The Research Of Spectrum Sharing Technology In Cognitive Radio

As the rapid development of wireless communication technology, the number of wireless users dramatic increased, Although the radio spectrum has a very large bandwidth, but still makes the spectrum resources scarcity. The scarceness of wireless spectrum hampers the sustainable development of wireless communication services. How to improve the utilization ratio of spectrum and the rational spectrum management scheme has become a pressing matter of the moment. In the above context, cognitive radio technology is put forward. Cognitive radio is presented at the beginning are generally considered to be resolve spectrum resource lack of new ideas and solutions, with the in-depth study more firmly the idea is correct. The cognitive users using the cognitive radio technology to sense the wireless environment, find out the "spectrum hole", and then according to their own transmission needs to select the appropriate channels of communication. At the same time when the channel environment changes or the primary user access, it will switch to other available channel. This dynamic spectrum switch will improve communication quality and reduction of the authorized user interference. These are mainly made use of spectrum sensing spectrum and decision technology. Cognitive radio also has a very important technology:spectrum sharing technology. Spectrum sharing technology in spectrum sensing based on spectrum sensing, according to results in the modulation of communication parameters for reliable communication, realize the spectrum sharing between cognitive users with authorized users and secondary users with secondary users.This article mainly aims at the cognitive radio technology spectrum sharing algorithm. Study on the properties of spectrum sharing algorithm under the dynamic environment. This paper mainly analyzes two different models:spectrum sharing algorithm based on game theory and spectrum sharing based on ant colony algorithm. Game theory based on the sharing model use the game theory analysis of the cognitive radio network dynamic spectrum allocation problem, and constructs the game theory based on the cognitive radio spectrum allocation problem model, is proposed based on game theory non-cooperative type spectrum allocation algorithm, and obtained the corresponding game process of Nash equilibrium. To master the user’s maximum profit as the goal, put forward QoS to measure the main user gains utility function. The new utility function is most in the Nash equilibrium. The simulation results show that the proposed algorithm can in a relatively short time converge to a stable state. Ant colony algorithm model is based on the task allocation of ant colony, the task execution probability mapping to channel selection probability. Cognitive users according to the probability of selection to chocse the ideal channel. Ant colony algorithm model enables each unlicensed user to distributively determine the appropriate channel over which it can communicate. Performance evaluations clearly reveal that algorithm achieves efficient dynamic spectrum sharing with high spectrum utilization and without any coordination among the users and hence yielding no spectrum handoff latency overhead due to coordination.