Cluster-Specific CSI-RS Configuration for Multi-Cell Coordination

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Solution Overview

Problem

Current cell coordination methods in LTE-Advanced networks face limitations in spectral capacity due to restricted CSI-RS configurations, particularly in multi-cell coordination scenarios, leading to increased interference and reduced spectral efficiency.

Innovation Solution

Implementing a cluster-specific CSI-RS configuration that synchronizes CSI-RS settings across all cells within a cluster, allowing for partitioned radio resources and additional ZP CSI-RS configurations to enhance interference measurement and rejection, thereby improving SINR reporting and multi-user MIMO transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If cell-specific reference symbols (CRS) are used for multi-antenna transmission, then the system can support up to four independent layers, but the reference signal overhead is high and limits spectral efficiency

Engineering Contradiction:
Improvenumber of independent layersVSAvoidreference signal overhead
Core Design Contradiction:
Quantity of substanceVSLoss of energy

Solution Approach 1:

The patent changes the reference signal type from cell-specific CRS to channel state information reference signals (CSI-RS), modifying the signal parameters to reduce overhead. CSI-RS uses fewer resource elements per antenna port per subframe, directly addressing the overhead issue while maintaining support for multiple layers through cluster-specific configuration

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent segments the network into clusters of cells, where each cluster shares a common CSI-RS configuration. This segmentation allows coordinated multi-point transmission across multiple cells while using efficient reference signals, enabling more than four independent layers through the clustered approach rather than relying on cell-specific CRS

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If traditional cell coordination methods are used, then inter-cell interference can be controlled, but spectral capacity is limited due to restricted CSI-RS configurations

Engineering Contradiction:
Improveinter-cell interference controlVSAvoidspectral capacity
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent implements a universal CSI-RS configuration that is shared across all cells in a cluster. This cluster-specific configuration serves multiple functions: it enables coordinated transmission, provides common reference for channel estimation across cells, and supports both interference measurement and rejection. The universal configuration approach increases spectral capacity while maintaining interference control through the shared resource structure

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

Solution Approach 2:

The patent introduces cluster-specific CSI-RS configurations as an intermediary mechanism that coordinates transmission across multiple cells. This intermediary configuration allows cells to share reference signal resources and coordinate their transmissions, thereby increasing spectral capacity while the network node uses the resulting CSI reports to control inter-cell interference through intelligent scheduling and precoding

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If each cell configures independent CSI-RS, then cell-specific optimization is possible, but feedback from wireless devices is limited and coordination efficiency is reduced

Engineering Contradiction:
Improvecell-specific configuration flexibilityVSAvoidfeedback information for coordination
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent merges the CSI-RS configurations of multiple cells into a cluster-specific configuration. Instead of each cell using independent configurations, the cluster shares a common CSI-RS setup that all wireless devices in the cluster can measure and report on. This merging enables comprehensive feedback information to be collected, as devices can now provide coordination-relevant CSI that reflects the combined transmission characteristics of the entire cluster, thereby reducing information loss for coordination purposes

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3335351B1Cluster-specific reference signal configuration for cell coordination
Publication Date: 2023.05.17 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3335351B1 patent drawingFigure 1
  • EP3335351B1 patent drawingFigure 2
  • EP3335351B1 patent drawingFigure 3

AI summary

A node for managing cell coordination is provided. The node includes processing circuitry including a processor, and a memory. The memory contains instructions that, when executed by the processor, configure the processor to determine a cluster of a plurality of cells including a first cell, the cluster of the plurality of cells having a plurality of antennas and determine a channel state information reference signal, CSI-RS, configuration corresponding to a total number of the plurality of antennas. The memory further includes instructions that, when executed by the processor, configure the processor to partition radio resources corresponding to the CSI-RS configuration into a plurality of partitioned radio resources, and cause the first cell to transmit at least one CSI-RS signal according to a first partition of the plurality of partitioned radio resources while muting the radio resources of the remaining plurality of partitioned resources.