Adaptive learning decision making in cognitive radio networks

Abstract

Being a type of intelligent communication technology, the features of dynamic spectrum allocation concept of cognitive radio renders a practical approach for spectrum resources sharing among the primary user and secondary users, which helps in resolving the present problem of spectrum resource deficit. In Cognitive Radio Networks, eventhough energy detection approach is uncomplicated with lesser sensing time, the same cannot be said for the performance, which is not reasonable under low Signal to Noise Ratio (SNR) scenarios. With the aim of rendering practical and effective spectrum allocation in wireless networks, this technical work also studies the common framework model that depends on game theory for cognitive radio spectrum allocation. The first research work, a Distribution Factor (DF) based fuzzy logic approach with spectrum sensing game theory model was proposed to minimize the bandwidth restrictions in CRN employing energy detection, which is considered to be the most simple spectrum sensing approach. The D-F based fuzzy logic mechanism works based on Signal to Noise Ratio (SNR), local sensing difference and threshold of energy detector of every sensor node. Each of these aspects are integrated applying Fuzzy Logic to improve the detection performance of the sensor nodes. As per the game theory framework, the secondary users (SU) can determine the sensing approach that has to be used depending on the utility function. The SU computes an estimate on the SNR of every channel in prior and generates the utility function in terms of the energy and throughput. After this, the sensing approach is decided in accordance depending on the SNR value, implying the Distribution Factor (DF) based fuzzy logic approach to minimize the bandwidth restrictions. But, there was no energy saving in this work. Therefore, a joint channel allocation and spectrum sensing approach has to be developed which should minimize the interference considerably and also the energy usage. newline