Research On The Technology Of Interference Avoidance Based On Wireless Hybrid Network

People’s request to communication quality becomes higher and higher, the existing mobilecellular technology can hardly meet the current demand. Introducing Ad hoc networks into cellularnetwork can bring advantages such as seamless coverage, blind spots elimination and better dataservices. However, differs from the other heterogeneous network, the hybrid cellular and Ad hocnetwork share the same frequency spectrum, there will be great interference among the sharedsystem channel resources, which will seriously block the development and deployment of thehybrid network. Owing to these problems, this paper tries to study how to avoid the interference inthe hybrid cellular and Ad hoc networks.This paper mainly focuses on the following aspects:1, Firstly, introduction of the background, current development, and key problems that need tobe solved of hybrid cellular and Ad hoc network; secondly, introduction of related concepts of Adhoc and cellular network, as well as the advantages and system model of hybrid network.2, Aiming at the serious interference to cellular network by introducing Ad hoccommunication mode, based on exchange strategy in condition of single-cell cellular network, thispaper proposes an Ad hoc user access algorithm so as to reduce or avoid the interference caused bydifferent communication modes. The proposed algorithm not only controls the interference withinan acceptable range, but also effectively improves the proportion of Ad hoc user access.3, In a hybrid multi-cell cellular network, the communication of those so called cell-edgeusers will be affected by the interference from cell-center users and neighboring cell-edge users. Inorder to avoid this interference, based on the interference coordination, this paper proposes asubcarrier assignment algorithm. Simulation results show that, the algorithm performs a goodfairness among users and achieves a higher throughput for cell-edge users.4, Aiming at resource scheduling of two-hop communication in hybrid multi-cell networkenvironment, this paper proposes a two-hop resource scheduling algorithms in OFDMA system.The main idea is that, the sub-channels are assigned according to the least good channel priorityprincipal, the power are allocated according to the waterfilling theorem. Simulation results showthat the algorithm effectively improves the throughput of the hybrid cellular and Ad hoc networkwith a good fairness.