CSI Report Collision Handling in Multicarrier Systems

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Solution Overview

Problem

In LTE-A systems, the limited uplink control channel capacity leads to collisions when multiple sets of channel state information (CSI) reports need to be transmitted simultaneously, resulting in inefficient communication due to potential losses in channel information.

Innovation Solution

The method involves dropping at least one CSI report when collision occurs and transmitting the second CSI report along with an indicator to the network, which indicates the dropped report, allowing the network to recognize and manage the transmitted CSI report effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If multiple sets of CSI reports are transmitted simultaneously to provide complete channel information, then the channel information completeness is improved, but the uplink control channel capacity is exceeded causing collisions

Engineering Contradiction:
Improvechannel information completenessVSAvoiduplink control channel capacity
Core Design Contradiction:
Loss of informationVSQuantity of substance

Solution Approach 1:

The patent segments the multiple CSI reports by introducing a collision indicator that identifies which specific CSI report collided. This allows the network to segment the recovery process by requesting only the collided report rather than retransmitting all reports, effectively dividing the problem into manageable parts.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent adds a new dimension to the CSI reporting system by introducing the collision indicator field. This additional dimension allows the system to track and manage collisions without increasing the actual CSI data volume, enabling efficient resource utilization while maintaining information completeness.

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

2Reliability

If all CSI reports are transmitted without dropping to ensure complete channel information, then the communication reliability is improved, but the overhead and resource consumption increase

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidoverhead and resource consumption
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent extracts only the essential collision information from the full CSI reports by transmitting a compact collision indicator. This extracted indicator conveys the critical information about which report collided without transmitting redundant data, reducing overhead while maintaining reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of transmitting all CSI reports simultaneously (which would waste resources), the patent discards the transmission of collided reports and recovers the lost information on-demand through targeted retransmission requests triggered by the collision indicator. This approach reduces unnecessary resource consumption while ensuring reliability.

Inventive Principle:
Principle #34Discarding and recovering

3Productivity

If CSI reports are dropped to avoid collisions and reduce overhead, then the uplink efficiency is improved, but the channel information completeness may be compromised

Engineering Contradiction:
Improveuplink efficiencyVSAvoidchannel information completeness
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent implements a feedback mechanism where the collision indicator provides information back to the network about which CSI report collided. This feedback enables the network to make informed decisions about retransmission, ensuring that channel information completeness is maintained while preserving uplink efficiency by avoiding unnecessary retransmissions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary action by detecting and indicating the collision before full retransmission is required. The collision indicator is generated in advance, allowing the network to proactively manage the missing information rather than reacting to complete transmission failures, thus maintaining both efficiency and completeness.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3107236B1Method of handling CSI report in multicarriers or comp communication systems and related communication device
Publication Date: 2019.07.24 ACER INC
  • EP3107236B1 patent drawingFigure 1
  • EP3107236B1 patent drawingFigure 2
  • EP3107236B1 patent drawingFigure 3

AI summary

A method of handling channel state information (CSI) reports for a communication device in a wireless communication system comprises dropping at least one first CSI report, when the at least one first CSI report collides with at least one second CSI report (602); and transmitting the at least one second CSI report and an indicator to a network of the wireless communication system, wherein the indicator indicates the at least one first CSI report or the at least one second CSI report (604); wherein the at least one first CSI report and the at least one second CSI report correspond to a plurality of component carriers, respectively, correspond to a plurality of transmission points of the network, respectively, or correspond to a plurality of coordinated multipoint (CoMP) configurations, respectively.