发明名称 |
SATELLITE RECEIVER SYSTEM HAVING DOPPLER FREQUENCY SHIFT TRACKING |
摘要 |
A satellite receiver system (400) provides acquisition and frequency tracking of a Doppler-shifted radio signal received from an orbiting satellite. The satellite receiver system (400) includes a Costas phase-lock loop (100) that receives the radio signal and provides an error signal at an error signal output (134) for controlling a conversion frequency generated by a voltage controlled oscillator (200). The voltage controlled oscillator (200) is coupled to the Costas phase-lock loop (100) and generates the conversion frequency for down-converting the radio signal in the Costas phase-lock loop (100). The satellite receiver system (400) further includes a Doppler frequency acquisition and tracking element (300) coupled to the voltage controlled oscillator (200). The Doppler frequency acquisition and tracking element (300) adjusts the conversion frequency to compensate for a Doppler frequency shift occuring in the radio signal due to orbital motion of the orbiting satellite.
|
申请公布号 |
WO9519666(A1) |
申请公布日期 |
1995.07.20 |
申请号 |
WO1995US00325 |
申请日期 |
1995.01.12 |
申请人 |
MOTOROLA INC. |
发明人 |
SIWIAK, KAZIMIERZ;PONCE DE LEON, LORENZO |
分类号 |
H04B7/01;H04B7/185;H04L27/227;(IPC1-7):H04B7/185;G01S5/02 |
主分类号 |
H04B7/01 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|