Distributed Markov-based Primary User Protection Framework for Cognitive Radio
Date Issued
2007
Date
2007
Author(s)
Fan, Hsin-Ping
DOI
en-US
Abstract
In recent years, with wireless technologies advanced, there are more and more wireless devices and base stations deployment. These wireless systems must occupy some frequency bands. As a result, with more and more wireless standards released and implemented frequency spectrum is getting treasurable. Although frequency spectrum exhibits scarcity, research shows that spectrum is inefficiently and unbalanced utilized. The idea of cognitive radio was proposed in 1999 by Joseph Mitola to efficiently utilized the unused frequency spectrum and increase overall utilization. It is defined as an intelligent wireless system that is aware of it surrounding environment and learns from it to adapt its internal parameters in realtime.
Based on the concept of cognitive radio, we propose "Markov-based Primary User Protection" in 802.11 environment. This scheme addresses the coexistence of primary users and cognitive radio users and guarantees the transmission of primary users will not be affected by cognitive radio users. At the same time, cognitive radio users can maximize their traffic to efficiently utilized the available channel resources. We first analyze the non-saturation Markov model of primary user as well as saturation Markov model of cognitive radio user. Combining two models together, we find out the relationship between current load of primary users and the optimal transmission parameter setting that can guarantee the usage of primary users.
We validate our model by comparing the calculation yielded by the model and the results of simulation. In addition, we also verify our proposed algorithm behaves well through simulations.
Subjects
感知無線電,保護優先使用者
Cognitive Radio, Primary User Protection
Type
thesis