发明名称 |
Keeping accurate time for a hybrid GPS receiver and mobile phone when powered off |
摘要 |
A hybrid navigation satellite receiver and mobile telephone uses only two crystal oscillators. One that operates a master clock around 27-MHz and that consumes milliwatts of power. The other oscillator consumes only microwatts of power and operates continuously on battery power at about 32-KHz. Only the second, low frequency oscillator is kept running during power "off". On power "restart", a real-time-clock counter is consulted to cause an estimate of the GPS system time to be regenerated and supplied to the GPS-DSP to quicken its initialization. The master clock is GPS-calibrated, and the accurate clock is used to drive NCO's for the mobile telephone part and host CPU.
|
申请公布号 |
US7362263(B2) |
申请公布日期 |
2008.04.22 |
申请号 |
US20050110200 |
申请日期 |
2005.04.20 |
申请人 |
SEIKO EPSON CORPORATION;ERIDE, INC. |
发明人 |
MCBURNEY PAUL W.;WOO ARTHUR N.;RODE FRANCE |
分类号 |
G01S19/25;G01S1/00;G01S19/03;G01S19/23;G01S19/27;G01S19/34;G01S19/37;H04B1/16;H04B1/38;H04B1/40 |
主分类号 |
G01S19/25 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|