Satellite Signal Demodulation Using Pilot Channel Phase Reference
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Solution Overview
Problem
Current satellite positioning system (SPS) receivers face challenges in demodulating data channels effectively, particularly when the power allocation between data and pilot channels is uneven, which affects signal acquisition and tracking performance.
Innovation Solution
The method involves demodulating a first channel portion of a multiple channel SPS signal based on a second channel portion, using techniques such as dot product calculations and filtering of correlation output signals, where the second channel portion, often a pilot channel, aids in improving the signal-to-noise ratio and phase estimation for the data channel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the data channel is transmitted with lower power to reduce interference, then the pilot channel can provide cleaner phase reference, but the data channel demodulation accuracy deteriorates
Solution Approach 1:
The patent introduces the pilot channel as an intermediary reference signal that mediates between the data channel transmission and the receiver's demodulation process. By using the pilot channel's clean phase reference (obtained through filtering and correlation) to modulate the local carrier for data demodulation, the system enables accurate data recovery even when data channel power is reduced, as the pilot channel acts as a phase reference intermediary
2Measurement precision
If the pilot channel power is increased to improve signal tracking, then phase estimation accuracy improves, but overall signal power allocation efficiency deteriorates
Solution Approach 1:
The patent changes the parameter of power allocation between pilot and data channels, allowing flexible adjustment of the power distribution ratio. By optimizing this parameter, the system can achieve sufficient phase estimation accuracy with moderate pilot power, improving overall power allocation efficiency. The receiver also adjusts correlation integration time and filtering parameters to maximize phase estimation accuracy within available power constraints
3Reliability
If correlation integration time is extended to improve signal-to-noise ratio, then demodulation reliability improves, but signal acquisition time increases
Solution Approach 1:
The patent performs preliminary correlation integration on the pilot channel to establish an initial phase reference before data demodulation begins. This preliminary action on the pilot channel creates a head start, allowing the data channel demodulation to proceed with sufficient reliability without requiring excessively long integration times, thus reducing overall acquisition time while maintaining demodulation reliability
Data Source
AI summary
Methods and apparatuses are provided which may be enabled within and/or for use with a Satellite Positioning System (SPS) receiver and/or other like apparatuses or device(s) to demodulate a first channel portion of a multiple channel SPS signal based, at least in part, on a second channel portion of the multiple channel SPS signal.