Interference Avoidance And Coordination In Hybrid Cellular And Ad-Hoc Network

The hybrid cellular and ad-hoc network is a new type of wireless access network structure. After introducing ad-hoc communication into cellular system, some of the existing limitation and difficult problems of the cellular network can be effectively solved by using the characteristics of ad-hoc networks. The hybrid network is considered to be a major development direction for future mobile communication systems, which may be 4G or future form of mobile communication system.Also some benefits could be brought by introducing ad-hoc communication into cellular system. Some technical difficulties are still unsolved e.g. resource allocation mechanism, communication form selection and traffic balance. Especially a series of interference emerge as channels sharing among a variety of communication forms, which is principle constraining factor to the development of hybrid networks. The main research topic in this paper is studying interference avoidance and coordination for hybrid cellular system and ad-hoc network. Firstly, two basic types of wireless access network, the concept of the hybrid network and research achievements at home and abroad was introduced. Secondly, the structure of a system-level simulation platform of hybrid cellular and ad-hoc network was described. Then, the third part of the paper was focused on how to manage access problem of the ad-hoc network users. In order to reduce or avoid the serious interference after introducing end-to-end communication, a user access algorithm was studied and analyzed. After that, the research scenario was extended to ad-hoc communication with link across cells. And an interference avoidance algorithm was given for strong interference avoidance. Finally, I studied the interference in the multi-cell situation. An optimal resource allocation algorithm was given using graph theory, which did not considering using same resource among different end-to-end links.