| The original release of TD-SCDMA system owns little spectrum. The bandwidth is not enough. And co-channel interference is strong. As the user numbers increase, TD-SCDMA network appears the phenomena that the system capacity is not enough and the communication quality deteriorates. China Mobile makes the network upgrade research project start-up in order to solve this problem. The upgrade releases include HSPA and LTE. Though the selection doesn't be decided, whatever, the co-channel interference need be controlled effectively. And how to control the co-channel interference is one of the key factors to improve the system performance.The co-channel interference will be produced when many users make use of same resources. The direct method to solve the co-channel interference is frequency coordination. But the effect is not perfect. Once the network is in heavy burden, this method will not gain the effect. Actually, because TD-SCDMA adopts several key technologies, such as smart antenna, joint detection, uplink synchronization and power control, it has the good character in controlling the interference. If we can search these technologies deeply, we can obtain the method.This paper gives an eye to these key technologies and gives priority to power control, scrambling layout and joint detection. I simulate the R4 and HSPA release system performance by the laboratory platform, design the power control scheme based on reference value and scrambling scheme based on complex code and space and evaluate the inter and intra cell joint detection. According to these parameters, such as the system throughout, SINR CDF curve and interference signal strength, we can conclude that these methods can control the co-channel interference effectively and improve the system performance. |
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