Broadcast TV Positioning Using Embedded Timing for GPS Backup
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Solution Overview
Problem
TV signal receivers lack a reliable method to determine their position without relying on GPS receivers, as TV broadcast signals can penetrate obstacles and provide coverage in areas where satellite signals are unreliable, and there is a need for a secondary or backup method to verify GPS positions.
Innovation Solution
A broadcast positioning system that includes a TV signal transmitter transmitting broadcast TV signals with embedded transmission times, allowing TV signal receivers to perform trilateration or multilateration using known TV broadcaster antenna locations, compensating for signal processing delays to determine their position accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If TV signal receivers rely on GPS receivers for position determination, then positioning accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The patent introduces TV broadcast signals as an intermediary medium for positioning. Instead of directly using GPS satellites, the system uses TV transmission towers as intermediaries that broadcast timing information. The receiver determines position by measuring time differences of arrival of these TV signals from multiple towers, eliminating the need for a dedicated GPS receiver while maintaining positioning capability through the TV signal infrastructure
Solution Approach 2:
The patent enables TV broadcast signals to serve multiple functions: traditional video/audio content delivery and positioning service provision. By embedding timing information in TV broadcasts and using existing TV transmission infrastructure, the system allows TV receivers to perform both content reception and position determination without requiring separate GPS hardware, thus achieving multi-functionality
2Reliability
If TV broadcast signals are used for positioning, then reliability in obstacle-penetrating scenarios is improved, but signal processing complexity increases
Solution Approach 1:
The patent extracts only the essential timing information from TV broadcast signals for positioning purposes. The receiver extracts transmission timing data embedded in the TV signal structure and uses it for time difference of arrival calculations, while ignoring other signal components. This extraction approach simplifies processing by focusing only on the positioning-relevant aspects of the broadcast signal
Solution Approach 2:
The patent employs preliminary synchronization actions where the receiver first synchronizes its timing reference with the TV broadcast signal structure before performing position calculations. By pre-synchronizing with the known broadcast timing framework and extracting timing information at predetermined signal intervals, the system reduces the complexity of real-time signal processing while maintaining accurate positioning
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables TV signal receivers to provide location services independently of GPS, offering a secondary method for position verification and enhancing reliability by comparing GPS-derived positions with broadcast-based calculations.
Implementation Method 1
TV broadcasters use high-power, high tower, terrestrial antennas to broadcast TV signals. The TV signals are modulated onto a radio frequency carrier and radiated from an antenna as over-the-air signals.
Implementation Method 2
The GPS receiver can determine its location through trilateration or multilateration based on receiving multiple satellite signals from known satellites that have known locations. The GPS receiver can calculate its position based on the differences in time-of-arrival (TOA) (and thus relative delay) in signal reception from the multiple satellites determined based on use of synchronized clocks.
Data Source
AI summary
Broadcast positioning systems supporting location services through over-the-air broadcast television (TV) signals are disclosed. The broadcast positioning system supports a broadcast TV signal format that includes a transmission time of the broadcast TV. The transmission time of the broadcast TV signal is used by a TV signal receiver to determine the propagation delay of the broadcast TV signal between the TV signal transmitter and the TV signal receiver. The TV signal receiver is also configured to receive multiple broadcast TV signals from multiple TV broadcasters, wherein the same delay of arrival for those broadcast TV signals can be determined. In this manner, the TV signal receiver can use the determined multiple delays of arrival from the multiple received broadcast TV signals as time-of-arrival (TOA) and the known locations of the antenna radiating these multiple broadcast TV signals to perform a trilateration or multilateration calculation to determine its position.