Two-Antenna AoA Estimation via Multi-Channel Channel Sounding
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Solution Overview
Problem
Existing narrow-band system (NBS) localization technologies face challenges due to high costs and the impracticality of using large antenna arrays in devices with strict dimension constraints, limiting accurate angle estimation and localization capabilities.
Innovation Solution
A method and device for angle estimation using channel sounding technology with a first and second antenna aligned along a direction, performing signal exchanges through multiple channels, storing I/Q samples, estimating channel frequency responses, and determining weights to calculate the angle of arrival based on these responses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple distributed anchors are used for position estimation, then localization accuracy is improved, but system cost increases
Solution Approach 1:
The system segments the localization function into two parts: angle estimation is performed at the access point using signal processing, while position calculation is distributed to client devices. This eliminates the need for multiple expensive anchor devices while maintaining localization accuracy through mathematical computation of position based on angle of arrival and device-to-access-point distance.
2Measurement precision
If large antenna arrays are used for direction finding, then angle estimation resolution is improved, but device dimension constraints are violated
Solution Approach 1:
The system changes the operating parameters by using frequency domain processing instead of spatial domain processing. By transmitting multiple frequencies and processing channel frequency responses in the frequency domain, the system achieves high angle estimation resolution with a compact two-antenna array, avoiding the need for large physical antenna arrays.
Solution Approach 2:
The system transitions from spatial dimension (large antenna array) to frequency dimension (multiple frequency channels) to achieve angle estimation resolution. By exploiting frequency diversity and processing channel frequency responses across multiple frequencies, the system obtains precise angle information without requiring large physical separation between antennas.
3Measurement precision
If conventional BLUETOOTH-LE direction finding is used, then angle estimation capability is improved, but device size requirements increase
Solution Approach 1:
The system modifies the conventional BLE DF approach by using multiple frequency channels and processing channel frequency responses rather than relying on phase differences at a single frequency. This parameter change enables accurate angle estimation with a compact antenna array suitable for mobile devices.
Solution Approach 2:
The system replaces the mechanical solution (large physical antenna array) with a signal processing solution (frequency domain processing of channel responses). By using mathematical processing of channel frequency responses across multiple frequencies, the system achieves the same angle estimation capability without the mechanical constraint of large antenna separation.
Data Source
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AI summary
A method for determining an angle of arrival at a first communication device having a first antenna and a second antenna aligned along a direction and defining a normal thereto. The method comprises performing a respective signal exchange through each of a plurality of channels between the first communication device and a second communication device, storing a first plurality of in-phase and quadrature(I/Q) samples; estimating channel frequency responses for the first antenna and the second antenna respectively; measuring a respective distance; creating respective standard channel frequency response components corresponding to the respective distances; for each propagation path, selecting a first respective weight and a second respective weight; selecting a weight w1 (1) and an other weight w2(1);determining, based on the weight w1 (1) and the other weight w2 (1), the angle of arrival, relative to the normal, of signals direct from the second communication device.