UE-Assisted LBT Acknowledgment for Multiple Candidate Beams

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Solution Overview

Problem

In wireless communication systems, particularly in higher frequency bands like the 60 GHz band, conventional listen before talk (LBT) procedures performed by transmitting devices may not accurately represent the interference levels experienced by the receiver, leading to inefficiencies and prolonged timelines for downlink data transmissions when multiple beams are involved.

Innovation Solution

Implementing a method where the receiver, such as a user equipment (UE), receives a pre-grant indicating multiple beams and performs a listen before talk (LBT) procedure on each, providing a single acknowledgment as a waveform (APG) to the transmitter, indicating successful LBT on one or more beams, allowing for flexible resource allocation and scheduling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple pre-grant and acknowledgment handshakes are used for multiple candidate beams, then reliability of beam selection is improved, but the timeline before downlink data transmissions can start is prolonged

Engineering Contradiction:

Improvebeam selection reliabilityVSAvoidtimeline before data transmission

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent merges multiple LBT procedures and multiple APG transmissions into a single consolidated process. The UE performs LBT on multiple candidate beams simultaneously or in parallel, and transmits a single APG that indicates success for one or more beams, rather than performing separate handshakes for each beam. This combining approach maintains reliability by still evaluating multiple beams while reducing the overall time required.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent implements preliminary action by having the UE perform LBT procedures on multiple candidate beams before the actual data transmission occurs. The base station indicates multiple candidate beams in advance, and the UE prepares the APG transmission with LBT results already obtained, allowing for faster subsequent data transmission without requiring additional handshakes.

Inventive Principle:

Principle #10Preliminary action

2Device complexity

If transmitter-side channel sensing is used for LBT, then device complexity is reduced, but receiver-side sensing requirements are not adequately met

Engineering Contradiction:

Improvesensing mechanism complexityVSAvoidreceiver condition accuracy

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent inverts the traditional LBT approach by having the receiver (UE) perform the LBT procedure instead of the transmitter (base station). The base station indicates multiple candidate beams, and the UE independently performs LBT on those beams and transmits an APG to confirm success. This inversion ensures that receiver-side sensing requirements are met while keeping the overall system complexity manageable, as the UE already has the necessary sensing capabilities for its own transmissions.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS12615667B2Receive assisted listen before talk with multiple candidate beams and waveform as single acknowledgment of pre-grant

Publication Date: 2026.04.28 QUALCOMM INC

AI summary

This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for a user equipment (UE) to provide listen before talk (LBT) assistance to a transmitting device. The UE may receive a pre-grant (PG) indicating a plurality of beams. The UE may performing a LBT procedure on each beam of the indicated plurality of beams. The UE may transmit an acknowledgment to the pre-grant (APG) as a waveform that indicates that the LBT procedure for one or more of the indicated plurality of beams was successful. The waveform may be a sounding reference signal (SRS) with a sequence that indicates that the LBT procedure was successful.