Strategies to improve wireless channel utilisation in cognitive radio networks

Abstract

The explosive demand of multimedia services over heterogeneous mobile devices has placed a huge spectrum requirement from Mobile Network Operators (MNOs) to cater to the growing demands of the customer. Advancement of technology in the communication field makes very high speed data of the order of 100s of Mbps possible per user over wireless communication which however requires wide Band Width (BW) of the order of 100 MHz and the same is not available to the MNOs. The present situation thus demands shared spectrum access among the MNOs, which is a disruption compared to the current licensed scenario, where each MNO operates in dedicated licensed band exclusively in the region without any interference and radio resource coordination. The drawback is however reduced channel utilization efficiency or trunking efficiency and hence the data rates. In heterogeneous network scenario, spectrum scarcity does not allow allocation of huge BW to several operators operating in the same geographical area. Hence new approaches for spectrum sharing and coordination among users/operators are required. With this objective, the research work in this thesis is presented in four parts. Cognitive radio systems are helpful to access the unused spectrum in heterogeneous networks by incorporating spectrum sensing techniques. In order to improve wireless channel utilization, there is a need to implement efficient spectrum sensing techniques to detect the spectrum white spaces. In this research work, a novel intelligent fuzzy system based cooperative spectrum sensing incorporating Selection Combining (SC) and Maximum Ratio Combining (MRC) concepts has been developed for improved detection accuracy. newline newline newline