Remote Radio Head Positioning via Uplink Signal Weighting

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Solution Overview

Problem

The use of remote radio heads in wireless communication networks leads to insufficient positioning accuracy due to the large granularity of cell coverage, which is inadequate for meeting the precision requirements of services like Enhanced-911 and indoor location-based messaging, especially since satellite-based positioning methods like GPS are often unavailable indoors.

Innovation Solution

A method involving a network node connected to multiple remote radio heads via a combiner, where the weighting of uplink signals is adjusted and measured to determine the position of wireless devices based on signal quality differences, allowing for precise location determination within the vicinity of specific remote radio heads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a single cell is spanned by multiple remote radio heads, then coverage is improved and handovers are avoided, but positioning accuracy deteriorates due to large granularity

Engineering Contradiction:
Improvecoverage areaVSAvoidpositioning accuracy
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent segments the cell coverage area into multiple zones, each associated with a specific remote radio head. By adjusting the weighting of uplink signals from different remote radio heads and measuring signal quality variations, the system can determine which remote radio head has the strongest influence on the wireless device's signal. This segmentation approach allows precise positioning within the cell by identifying the specific remote radio head vicinity where the device is located, thereby resolving the contradiction between maintaining large coverage area and achieving fine positioning accuracy.

Inventive Principle:
Principle #1Segmentation

2Productivity

If many small cells are deployed to improve capacity, then throughput is improved, but coverage deteriorates and deployment cost increases

Engineering Contradiction:
Improvenetwork capacityVSAvoidcoverage area
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

The patent introduces a new dimension for coverage extension by connecting multiple remote radio heads to a single radio base station through a combiner. This allows the system to extend coverage spatially across multiple locations without creating separate cells. The remote radio heads transmit and receive signals as if they were part of the same cell, enabling coverage expansion in the spatial dimension while maintaining single-cell operation, thus improving both coverage area and network capacity simultaneously.

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

3Area of stationary object

If remote radio heads are deployed indoors, then indoor coverage is improved, but positioning accuracy deteriorates due to unavailability of satellite-based positioning

Engineering Contradiction:
Improveindoor coverageVSAvoidpositioning accuracy
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent replaces satellite-based positioning systems (which rely on electromagnetic signals from space) with a ground-based signal quality measurement system. By measuring the quality of uplink signals received at different remote radio heads and analyzing how signal quality changes when weighting is adjusted, the system determines the wireless device's position without requiring satellite signals. This substitution enables accurate indoor positioning by using the existing cellular infrastructure and signal characteristics rather than external satellite systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3314961B1Determining the position of a wireless device using remote radio heads
Publication Date: 2020.08.05 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3314961B1 patent drawingFigure 1A~1D
  • EP3314961B1 patent drawingFigure 2~3
  • EP3314961B1 patent drawingFigure 4~5B

AI summary

It is presented a method for determining a position of a wireless device, the method being performed in a network node connected to a plurality of remote radio heads via a combiner. The method comprises the steps of: adjusting a weighting of an uplink signal for at least one of the remote radio heads; measuring a signal quality of a combined uplink signal received via the combiner; repeating the steps of adjusting and measuring until an exit condition is true; and determining a position of the wireless device based on how the measured signal quality differs for adjustments of weighting of the uplink signal for different remote radio heads.