Primary Uplink Carrier Selection for LTE-A Control Reporting

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Solution Overview

Problem

Current multicarrier communication systems, such as LTE-A, face challenges in efficiently reporting control information on the uplink for multiple concurrent downlink carriers, leading to potential collisions and inefficiencies in HARQ feedback, CQI, SR, power headroom, and buffer status reporting.

Innovation Solution

The method involves designating a primary uplink carrier to consolidate HARQ feedback, CQI, SR, and buffer status reports, allowing for centralized management and reducing collisions by selecting and reselecting the primary carrier through various procedures, including RACH and RRC signaling, to support asymmetrical and symmetrical deployment scenarios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If control information is reported on multiple uplink carriers simultaneously, then the reporting capacity is improved, but collisions and interference between reports increase

Engineering Contradiction:
Improvereporting capacityVSAvoidcollisions and interference
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent segments control information reporting by designating specific uplink carriers as primary carriers for specific downlink carriers. This segmentation assigns dedicated reporting paths, preventing multiple control reports from colliding on the same uplink resources while maintaining the ability to report on multiple carriers simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements preliminary action by pre-configuring primary uplink carrier associations with downlink carriers through RRC signaling before data transmission begins. This advance configuration establishes a predetermined reporting structure that eliminates the need for dynamic carrier selection during transmission, thereby preventing collisions.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a primary uplink carrier is designated for each downlink carrier, then control information reporting is improved, but system complexity increases

Engineering Contradiction:
Improvecontrol information reportingVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies universality by implementing a standardized primary uplink carrier designation mechanism that works across all downlink carriers in the system. The same RRC signaling procedure and carrier association rules apply universally, regardless of the number or configuration of carriers, thereby improving reliability without proportionally increasing complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If carrier reselection procedures are implemented, then adaptability to changing conditions is improved, but signaling overhead and processing time increase

Engineering Contradiction:
Improvecarrier reselection capabilityVSAvoidsignaling overhead and processing time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent implements dynamics by allowing the primary uplink carrier designation to be changed through RRC reconfiguration when channel conditions or traffic requirements change. This dynamic adaptation enables the system to respond to varying conditions while using efficient signaling procedures that minimize the time and overhead required for reconfiguration.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2675231B1Method and apparatus for selecting and reselecting an uplink primary carrier
Publication Date: 2019.01.16 INTERDIGITAL PATENT HOLDINGS INC
  • EP2675231B1 patent drawingFigure 1
  • EP2675231B1 patent drawingFigure 2
  • EP2675231B1 patent drawingFigure 3

AI summary

A method and apparatus are described for using an uplink (UL) primary carrier for long term evolution-advanced (LTE-A) to support hybrid automatic repeat request (HARQ) feedback, a channel quality indicator (CQI), a scheduling request (SR), power headroom, and at least one buffer status report in the context of asymmetrical deployment and symmetrical deployment.