中心导航系统终端地图预取和更新策略研究

Research of central navigation system terminal's E-map data pre-fetch and updating strategy

为解决中心导航系统终端通过网络下载电子地图时,网络延时问题对终端地图实时显示的影响,根据空间相关性原理,提出了一种电子地图数据的预取和更新策略。该策略采用对电子地图分块传输和分块存储方法,对地图数据进行预取,并且使用二级缓存的方法,提高地图显示效率。仿真实验和实际车载实验结果表明,在CDMA的数据链路性能条件下,该预取和更新策略可以保证中心导航系统车载终端地图显示的实时性。

To meet the real-time demand of the e-map updating and display on the central navigation system terminal, an online e-map data pre-fetch and updating strategy is put forward based on spatial correlation. This strategy transmits and stores map data in blocks, at the same time displays map data by secondary cache. Tests based on simulation and test-bed both show that the pre-fetch and updating strategy can achieve good performance of online e-map distribution by using CDMA on the central navigation system terminal.