公开(公告)号：US20060267703A1

公开(公告)日：2006-11-30

申请号：US11140492

申请日：2005-05-26

申请人： Chi-Shin Wang ,  Kudrethaya Shridhara ,  Jun Mo ,  Shaowei Han ,  Hansheng Wang

发明人： Chi-Shin Wang ,  Kudrethaya Shridhara ,  Jun Mo ,  Shaowei Han ,  Hansheng Wang

IPC分类号： H03L1/00

CPC分类号： H03L1/026 ,  G01S19/235

摘要： The invention provides a method and apparatus to optimally estimate and adaptively compensate the temperature-induced frequency drift of a crystal oscillator in a navigational signal receiver. A Read-Write memory encodes two tables, one for looking up frequency drift values versus temperature readings and another one for valid data confirmation on the first table. The initially empty look-up table is gradually populated with frequency drift values while the receiver computes the frequency drift along with its position. During initial start of the receiver or re-acquisition of satellite signals, the stored frequency drift value corresponding to the current temperature is used. If no valid frequency drift value is available, the frequency drift value is computed based on the existing frequency drift values in the table. This invention reduces the Time-To-First-Fix (TTFF) of the receiver and enables the receiver to self-calibrate, thus no additional factory calibration would be necessary.

摘要翻译： 本发明提供了一种方法和装置，用于对导航信号接收机中的晶体振荡器的温度感应频率漂移进行最佳估计和自适应补偿。 读写存储器编码两个表，一个用于查找频率漂移值与温度读数，另一个用于在第一个表上进行有效数据确认。 初始空的查找表逐渐填充频率漂移值，而接收器计算频率漂移及其位置。 在接收机初始启动或重新采集卫星信号时，使用与当前温度对应的存储频率漂移值。 如果没有有效的频率漂移值可用，则基于表中现有的频率漂移值来计算频率漂移值。 本发明减少了接收机的首次定时（TTFF），使得接收机能够自校准，因此不需要额外的工厂校准。

公开(公告)号：US20060250304A1

公开(公告)日：2006-11-09

申请号：US11124413

申请日：2005-05-06

申请人： Jun Mo ,  Hansheng Wang ,  Chi-Shin Wang ,  Shaowei Han ,  Kudrethaya Shridhara

发明人： Jun Mo ,  Hansheng Wang ,  Chi-Shin Wang ,  Shaowei Han ,  Kudrethaya Shridhara

IPC分类号： G01S5/14

CPC分类号： G01S19/28

摘要： The present invention provides a method and apparatus for a satellite navigation receiver to lock onto satellite signals in the cold start mode with no information on the receiver position, the satellite position, or time estimates stored in the receiver's memory. All satellites in a positioning system are divided into groups based on the satellite constellation structure. In an embodiment, the positioning system is the Global Positioning System (GPS) and all GPS satellites are divided into three groups. During initialization of the receiver, the satellites are searched per group to lock onto at least one satellite signal. Other satellites are then searched in a given order based on their respective distance or proximity to the first satellite acquired. This method reduces the Time-to-First-Fix (TTFF) ordinarily required by conventional receivers in the cold start mode.

摘要翻译： 本发明提供了一种用于卫星导航接收机在冷启动模式下锁定卫星信号的方法和装置，其中没有关于存储在接收机的存储器中的接收机位置，卫星位置或时间估计的信息。 基于卫星星座结构将定位系统中的所有卫星分成几组。 在一个实施例中，定位系统是全球定位系统（GPS），所有GPS卫星分为三组。 在接收机的初始化期间，每组搜索卫星以锁定至少一个卫星信号。 然后根据其相应的距离或与所获取的第一卫星的距离，以给定的顺序搜索其他卫星。 这种方法减少了常规接收机在冷启动模式下通常要求的首次固定时间（TTFF）。