高空平台通信系统中基于预测的小区切换算法

在平流层的环境中,高空平台(HAPS)的扰动特性严重影响了通信系统的小区切换性能。在平台扰动和终端移动的场景中,基于固定门限的切换算法容易增加不必要的切换次数,切换性能较差。建立HAPS覆盖模型,用户终端根据其速度动态选择切换检测周期,提出基于接收信号强度差分最小均方预测的自适应切换算法,推导了无线链路失败率的上限。仿真结果表明,相比传统固定门限的切换算法,本文算法有效降低了不必要的切换,同时还可将无线链路失败率控制在1%以下,能够适应多种通信场景。

Cell handover algorithm based on prediction in HAPS communication system

In the environment of stratosphere,the quasi-stationary characteristics of high altitude platform station (HAPS) seriously affect handover performance of the communication system.In the scenes of platform disturbance and mobility of terminal,the handover algorithm based on fixed thresholds is easy to increase the number of unnecessary handover and shows poor handover performance.HAPS coverage model was established,and the handover detection period can be changed with speed of user terminals.Then the adaptive handover algorithm was proposed to trigger handover based on signal strength,which is predicted by differential least mean square method.The upper limit of the radio link failure rates was also derived.The results of simulation indicate that compared with traditional fixed-threshold methods,the proposed algorithm effectively reduces the unnecessary handover,and keeps radio link failure rate under 1％,which makes it adaptable to a variety of communication scenarios.