Estimating Device Using Multicarrier Signal Correlation
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Solution Overview
Problem
Conventional methods for estimating the direction or position of a moving body using radio signals face challenges in accuracy and require dedicated hardware, making them costly and inefficient for widespread use.
Innovation Solution
An estimating device employing a multicarrier signal, such as an OFDM signal, with a transmission antenna and reception antenna array, calculates complex transfer functions and moving body correlation matrices to enhance accuracy and reduce processing complexity, allowing for the use of existing communication devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional methods use dedicated hardware for radio signal processing, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent applies universality by enabling existing communication devices to perform both communication and movement detection functions. The base station uses standard communication antennas and signal processing capabilities to simultaneously handle data transmission and extract movement information from reflected signals, eliminating the need for dedicated detection hardware.
Solution Approach 2:
The communication infrastructure serves itself by using its own transmitted signals to detect moving bodies. The base station's communication signals are reflected by moving objects and captured by the same or other communication antennas, allowing the system to perform detection without external specialized equipment.
2Measurement precision
If conventional methods process signals to estimate moving body position, then measurement precision is improved, but loss of time increases due to complex processing
Solution Approach 1:
The patent applies preliminary action by continuously maintaining correlation matrices and transfer function information during normal communication operations. When movement detection is needed, the system can quickly process pre-collected signal data without requiring additional signal transmission or extensive new processing, reducing detection time.
Solution Approach 2:
The patent merges movement detection processing with existing communication signal processing workflows. By integrating the detection algorithms into the base station's normal operation and utilizing already-acquired communication signals, the system avoids separate dedicated processing steps that would increase time loss.
3Device complexity
If conventional methods use simple antenna configurations, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent applies dimensionality change by transitioning from analyzing simple signal strength to processing complex transfer functions that include phase and amplitude information across multiple antennas. This multi-dimensional signal characterization enables accurate direction estimation even with moderate antenna configurations by utilizing the full complexity of the received signal.
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 more accurate and cost-effective estimation of a moving body's direction or position by integrating moving body correlation matrices across subcarriers, improving estimation accuracy and reducing hardware and processing costs.
Implementation Method 1
a reflected signal which is the multicarrier signal transmitted from each of the M transmission antenna elements that has been reflected or dispersed by the moving body
Implementation Method 2
a reflected signal which is the multicarrier signal transmitted from each of the M transmission antenna elements that has been reflected or dispersed by the moving body
Implementation Method 3
PTL 1, 2, and 3 disclose techniques of estimating the position and state of a person that is a detection target by analyzing a component including a Doppler shift
Data Source
AI summary
An estimating device includes: a transmission antenna; a transmission signal generator that generates a multicarrier signal; a transmitter that outputs the multicarrier signal to the transmission antenna; a reception antenna; a receiver that measures reception signals including a reflected signal which is the transmitted multicarrier signal that has been reflected or dispersed by the moving body; a complex transfer function calculator that calculates, from the measured reception signals, a plurality of complex transfer functions indicating propagation characteristics between a transmission antenna element and a reception antenna element; a moving body correlation matrix calculator that calculates, for each of subcarriers, a moving body correlation matrix from the complex transfer functions; a subcarrier integrator that integrates the moving body correlation matrices; and an estimation processor that estimates the direction or position in which the moving body is present, using the integrated moving body correlation matrix obtained by the integration.