Reference Signal Sub-Symbol Layout for OFDM Symbol Alignment

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Solution Overview

Problem

In LTE/LTE-A and NR systems, using a complete CP-OFDM symbol for reference signals results in high signaling overheads, leading to misalignment of CP-OFDM symbols among users and loss of frequency orthogonality, causing channel demodulation failures.

Innovation Solution

Splitting the main symbol into multiple sub-symbols for both reference signals and data transmission, ensuring alignment and reducing overheads while maintaining frequency orthogonality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complete CP-OFDM symbol is used for reference signal transmission, then channel tracking is implemented, but signaling overheads increase

Engineering Contradiction:
Improvechannel trackingVSAvoidsignaling overheads
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent divides a main symbol into multiple sub-symbols, where only certain sub-symbols carry reference signals while others carry data. This segmentation reduces the overhead of reference signals while maintaining channel tracking capability. Specifically, the main symbol is segmented in the time domain into multiple sub-symbols, allowing selective placement of reference signals.

Inventive Principle:
Principle #1Segmentation

2Quantity of substance

If the subcarrier width of CP-OFDM symbol is increased to reduce signaling overheads, then overheads are reduced, but misalignment of CP-OFDM symbols among users occurs

Engineering Contradiction:
Improvesignaling overheadsVSAvoidalignment precision
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent introduces a new dimension by defining sub-symbols within main symbols, creating a hierarchical structure. This allows reference signals to be placed in specific sub-symbols while maintaining the original subcarrier width and timing alignment of main symbols, thus reducing overhead without sacrificing alignment precision.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Quantity of substance

If the subcarrier width of CP-OFDM symbol is increased, then signaling overheads are reduced, but frequency orthogonality between users is lost

Engineering Contradiction:
Improvesignaling overheadsVSAvoidfrequency orthogonality
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

By segmenting the main symbol into sub-symbols and selectively placing reference signals in specific sub-symbols, the patent reduces the total resources dedicated to reference signals while maintaining the original subcarrier width. This preserves frequency orthogonality among users while achieving overhead reduction through more efficient resource utilization.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4694014A1Communication method, communication apparatus and computer-readable storage medium
Publication Date: 2026.02.11 HUAWEI TECH CO LTD
  • EP4694014A1 patent drawingFigure 1
  • EP4694014A1 patent drawingFigure 2(a)~2(e)
  • EP4694014A1 patent drawingFigure 3(a)~5

AI summary

This application provides a communication method, a communication apparatus, and a computer-readable storage medium. The method includes: determining a position of a main symbol occupied by a reference signal when a single subcarrier width is used, where the main symbol includes N sub-symbols including a sub-symbol used for sending a reference signal and a sub-symbol used for sending data, N>1, and N is an integer; and sending or receiving a reference signal by using the sub-symbol used for sending a reference signal, and sending or receiving the reference signal by using the sub-symbol used for sending data. According to the method provided in this application, the main symbol is split into a plurality of sub-symbols, some for sending or receiving reference signals, and some for sending or receiving data. In this way, signaling overheads can be reduced while alignment between a plurality of main symbols is ensured.