Orthogonal Reference Signal Pilot Positioning in CoMP Systems

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Solution Overview

Problem

In CoMP scenarios, user equipment (UE) struggles to accurately measure downlink channel information from multiple cells due to reference signal collisions and interference from data symbols, limiting its ability to obtain precise channel information from neighboring cells.

Innovation Solution

The method involves sending reference signals in orthogonally separated pilot positions and performing data puncturing on data symbols from other cells in the CoMP set, allowing the UE to receive and measure downlink channels without interference, using cell IDs and virtual IDs to notify the UE of the pilot positions through high-layer signaling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If CRS pilot positions are implicitly mapped to cell IDs to prevent collisions, then CRS collision between neighboring cells is reduced, but the system can only support three cells at most while CoMP sets require support for multiple cells

Engineering Contradiction:
ImproveCRS collision avoidanceVSAvoidnumber of supported cells in CoMP set
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent segments the pilot position determination into two independent components: cell ID for serving cell identification and virtual ID for pilot position selection. This segmentation allows the system to support multiple cells in CoMP sets by decoupling the pilot position mapping from the cell ID, enabling flexible configuration of pilot positions for multiple cells without collision

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension (virtual ID) to the pilot position determination system. Instead of relying solely on cell ID for pilot position mapping, the virtual ID provides an additional degree of freedom, allowing multiple cells to share the same cell ID structure while having distinct pilot positions, thus supporting larger CoMP sets

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

2Productivity

If CRS from non-serving cells are transmitted without data puncturing, then resource utilization is improved, but data symbols from serving cells cause strong interference to CRS measurements

Engineering Contradiction:
Improveresource utilizationVSAvoiddownlink channel measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary anti-action by performing data puncturing on data symbols from serving cells at positions where CRS from non-serving cells will be transmitted. This preemptive removal of potentially interfering data symbols ensures that when the UE measures CRS from non-serving cells, there is no strong interference from serving cell data, thus preserving measurement precision while maintaining efficient resource utilization

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent introduces data puncturing as an intermediary mechanism between data transmission and CRS measurement. By selectively removing data symbols that would interfere with CRS measurements, the system mediates between the competing requirements of resource utilization and measurement precision, allowing both functions to coexist effectively

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2451202B1Method, device and system for reference signal processing
Publication Date: 2017.08.23 HUAWEI TECH CO LTD
  • EP2451202B1 patent drawingFigure 1~2
  • EP2451202B1 patent drawingFigure 3~4
  • EP2451202B1 patent drawingFigure 5~6

AI summary

Embodiments of the present invention disclose a method, an apparatus, and a system for processing a reference signal. The present invention relates to the field of radio communications technologies, and solves a technical problem that it is impossible to meet a requirement for measurement of downlink channels of multiple cells in a coordinated multipoint transmission/reception (CoMP) scenario in the prior art. According to the embodiments of the present invention, a reference signal is sent in a specified pilot position to a target user equipment (UE), where data puncturing is performed, in positions corresponding to the specified pilot position, with respect to data symbols simultaneously sent by an evolved NodeB (eNB) to which another cell in a CoMP set of the UE belongs, and the specified pilot position is orthogonally separated from a reference signal pilot position of the another cell in the CoMP set. The embodiments of the present invention are mainly applicable to the CoMP scenario.