Hotspot Carrier Active Set Management via Reverse Link Power Estimation

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Solution Overview

Problem

Wireless communication systems face interference issues due to transmissions between terminals and base stations, which affect the performance of all affected base stations, particularly in multiple-access systems like CDMA, TDMA, and OFDMA, where hotspot carriers can cause adjacent channel interference and reduce system capacity.

Innovation Solution

A method where mobile devices measure signal strength and estimate reverse link transmit power for hotspot carriers, determining whether to add, remove, or maintain them in the active set based on the estimated power level to limit interference to non-hotspot sectors, using a power control module to compare power differentials and set thresholds to manage the active set effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If hotspot carriers are deployed to extend coverage and improve capacity, then system capacity and coverage area are improved, but adjacent channel interference to non-hotspot sectors increases

Engineering Contradiction:
Improvesystem capacityVSAvoidadjacent channel interference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the parameter of transmit power level for hotspot carriers. By controlling the power level of hotspot carrier transmissions, the system can extend coverage and improve capacity while limiting the adjacent channel interference to non-hotspot sectors through power parameter adjustment

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies different power control strategies to different sectors. Hotspot sectors use elevated power levels to extend coverage, while non-hotspot sectors maintain normal power levels, creating local quality differences that allow capacity improvement in specific areas without causing system-wide interference

Inventive Principle:
Principle #3Local quality

2Reliability

If mobile devices add more carriers to active set for better service, then service quality is improved, but interference to reverse link of non-hotspot sectors increases

Engineering Contradiction:
Improveservice qualityVSAvoidreverse link interference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent implements feedback control where mobile devices measure signal strength and estimate reverse link power levels, then report this information to the base station. The base station uses this feedback to make informed decisions about active set management, adjusting carrier inclusion based on actual interference conditions rather than fixed rules

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent makes the active set management dynamic by allowing mobile devices to continuously measure signal conditions and power levels, and by enabling the base station to adjust active set composition in real-time based on changing interference conditions, rather than using static carrier assignments

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2359655B1Management of active set with hotspot carriers
Publication Date: 2017.11.22 QUALCOMM INC
  • EP2359655B1 patent drawingFigure 1
  • EP2359655B1 patent drawingFigure 2
  • EP2359655B1 patent drawingFigure 3

AI summary

Techniques for managing communications in a cellular network are disclosed. The cellular network can include one or more sectors in which hotspot carriers are deployed. The hotspot carriers can be available to mobile devices beyond sector boundaries defined by the signal strength of ubiquitous carriers. A mobile device can measure a signal strength of a candidate hotspot carrier and estimate a reverse link mobile device transmit power level for communicating on the hotspot carrier. The mobile device may determine whether to add, remove, or maintain the hotspot carrier in its active set based on the estimated transmit power level so as to limit interference to the reverse link of non-hotspot sectors.