Research On Link Scheduling Technology Combined With Routing Optimization In Wireless Cognitive Radio Mesh Networks

As a new kind network, wireless cognitive radio mesh network has become the focus of attention in the wireless communication field. With the continuously increasing communication demands of wireless user, higher requirements for network throughput and communication reliability are needed accordingly. However, the interference caused by the lack of spectrum resources has limited network capacity and reduced the communication reliability. In this paper, to minimize the network scheduling period, link scheduling and routing technology is deeply studied in wireless cognitive radio mesh network.Considering that the resource allocation problem in multi-radio multi-channel wireless cognitive radio mesh network involves link scheduling, routing, channel assignment and many other aspects, the link scheduling technology combined with routing optimization is researched with a brand-new perspective in this thesis. Firstly, for the requirements of the whole network, a heuristic routing mechanism based on degree constraint and link load constraint is proposed, which is applied to determine the path under different routing circumstances and the time slot demands of each active link. Further, by using the ability of iterative optimization of genetic algorithms, a heuristic link scheduling mechanism is presented joint with channel allocation. Eventually, the optimal channel allocation which meets the whole network routing demands and the optimal link scheduling under such an optimal channel allocation scheme are obtained. Simulation results show that the proposed algorithm can effectively improve the transmission concurrency of non-interference links and reduce the network scheduling period.To the joint optimization problem of routing and link scheduling in wireless cognitive radio mesh network, the 0-1 integer programming model of link scheduling problem is presented for the fixed channel assignment mode. In consideration of the conditions of interference-free transmission and flow conservation, the optimal routing and link scheduling strategy is achieved to satisfy the routing demands of the whole network. By reducing the variables, an integer programming based link scheduling algorithm is proposed. Further, from the overall point of view, for the cross-layer optimization problem involving routing optimization, channel assignment and link scheduling,0-1 integer programming model of link scheduling is presented for dynamic channel assignment mode, and an integer programming algorithm is proposed for integrated routing optimization and link scheduling. Extensive simulation results verify the effectiveness of the proposed algorithms.