Wireless Location Measurement Using Frequency Domain Channel Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless location measurement methods using correlators require a long location measurement period and extensive correlation calculations, leading to reduced accuracy due to the need for accumulating signals over multiple preambles, which can result in position changes during the measurement process.
Innovation Solution
A method and apparatus for wireless location measurement that estimates radio channels in the frequency domain using received pilot signals, extracts propagation delay tab profiles, and calculates distances between transmitters and receivers, allowing for faster and more accurate location determination by converting these profiles from the frequency domain to the time domain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a correlator accumulates received signals to extract a propagation delay tab profile using preambles, then the propagation delay tab profile can be obtained, but the location measurement period becomes longer than the superframe duration requiring multiple superframes for accumulation
Solution Approach 1:
The patent changes the measurement parameter from using preambles in the time domain to using pilot signals in the frequency domain. This parameter change allows the system to extract propagation delay tab profiles within a single superframe duration by utilizing frequency domain channel estimation, thereby reducing the location measurement period while maintaining extraction accuracy
Solution Approach 2:
Instead of accumulating signals in the time domain as done by traditional correlators, the patent inverts the approach by performing channel estimation in the frequency domain using pilot signals. This inversion enables the extraction of propagation delay tab profiles without requiring multiple superframe accumulations, thus reducing the measurement period
2Productivity
If a correlator uses a limited number of preambles for location measurement, then the measurement can be performed with available signals, but the amount of correlation calculation becomes large
Solution Approach 1:
The patent replaces the mechanical correlation calculation process with a frequency domain channel estimation approach using pilot signals. This substitution eliminates the need for complex time-domain correlation operations while achieving the same goal of extracting propagation delay tab profiles, thereby reducing computational complexity and improving processing efficiency
3Quantity of substance
If the location measurement period is extended to accumulate multiple superframes, then sufficient signals can be collected for measurement, but the position of the wireless location measurement apparatus may change during this period reducing accuracy
Solution Approach 1:
The patent performs channel estimation in the frequency domain using pilot signals that are preliminarily embedded in each subframe. This preliminary action allows the system to obtain sufficient channel information within a single superframe without extending the measurement period, thereby preventing position changes during measurement and maintaining high accuracy
Data Source
AI summary
A method for wireless location measurement of a receiver is provided. The method includes: estimating radio channels of a plurality of frequency domains respectively corresponding to a plurality of transmitters by using received signals from the plurality of transmitters; extracting a plurality of propagation delay tab profiles based on the radio channels of the plurality of frequency domains; calculating the distance between each of the transmitters corresponding to the respective propagation delay tab profiles and the receiver by using the propagation delay tab profiles; and estimating the location of the receiver by using the distance between each transmitter and the receiver.