Wireless Positioning via Cross-Correlation and CIR Analysis

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Solution Overview

Problem

Existing positioning methods in wireless telecommunications, such as OTDOA and UTDOA, face challenges in accurately determining the time-of-arrival (TOA) measurements due to multipath propagation, leading to errors in positioning calculations, especially in non-line-of-sight (NLOS) conditions where additional path information is not reliably reported.

Innovation Solution

A method that involves determining the cross-correlation between received and transmitted signals to identify and classify reflecting clusters/objects based on their temporal behavior, allowing for the reporting of additional path information to improve TOA estimation and reduce data reporting resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If TOA measurements are performed in multipath propagation conditions, then positioning can be achieved, but measurement accuracy deteriorates due to multipath components causing early false detection or late detection

Engineering Contradiction:
ImproveTOA measurement accuracyVSAvoidpositioning reliability in multipath conditions
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces an intermediary processing stage between signal reception and TOA measurement. A correlation function is computed between the received signal and a reference signal, and this correlation function serves as an intermediary representation that helps identify the direct path component more reliably in multipath conditions. The correlation peak detection in the intermediary domain provides more robust TOA estimation than direct signal analysis.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent transforms the TOA measurement problem from the time-domain signal analysis to the correlation-domain analysis. By computing the correlation function between received and reference signals, the measurement is performed in an additional dimension (correlation magnitude and phase), which provides more information for distinguishing the direct path from multipath components.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If additional path information is reported to correct TOA errors, then positioning accuracy improves, but data reporting resources increase

Engineering Contradiction:
Improvepositioning accuracyVSAvoiddata reporting volume
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts only the essential correction information from the full correlation function. Instead of reporting the entire correlation function or all multipath components, the method identifies and reports only the parameters of significant multipath components (relative time difference, relative power, and phase) that need correction. This selective extraction reduces data volume while maintaining positioning accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the reporting parameters from raw signal data to processed correlation parameters. Instead of reporting full correlation functions or raw TOA measurements, the system reports derived parameters including relative time difference, relative power, and phase information of multipath components. This parameter transformation reduces data volume and focuses on the most relevant correction information.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If correlation function analysis is performed to identify multipath components, then TOA error correction capability improves, but computational complexity increases

Engineering Contradiction:
Improveerror correction capabilityVSAvoidcomputational complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies partial action by focusing computational resources on identifying only the most significant multipath components rather than analyzing all possible paths. The method identifies multipath components that exceed certain thresholds in terms of power or time difference, and processes only these significant components for correction. This selective processing reduces computational complexity while maintaining error correction capability for the dominant error sources.

Inventive Principle:
Principle #16Partial or excessive action

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 enhances the accuracy of position calculations by providing additional Channel Impulse Response (CIR) information beyond TOA, reducing data usage and improving positioning in challenging environments, while minimizing resource consumption.

Implementation Method 1

determining a cross-correlation between a received signal and a transmitted reference signal

Methodology Applied
Scientific EffectCross-correlation:

Implementation Method 2

determining a Channel Impulse Response (CIR) of the cross-correlation related to a first lobe detected above a selected threshold in the CIR

Methodology Applied
Scientific EffectChannel Impulse Response:

Data Source

PatentUS20240319310A1Methods and Apparatuses for Positioning in a Wireless Communications Network
Publication Date: 2024.09.26 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • US20240319310A1 patent drawing
  • US20240319310A1 patent drawing
  • US20240319310A1 patent drawing

AI summary

The present disclosure relates to methods and apparatuses for improving positioning of a device in a wireless communications network. An example method, performed by a measuring device configured to communicate with a positioning device, includes determining a cross-correlation between a received signal and a transmitted reference signal; determining a channel impulse response (CIR) of the cross-correlation related to a first lobe detected above a selected threshold in the CIR; analyzing a temporal behavior of reflecting clusters/objects based on determined CIR instances of a time-of-arrival (TOA); classifying the reflecting clusters/objects based at least on their temporal behavior; and reporting at least one classified reflecting cluster/object to the positioning device.