Sidelink Transport Block Sizing for Two-Stage Control Decoding

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Solution Overview

Problem

Current techniques for decoding control information and data messages in wireless communication channels are inefficient, leading to communication failures due to mismatches in coding rates between transmitting and receiving devices, particularly when control messages occupy a significant portion of the data channel.

Innovation Solution

Implement a two-stage control transmission method where devices determine a shared or mutually understood transport block size (TBS) and coding rate by estimating the resource element overhead of control messages, allowing both devices to encode and decode using the same coding rate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If control information is transmitted in the data channel, then communication efficiency is improved, but decoding reliability deteriorates due to coding rate mismatches

Engineering Contradiction:
Improvecommunication efficiencyVSAvoiddecoding reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The transmitting device performs preliminary calculation of the transport block size (TBS) by estimating the resource element overhead of the control information before encoding. This preliminary action ensures that both devices use the same TBS value for coding rate calculation, preventing decoding failures while maintaining efficient data channel utilization.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If control message occupies significant portion of data channel, then spectral efficiency is improved, but manufacturing precision (coding rate alignment) deteriorates

Engineering Contradiction:
Improvespectral efficiencyVSAvoidcoding rate alignment
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention dynamically adjusts the TBS parameter based on the estimated resource element overhead of the control message. By changing the TBS parameter to account for the control message occupancy, the system maintains accurate coding rate alignment even when control messages occupy significant portions of the data channel, thus preserving both spectral efficiency and coding precision.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If TBS is determined using approximate RE overhead, then device complexity is reduced, but measurement precision (TBS accuracy) deteriorates

Engineering Contradiction:
ImproveTBS determination complexityVSAvoidTBS accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The invention uses a standardized approximation model for calculating the resource element overhead of the control message, which copies the essential overhead characteristics without requiring complex exact measurements. This copying approach simplifies the TBS determination process while maintaining sufficient accuracy for reliable coding rate alignment, balancing device complexity and measurement precision.

Inventive Principle:
Principle #26Copying

Data Source

PatentEP4104370B1Transport block size determination for two stage control
Publication Date: 2025.12.10 QUALCOMM INC
  • EP4104370B1 patent drawingFigure 1
  • EP4104370B1 patent drawingFigure 2
  • EP4104370B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communications are described. In some systems, two devices may communicate over a sidelink and support a mutually understood transport block (TB) size (TBS) determination procedure associated with a data channel including a control message. A first device may encode and transmit information on the data channel, including the control message and a data message. A second device may receive and decode the information on the data channel. The first device and the second device may determine a TBS for encoding and decoding the data channel, respectively, based on determining an estimated resource element (RE) overhead for the control message and determining an approximate TBS based on the estimated RE overhead.