Re-transmission Extension Carrier for Wireless Scheduling

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Solution Overview

Problem

The random timing of ARQ re-transmissions in wireless communication networks impedes efficient scheduling and inter-cell coordination, as the scheduler cannot predict when re-transmissions will occur, leading to suboptimal performance and coordination challenges across cells.

Innovation Solution

The implementation of a Re-transmission Extension Carrier (REC) shifts ARQ/HARQ re-transmissions from the main carrier to a separate extension carrier, allowing the main carrier scheduler to operate more deterministically and improving inter-cell scheduling by isolating re-transmissions on a dedicated carrier.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ARQ re-transmissions are handled on the main carrier, then the system can recover from errors, but the scheduler cannot predict when re-transmissions will occur, leading to suboptimal scheduling efficiency

Engineering Contradiction:
Improveerror recoveryVSAvoidscheduling efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent segments the carrier into a main carrier for initial data transmissions and a separate extension carrier for ARQ re-transmissions. This separation allows the main carrier scheduler to operate deterministically without random interruptions from re-transmissions, while the extension carrier handles error recovery independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts ARQ re-transmission functionality from the main carrier and places it on a dedicated extension carrier. This extraction removes the random timing interruptions from the main carrier scheduler, enabling more efficient and predictable scheduling of initial data transmissions.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If ARQ re-transmissions occur on the main carrier, then error correction is maintained, but inter-cell coordination is impeded due to random timing of re-transmissions

Engineering Contradiction:
Improveerror correctionVSAvoidinter-cell coordination
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent segments the transmission functions by carrier type, with the extension carrier dedicated to re-transmissions. This segmentation allows each cell to coordinate re-transmissions independently on the extension carrier while maintaining deterministic scheduling on the main carrier, thereby improving inter-cell coordination.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The extension carrier acts as an intermediary channel that mediates between the main carrier and the error correction requirements. By offloading re-transmissions to this intermediate carrier, the system maintains error correction capabilities while enabling better coordination across multiple cells.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If re-transmissions are integrated with initial transmissions on the same carrier, then resource utilization is maximized, but scheduling predictability and efficiency deteriorate

Engineering Contradiction:
Improveresource utilizationVSAvoidscheduling predictability
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent segments the transmission timeline and frequency resources into distinct phases: initial transmissions on the main carrier and re-transmissions on the extension carrier. This segmentation sacrifices some resource utilization efficiency to gain significant improvements in scheduling predictability and efficiency.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2904729B1Extension carrier for ARQ
Publication Date: 2022.12.14 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2904729B1 patent drawingFigure 1
  • EP2904729B1 patent drawingFigure 2~3
  • EP2904729B1 patent drawingFigure 4

AI summary

In a wireless communication network (10), HARQ acknowledgements, re- transmissions, and related signaling (e.g., channel quality reports) are performed on a Re-transmission Extension Carrier, REC, separate from the primary downlink traffic carrier(s). In various embodiments, the REC may comprise an aggregated wireless communication network channel, which may be cross-channel scheduled or may have its own scheduler. The REC may be Frequency Domain Duplex, FDD, or Time Domain Duplex, TDD, The REC may be dedicated to a main downlink carrier, or may be shared across a plurality of aggregated component carriers. The REC may be transmitted from the same base station (14) as one or more associated main carriers, or from a different base station (14). A shared REC may be operated in cooperative or contention modes. The REC may be implemented in unlicensed spectrum.