Abstract: A novel scheme to enable asynchronous time slots assignment is proposed for TDD-CDMA (time division duplex_code division multiple access) systems. Analysis of inherent inter-cell interference due to asynchrony between adjacent cellsis presented first, including BS-BS and MS-MSinterference. Then, wired connections between base stations are used to construct the adaptive RFinterferences canceller. MS-MS interference is suppressed by time slots allocation to MSs according to their locations. Both theoretical analysis and simulation results show that the inter-cell interference can be decreased to a negligible level and no longer a threat to the system performance. Therefore, the ability of dynamic resource allocation is improved for TDD-CDMA systems.

Key words: time division duplex-code division multiple access, inter-cell interference, interference cancellation

摘要： 提出一种可实现TDD-CDMA(时分双工 码分多址)系统小区间时隙异步的技术。首先分析了TDD通信系统实现小区时隙异步存在的困难, 重点分析了异步小区之间存在的基站间干扰和移动台间干扰。针对基站间干扰,提出一种利用基站间的有线连接构建自适应射频干扰消除器的方法;针对移动台间干扰, 提出一种将小区划分为内外两层, 根据用户所处位置进行时隙分配的方法。理论分析和仿真结果均表明, 上述方法可以满足小区间异步工作的要求, 提高了TDD-CDMA系统动态分配上、下行资源的能力。

关键词: 时分双工码分多址, 小区间干扰, 干扰消除