The Copatibility Study Of Radar Systems With IMT-Advanced Systems

In2006, the International Telecommunication Union officially confirmed the IMT-Advanced as the fourth generation mobile communication standard. As the main scheme proposed by3GPP, LTE although does not meet the IMT-Advanced technical indicators, but already has the distinct characteristics of the4G technology. At present, the world’s major countries including China put LTE as the new generation mobile communication standard, and the LTE networks have been deployed widespread all over the world.In2009, China submitted TD-LTE-Advanced4G technology solutions to the ITU. In October.2010, during the world communication conference, ITU formally division2500-2690MHz band to the use of TD-LTE standard. Although the LTE frequency planning in our country has been established, but the problem between LTE and coexistence systems in its related frequencies still exists, so it is necessary to study on the interference coexistence.Radar is an electromagnetic system that is used for the detection of target objects, and has a history of more than one hundred years. In practice, radar systems are deployed in a number of different frequency bands, including the2700～2900MHz bands, in which deploys the radionavigation service and meteorological radar service in our country. The system will be with the TD-LTE system to produce a certain frequency interference.In this paper, first we introduce the basic characteristics of the radar system and LTE system, and put forward the system parameters, the propagation model, coexistence research interference protection standards, etc, according to the3GPP LTE series standards and the international telecommunication union ITU series recommendation about radar, which provide theoretical basis for the coexistence study. Then we use the deterministic analysis method to calculate the adjacent frequency interference and blocking interference between radar system and LTE base station within the2500～2690MHZ band, obtain the required additional isolation under different distance. Finally, through the method of system level simulation, we simulate the relationship between radar interference probability and physical isolation distance, and obtain the required isolation distance by the threshold of radar interference probability.The deterministic calculation and system level simulation results show that the interference of LTE system and radar is serious, need to adopt some certain isolation measures that can ensure the coexistence of two systems.