Application of SDMA Technique for Cell-Replanning in Mobile Communication Systems

Abstract

The thesis objectives are (1) to understand the essential knowledge of mobile communication systems, cell planning and re-planning processes, especially the SDMA technique for cell re-planning including LCMV and GSC methods, and (2) to implement a simulation program for planning and re-planning by dividing a cell into many smaller sectors using antenna array (smart antennas). When the congestion in a hot-spot cell happens, capacity of system is not enough for subscribers; therefore there is a need for cell re-planning. There are many existing methods for cell re-planning such as cell overlapping and cell splitting. The cell overlapping is used provisionally since it causes interference (C/I). Even though, the cell splitting is the main method which many providers are using now, it also has limitation since it requires new BTS and new wire/wireless connection between the MSC and new BTS, which are costly and in some cases it is much difficult for deployment. Therefore, in this thesis, it is concentrated on the SDMA technique which can be used for realizing cell sectoring in a dynamic and flexible manner. The use of antenna array within the SDMA technique allows control the main beam, the beam width and the number of beams in other to increase the capability of frequency re-use. Hence, system capacity is increased and it is able to relieve the congestion in the hot-spot cell.