HARQ Feedback Buffering for SPS Packet Matching

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In hybrid automatic repeat request (HARQ) data transmission systems, measurement gaps (MGs) can cause feedback message loss, leading to missed retransmissions of semi-persistent scheduling (SPS) data packets, resulting in decoding failures and time delays due to incorrect packet matching at the receiver.

Innovation Solution

The system reduces the time period and frequency of measurement gaps by allowing early reporting of measurement results and uses a HARQ ID in a radio resource control message to ensure correct identification and retransmission of SPS data packets via dynamic scheduling, ensuring accurate packet matching and decoding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the receiver transmits feedback message during measurement gap, then feedback can be sent, but feedback message may be lost

Engineering Contradiction:

Improvefeedback message deliveryVSAvoidfeedback message loss

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The patent applies preliminary action by having the receiver buffer the feedback message during the measurement gap before the gap ends. The feedback message is prepared and stored in advance, then transmitted immediately when the measurement gap concludes, ensuring no information loss occurs during the gap period.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If the transmitter re-transmits SPS data packet without HARQ ID, then retransmission can occur, but receiver cannot match packets causing decoding failure

Engineering Contradiction:

Improveretransmission efficiencyVSAvoidpacket matching accuracy

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent implements feedback by including a HARQ ID in the downlink control information that identifies the specific SPS data packet being re-transmitted. This feedback mechanism allows the receiver to accurately match the re-transmitted packet with the original packet buffer, ensuring correct decoding while maintaining efficient retransmission productivity.

Inventive Principle:

Principle #23Feedback

3Loss of information

If measurement gap time period is reduced, then feedback loss decreases, but measurement accuracy may be compromised

Engineering Contradiction:

Improvefeedback message lossVSAvoidfrequency measurement accuracy

Core Design Contradiction:

Loss of informationVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by buffering the feedback message during the measurement gap period. This allows the system to reduce the measurement gap time period to minimize feedback loss, while the buffered message ensures that measurement accuracy is maintained since the feedback is captured and preserved during the shortened gap.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS10079659B2Processing method and system for hybrid automatic repeat request data transmissions

Publication Date: 2018.09.18 HON HAI PRECISION INDUSTRY CO LTD

AI summary

In data transmissions, a processing method for hybrid automatic repeat request (HARQ) is applied to a transmitter transmitting a first semi-persistent scheduling (SPS) data packet to a receiver. The receiver receives the first SPS data packet and transmits feedback to the transmitter. The transmitter which receives the feedback message can determine that a transmission of a repeat SPS data packet is required when the feedback message is a negative acknowledgement, and a repeat SPS data packet together with a HARQ ID corresponding to the repeat SPS data packet is transmitted to the receiver. If the receiver can match the repeat SPS data packet with the first SPS data packet according to the HARQ ID, a combination of the first SPS data packet and the repeat SPS data packet can be decoded.