Coexistence Interference Research Of TD-SCDMA And WiMAX

Various wireless access systems coexist at present. This situation is the need of both telecommunication situation and telecommunication industry to remain its competitiveness. But the coexistence of wireless access systems brings interference problems among them. Because the receiver and transmitter in engineering are not as perfect as those ideal modules, stray power and power leakage do exist. If the frequency bands of different systems assigned in frequency planning are adjacent or close, interferences among various wireless access systems are brought in.With the research and development of the third generation mobilecommunication, the 3G frequency band of china has been decide the TD-SCDMA system, which is the first global communication system standard in China, has become a focus of attention. At the same time, WiMAX has a wide developing as its high data rate. If the frequencies are allotted nearly, WiMAX and TD-SCDMA will cause the interference to each other.In this paper, the main interference between TD-SCDMA BS and WiMAX BS is analyzed and simulated based on certainty calculation and Monte Carlo static simulation. Firstly, the interference from TD-SCDMA BS to WiMAX BS is analysed by certainty calculation, and appropriate isolations are calculated in differenct MCL. Methods above are only adaptive in theory evaluation and analysis. Although the conclusion is different from actual system, the method is simple and effective which has a guide meaning.Meanwhile, Monte Carlo static simulation is used to analyse the interference at the actual situation. As found , the main interferences are between WiMAX BS and TD-SCDMA BS.When TD-SCDMA BS interferes WiMAX BS, extra isolation of 10～15dB will be needed to guarantee a normal coexistence between WiMAX and TD-SCDMA. While interference from WiMAX to TD-SCDMA is more serious, extra isolation of 30～40dB is advised to make a normal working. If equipment-parameter-limit method is adopted, extra ACIR can be added to decrease the interference in coexistence systems.