GPS receiver and method for processing GPS signals
First Claim
1. A computer readable medium containing a computer program having executable code for a GPS receiver, said computer program comprising:
- first instructions for receiving GPS signals from in view satellites, said GPS signalscomprising pseudorandom (PN) codes;
second instructions for digitizing said GPS signals at a predetermined rate to producesampled GPS signals;
third instructions for storing said sampled GPS signals in a memory; and
fourth instructions for processing said sampled GPS signals by performing a plurality ofconvolutions on said sampled GPS signals, said processing comprising performing said plurality of convolutions on a corresponding plurality of blocks of said sampled GPS signals to provide a plurality of corresponding results of each convolution and summing a plurality of mathematical representations of said plurality of corresponding results to obtain a first position information.
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Accused Products
Abstract
A GPS receiver in one embodiment includes an antenna which receives GPS signals at an RF frequency from in view satellites; a downconverter coupled to the antenna for reducing the RF frequency of the received GPS signals to an intermediate frequency (IF); a digitizer coupled to the downconverter and sampling the IF GPS signals at a predetermined rate to produce sampled IF GPS signals; a memory coupled to the digitizer storing the sampled IF GPS signals (a snapshot of GPS signals); and a digital signal processor (DSP) coupled to the memory and operating under stored instructions thereby performing Fast Fourier Transform (FFT) operations on the sampled IF GPS signals to provide pseudorange information. These operations typically also include preprocessing and post processing of the GPS signals. After a snapshot of data is taken, the receiver front end is powered down. The GPS receiver in one embodiment also includes other power management features and includes, in another embodiment the capability to correct for errors in its local oscillator which is used to sample the GPS signals. The calculation speed of pseudoranges, and sensitivity of operation, is enhanced by the transmission of the Doppler frequency shifts of in view satellites to the receiver from an external source, such as a basestation in one embodiment of the invention.
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Citations
22 Claims
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1. A computer readable medium containing a computer program having executable code for a GPS receiver, said computer program comprising:
- first instructions for receiving GPS signals from in view satellites, said GPS signals
comprising pseudorandom (PN) codes;
second instructions for digitizing said GPS signals at a predetermined rate to producesampled GPS signals;
third instructions for storing said sampled GPS signals in a memory; and
fourth instructions for processing said sampled GPS signals by performing a plurality ofconvolutions on said sampled GPS signals, said processing comprising performing said plurality of convolutions on a corresponding plurality of blocks of said sampled GPS signals to provide a plurality of corresponding results of each convolution and summing a plurality of mathematical representations of said plurality of corresponding results to obtain a first position information. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
- first instructions for receiving GPS signals from in view satellites, said GPS signals
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12. A computer readable medium containing an executable computer program for use in a digital processing system, said executable computer program when executed in said digital processing system causing said digital processing system to perform the steps of:
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performing a plurality of convolutions on a corresponding plurality of blocks of sampled GPS signals to provide a plurality of corresponding results of each convolution; summing a plurality of mathematical representations of said plurality of corresponding results to obtain a first position information. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification