Orthogonal Beacon Antenna Arrays for GPS-Free Mobile Location
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional GPS-based location determination is limited by environmental interferences and satellite signal availability, necessitating a method to accurately determine the location of mobile units without relying on satellite signals.
Innovation Solution
A technique using a transmission station with an antenna array transmitting orthogonal beacon signals, allowing mobile units to determine their position based on beacon signals from a single ground station, utilizing orthogonal frequency division multiplexing and clock synchronization to estimate angular and distance data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS satellite signals are used for location determination, then high location accuracy can be achieved, but the system becomes limited by environmental interferences and satellite signal availability
Solution Approach 1:
The patent introduces ground-based transmission stations as intermediary devices between the location determination system and the mobile unit. These stations transmit beacon signals that serve as intermediaries to enable location determination without direct satellite signal dependency, thereby resolving the contradiction between maintaining accuracy and improving environmental adaptability
Solution Approach 2:
The patent segments the location determination system into multiple ground-based transmission stations distributed across different locations. Each station independently transmits beacon signals, and the mobile unit processes signals from multiple stations to determine its position. This segmentation provides geographic redundancy and eliminates single-point failure, improving both accuracy and environmental adaptability
2Adaptability or versatility
If conventional triangulation methods using multiple transmission locations are used, then location can be determined without satellites, but the system complexity increases requiring multiple transmission stations
Solution Approach 1:
The patent transitions from conventional two-dimensional triangulation (requiring multiple spatially distributed stations) to a method that exploits the temporal and signal structure dimensions. By using orthogonal signal portions transmitted from multiple antenna elements at a single station, the system achieves location determination with reduced spatial complexity while maintaining GPS-free operation capability
3Measurement precision
If orthogonal signal portions are transmitted from multiple antenna elements, then the mobile unit can differentiate signals and determine precise angular position, but the device complexity increases
Solution Approach 1:
The patent changes the signal parameter dimension by assigning orthogonal signal portions (different frequencies, codes, or time slots) to different antenna elements. This parameter differentiation enables the mobile unit to distinguish signals from individual antenna elements through correlation processing, achieving precise angular position measurement while managing device complexity through systematic signal design
Solution Approach 2:
The patent implements preliminary orthogonal signal assignment to antenna elements before transmission. The transmission station pre-configures orthogonal signal portions for each antenna element, and the mobile unit has pre-stored reference signals for correlation processing. This preliminary action simplifies real-time processing and reduces computational complexity during operation
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 accurate location determination of mobile units by differentiating beacon signals from multiple antenna elements, mitigating environmental interference and providing precise angular and distance data without satellite reliance.
Implementation Method 1
The antenna elements are configured to transmit orthogonal signal portions of the beacon signal, such that each antenna element transmits signal portions that are orthogonal to signal portions transmitted by other antenna elements
Implementation Method 2
an antenna array formed by a plurality of antenna elements arranged in a predetermined arrangement... configured to transmit beacon signals
Implementation Method 3
determining time difference between the transmission timestamp and time of reception of the at least one beacon signal and using the time difference for determining data on distance
Implementation Method 4
The complex amplitudes and phases provide data on estimated wireless channel values relating to path of the signal portions transmitted from the different transmitting antenna element arriving to the receiving antenna. Generally, the estimated wireless channel state values are associated with angle of departure of the signal with respect to boresight of the antenna array
Data Source
AI summary
A system and corresponding method for use in determining location of a mobile unit are described. The method comprises transmitting at least one beacon signal from an antenna array formed by an array of antenna elements located in a predetermined position and having predetermined boresight facing and receiving said at least one beacon signal by the mobile unit and using a processor for determining location of said mobile unit with respect to said predetermined position. The array of antenna elements comprises an arrangement of a plurality of antenna elements with predetermined arrangement configured such that each antenna element transmits signal portion having orthogonal signal portions with respect to other antenna elements of the array. Processing at the mobile unit utilizes variations in wireless channel states of signal portions received from the different antenna elements of the array for determining at least angular position of said mobile unit with respect to said boresight of said antenna array.