HARQ Feedback Frame Tone Set Segmentation for WLAN

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Solution Overview

Problem

Current wireless local area network (WLAN) technologies face challenges in efficiently and accurately transmitting and receiving hybrid automatic repeat request (HARQ) feedback frames, particularly in distinguishing acknowledgments (ACK) and negative acknowledgments (NACK) for physical layer protocol data units (PPDUs).

Innovation Solution

A method and apparatus are introduced that utilize a specific sequence transmitted in a WLAN system, where the HARQ feedback frame is divided into tone sets, with ACKs and NACKs distinguished by being transmitted only in specific subsets of tones, allowing accurate and efficient feedback transmission and reception.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If HARQ feedback frames are transmitted using conventional methods, then the feedback can be sent, but the accuracy of distinguishing ACK and NACK is insufficient

Engineering Contradiction:

Improvefeedback distinction accuracyVSAvoiddata transmission reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The feedback frame is segmented into multiple tone sets, where each tone set corresponds to a specific HARQ burst. This segmentation allows the receiver to accurately identify which burst is being acknowledged and distinguishes ACK from NACK based on the presence or absence of sequences in specific tone sets, thereby improving feedback distinction accuracy and data transmission reliability

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different tone sets are assigned different local qualities (presence or absence of specific sequences) to encode ACK/NACK information. Each tone set has a specific quality state that indicates the feedback type for its corresponding HARQ burst, enabling accurate local differentiation of feedback types without affecting other bursts

Inventive Principle:

Principle #3Local quality

2Productivity

If the feedback frame structure is simplified, then transmission efficiency improves, but the ability to accurately convey ACK/NACK information deteriorates

Engineering Contradiction:

Improvefeedback transmission efficiencyVSAvoidACK/NACK distinction accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent introduces a frequency-domain dimension by dividing the feedback frame into multiple tone sets. Instead of using time-domain multiplexing or complex signaling, the ACK/NACK information is encoded in the frequency domain where different tone sets can simultaneously carry distinct feedback information, improving both transmission efficiency and distinction accuracy

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent uses the presence or absence of specific sequences in different tone sets as analogous to 'color changes' to encode feedback information. Each tone set can be in one of two states (sequence present or absent), providing a simple yet effective mechanism to convey ACK/NACK information efficiently while maintaining high distinction accuracy

Inventive Principle:

Principle #32Color changes

Data Source

PatentUS11349611B2Method for transmitting or receiving frame in wireless LAN and device therefor

Publication Date: 2022.05.31 LG ELECTRONICS INC

AI summary

A method by which a station (STA) transmits an HARQ feedback frame in a wireless LAN system for supporting an HARQ process, according to one embodiment of the present invention, comprises: receiving an HARQ PPDU including a plurality of HARQ bursts; determining an ACK/NACK for at least one HARQ burst allocated to the STA, among the plurality of HARQ bursts; and transmitting, on the basis of the ACK/NACK determination result, an HARQ feedback frame including a predetermined sequence.