Time Delay Estimation via Time Domain Peak Interpolation
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Solution Overview
Problem
Current time delay estimation methods in wireless local area networks lack sufficient accuracy, particularly in indoor localization and synchronization applications, where precise location and synchronization are critical, and existing techniques using frequency domain channel estimates are not sufficient for applications requiring centimeter-level accuracy.
Innovation Solution
A method for time delay estimation in wireless communication systems that involves computing a complex channel impulse response, identifying peaks in its time domain representation, interpolating adjacent data points, and determining the time delay caused by hardware components in the receiver, using both in-phase and quadrature components to enhance accuracy and reduce computational complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If frequency domain channel estimates are used for time delay estimation, then the estimation can be obtained through group delay calculation, but the accuracy is insufficient for applications requiring centimeter-level precision
Solution Approach 1:
The patent replaces frequency domain group delay calculation with time domain peak detection and interpolation methods. Specifically, it uses inverse fast Fourier transform to convert frequency domain channel estimates to time domain impulse response, then applies peak detection and quadratic interpolation to achieve higher accuracy time delay estimation, substituting the conventional frequency domain approach with a time domain alternative that provides centimeter-level precision
Solution Approach 2:
The patent changes the domain of analysis from frequency domain to time domain, and further refines the measurement by applying interpolation to sub-sample accuracy. This parameter transformation allows the system to achieve higher precision by examining the signal characteristics in the time domain where peak locations can be determined with greater accuracy through mathematical interpolation techniques
2Measurement precision
If time domain channel estimates with peak interpolation are used, then accuracy is improved, but computational complexity increases
Solution Approach 1:
The patent applies partial interpolation only around detected peak regions rather than processing the entire time domain signal. By identifying peak locations first and then applying quadratic or higher-order interpolation only in the vicinity of these peaks, the system achieves high accuracy while minimizing the computational burden that would result from full-signal processing
Solution Approach 2:
The patent segments the time domain impulse response into distinct peak regions and processes each peak independently. This segmentation allows the system to apply interpolation algorithms only where necessary (at peak locations) rather than across the entire signal, reducing overall computational complexity while maintaining accuracy at critical measurement points
Data Source
AI summary
Embodiments described herein provide a method for time delay estimation in a wireless communication system. A signal received, from a transmitter, is delayed due to hardware components in the receiver. A time domain representation of a computed complex channel impulse response (CIR) is generated. A first set of peaks of a time domain representation of the complex CIR is determined and a first peak, having a lowest time delay of the first set of peaks relative to the arrival time of the signal at the receiver, is identified. Following the interpolation of a region corresponding to the first peak, a second set of peaks is determined, and a more accurate estimation of the delay experienced by the signal through the receiver is determined.