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Advantage Of Fuzzy Logic

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Abstract: It is a well known widely accepted fact that the static spectrum allocation has led to the under exploitation of the available frequency band. This problem can be mitigated by cognitive radio technology. It is a concept which with its learning ability is aware about its environment and intelligently adapts to it with objectives like reliable communication, efficient utilization of spectrum and minimal or no interference among users.
Various techniques have been suggested in the research works to access the spectrum dynamically in a cognitive radio environment. These techniques basically use the concepts of Artificial Intelligence. Game theory, Markov chain models, Auctioning, Neural Networks, Multi Agent Systems and Fuzzy Logic approaches …show more content…

Fuzzy logic is an attractive technique particularly in cases where target problems are difficult to model with traditional mathematical models, but are easier to understand by human at the same time With the characteristic of future cognitive radio in mind, the capability of fuzzy logic offer good potential to be applied. Instead of using complicated mathematical formulations, fuzzy logic uses human-understandable fuzzy sets and inference rules (e.g. IF, THEN, ELSE, AND, OR, NOT) to obtain the solution that satisfies the desired system objectives. The main advantage of fuzzy logic is its low complexity. Therefore, fuzzy logic is suitable for real-time cognitive radio applications in which the response time is critical to system performance. A fuzzy logic control system can be used to obtain the solution to a problem given imprecise, noisy, and incomplete input information. In general, there are three major components in a fuzzy logic control system: fuzzifier, fuzzy logic processor, and defuzzifier (Figure 4.4). While the fuzzifier is used to map the crisp inputs into fuzzy sets, the fuzzy logic processor implements an inference engine to obtain the solution based on predefined sets of rules. Then, the defuzzifier is applied to transform the solution to the crisp output. Fuzzy logic is often used in decision making to select the best suited SU for spectrum access at a given time. This technique when combined with neural networks is used in CR networks, multihop routing or for detecting unauthorized

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