Reducing memory usage in noncoherent signal processing
AssigneeSiRF Technology, Inc.
InventorsJulien Basch, Andrew Chou, Robert Lorenz, Jesse Stone
Life of this patent
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Abstract
A method for detecting a positioning signal includes (a) correlating a segment of a received positioning signal with a reference signal of a selected code phase and frequency to obtain a correlation value, (b) if the correlation value is less than a predetermined minimum, assigning the correlation value to the predetermined minimum, and (c) accumulating the correlation value in a sum of correlation values obtained using other segments of the received positioning signal. In addition, the correlation value may be reduced by a predetermined value, which is preferably an expected mean value for a noise component in the segment of the received positioning signal.
Claims7
A satellite-based positioning receiver, comprising:
- a signal processor configured to process a positioning signal from a satellite, the positioning signal being divided into segments, wherein the signal processor is configured to process the positioning signal using the acts of:
- processing each segment in a subset of the segments by:
- correlating the segment with a reference signal of a selected code phase and frequency to obtain a complex correlation value;
- processing the complex correlation value to provide a non-coherent correlation value;
- summing the non-coherent correlation value with a previously-calculated non-coherent integration sum to provide a current non-coherent integration sum;
- if the current non-coherent integration sum is less than a predetermined minimum, assigning the current non-coherent integration sum to the predetermined minimum;
- and
- processing the current non-coherent integration sum to determine whether the positioning signal is detected according to the selected code phase and frequency.
Dependencies are inferred from the claim text.