摘要: |
在用户对系统带宽以及传输速率要求越来越严格的当下,小蜂窝技术成为解决室内和热点场景覆盖和容量问题的有效途径。为了缓解小蜂窝中切换失败率和乒乓切换率之间的矛盾,首先建立了小蜂窝网络场景下的切换模型,通过采用参考信号接收功率方案对用户终端(UE)的移动轨迹进行跟踪而达到速度估计的目的;之后,推导分析了该模型中切换失败概率、乒乓切换概率与切换触发时间、UE速度的关系;最后,采用遍历算法对切换触发时间进行优化选择。仿真结果表明,所提方案能够将切换失败概率降低到接近于零,同时将乒乓切换率降低了10%,很好地缓解了两者之间的矛盾,更适合于对乒乓切换敏感的高速移动UE。 |
关键词: 小蜂窝网 切换触发时间 切换失败率 乒乓切换率 参考信号接收功率 速度估计 |
DOI: |
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基金项目:国家科技重大专项(2014ZX03003010-004);重庆市自然科学基金资助项目(cstc2012jjA40049) |
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Time to trigger selection scheme based on speed estimation in small cell |
LENG Jia-li,CAO Yong-min,WANG Dong-jun |
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Abstract: |
With the more and more strict requirements for system bandwidth and transmission rate, small cell technology is an effective way to solve indoor and hot scenes coverage and capacity issues. In order to alleviate the contradiction between handover failure probability and ping-pang handover probability well, the handover model in heterogeneous networks is established and UE speed is estimated through using the reference signal received power(RSRP)scheme to track UE moving locus. And then the relationship between handover failure probability (HOF) and ping-pang handover probability (PP) with respect to time to trigger(TTT) and UE speed is derivated and analyzed. Finally,TTT is optimized and selected by using traversal algorithm. Simulation results show that the proposed scheme can reduce handover failure probability close to zero while decreasing the ping-pong handover rate by 10 percent. Therefore, it can alleviate above contradiction well and is more suitable for high-speed UE which is sensitive to ping-pong handover. |
Key words: small cell time to trigge handover failure probability ping-pang handover probability reference signal received power speed estimation |