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）。

公开(公告)号：US07459984B2

公开(公告)日：2008-12-02

申请号：US11140492

申请日：2005-05-26

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

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

IPC分类号： H03L1/00 ,  G01S1/00

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：US07324045B2

公开(公告)日：2008-01-29

申请号：US11124413

申请日：2005-05-06

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

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

IPC分类号： G01S1/00 ,  H04B7/185 ,  H04B1/00

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）。

公开(公告)号：US20080151971A1

公开(公告)日：2008-06-26

申请号：US11615704

申请日：2006-12-22

申请人： Jun Mo ,  Shaowei Han

发明人： Jun Mo ,  Shaowei Han

IPC分类号： H04B1/707

CPC分类号： H04B1/7085 ,  H04B1/709 ,  H04B2201/70715

摘要： The present invention provides systems and methods for implementing narrowly spaced correlators to mitigate multipath error, and systems and methods for adaptively changing the correlator spacing for varying multipath conditions. In an embodiment, two sets of correlators with the same code frequency but different code phases are used to implement an adjustable correlator spacing. The correlator spacing is determined by the code phase difference between the two sets of correlators, which can be adjusted, e.g., by adjusting the code phase values of Numerically Controlled Oscillators (NCOs). An advantage of embodiments of the present invention is that they can achieve much narrower correlator spacings than conventional techniques, e.g., by making the code phase difference between the two sets of correlators very small. Further, the correlator spacing can be adjusted for varying multipath conditions, whereas the correlator spacing in conventional techniques is fixed.

摘要翻译： 本发明提供了用于实现窄间隔相关器以减轻多路径误差的系统和方法，以及用于自适应地改变相关器间隔以用于变化的多径条件的系统和方法。 在一个实施例中，使用具有相同代码频率但不同代码阶段的两组相关器来实现可调整的相关器间隔。 相关器间距由两组相关器之间的码相位差确定，这可以通过例如调节数控振荡器（NCO）的码相位值来调整。 本发明的实施例的优点在于，它们可以实现比常规技术更窄的相关器间隔，例如通过使两组相关器之间的码相位差非常小。 此外，可以针对变化的多径条件来调整相关器间距，而常规技术中的相关器间隔是固定的。

公开(公告)号：US07439907B2

公开(公告)日：2008-10-21

申请号：US11561758

申请日：2006-11-20

申请人： Chi-Shin Wang ,  David Wang ,  Wentao Zhang ,  Jun Mo ,  Lei Dong

发明人： Chi-Shin Wang ,  David Wang ,  Wentao Zhang ,  Jun Mo ,  Lei Dong

IPC分类号： G01S3/14

CPC分类号： G01S19/49 ,  G01S19/40

摘要： The present invention provides methods and systems that enable a mobile navigation receiver to accurately determine its trajectory with non-current ephemeris in stand-alone mode. In an embodiment, the receiver computes the position for the same location using non-current ephemeris and current ephemeris at different time instances. The receiver then determines a position correction by finding the difference between these two computed positions, and applies this correction to the trajectory generated with non-current ephemeris to obtain a more accurate trajectory. In another embodiment, the receiver computes an initial position of the receiver using non-current ephemeris and finds the difference between the computed initial position and an accurate approximation of the initial position. The receiver then shifts the subsequent receiver trajectory computed using non-current ephemeris by the difference to obtain a more accurate trajectory.

摘要翻译： 本发明提供使移动导航接收机能够以独立模式的非当前星历精确地确定其轨迹的方法和系统。 在一个实施例中，接收机使用不同时间的非当前星历和当前星历表计算相同位置的位置。 然后，接收机通过找到这两个计算位置之间的差异来确定位置校正，并将该校正应用于由非当前星历产生的轨迹，以获得更准确的轨迹。 在另一个实施例中，接收机使用非当前星历表计算接收机的初始位置，并且找出所计算的初始位置与初始位置的精确近似之间的差。 然后，接收器将使用非当前星历计算的后续接收器轨迹移动该差，以获得更准确的轨迹。

公开(公告)号：US08000378B2

公开(公告)日：2011-08-16

申请号：US11615704

申请日：2006-12-22

申请人： Jun Mo ,  Shaowei Han

发明人： Jun Mo ,  Shaowei Han

IPC分类号： H04B1/00 ,  H04L27/06

CPC分类号： H04B1/7085 ,  H04B1/709 ,  H04B2201/70715

摘要： The present invention provides systems and methods for implementing narrowly spaced correlators to mitigate multipath error, and systems and methods for adaptively changing the correlator spacing for varying multipath conditions. In an embodiment, two sets of correlators with the same code frequency but different code phases are used to implement an adjustable correlator spacing. The correlator spacing is determined by the code phase difference between the two sets of correlators, which can be adjusted, e.g., by adjusting the code phase values of Numerically Controlled Oscillators (NCOs). An advantage of embodiments of the present invention is that they can achieve much narrower correlator spacings than conventional techniques, e.g., by making the code phase difference between the two sets of correlators very small. Further, the correlator spacing can be adjusted for varying multipath conditions, whereas the correlator spacing in conventional techniques is fixed.

