The Analysis Of Remote Base Stations Based On Fibre And The Applications In High-speed Railways

With the booming development of wireless communication technology, the fiber based remote base stations play an increasingly important role in the realm of wireless communication.The evolution of fiber based remote base station techniques went through the stages of Repeater System, digital fiber-optic repeater, RRU (GRRU)and RoF. Remote fiber-optic technology has also progressed from simple optical signal transmission in the beginning to the present combination of advanced fiber-optic radio techniques with digital transmission and unified interface specification, such that a complete set of base station solution has been formed gradually. Also in the GSM network, there exist a wide range of remote optical fiber solutions, so the problem of how to choose the right solution in any specific scenario becomes particularly important. The problem gets even more serious if we consider the newly introduced RoF technology. Unfortunately, we have found that there is a lack of comparative study on this variety of different solutions. Although this new high-speed railway cover solution based on RoF technoloy have a clear advantage in the environment of high-speed railway traffic, it has still a disadvantage relating to the need of frequent handover between different communication zones. We are facing the challenge of reducing the frequency and time of communication handover. With the ever growing requirement of bandwidth and QoS of wireless communications, it is necessary to reduce handover time further to meet the development needs.In this thesis, an analysis of a variety of different fiber-optic communications technology is given. We have also selected some appropriate cases as example to illustrate the conclusions. Then, we analyse the handover concept of this new high-speed railway cover solution based on RoF technoloy. To the handover between two different BS's, we propose and evaluate new schemes for channel reservation motivated by the rapidly evolving technology of mobile positioning. The schemes, called predictive channel reservation (PCR), work by sending reservation requests to neighboring cells based on extrapolating the motion of mobile stations (MS's). To the handover in the same BS, we propose Optical Switching based on Position-Tracking (OSPT) algorithm to realize "Moving Cells" in a RoF network. The proposed OSTP algorithm can reduce the latency time and increase the channel utilization in the optical switching architecture in train communication network.