V2X Signaling Bandwidth Allocation via Implicit DFT Mapping

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Solution Overview

Problem

In V2X communications, the existing LTE-based systems face challenges in efficiently allocating radio resources due to limitations in Discrete Fourier Transform (DFT) sizes, leading to inefficiencies in signaling overhead and bandwidth utilization, particularly when transmitting data and control information simultaneously.

Innovation Solution

The method involves a UE determining the transmission bandwidth based on allowed DFT sizes and implicitly determining the allocated bandwidth, thereby reducing signaling overhead by indicating the number or subset of scheduling assignments and data subchannels, which conserves radio resources and improves operational efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the UE transmits both control information and data using allocated bandwidth, then the communication functionality is complete, but the signaling overhead increases and bandwidth utilization becomes inefficient

Engineering Contradiction:
Improvecommunication functionalityVSAvoidsignaling overhead
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent extracts the bandwidth indication information from the full scheduling assignment signaling. Instead of signaling the complete allocated bandwidth details, the system extracts only the essential bandwidth indicator and uses it to implicitly determine the transmission bandwidth based on allowed DFT sizes, thereby reducing signaling overhead while maintaining communication functionality

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces allowed DFT sizes as an intermediary parameter that mediates between the signaled bandwidth and the actual transmission bandwidth. The UE uses the signaled bandwidth indicator combined with the predefined allowed DFT sizes to determine the transmission bandwidth, eliminating the need for direct signaling of the complete bandwidth allocation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the transmission bandwidth is explicitly signaled for each UE, then the bandwidth allocation is precise, but the signaling overhead increases

Engineering Contradiction:
Improvebandwidth allocation precisionVSAvoidsignaling overhead
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent changes the parameter representation from explicit bandwidth values to bandwidth indicators that reference predefined allowed DFT sizes. Instead of signaling the actual bandwidth in bits, the system signals an index or identifier that maps to predefined bandwidth configurations, achieving precise bandwidth allocation with reduced signaling overhead

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies partial action by signaling only the essential bandwidth indicator rather than the complete bandwidth allocation details. The full bandwidth information is derived through the combination of the indicator and the predefined allowed DFT sizes, avoiding unnecessary signaling of redundant information

Inventive Principle:
Principle #16Partial or excessive action

3Ease of operation

If the UE divides RBs for control information and data transmission, then the communication is functional, but the overhead in signaling data allocation becomes challenging

Engineering Contradiction:
Improvecommunication functionalityVSAvoidsignaling complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges the control information and data transmission bandwidth indication into a single scheduling assignment signaling structure. Instead of separately signaling the bandwidth for control information and data, the system uses a unified bandwidth indicator that applies to both, simplifying the signaling complexity while maintaining functional separation

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3767869B1Methods for efficient signaling in v2x communications
Publication Date: 2023.02.15 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3767869B1 patent drawingFigure 1~2
  • EP3767869B1 patent drawingFigure 3
  • EP3767869B1 patent drawingFigure 4~6

AI summary

Various operations that can be performed by a transmitting UE to schedule radio frequency resources for use in a data transmission are presented. The transmitting UE determines the transmission bandwidth, subject to certain restrictions, such as allowed DFT sizes for the UE for a data transmission. The determination may be performed through autonomous resource selection operations and/or may be performed using information received through signaling received from the network node as part of a scheduling grant. The UE further determines the ALLOCATED BANDWIDTH. The ALLOCATED BANDWIDTH can be determined based on the TRANSMISSION BANDWIDTH, which has been determined, using a defined rule. Furthermore, the UE generates and transmits towards a receiving UE a scheduling assignment (SA) that indicates the number or the set of subchannels that are within, and conform to, the ALLOCATED BANDWIDTH which was determined. The UE can then perform the data transmission using the SA indicated number or set of subchannels. Corresponding operations and methods are presented for a receiving UE.