摘要翻译： 本发明提供了用于实现窄间隔相关器以减轻多路径误差的系统和方法，以及用于自适应地改变相关器间隔以用于变化的多径条件的系统和方法。 在一个实施例中，使用具有相同代码频率但不同代码阶段的两组相关器来实现可调整的相关器间隔。 相关器间距由两组相关器之间的码相位差确定，这可以通过例如调节数控振荡器（NCO）的码相位值来调整。 本发明的实施例的优点在于，它们可以实现比常规技术更窄的相关器间隔，例如通过使两组相关器之间的码相位差非常小。 此外，可以针对变化的多径条件来调整相关器间距，而常规技术中的相关器间隔是固定的。

公开(公告)号：US20090002226A1

公开(公告)日：2009-01-01

申请号：US11771845

申请日：2007-06-29

申请人： Jun Mo ,  Shaowei Han

发明人： Jun Mo ,  Shaowei Han

IPC分类号： G01S1/00

CPC分类号： G01S19/24 ,  G01S19/42

摘要： Described herein are systems and methods that are capable of determining receiver position and system time under weak signal conditions. When the receiver is unable to accurately determine the satellite signal travel time, e.g., due to weak signal reception or some other condition, the receiver can still estimate the pseudo-range for the satellite based on an initial receiver position and system time. In this case, the system and methods described herein provide the necessary initial receiver position and system time with enough accuracy to estimate the pseudo-range, even under weak signal conditions. The receiver can then use the estimated pseudo-range to determine a more accurate receiver position.

摘要翻译： 这里描述的是能够在弱信号条件下确定接收机位置和系统时间的系统和方法。 当接收机不能准确地确定卫星信号传播时间时，例如由于信号接收弱或某种其他条件，接收机仍然可以基于初始的接收机位置和系统时间来估计卫星的伪距离。 在这种情况下，即使在弱信号条件下，本文所述的系统和方法也提供了足够准确的必要的初始接收机位置和系统时间来估计伪距离。 然后，接收机可以使用估计的伪距来确定更准确的接收机位置。

公开(公告)号：US07570208B2

公开(公告)日：2009-08-04

申请号：US11324144

申请日：2005-12-29

申请人： Chi-Shin Wang ,  Zongde Qiu ,  Shridhara A. Kudrethaya ,  Jun Mo

发明人： Chi-Shin Wang ,  Zongde Qiu ,  Shridhara A. Kudrethaya ,  Jun Mo

IPC分类号： G01S5/14 ,  H04B1/16

CPC分类号： G01S19/24 ,  G01S19/246 ,  G01S19/27 ,  G01S19/29 ,  G01S19/34

摘要： The present invention provides GPS receivers capable of tracking very weak GPS signals particularly in an indoor environment without assistance from an external server or a network. In a preferred embodiment, a GPS receiver initially acquires and locks onto GPS satellite signals to compute receiver position outdoors. The GPS receiver then tracks at least one satellite signal indoors to maintain acquisition parameters for quick acquisition of GPS signals. To save power, the receiver automatically goes to the sleep state and periodically wakes up, i.e., powers up, to maintain the at least one satellite signal tracking. During the wakeup state, the receiver collects ephemeris data from the at least one satellite signal when the ephemeris data needs to be updated for quick acquisition of GPS signals.

摘要翻译： 本发明提供了能够跟踪非常弱的GPS信号的GPS接收机，特别是在室内环境中，无需外部服务器或网络的协助。 在一个优选实施例中，GPS接收机最初获取并锁定到GPS卫星信号上以在室外计算接收器位置。 GPS接收机然后在室内跟踪至少一个卫星信号，以维持采集参数，以便快速获取GPS信号。 为了节省电力，接收机自动进入睡眠状态并周期性地唤醒，即上电，以维持至少一个卫星信号跟踪。 在唤醒状态期间，当需要更新星历数据以快速获取GPS信号时，接收器从至少一个卫星信号收集星历数据。

公开(公告)号：US20080117100A1

公开(公告)日：2008-05-22

申请号：US11561758

申请日：2006-11-20

申请人： Chi-Shin Wang ,  David Wang ,  Wentao Zhang ,  Jun Mo ,  Lei Dong

发明人： Chi-Shin Wang ,  David Wang ,  Wentao Zhang ,  Jun Mo ,  Lei Dong

IPC分类号： G01S5/14

CPC分类号： G01S19/49 ,  G01S19/40

摘要： The present invention provides methods and systems that enable a mobile navigation receiver to accurately determine its trajectory with non-current ephemeris in stand-alone mode. In an embodiment, the receiver computes the position for the same location using non-current ephemeris and current ephemeris at different time instances. The receiver then determines a position correction by finding the difference between these two computed positions, and applies this correction to the trajectory generated with non-current ephemeris to obtain a more accurate trajectory. In another embodiment, the receiver computes an initial position of the receiver using non-current ephemeris and finds the difference between the computed initial position and an accurate approximation of the initial position. The receiver then shifts the subsequent receiver trajectory computed using non-current ephemeris by the difference to obtain a more accurate trajectory.

摘要翻译： 本发明提供使移动导航接收机能够以独立模式的非当前星历精确地确定其轨迹的方法和系统。 在一个实施例中，接收机使用不同时间的非当前星历和当前星历表计算相同位置的位置。 然后，接收机通过找到这两个计算位置之间的差异来确定位置校正，并将该校正应用于由非当前星历产生的轨迹，以获得更准确的轨迹。 在另一个实施例中，接收机使用非当前星历表计算接收机的初始位置，并且找出所计算的初始位置与初始位置的精确近似之间的差。 然后，接收器将使用非当前星历计算的后续接收器轨迹移动该差，以获得更准确的轨迹。