Wireless Location Estimation Using Signal Strength Reliability and Sensor Constraints
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Solution Overview
Problem
Current location estimation methods in wireless communication systems, particularly in interior environments, face challenges with low accuracy and high complexity, especially in environments with weak GPS signals, where fingerprint-based schemes require extensive manpower and data transmission, while parametric approaches offer lower accuracy.
Innovation Solution
The proposed method increases location estimation accuracy by selecting candidate locations based on reliability tests and restricting movable distances using sensor information, such as acceleration and angular velocity sensors, to reduce complexity and data requirements, and enhances reliability and efficiency in location estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fingerprint-based interior location estimating scheme is used, then location estimation accuracy is improved, but training phase complexity and data transmission requirements increase
Solution Approach 1:
The patent extracts only the necessary signal strength information from the fingerprint database rather than transmitting complete fingerprint data for all grid points. The mobile terminal receives minimal reference information and performs location estimation locally by comparing current signal measurements with stored reference signal strengths, significantly reducing data transmission requirements while maintaining accuracy.
Solution Approach 2:
The patent segments the location estimation process into two phases: a training phase where reference signal strengths are stored at grid points, and an estimation phase where the mobile terminal compares current measurements with reference data. This segmentation allows the system to pre-process location data offline, reducing online computational complexity and data transmission needs.
2Device complexity
If parametric interior location estimating scheme is used, then device complexity is reduced, but location estimation accuracy deteriorates
Solution Approach 1:
The patent merges the advantages of both fingerprint and parametric approaches by using signal strength measurements (fingerprint characteristic) combined with path loss model parameters (parametric characteristic). The system stores reference signal strengths at grid points like fingerprint methods but uses path loss parameters to interpolate and estimate location, achieving high accuracy with reduced complexity.
Solution Approach 2:
The patent changes the parameter representation from complete fingerprint databases to condensed path loss parameters and reference signal strengths. By transforming the data representation to use physical propagation parameters, the system reduces data transmission requirements while maintaining the accuracy benefits of signal strength-based estimation.
3Adaptability or versatility
If GPS satellite signal is used for location estimation, then global coverage is achieved, but accuracy deteriorates in interior environments
Solution Approach 1:
The patent introduces WLAN infrastructure as an intermediary system for location estimation in interior environments where GPS signals are unavailable. The mobile terminal uses signal strength measurements from nearby WLAN access points to estimate location, providing a complementary positioning method that works indoors while GPS works outdoors, achieving both global coverage and interior accuracy.
Data Source
AI summary
Disclosed is a method for increasing location estimation accuracy of a communication device, including identifying a set including at least one sample among a plurality of samples of a probability distribution for estimated locations of the communication device, and determining a location of the communication device among the at least one sample based on a reliability of each of the at least one sample, by determining the reliability of each of the at least one sample in the set, when a difference between a first location of the communication device which is estimated based on a first scheme and a second location of the communication device which is estimated based on a second scheme is greater than or equal to a preset threshold value, and determining a sample of which a reliability is greatest among the at least one sample as the location of the communication device.