Invention Application
- Patent Title: AN UNASSISTED INDOOR GPS RECEIVER
- Patent Title (中): 一个内置的室内GPS接收器
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Application No.: PCT/US2006/062732Application Date: 2006-12-29
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Publication No.: WO2007076539A2Publication Date: 2007-07-05
- Inventor: WANG, Chi-Shin , QIU, Zongde , KUDRETHAYA, Shridhara , MO, Jun
- Applicant: CENTRALITY COMMUNICATIONS, INC. , WANG, Chi-Shin , QIU, Zongde , KUDRETHAYA, Shridhara , MO, Jun
- Applicant Address: 900 Island Drive, Suite 170, Redwood City, California 94065 US
- Assignee: CENTRALITY COMMUNICATIONS, INC.,WANG, Chi-Shin,QIU, Zongde,KUDRETHAYA, Shridhara,MO, Jun
- Current Assignee: CENTRALITY COMMUNICATIONS, INC.,WANG, Chi-Shin,QIU, Zongde,KUDRETHAYA, Shridhara,MO, Jun
- Current Assignee Address: 900 Island Drive, Suite 170, Redwood City, California 94065 US
- Agency: STONE, Samuel, B. et al.
- Priority: US11/324,144 20051229
- Main IPC: G01S5/14
- IPC: G01S5/14
Abstract:
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.
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