Control Channel CSI Feedback for Reliable Low-Latency Transmission

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Solution Overview

Problem

Existing wireless communication systems face challenges in achieving reliable and efficient transmission of control information with low error rates and latency, particularly in ultra-reliable low latency communications (URLLC) scenarios, as current feedback mechanisms primarily focus on data channels and are insufficient for control channels.

Innovation Solution

Implementing dedicated channel state information reporting for control channels, where UEs provide feedback on channel quality to adjust coding protection levels, allowing for optimized retransmissions based on initial and subsequent transmissions to meet error rate and latency specifications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If retransmission is performed to reduce error rate, then reliability is improved, but latency increases

Engineering Contradiction:
Improveerror rateVSAvoidlatency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements feedback mechanisms where UEs report channel state information (CSI) for control channels, enabling the base station to adaptively adjust transmission parameters. This feedback loop allows the system to optimize retransmission strategies by selecting appropriate coding rates and aggregation levels based on current channel conditions, thereby reducing the need for multiple retransmissions and lowering latency while maintaining reliability

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts coding protection levels and aggregation levels based on reported channel conditions. Instead of using fixed transmission parameters, the base station adapts the coding rate and aggregation level in response to changing channel states, allowing optimal balance between reliability and latency for each transmission attempt

Inventive Principle:
Principle #15Dynamics

2Reliability

If coding protection level is increased to reduce error rate, then reliability is improved, but transmission efficiency deteriorates

Engineering Contradiction:
Improveerror rateVSAvoidtransmission efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes transmission parameters (coding rate, aggregation level) based on channel conditions. The base station adjusts these parameters dynamically according to CSI feedback from UEs, selecting higher protection levels only when channel conditions warrant them, thus avoiding unnecessary efficiency loss while maintaining required reliability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system applies coding protection selectively based on channel conditions rather than always using maximum protection. When channel conditions are good, lower coding rates are used to maximize efficiency; when conditions deteriorate, protection levels are increased only to the extent needed to maintain reliability

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If dedicated feedback reporting for control channel is implemented, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvecontrol channel transmission reliabilityVSAvoidfeedback mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent reuses existing feedback reporting structures and procedures for control channel CSI reporting, leveraging the universal feedback framework already present in the system. This approach avoids creating entirely new complex feedback mechanisms while still achieving dedicated control channel feedback functionality through adaptive modulation and coding adjustments

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

Data Source

PatentEP3659282B1Dedicated channel state information reporting for a control channel
Publication Date: 2025.09.17 QUALCOMM INC
  • EP3659282B1 patent drawingFigure 1
  • EP3659282B1 patent drawingFigure 2
  • EP3659282B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communication are described. A method may include measuring channel quality of a reference signal communicated via a control channel, determining a code rate for a control channel based on the measured reference signal, generating feedback data for the control channel based on the code rate, and transmitting the feedback data. Another method may include transmitting a reference signal in a control channel, receiving channel quality feedback data for the control channel in response to the reference signal, and transmitting a control channel transmission in the control channel using a modulation and coding scheme selected based on the feedback data.