The development of radio communication technology leads to the shortage of spectrum resource. However, recent researches show that the lack of wireless spectrum is a relative term, since a small amount of spectrum has been implemented quite a lot of services, while other parts of spectrum waste much, or say have fewer efficiency of utility. Point against such wedding dresses 2nd problem, the concept of cognitive radio has been proposed in order to improve spectrum efficiency and use spectrum in flexibility.The cognitive radio is an intelligent wireless radio which can sense the Lacoste Shirts outside world and learn the information of surroundings by its artificial intelligence. It can communicate on a reliable basis at anytime and anyplace while using the frequency chi flat iron efficiency by changing real time operation parameters such as transmit power, carrier frequency to accommodate the internal to the outside world. Cognitive radio accesses the spectrum opportunisticly, while keeps the chi flat iron interference to the licensed user under a certain level. And how to allocate spectrum among cognitive radios is a research focus.Firstly, the dissertation introduces the basic concept and research of hair straighteners cognitive radio as the background and theory basis.Since the main content of this dissertation is dynamic spectrum allocation in cognitive radio system, thus in the second part, we introduce spectrum chi dazzle sharing model of cognitive radio at the beginning, as well as the allocation principle and technologies, respectively.
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Computer Technology
