Centralized And Distributed Design Methods For Wirelessnetworks With Interference Cancellation Capabilities

Wireless networks can enable end-to-end wireless transmission between nodes without the need for any infrastructure deployment. Owing to their low cost, high scalability and ubiquity, wireless networks have been widely used in civil and military communications, environmental monitoring, telemedicine, etc. Due to the effect of wireless spectrum sharing and limited wireless node resources(such as power, computing scalability), the wireless network performance highly depends on link interference management capabilities and protocols. Based on random access(e.g., CSMA) or deterministic access(e.g., TDMA, FDMA, CDMA), the design method of existing studies is to avoid interference between adjacent wireless links in the network. The above traditional design methods ensure the link transmission success rates while limiting the number of concurrent transmissions in the wireless network(spectrum spatial reuse), thus limiting network performance improvement. Recently, there has been a growing interest to improve the spatial reuse in the network by exploiting interference(such as parallel interference cancellation, successive interference cancellation, and cooperative relay), rather than avoiding it.In wireless networks, when considering optimization of protocol layers individually, the hierarchical design methods cannot effectively use limited resources across the system. Through joint optimization between multiple layers of the protocol, cross-layer design methods can be used to further improve the resource utilization and the network performance. The objective of our study is to maximize the end-to-end network throughput. Based on interference cancellation and crosslayer optimization techniques, our work focuses on developing centralized and distributed algorithms to enhance the performance of wireless multi-hop network. The main contributions are as follows:(1) We study the cross-layer optimization algorithm in wireless multi-rate networks based on interference cancellation. First, by considering joint routing, link scheduling and end-to-end rate control problem, we propose wireless multi-hop network cross layer optimization framework based on multi-rate physical interference model and interference cancellation technology; second, for reducing algorithm complexity, we use column generation technology to decompose above optimization problem into rate control sub-problem and routing/link scheduling sub-problem. The former has been converted into a linear programming problem which has easy solution, and the latter has been converted into an integer programming problem; for solving the integer programming problems efficiently, we proposed greedy algorithm based on searching tree and heuristic algorithm based on simulated annealing. The simulation results show that multi-rate transmission links can further increase interference cancellation capacity, which results a greater throughput performance gains.(2) We study the cross-layer optimization algorithm by joint power control and interference cancellation. By considering power control problem at transmission node in wireless multi-hop networks, we further extend the cross-layer optimization as joint optimization problem between power optimization and interference cancellation. The novelty of our work is that we divide the power optimization problem into the discrete power control and continuous power control, and study both of them in multi-rate wireless network. With power control, the framework of crosslayer optimization scheduling problems has been proposed by introducing the nonlinear constraints. In order to linearize the nonlinear constraints, we introduce multiple auxiliary variables and convert the scheduling sub-problem into a mixed integer programming problem. We solve this problem by using the CPLEX. The simulation results show that, compared to cross-layer optimization without power adaptation, the proposed power control algorithms achieve high end-to-end throughput performance.(3) We study the distributed cross-layer solution with interference cancellation in wireless multi-hop networks. Distributed algorithm can reduce the overhead of network control messages. Therefore, it is more suitable for the practical deployment. In this dissertation, based on the results of our centralized cross-layer solution, we further analysis the distributed cross-layer solution in wireless multi-hop network based on interference cancellation as follows. In our distributed solution, by considering the back-pressure routing policy and the interference cancellation based physical interference model, the revised Interference Localization method is introduced to limit interference areas of network transmission nodes. And the distributed scheduling algorithm with local interference information is proposed. Simulation results verified the effectiveness of our distributed solution.