Uplink Reference Signal Transmission Using Virtual Cell IDs

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Solution Overview

Problem

The increasing number of user equipment (UEs) and data/control information transmitted/received by eNBs in wireless communication systems poses a challenge in efficiently utilizing finite radio resources for uplink/downlink data and control information transmission/reception.

Innovation Solution

A method for transmitting an uplink reference signal that supports enhanced uplink transmission, involving the use of a virtual cell ID for generating DMRS sequences, ensuring orthogonality between uplink DMRSs in a multi-cell environment, and dynamic indication of cell IDs for PUSCH and PUCCH DMRS sequences through higher-layer signaling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of UEs served by an eNB increases to satisfy growing data throughput demands, then data throughput capacity improves, but radio resource efficiency deteriorates due to finite available resources

Engineering Contradiction:
Improvedata throughput capacityVSAvoidradio resource efficiency
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent segments the uplink DMRS sequences by introducing different virtual cell IDs for PUCCH and PUSCH transmissions. This segmentation allows multiple UEs to be served simultaneously with orthogonal reference signals, increasing productivity while maintaining radio resource efficiency through proper resource division.

Inventive Principle:
Principle #1Segmentation

2Productivity

If multi-cell cooperative communication is introduced to increase data throughput, then throughput capacity improves, but system complexity increases due to coordination requirements between multiple eNBs

Engineering Contradiction:
Improvedata throughputVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies universality by using the same virtual cell ID mechanism for both PUCCH and PUSCH DMRS sequences. This multi-functional approach enables coordinated multi-point reception across multiple eNBs while maintaining a unified, relatively simple system architecture that does not require fundamentally different mechanisms for different functions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If uplink CoMP operations are supported to enhance reception performance, then reception reliability improves, but signal processing complexity increases due to multi-point coordination

Engineering Contradiction:
Improvereception reliabilityVSAvoidsignal processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses parameter changes by dynamically indicating virtual cell IDs through higher-layer signaling for PUSCH and using predefined rules for PUCCH. This allows the system to adapt reference signal characteristics for CoMP operations without requiring complex real-time processing changes, thereby improving reliability while controlling signal processing complexity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2817912B1Method and apparatus for transmitting uplink signal in wireless communication system
Publication Date: 2020.09.16 LG ELECTRONICS INC
  • EP2817912B1 patent drawingFigure 1(a)~1(b)
  • EP2817912B1 patent drawingFigure 2
  • EP2817912B1 patent drawingFigure 3

AI summary

The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting an uplink signal. A method for transmitting an uplink signal at a UE in a wireless communication system includes, when a virtual cell ID for a reference signal for demodulation of a physical uplink channel is provided, generating a sequence of the reference signal on the basis of the virtual cell ID, and transmitting the generated reference signal to an eNB. A sequence hopping pattern of the reference signal can be determined on the basis of the virtual cell ID.