PRN Receiver Ranging Accuracy via Time-Shifted Component Codes
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Solution Overview
Problem
Conventional PRN receivers face limitations in ranging accuracy due to the filtering of high-frequency components of PRN codes with higher chip rates, which reduces signal resolution and effectiveness.
Innovation Solution
Generating and transmitting time-shifted component codes, which are combined into a composite code using an exclusive OR operation, allowing for a higher effective chip rate without requiring increased signal bandwidth or higher frequency carriers, thus enhancing ranging accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a PRN code with higher chip rate is employed to improve ranging accuracy, then ranging accuracy and time of arrival error estimation improve, but signal bandwidth increases and high frequency components are filtered out by conventional PRN receiver hardware
Solution Approach 1:
The patent divides a high chip rate PRN code into multiple lower chip rate component codes. Each component code is transmitted separately, allowing the receiver to process them individually without requiring high bandwidth filtering. The component codes are then combined through correlation to achieve the ranging accuracy equivalent to using the original high chip rate code.
Solution Approach 2:
The patent transforms the chip rate parameter by decomposing a high chip rate code into multiple lower chip rate codes. This parameter transformation allows the system to maintain the effective ranging accuracy of high chip rates while operating at lower actual transmission rates that are compatible with conventional receiver bandwidth limitations.
2Reliability
If conventional filtering is applied to attenuate noise and interfering signals, then noise and interference are reduced, but high frequency components of high chip rate PRN codes are unintentionally filtered out, reducing signal resolution
Solution Approach 1:
By segmenting the high chip rate code into multiple lower chip rate component codes, each component code has its spectral content concentrated at lower frequencies. This allows conventional band-limited filters to pass the component codes without attenuating their essential frequency content, thereby maintaining signal resolution while still providing noise attenuation.
3Measurement precision
If multiple component codes are time shifted and combined to form a composite code, then effective chip rate increases without requiring increased bandwidth, but device complexity increases
Solution Approach 1:
The patent segments a high complexity high chip rate code into multiple simpler lower chip rate component codes. The receiver generates local replicas of these component codes, time-shifts them appropriately, and combines them through correlation. This segmentation reduces the complexity of individual code processing while achieving the same effective ranging performance.
Data Source
AI summary
In accordance with one or more aspects of the present disclosure, a method for ranging of a PRN receiver including generating, at a PRN transmitting device that includes a processor and wireless transmitter and is in a line-of-sight position with the PRN receiver, at least two component codes, time shifting, with the processor of the PRN transmitting device, the at least two component codes relative to each other to form time shifted component codes, wirelessly transmitting, with the PRN transmitting device, the time shifted component codes to the PRN receiver with a predetermined modulation, and receiving the time shifted component codes with the PRN receiver that includes a PRN receiver processor, and determining a range estimate of the PRN receiver based on a combination of the time shifted component codes with the PRN receiver processor.