SAW Device AOA Determination for Short Signals
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Solution Overview
Problem
Conventional methods for determining the location of transmitting devices that send short-duration signals or signals with low signal-to-noise ratios (SNRs) face challenges in accurately measuring angles-of-arrival (AOA) and time-difference-of-arrival (TDOA) due to the difficulty in obtaining precise signal measurements.
Innovation Solution
The system employs spatially-diverse antennas and surface-acoustic-wave (SAW) devices to process signals from pairs of antennas, injecting non-inverted and inverted signal versions into SAW devices to determine TDOA, which is then used to calculate AOA, enabling accurate location determination of transmitting devices even with short-duration or low SNR signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional triangulation methods are used to determine location of transmitting devices, then location estimation can be achieved, but measurement precision of angles-of-arrival deteriorates for short-duration signals and low SNR signals
Solution Approach 1:
The patent segments the signal processing into multiple correlated output signals from the SAW device, each representing different time-delay components. By processing these segmented signals through multiple correlators with different reference signals, the system achieves precise TDOA measurement even for short-duration inputs, resolving the contradiction between short signal duration and measurement precision.
Solution Approach 2:
The patent introduces SAW devices as intermediary components that physically correlate incoming signals with stored reference signals. This intermediary mechanism enables precise time-difference measurement without requiring long signal durations, as the SAW device's physical correlation process extracts timing information efficiently from brief signal segments.
2Measurement precision
If conventional triangulation methods are used to determine location of transmitting devices, then location estimation can be achieved, but measurement precision of angles-of-arrival deteriorates for low SNR signals
Solution Approach 1:
The patent employs SAW devices as intermediary correlation processors that physically match incoming signals with stored references. This intermediary correlation process inherently enhances SNR by coherently integrating signal energy while averaging out noise, enabling precise AOA measurement even when input signals have low signal-to-noise ratios.
Solution Approach 2:
The patent performs preliminary correlation processing through the SAW device before final AOA calculation. By pre-processing signals to extract time-difference information and enhance signal characteristics through physical correlation, the system prepares optimized input data for subsequent AOA computation, improving measurement precision under low SNR conditions.
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 effectively determines the AOA and location of transmitting devices with improved accuracy for short-duration and low SNR signals, enhancing the precision in electronic warfare and communication systems.
Implementation Method 1
surface-acoustic-wave (SAW) devices
Implementation Method 2
An inverted version of the signals received through a second antenna of the pair is injected into a second input of the SAW device
Data Source
AI summary
Embodiments of a system and method for determining an angle-of-arrival (AOA) of signals received from a transmitting device are shown. Signals from the transmitting device are received through two or more pairs of spatially-diverse antennas. A non-inverted version of the signals received through a first antenna of a pair is injected into a first input of a surface-acoustic-wave (SAW) device. An inverted version of the signals received through a second antenna of the pair is injected into a second input of the SAW device. Signals present at tap outputs are processed to determine a time-difference-of-arrival (TDOA) between the signals received through each pair of antennas. The AOA may be calculated from the TDOAs determined from two or more pairs of antennas.