Implementation Of LTE-based Cognitive Wireless Networks And Research Of Carrier Aggregation In 700MHz

The coexistence of various heterogenous wireless networks and the scarcity of spectrum resource have become the key problem that restricts the development of wireless network towards wideband and ubiqitous networks.In order to solve the problem,the concept of cognitive wirless network has been proposed.In China,SARFT has the right to use 700 MHz frequency band for analog broadcast TV.But with the economy development,digital cable TV technology has become the mainstream of the common people's selection,it has emerged a large number of spectrum hole in 700MHz band.We urgently need to develope a cognitive radio technology test bed in 700 MHz band to demonstrate how cognitive radio improves spectrum utilization efficiency.The main content of this paper is how to design and development such a platform and research carrier aggregation technology to improve spectrum utilization efficiency based on it.Considering the trend of broadband wireless communication,we select TD-LTE system as the secondary user in the demonstration platform.We also design and modify the standard protocol to add the cognitive function in compatible existing LTE standard protocol as far as possible.In this scenario,analog broadcast TV is the primary user and TD-LTE system is the secondary user.The secondary user TD-LTE system detect spectrum hole and dynamically access free spectrum band through the spectrum sensing technology.I am respnsonsible for the development of demonstration platform and research of CA technology in this senario.In detail,this paper will expound the two main research points in the following structure:At first,we introduce the background of cognitive wireless networt and TD-LTE technology.Combining with China's broadband wireless communication development and evolution route,we inlustrate the meaning of demonstration platform of cognitive radio network based on TD-LTE.Secondly,this paper introduces the software radio technology and platform development including baseband DSP development.Then,based on the cognitive LTE protocol stack design,we detailed elaborate the process of developing test bed to demonstrate coexistence of TD-LTE and analog broadcast TV in 700 MHz band.After that,based on the platform we research the carrier aggregation technology to improve the spectrum utilization efficiency.At last,we make a conclusion to summarize all the research points and point the future research direction and unsolved problems.