Composite HARQ Acknowledgement Signaling Overhead Reduction

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Solution Overview

Problem

In wireless communication systems, particularly in LTE-TDD and MIMO environments, the current methods for generating composite acknowledgement information for HARQ processes lead to increased overhead signaling, delayed transmissions, and inefficient resource allocation, especially at the cell border where radio propagation conditions are poor, resulting in potential handover failures.

Innovation Solution

A method and arrangement for generating composite acknowledgement information by providing a positive or negative acknowledgement indication for each transport block across multiple transmissions, allowing for the generation of accurate composite ACK/NAK messages based on the maximum function of individual ACK/NAK indications, thereby reducing unnecessary retransmissions and improving resource allocation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If composite acknowledgement information is generated using current methods in LTE-TDD and MIMO environments, then acknowledgement coverage is provided, but overhead signaling is increased

Engineering Contradiction:

Improveacknowledgement coverageVSAvoidoverhead signaling

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent combines multiple individual ACK/NAK indications into a single composite acknowledgement message. The receiving node generates a composite ACK/NAK message that bundles acknowledgment information for multiple transport blocks and HARQ processes, thereby reducing the number of separate signaling messages and lowering overhead while maintaining complete acknowledgment coverage.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The composite acknowledgement message serves multiple functions simultaneously: it acknowledges receipt of multiple transport blocks, indicates HARQ process status, and provides retransmission requests all in a single message structure. This multi-functionality reduces the need for separate signaling channels and messages.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Productivity

If current HARQ process methods are used, then data transmission is performed, but transmission delay is increased

Engineering Contradiction:

Improvedata transmissionVSAvoidtransmission delay

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The receiving node prepares the composite acknowledgement message by accumulating ACK/NAK indications for multiple transport blocks and HARQ processes in advance. This preliminary preparation allows the acknowledgment to be sent as soon as possible after receiving all relevant data, reducing the overall transmission cycle time and preventing delays.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent maintains continuous data transmission by efficiently managing HARQ processes and generating acknowledgments without unnecessary interruptions. The composite ACK/NAK mechanism enables continuous feedback loops between transmitter and receiver, keeping the data transmission pipeline full and reducing idle time.

Inventive Principle:

Principle #20Continuity of useful action

3Adaptability or versatility

If current acknowledgement generation methods are used, then HARQ processes are managed, but resource allocation is made inefficient

Engineering Contradiction:

ImproveHARQ process managementVSAvoidresource allocation efficiency

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The composite acknowledgement message provides comprehensive feedback to the transmitting node about the status of multiple transport blocks and HARQ processes. This feedback includes which blocks were successfully received and which require retransmission, enabling the transmitter to allocate resources efficiently by retransmitting only the necessary data rather than sending redundant information.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent changes the structure and parameters of the acknowledgement message from individual separate ACK/NAK signals to a composite message format that encodes multiple status indications. This parameter change in the signaling structure enables more information to be conveyed with fewer resources, improving resource allocation efficiency.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP2847913B1Methods, arrangements and nodes for providing composite acknowledgement information in a wireless communication system

Publication Date: 2018.03.07 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

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AI summary

There is provided a method, performed by a receiving node, for generating composite acknowledgement information for a Hybrid Automatic Repeat Request, HARQ, process. The composite acknowledgement information is generated in response to transport blocks received from a transmitting node. The method comprises the step (301 ) of providing, for each transport block, a positive acknowledgement/negative acknowledgement, ACK/NAK, indication for each of a plurality of transmissions of the transport block to define a respective set of ACK/NAK indications. The method also comprises the step (302) of generating the composite acknowledgement information based on the respective sets of ACK/NAK indications for the transport blocks over the plurality of transmissions. In this way, by considering respective sets of ACK/NACK indications over a plurality of transmissions, it is possible to generate an appropriate composite acknowledgment. A direct consequence of the proposed technology is that the composite acknowledgement information is generated as a positive acknowledgment, ACK, if two transport blocks have been successfully received even though the two transport blocks do not belong to the same transmission.