Repeater Location Accuracy via Calibration Parameters
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Solution Overview
Problem
Repeater-induced inaccuracies in mobile station location determination due to additional transmission delays and altered signal coverage areas, which current terrestrial positioning methods struggle to accurately account for, leading to insufficient signal availability and increased uncertainty in location estimates.
Innovation Solution
Incorporating repeater-specific location-determination parameters, such as forward link calibration values and coverage area center points, into the base station almanac to correct for transmission delays and signal amplification effects, allowing for accurate location calculation using measured power and phase data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If repeaters are used to expand wireless coverage, then coverage area is improved, but location determination accuracy deteriorates due to additional transmission delays
Solution Approach 1:
The system performs preliminary calibration by having mobile stations at known GPS-determined locations measure signal phases from the repeater. These measurements are used to calculate calibration values that compensate for the repeater's fixed transmission delay before normal location determination begins. This preliminary action stores the delay characteristics for future use.
Solution Approach 2:
The system changes the parameter used for location determination by replacing the raw signal phase measurement with a corrected phase measurement that has been adjusted using the calibration value. This parameter transformation eliminates the repeater-induced delay error from the location calculation.
2Quantity of substance
If repeaters amplify signals to improve coverage, then signal availability is improved, but location determination reliability deteriorates due to uncertainty in transmission delays
Solution Approach 1:
The system uses GPS-determined locations as feedback to verify and refine the calibration values. Mobile stations provide feedback measurements of signal phases, and the system compares these against expected values based on known positions and stored calibration data. This feedback loop ensures the calibration remains accurate and reliable.
Solution Approach 2:
The repeater system performs self-calibration by using its own signal measurements from mobile stations at known positions to generate its own calibration values. The system serves itself by automatically determining and storing the transmission delay characteristics without requiring external intervention or manual configuration.
3Measurement precision
If current terrestrial positioning methods exclude signals from repeaters, then location determination accuracy is maintained, but signal availability deteriorates
Solution Approach 1:
The system extracts the repeater-induced delay component from the signal phase measurement by using calibration values derived from GPS-referenced measurements. This extraction separates the useful location information from the repeater delay error, allowing the signal to be used for location determination.
Solution Approach 2:
The calibration value acts as an intermediary that mediates between the repeater signal and the location determination process. Instead of directly using the raw signal phase or excluding the signal entirely, the calibration value serves as an intermediate correction that enables accurate use of repeater signals.
Data Source
AI summary
A base station almanac (BSA) includes entries for a plurality of repeaters. An entry for a repeater includes location-determination parameters associated with that repeater, such as (i) a repeater forward link calibration (FLC) value that correct for transmission delay associated with the repeater and (ii) a center point of the repeater's coverage area. A measured power level and a measured phase of a wireless signal transmitted by a base transceiver station (BTS) and received by the mobile station are obtained. An expected received power level is calculated based on the measured phase and the transmit power level of the BTS. If the measured power level exceeds the expected received power level by at least a predetermined amount, then it is determined that the mobile station received the wireless signal via a repeater and one or more location-determination parameters associated with the repeater are used to determine the mobile station's location.