Hybrid Automatic Repeat Request Feedback Method Reducing Latency

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Solution Overview

Problem

Existing hybrid automatic repeat request (HARQ) feedback methods in wireless communications systems require a long transmission time for decoding and cyclic redundancy check (CRC) processes, making it difficult to meet low-latency service requirements.

Innovation Solution

The receive end determines a measurement value, such as the accumulated conditional mutual information (ACMI) or signal-to-noise ratio, to generate feedback information without performing a CRC, allowing the transmit end to decide on retransmission based on the received feedback, thereby reducing the time interval for sending feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the receive end performs sequential decoding and CRC checks before sending feedback, then the reliability of data transmission is improved, but the feedback time is extended and low-latency service requirements cannot be met

Engineering Contradiction:
Improvedata transmission reliabilityVSAvoidfeedback time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The receive end performs preliminary quality assessment of received data using metrics like signal-to-noise ratio or channel quality indicators before completing full decoding and CRC checks. This preliminary action allows the system to predict likely outcomes and prepare feedback decisions in advance, reducing the actual feedback time while maintaining reliability through selective application of full verification procedures.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Instead of always performing complete decoding and CRC verification, the system applies partial verification based on data quality metrics. When quality indicators suggest high probability of successful reception, the system may skip or reduce the scope of CRC checks, performing only essential verification. This partial action approach maintains sufficient reliability while significantly reducing processing time for feedback generation.

Inventive Principle:
Principle #16Partial or excessive action

2Measurement precision

If the receive end performs complete decoding and CRC checks, then the accuracy of feedback information is improved, but the processing complexity and time consumption increase

Engineering Contradiction:
Improvefeedback information accuracyVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system performs preliminary assessment of data quality using easily computable metrics such as signal-to-noise ratio, channel quality indicators, or initial decoding statistics. This preliminary action provides an early indication of likely decoding success, allowing the system to adjust the depth of subsequent verification procedures and reduce overall processing complexity while maintaining feedback accuracy for critical cases.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts verification parameters such as CRC check depth, decoding algorithm complexity, or threshold values based on measured data quality parameters. When quality metrics indicate poor reception conditions, the system increases verification rigor; when conditions are good, it reduces verification intensity. This parameter adaptation maintains feedback accuracy across varying conditions while optimizing processing complexity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3540996B1Hybrid automatic retransmission request feedback method and apparatus
Publication Date: 2022.10.26 HUAWEI TECH CO LTD
  • EP3540996B1 patent drawingFigure 1-1~1-2
  • EP3540996B1 patent drawingFigure 2
  • EP3540996B1 patent drawingFigure 3-1~3-2

AI summary

The present invention discloses a hybrid automatic repeat request feedback method and apparatus, and relates to the field of communications technologies. The hybrid automatic repeat request feedback method is applied to a receive end. After receiving data information sent by a transmit end, the receive end may determine, when target data in the data information is not checked, a measurement value of the target data, then generate feedback information based on the measurement value, and subsequently, send the feedback information to the transmit end, so that the transmit end can determine, based on the feedback information, whether the target data needs to be retransmitted. Because a total time for sending the feedback information is reduced and a consumed TTI is shorter, the present invention resolves a prior-art problem that a low-latency service requirement cannot be met, and can meet the low-latency service requirement for data transmission.