Distributed Antenna System Time of Arrival Location Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional distributed antenna systems (DAS) face challenges in accurately determining the location of wireless devices due to combined signals from distributed antennas, which hinders precise location estimation, especially in emergency situations.
Innovation Solution
The method involves identifying the time of arrival of wireless signals at multiple active antenna units and estimating the location of the wireless device based on the difference in arrival times, sending this information to the baseband unit or serving mobile location center along with an indication of the corresponding time and frequency unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If signals are combined in the uplink before reaching the baseband unit, then the distributed antenna system provides enhanced coverage, but the baseband unit cannot accurately determine the location of the wireless device
Solution Approach 1:
The patent segments the signal processing function by separating location measurement from signal combining. Individual antenna units measure time of arrival of signals independently before combining, preserving location information that would otherwise be lost in the combined signal. This segmentation allows the system to maintain both enhanced coverage through signal combining and accurate location determination through distributed time of arrival measurement.
2Measurement precision
If time of arrival measurement is performed at distributed antenna units, then location estimation accuracy is improved, but system complexity increases due to coordination requirements
Solution Approach 1:
The patent introduces a location server as an intermediary that coordinates time of arrival measurements across distributed antenna units. The location server collects measurement data from individual antenna units and performs centralized location calculation, simplifying the coordination complexity by centralizing the management function while maintaining the distributed measurement architecture that provides accurate location estimation.
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
This approach enables accurate location estimation of wireless devices within the distributed antenna system, enhancing emergency response capabilities by providing precise location information.
Implementation Method 1
identifying a first time of arrival of a wireless signal in a time and frequency unit at a first active antenna unit (AAU). A second time of arrival of the wireless signal in the time and frequency unit at a second AAU is also identified. A location of a wireless unit transmitting the wireless signal is estimated based on a location of the first AAU, a location of the second AAU, and a difference between the first time of arrival and the second time of arrival.
Data Source
AI summary
Embodiments described herein provide for a method for obtaining location information regarding a wireless unit in a distributed antenna system (DAS). The method includes identifying a first time of arrival of a wireless signal in a time and frequency unit at a first active antenna unit (AAU). A second time of arrival of the wireless signal in the time and frequency unit at a second AAU is also identified. A location of a wireless unit transmitting the wireless signal is estimated based on a location of the first AAU, a location of the second AAU, and a difference between the first time of arrival and the second time of arrival. The location of the wireless unit and an indication that the location corresponds to the time and frequency unit is sent to a baseband unit or serving mobile location center (SMLC).