Study And Implementation Of Hybrid Dynamic Spectrum Access

The growing requirements of a new generation of wireless communication system for high-speed data communication and bandwidth makes the scarcity of spectrum resources become an unavoidable inevitable problem. In addition, such phenomenon also reveals the problem of low efficiency of spectrum utilization caused by static spectrum access technology.Therefore, the application of dynamic spectrum access technology is more and more being paid attention. However, existing studies on hybrid access method of Overlay and Underlay is in the initial stage. Since the hybrid access method has obvious performance improvement compared with the traditional access model, it has a broad space for development in the new generation of intelligent wireless communication systems.Firstly, we study the key technology of the physical layer which is necessary for the implementation of hybrid dynamic spectrum access technology. The design method of multi carrier signal generation technology in generating Overlay waveform is disscussed and we propose a wireless link establishment and switching method based on the hybrid spectrum access technology.Then, based on the given transmission channel model, we analyze the maximum access capacity of Overlay, and propose three different sub channel selection strategy. At the same time,we analyze the reliability of Underlay. A hybrid access method based on Enhanced Learning Model is proposed for the power allocation problem of the transmission channel and the control channel. Simulation analysis show that the two strategy update methods have significant performance improvement in the performance of the tradeoff between the reliability of the control channel and the efficiency of the transmission channel.Finally, we test and verify the function of the wireless link establishment and switching method based on the hybrid spectrum access technology. After building the experimental environment,we used the spectrum sensing module to detect the activities of Primary Users.Under hybrid spectrum access technology, Secondary users succeed to avoid the activities of Primary Users.