The Research And Simulation Of The Co-existing Interference Between TD-SCDMA System And GSM System

TD-SCDMA, as the 3rd international mobile communication standard which was issued firstly by China, becomes the official member in IMT2000 together with WCDMA and CDMA2000, which is a milestone in the history of Chinese mobile communication.There are many telecommunication operators today in our country. They are applying for the 3G licenses actively, and different operators also have different choices with regard to the standard systems. Thus, three kinds of the 3rd mobile communication technology standard will be operated simultaneously in China. together with some already existed 2G systems(for example, PHS,GSM1800),which will possibly lead to the situation that many operators with different mobile communication systems take up the 2GHz adjacent frequency bands in the same physiographic region. Owing to the high frequency components' nonlinear characteristic, these different systems or standards may disturb one another and result in systematic capacity loss. With the commercial application date approaching day by day, many operators and the coexistence of interferences from different mobile communication systems become a common concern in the industries of this field.As part of the research about the above simultaneous interference, mis essay mainly focuses on coexistence and simultaneous interference between the TD-SCDMA system and the GSM system. By studying the influence on communication quality from the coexistence and simultaneous interference between the TD-SCDMA system and the GSM system, it not only provides some references and guidance for the research in coexistence and simultaneous interference, but also offers some specific suggestions for the on-going TD-SCDMA and GSM integration network planning. Firstly, this essay systematically introduces the basic concepts of co-existence and interference and its basic features with an emphasis on the principle of adjacent frequency interference, the measurement methods and the composition of interference. The patterns of coexistence and simultaneous interference between the TD-SCDMA and GSM systems are generalized and according to that, with the above theory, the models about interferences in different systems between TD-SCDMA and GSM are established. Finally, Monte Carlo Simulation Method is used to conduct simulation on TD-SCDMA and GSM systems, which confirms that when two coexisted systems' simultaneous interference is relatively small, it will not cause obvious effect to the communication quality and system capacity.