CSI Report Collision Handling in CoMP Wireless Systems

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Solution Overview

Problem

In wireless communication systems, collisions among channel state information (CSI) reports lead to prioritization issues, particularly in LTE and LTE-Advanced systems, where CSI reports with certain PUCCH reporting types are dropped, and existing methods do not adequately consider coordination among transmission points, especially in CoMP technologies.

Innovation Solution

The method involves separating CSI reports into sets and groups based on channel state information reference signal (CSI-RS) resources and interference hypotheses, determining priorities based on channel qualities, transmission schemes, and fairness among transmission points, to ensure that higher-priority reports are transmitted first, especially in CoMP systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If CSI reports are prioritized based only on PUCCH reporting type and serving cell index, then collision handling is simplified, but coordination among transmission points in CoMP systems is compromised

Engineering Contradiction:
Improvecollision handling complexityVSAvoidCoMP coordination reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent changes the prioritization parameters from simple PUCCH reporting type and serving cell index to include CSI report quantities, CSI-RS resource configurations, and transmission point coordination factors. This allows differentiated priority assignment that maintains CoMP coordination while handling collisions, resolving the contradiction between simplicity and reliability.

Inventive Principle:
Principle #35Parameter changes

2Loss of information

If multiple CSI reports are transmitted in the same subframe, then reporting completeness is improved, but collision and prioritization conflicts increase

Engineering Contradiction:
ImproveCSI reporting completenessVSAvoidprioritization conflict complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent performs preliminary prioritization assignment based on CSI report quantities and CSI-RS resource configurations before collision occurs. By pre-establishing priority rules considering transmission point coordination, the system can handle multiple CSI reports in the same subframe without complex runtime conflicts, reducing both information loss and prioritization complexity.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If CSI reports with higher priority are always transmitted, then reporting reliability is improved, but fairness among different transmission points deteriorates

Engineering Contradiction:
ImproveCSI reporting reliabilityVSAvoidtransmission point fairness
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies different priority assignment rules for different transmission points based on their local conditions, including CSI-RS resource configurations and coordination roles. This localized quality approach ensures that each transmission point receives appropriate priority treatment, maintaining both reporting reliability and fairness among transmission points in CoMP systems.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2680477B1Method and apparatus of handling collisions among channel state information reports
Publication Date: 2015.07.29 HTC CORP
  • EP2680477B1 patent drawingFigure 1
  • EP2680477B1 patent drawingFigure 2
  • EP2680477B1 patent drawingFigure 3

AI summary

A method of handling collisions among channel state information (CSI) reports for a user equipment in a wireless communication system supporting a technology of coordinated multipoint (CoMP) transmission/reception includes separating a plurality of CSI reports into report sets according to channel state information reference signal (CSI-RS) resources; determining priorities of the report sets; and transmitting a CSI report having a superior priority among the plurality of CSI reports to a network of the wireless communication system according to the priorities when the plurality of CSI reports have to be reported at a reporting instance.