DM RS Sequence Segmentation for Carrier Aggregation

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Solution Overview

Problem

In the LTE-A system, there is a challenge in transmitting demodulation reference signals (DM RS) when a user equipment transmits the Physical Uplink Shared Channel (PUSCH) on multiple component carriers and across multiple sections of bandwidth, particularly with non-continuous resource allocation.

Innovation Solution

A method and apparatus for transmitting DM RS, where the DM RS sequences on each section of bandwidth are independent or part of an independent sequence, forming an independent sequence across multiple sections, with cyclic shift quantities and group hopping patterns adjusted to ensure orthogonality and efficient transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a user equipment transmits PUSCH on multiple component carriers with non-continuous resource allocation, then bandwidth utilization and transmission flexibility are improved, but the complexity of transmitting demodulation reference signals (DM RS) increases

Engineering Contradiction:
Improvebandwidth utilization and transmission flexibilityVSAvoidDM RS transmission complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the DM RS transmission by defining separate DM RS sequences for each section of bandwidth occupied by PUSCH on each component carrier. This segmentation allows the system to handle non-continuous resource allocation by treating each bandwidth section independently, thus managing the complexity through modular sequence generation rather than a monolithic approach.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by making DM RS sequences locally independent for each bandwidth section. Each DM RS sequence is generated with specific parameters (cyclic shift quantity, group hopping pattern) tailored to its local bandwidth section, allowing optimized transmission characteristics for each section while maintaining overall system functionality.

Inventive Principle:
Principle #3Local quality

2Reliability

If independent DM RS sequences are used for each bandwidth section, then orthogonality and transmission reliability are improved, but sequence management complexity increases

Engineering Contradiction:
Improvetransmission reliability and orthogonalityVSAvoidsequence management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent ensures orthogonality by dynamically adjusting parameters of DM RS sequences, specifically cyclic shift quantities and group hopping patterns, for each bandwidth section. These parameter changes allow independent sequences to maintain orthogonality relationships even when transmitted on multiple component carriers with non-continuous allocation, thus improving reliability through parameter optimization.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2472809B1Method and apparatus for transmitting reference signal
Publication Date: 2015.02.11 ZTE CORP
  • EP2472809B1 patent drawingFigure 1
  • EP2472809B1 patent drawingFigure 2
  • EP2472809B1 patent drawingFigure 3(a)~5

AI summary

A method for transmitting reference signal is provided, which includes the following steps: when carriers aggregate, User Equipment (UE) transmits a Physical Uplink Shared Channel (PUSCH) on one component carrier or multiple component carriers, and transmits a Demodulation Reference Signal (DM RS) for PUSCH on each bandwidth section occupied by the PUSCH on each component carrier, wherein a DM RS sequence on a bandwidth section is an independent sequence or a part of independent sequence which composes an independent sequence with DM RS sequences on several other bandwidth sections except said bandwidth, wherein said a bandwidth section is a continuous bandwidth section which is occupied by the PUSCH on any one of component carriers, or any one of several bandwidth sections occupied by the PUSCH on any one of component carriers. The present invention also provides a corresponding apparatus. The present invention solves the problem of transmitting the DM RS of PUSCH when multiple component carriers aggregate, and the problem of transmitting the DM RS when allocating PUSCH non-continuous resources in one component carrier.