Satellite receiver system having doppler frequency shift tracking
First Claim
1. A satellite receiver system that provides acquisition and frequency tracking of a Doppler-shifted radio signal received from an orbiting satellite, said satellite receiver system comprising:
- a Costas phase-lock loop that receives the radio signal and provides an error signal at an error signal output for controlling a conversion frequency generated by a voltage controlled oscillator;
said voltage controlled oscillator coupled to said Costas phase-lock loop, wherein said voltage controlled oscillator generates the conversion frequency for down-converting the radio signal in said Costas phase-lock loop, and wherein said voltage controlled oscillator comprises a programmable frequency synthesizer that can be programmed to generate a plurality of frequencies selectable in steps; and
.a Doppler frequency acquisition and tracking element coupled to said voltage controlled oscillator, wherein said Doppler frequency acquisition and tracking element adjusts the conversion frequency to compensate for a Doppler frequency shift occurring in the radio signal due to orbital motion of said orbiting satellite, and wherein said Doppler frequency acquisition and tracking element comprises;
a coarse adjustment element coupled to said programmable frequency synthesizer for selecting a suitable one of the plurality of frequencies to provide a coarse adjustment of the conversion frequency to compensate for the Doppler frequency shift; and
a fine adjustment element coupled to said error signal output for generating a fine adjustment signal at an adjusted error signal output for providing a fine adjustment of the conversion frequency to compensate for the Doppler frequency shift.
4 Assignments
0 Petitions
Accused Products
Abstract
A satellite receiver system provides acquisition and frequency tracking of a Doppler-shifted radio signal received from an orbiting satellite. The satellite receiver system includes a Costas phase-lock loop that receives the radio signal and provides an error signal at an error signal output for controlling a conversion frequency generated by a voltage controlled oscillator. The voltage controlled oscillator is coupled to the Costas phase-lock loop and generates the conversion frequency for down-converting the radio signal in the Costas phase-lock loop. The satellite receiver system further includes a Doppler frequency acquisition and tracking element coupled to the voltage controlled oscillator. The Doppler frequency acquisition and tracking element adjusts the conversion frequency to compensate for a Doppler frequency shift occurring in the radio signal due to orbital motion of the orbiting satellite.
-
Citations
16 Claims
-
1. A satellite receiver system that provides acquisition and frequency tracking of a Doppler-shifted radio signal received from an orbiting satellite, said satellite receiver system comprising:
-
a Costas phase-lock loop that receives the radio signal and provides an error signal at an error signal output for controlling a conversion frequency generated by a voltage controlled oscillator; said voltage controlled oscillator coupled to said Costas phase-lock loop, wherein said voltage controlled oscillator generates the conversion frequency for down-converting the radio signal in said Costas phase-lock loop, and wherein said voltage controlled oscillator comprises a programmable frequency synthesizer that can be programmed to generate a plurality of frequencies selectable in steps; and
.a Doppler frequency acquisition and tracking element coupled to said voltage controlled oscillator, wherein said Doppler frequency acquisition and tracking element adjusts the conversion frequency to compensate for a Doppler frequency shift occurring in the radio signal due to orbital motion of said orbiting satellite, and wherein said Doppler frequency acquisition and tracking element comprises; a coarse adjustment element coupled to said programmable frequency synthesizer for selecting a suitable one of the plurality of frequencies to provide a coarse adjustment of the conversion frequency to compensate for the Doppler frequency shift; and a fine adjustment element coupled to said error signal output for generating a fine adjustment signal at an adjusted error signal output for providing a fine adjustment of the conversion frequency to compensate for the Doppler frequency shift. - View Dependent Claims (2, 3, 4)
-
-
5. A satellite receiver system that provides acquisition and frequency tracking of a Doppler-shifted radio signal received from an orbiting satellite, said satellite receiver system comprising:
-
a Costas phase-lock loop that receives the radio signal and provides an error signal at an error signal output for controlling a conversion frequency generated by a voltage controlled oscillator; said voltage controlled oscillator coupled to said Costas phase-lock loop, wherein said voltage controlled oscillator generates the conversion frequency for down-converting the radio signal in said Costas phase-lock loop; and Doppler frequency acquisition and tracking means coupled to said voltage controlled oscillator, wherein said Doppler frequency acquisition and tracking means adjusts the conversion frequency to compensate for a Doppler frequency shift occurring in the radio signal due to orbital motion of said orbiting satellite, and wherein said Doppler frequency acquisition and tracking means comprises fine adjustment means coupled to said error signal output for generating a fine adjustment signal at an adjusted error signal output for providing fine adjustment of the conversion frequency to compensate for the Doppler frequency shift. - View Dependent Claims (6, 7, 8, 9, 10)
-
-
11. A satellite receiver system that provides acquisition and frequency tracking of a Doppler-shifted radio signal received from an orbiting satellite, said satellite receiver system comprising:
-
a Costas phase-lock loop that receives the radio signal and provides an error signal at an error signal output for controlling a conversion frequency generated by a voltage controlled oscillator; said voltage controlled oscillator coupled to said Costas phase-lock loop, wherein said voltage controlled oscillator generates the conversion frequency for down-converting the radio signal in said Costas phase-lock loop; and a Doppler frequency acquisition and tracking element coupled to said voltage controlled oscillator, wherein said Doppler frequency acquisition and tracking element adjusts the conversion frequency to compensate for a Doppler frequency shift occurring in the radio signal due to orbital motion of said orbiting satellite, and wherein said Doppler frequency acquisition and tracking element comprises a fine adjustment element coupled to said error signal output for generating a fine adjustment signal at an adjusted error signal output for providing fine adjustment of the conversion frequency to compensate for the Doppler frequency shift. - View Dependent Claims (12, 13, 14, 15, 16)
-
Specification