D2DMRS Interval Distribution for Channel Reliability

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Solution Overview

Problem

In device-to-device (D2D) communication, the reliability of data transmission is low due to rapid changes in channel characteristics, especially when high-frequency resources are used or terminals move quickly, making it difficult for receiving terminals to accurately demodulate signals.

Innovation Solution

A method and device that utilize a subframe structure with a minimum of 3 orthogonal frequency division multiplexing (OFDM) symbols for demodulation reference signals (DMRS) distributed at intervals, allowing for accurate demodulation and improved reliability in D2D communication by increasing pilot density and reducing channel estimation errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If high-frequency resources are used or terminals move quickly, then communication speed is improved, but channel characteristics change quickly making data transmission reliability low

Engineering Contradiction:
Improvecommunication speedVSAvoiddata transmission reliability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent applies preliminary action by distributing DMRS symbols at multiple predetermined positions within the subframe before data transmission occurs. This allows the receiving terminal to have reference signals ready in advance at strategic locations, enabling accurate channel estimation even when channel conditions change rapidly during high-speed communication.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the subframe by placing DMRS symbols at multiple distributed positions (at least 3 OFDM symbols) rather than using a single reference signal. This segmentation of reference signals across different time positions allows the system to capture channel characteristics at multiple points, improving reliability when channel conditions vary rapidly.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If DMRS symbols are distributed at intervals with minimum 3 OFDM symbols, then demodulation accuracy is improved, but subframe structure complexity increases

Engineering Contradiction:
Improvedemodulation accuracyVSAvoidsubframe structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by specifying that at least 3 OFDM symbols are used for DMRS transmission with distributed positioning. This parameter specification optimizes the balance between having enough reference signals for accurate demodulation and maintaining reasonable subframe structure, avoiding excessive complexity while ensuring demodulation accuracy.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3300283B1Device to device data transmission method and device
Publication Date: 2019.09.04 HUAWEI TECH CO LTD
  • EP3300283B1 patent drawingFigure 1~3
  • EP3300283B1 patent drawingFigure 4a~6b
  • EP3300283B1 patent drawingFigure 6c~8a

AI summary

Embodiments of the present invention provide a terminal-to-terminal data transmission method and a device. The terminal-to-terminal data transmission method includes: determining, by a terminal, a frame structure of a subframe used for communication; and implementing, by the terminal, communication with another terminal by using the subframe; where a minimum quantity of orthogonal frequency division multiplexing OFDM symbols used for transmitting demodulation reference signals DMRSs in the subframe is 3, and the OFDM symbols used for transmitting the DMRSs are distributed at intervals in the subframe. The embodiments of the present invention are used to improve reliability of data transmission in D2D communication when a channel changes quickly.