Broadcast TV Positioning With Embedded Timing for GPS Fallback
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Solution Overview
Problem
Existing TV signal receivers lack a reliable method to determine their position without relying on GPS receivers, as TV broadcast signals can penetrate obstacles and are less susceptible to weather interference, and there is a need for a secondary or fallback method to ensure accurate location determination.
Innovation Solution
A broadcast positioning system that includes a TV signal transmitter capable of transmitting broadcast TV signals with embedded transmission times, allowing TV signal receivers to calculate their position through trilateration or multilateration using multiple TV broadcaster antennas, compensating for signal processing delays to accurately determine propagation delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If GPS satellite signals are used for position determination, then location services can be provided, but the system is vulnerable to weather interference, signal blocking by obstacles, and spoofing attacks
Solution Approach 1:
The patent introduces TV broadcast signals as an intermediary medium for position determination. Instead of directly using GPS satellite signals that are vulnerable to blocking and weather interference, the system uses TV broadcast transmitters as intermediate reference points that emit signals capable of penetrating obstacles and resisting weather effects, thereby providing a more reliable position determination mechanism
Solution Approach 2:
The patent changes the fundamental parameter of signal transmission medium from GPS radio frequency signals to TV broadcast signals. TV signals operate at different frequencies and have different propagation characteristics that allow them to penetrate obstacles and resist weather interference, thus changing the physical parameters of the positioning system to improve reliability
2Adaptability or versatility
If TV broadcast signals are used for position determination, then a secondary location method is provided, but TV signal transmitters must embed transmission time information and receivers must process multiple signals
Solution Approach 1:
The patent makes TV broadcast transmitters serve multiple functions: their primary function of transmitting television content is combined with a secondary function of providing positioning reference signals. By embedding transmission time information in the TV broadcast signals, the same infrastructure is used for both entertainment and positioning purposes, reducing the need for separate positioning infrastructure
Solution Approach 2:
The TV broadcast signals themselves carry the necessary positioning information (transmission time stamps) within their own signal structure. The signals are self-contained with all required data for position calculation, eliminating the need for separate communication channels or additional infrastructure, and allowing receivers to extract positioning data directly from the broadcast signals
3Measurement precision
If transmission time information is embedded in TV broadcast signals, then accurate propagation delay calculation is enabled, but signal processing delays in the transmitter must be compensated
Solution Approach 1:
The patent applies preliminary compensation for signal processing delays at the transmitter side before the signals are broadcast. By pre-calculating and compensating for the group delay in the transmission time information, the system eliminates the need for complex real-time delay measurement and compensation at the receiver, simplifying the overall system while maintaining high precision
Solution Approach 2:
The system uses the embedded transmission time information as a reference that enables receivers to calculate propagation delay. The known transmission time acts as a feedback reference point that allows the receiver to determine the time of flight of the signal and thus calculate its position accurately, creating a closed-loop measurement system
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 determine their location without a GPS receiver, providing a reliable secondary method for position calculation and ensuring accuracy by synchronizing clocks with TV broadcasters, thus offering independent position verification and backup to GPS systems.
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 TV signal receiver can determine its location through trilateration or multilateration based on receiving multiple TV broadcast signals from known TV broadcasters that have known locations. The TV signal 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.