分层小区系统中预留资源的切换策略分析

分层小区结构是增强覆盖,提高系统容量,为具有不同移动特性的用户提供更好服务质量的一种有效的解决方案.本文讨论了具有分层小区结构的CDMA(码分多址)系统中切换策略的性能,分别用一维和二维的马尔可夫模型来分析微蜂窝和宏蜂窝中的状态.CDMA的自干扰特性使得其系统容量与干扰水平相关,因此我们采用状态空间无限的马尔可夫模型来进行分析.另外,考虑到切换用户的优先级问题,以及具有不同移动特性的用户的公平性问题,我们在系统中设置了多级接入门限,同时分析了资源预留量对系统性能的影响.

Handover Analysis with Resource Reservation in Hierarchical Cell Structure

Hierarchical cell structure is an effective solution to guarantee continuous coverage,to improve system capacity,and to provide better service for users with different mobility. This paper discusses CDMA(Code Division Multiple Access) system performance with Hierarchical cell structure and analyzes handover strategy with one-dimensional Markov model in micro-layer and iwo-dimensional Markov model in macro-layer. Capacity of CDMA system is related to interference level because of its self-interference characteristic. So the state space of Markov models adopted by us are unlimited. Moreover, considering priority of handover users and justice of users with different mobility,multi-level admission thresholds are set in system for different useis.The impact of the amount of reserved resource on system performance is also analyzed in this paper.