Analysis Of Coexistence Interference Between LTE And DTV System

As the new broadband wireless mobile communications network develop fast, the need for wide enough spectrum to support its communication increases. China has decided to transform the broadcasting and TV system to release the698-806MHz band for the deployment of LTE systems. Cognitive radio technology is considered to be the key technology for reusing the allocated spectrum resources, as well as one of the effective methods to ease the contradiction between supply and demand and improve the spectrum utilization. Cognitive radio technology provides a way to solve the problems.On one hand, the use of UHF band resources was studied in this paper. A one week monitoring of the spectrum was ran at five typical locations at Beijing, the monitoring program was determined according to the test location, measuring time, measurement equipment and parameter settings. Matlab was used for data processing to generate spectrum charts of one week spectrum occupancy, and bar charts of one week band occupancy. The final data results showed that the highest spectrum occupancy of the five locations only reached25.40%, which meant the698-806MHz band where the DTV system was could be a suitable candidate band for cognitive radio to deploy LTE systems.When LTE system is deployed in DTV frequency, it would inevitably produce interference. Naturally, this paper also discusses coexistence between LTE system and DTV system interference. In order to analyze varieties of scenarios where these two systems coexist, uncertainty analysis and Monte Carlo simulation method are adopted. Detailed means to establishing system interference model is collecting data in cities and suburbs. The classification of interference includes djacent-channel interference and blocking interference. We can gain minimum protection distance and additional loss according to uncertainty analysis. Interference link has DTV interference LTE base station and terminals, LTE system interference DTV receiver. Data simulation shows ACIR minimum value and minimum isolation ratio under different interference.