes the common channel model of satellite network, channel assignment algorithm, handoff algorithm and routing algorithm, at last explains the research content and the arrangement of this dissertation.Chapter 2 studies the influence of satellite network handoff by channel transmission characteristic. There are complex and time-varying channel conditions between LEO satellite and terrestrial users, and these factors would have important impact on handover performance. This paper constructs satellite-earth channel model firstly and applies the model in the process of handoff. At last, the influence of channel model on handoff performance is got by simulation.Chapter 3 mainly studies the influence of resource assignment by channel transmission characteristic. With channel transmission characteristic apply power truncation threshold to channel assignment. In study of channel assignment, those literatures just study how to assign the channel. However in actual system, the channel resource have been assigned in some extreme situation, but that can not be satisfied with based communication condition, make the channel resource can't be used efficiently and recede the system performance. So power truncation threshold is used for channel assignment. The system judges whether the channel condition meets communication requirements based on the user's emission power, if not, the system intermits this operation constrainedly, and assigns channel resource to other operation. Chapter 4 proposes a least time-delay routing algorithm with priority, voice and data service are both taken into account, and voice service is preferential. Then measure metric of path delay to carry out calculation for best path based on positions of source and objective satellite, and get a candidate path collection by good and inferior sorting. The simulation results indicate that the algorithm can reduce the time-delay of voice service obviously, and improve the call quality effectively.The dissertation is summarized in the chapter 5.