PCFICH Power Boosting for High-Reliability LTE Control Channels

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Solution Overview

Problem

The physical control format indicator channel (PCFICH) in LTE systems is not adapted for high-reliability modes and increased aggregation levels, leading to performance bottlenecks and potential backwards compatibility issues when trying to enhance its reliability through aggregation.

Innovation Solution

Power boosting of the PCFICH channel by the eNB when high-reliability-mode UEs are present or when a UE would benefit from increased reliability, based on factors like signal-to-noise ratio, aggregation levels, and specific transmission schemes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If aggregation is applied to PCFICH to enhance reliability, then reliability is improved, but backwards compatibility is compromised and device complexity increases

Engineering Contradiction:
ImprovePCFICH reliabilityVSAvoidbackwards compatibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies different transmission strategies to different UE groups: power boosting is applied specifically to UEs in high-reliability mode while maintaining standard PCFICH transmission for legacy UEs. This local differentiation resolves the contradiction by providing enhanced reliability only where needed without affecting backwards compatibility for other devices.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the transmission power parameter for PCFICH specifically for high-reliability mode UEs rather than changing the aggregation level structure. This parameter change achieves reliability improvement without modifying the fundamental PCFICH format, thereby maintaining backwards compatibility with legacy devices.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If aggregation is applied to PCFICH to enhance reliability, then reliability is improved, but device complexity increases due to additional CFI candidate evaluations

Engineering Contradiction:
ImprovePCFICH reliabilityVSAvoidUE complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies power boosting selectively only to UEs operating in high-reliability mode, while legacy UEs continue to use standard PCFICH reception. This localized application ensures that only high-reliability mode UEs experience the simplified single-CFI reception, while legacy UEs maintain their existing evaluation processes without additional complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses the existing PCFICH structure and single-CFI transmission format as a template for high-reliability mode, copying the familiar structure but enhancing it with power boosting. This approach allows high-reliability mode UEs to use the same simple reception logic as legacy UEs while achieving better reliability through power enhancement rather than structural changes.

Inventive Principle:
Principle #26Copying

3Reliability

If PCFICH transmission power is increased for high-reliability mode, then reliability is improved, but power consumption increases

Engineering Contradiction:
ImprovePCFICH reliabilityVSAvoideNB power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies power boosting only to PCFICH transmissions targeted at high-reliability mode UEs, while maintaining standard power levels for other transmissions and for legacy UE service. This selective local quality enhancement minimizes the overall power consumption increase while providing reliability improvements only where specifically needed.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent applies power boosting as a partial action rather than system-wide power increase. By boosting power only for specific PCFICH transmissions to high-reliability mode UEs and not for all transmissions, the patent achieves the necessary reliability improvement with minimal additional power consumption, avoiding excessive power usage.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3753309B1Improved pcfich reliabilty using power boosting
Publication Date: 2024.07.17 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3753309B1 patent drawingFigure 1
  • EP3753309B1 patent drawingFigure 2
  • EP3753309B1 patent drawingFigure 3

AI summary

According to some embodiments, a method performed by a network node for transmitting a physical control format indicator channel (PCFICH) comprises determining a wireless device will benefit from increased reliability of a PCFICH between the network 5 node and the wireless device; and increasing the transmission power of the PCFICH transmitted between the network node and the wireless device. In particular embodiments, determining the wireless device will benefit from increased reliability of the PCFICH comprises determining the wireless device is operating in high-reliability mode.