Dissertation > Industrial Technology > Radio electronics, telecommunications technology > Wireless communications > Mobile Communications

Modeling and Mitigating Interference for Wireless Ad Hoc Networks

Author LiuYongZhen
Tutor ZhangXinMing
School University of Science and Technology of China
Course Computer Software and Theory
Keywords Wireless ad hoc networks Interference model Spatial multiplexing Routing mechanism Physical carrier sensing Topology control Power Control Cross-layer design
CLC TN929.5
Type Master's thesis
Year 2009
Downloads 214
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The major factor in limiting the capacity of the wireless network is a signal interference. Wireless ad hoc networks and other wireless networks have a significantly different way to share channel, multi-hop shared broadcast channel. Under the the wireless multihop shared broadcast channel scene to solve signal interference has become increasingly important. Interference affect the performance of wireless ad hoc networks, such as the throughput of the network, the network lifetime, energy consumption. Therefore, in-depth understanding and analysis of the impact of interference on wireless ad hoc network performance aroused the interest of many researchers. In this paper, we decompose the interference problem for interference modeling interference optimization goals, interference control strategy three parts. Research interference major challenge is how the model of the physical phenomenon of interference. The theory existing physical interference model is mainly used for network performance analysis, the algorithm is not suitable for the analysis and design of network protocols. Interference model, the signal is divided into a conflict caused by the competition and interference. Then the interference of the radio signal is divided into the the synchronous interference and asynchronous interference. In time, the synchronous interference is the the node conflicts caused by the access to the same physical channel in the same time slot, the asynchronous interference on this precisely received signal generates a signal of other node is the master node in the communication process node damage. Design interference-aware network protocols and a basic challenge is how to reduce or eliminate the interference, to achieve the best performance of the network. In this paper, three cross-layer interference-aware method. 1 channel interference the access delay routing mechanism. Any concurrent transmission in wireless ad hoc networks, interference and conflict will have other nodes. The interference intensity of the spatial multiplexing of the transmission link depends on two factors: the receiving node, the sending node channel contention probability of conflict. Considering these two factors, the proposed channel interference access delay routing mechanism. Channel can avoid interference and high competition, and thus increase the network throughput, reduce the network end-to-end delay and packet loss rate. 2 carrier sense threshold interference-aware adaptive adjustment agreement. Physical carrier sensing threshold affects the activity of the channel. Nodes active channel and packet loss rate by cumulative interference. This paper presents a novel analytical method used to confirm how to adjust the perception threshold in order to achieve the purpose of reducing interference. The protocol is to monitor the state of the channel through the dynamic heuristic approximation of the best perceptual threshold. Optimal perception threshold is a tradeoff between the network spatial multiplexing and low interference, in order to maximize network throughput. Hybrid interference model-based topology control algorithm. Previous topology control study on the pure geometry of the network, ignoring the wireless network is a very important characteristic: capture effect. From the point of view of communication theory, it did not consider the characteristics of the actual link scheduling SINR. Integration of physical interference in the geometric model of the wireless network, mixed interference model and topology control algorithm in the model. It effectively meet the characteristics of the topology control, and reduce interference.

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