Aperiodic Feedback Triggering in LTE PUCCH

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Solution Overview

Problem

Current communication systems face inflexibility in feedback messaging, particularly with periodic CSI feedback, which can lead to resource wastage and increased overhead, especially in scenarios requiring only a small number of dynamic feedback bits, such as in LTE's aperiodic feedback mechanisms.

Innovation Solution

Incorporating an indication of aperiodic feedback messaging into scheduling information entities sent to communication devices configured for periodic feedback, allowing dynamic triggering and content control on the physical uplink control channel, enabling flexible and efficient feedback transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If periodic feedback messaging is used on PUCCH, then feedback transmission is reliable and continuously tracked, but resource allocation becomes inflexible and PUCCH resources are reserved even when not necessary

Engineering Contradiction:

Improvefeedback transmission reliabilityVSAvoidresource allocation flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic aperiodic feedback messaging that can be triggered on-demand by the network, allowing the feedback system to adapt its behavior based on current channel conditions and network needs. This transforms the static periodic feedback mechanism into a dynamic system that can switch between periodic and aperiodic modes, resolving the contradiction between reliability and flexibility.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameters of feedback messaging by introducing a trigger mechanism that dynamically controls when aperiodic feedback is sent. The network can adjust feedback frequency and timing by controlling trigger signals, allowing optimal resource utilization while maintaining reliable feedback transmission when needed.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If aperiodic feedback is transmitted on PUSCH, then resource allocation flexibility is improved, but uplink resources are wasted due to coarse granularity and additional DCI overhead is increased

Engineering Contradiction:

Improvefeedback triggering flexibilityVSAvoiduplink resource wastage

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent merges the advantages of both periodic and aperiodic feedback by implementing a hybrid mechanism where aperiodic feedback triggers are sent via PDCCH (efficient control channel) rather than requiring full PUSCH allocations. This combines the flexibility of aperiodic triggering with the efficiency of fine-grained resource allocation, avoiding the resource wastage associated with coarse PUSCH granularity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent segments the feedback messaging into control plane (PDCCH) for triggering and data plane (PUCCH/PUSCH) for actual feedback transmission. This segmentation allows the trigger signal to be transmitted efficiently with minimal overhead while the actual feedback data is sent only when needed, reducing overall resource wastage compared to always allocating full PUSCH resources.

Inventive Principle:

Principle #1Segmentation

3Adaptability or versatility

If aperiodic PUSCH feedback is used, then dynamic feedback capability is enhanced, but PDCCH overhead is increased due to dedicated separate UL grant DCI

Engineering Contradiction:

Improvefeedback timing flexibilityVSAvoidcontrol channel overhead

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent makes the PDCCH universal by using it for both scheduling control and feedback triggering functions. Instead of requiring separate DCI formats for UL grants and feedback triggers, the system uses the existing PDCCH infrastructure for dual purposes, reducing control channel overhead while maintaining flexible feedback timing capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP2777314B1Feedback messaging

Publication Date: 2020.05.13 NOKIA SOLUTIONS & NETWORKS OY

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AI summary

The disclosure relates to methods and apparatuses for feedback messaging in a communication system. A station can include into a scheduling information entity an indication of aperiodic feedback messaging on a physical uplink control channel and dynamically send the scheduling information entity with the indication to a communication device configured for periodic feedback messaging to trigger aperiodic feedback messaging by the communication device on the physical uplink control channel. Upon receiving the scheduling information entity the device can determine that it includes the indication and in response to the determining send at least one aperiodic feedback message on the physical uplink control channel.