User Equipment CQI Reporting for 5G URLLC Reliability

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Solution Overview

Problem

Current LTE systems face difficulties in reporting a channel quality indicator with a block error rate lower than 10%, which is necessary for achieving the high reliability and low latency required in 5G ultra-reliable and low latency communications (URLLC).

Innovation Solution

The user equipment is enabled to calculate and report a channel quality indicator with a block error rate of 1% or less by using a CQI table with predefined index values and offset values, allowing for flexible CQI calculation methods and coding schemes, and switching between different CQI tables based on instruction messages from the base station.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the channel quality indicator is fixedly defined with a block error rate of 10% or less in current LTE, then the system maintains compatibility and simplicity, but the reliability requirement for URLLC (99.999% packet reception success rate) cannot be met

Engineering Contradiction:
Improvepacket reception success rateVSAvoidCQI reporting mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces dynamic CQI reporting mechanisms where the user equipment can switch between different CQI tables (first CQI table for conventional 10% BLER, second CQI table for stricter BLER requirements) based on service type and base station instructions. This dynamic adaptability allows the system to meet URLLC reliability requirements without permanently complicating the overall CQI reporting framework.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameters of the CQI reporting mechanism by introducing multiple CQI tables with different block error rate assumptions (10% for conventional, 1% or lower for URLLC). The base station can instruct the user equipment to use different tables or apply offset values to CQI indices, effectively changing the error rate parameter to match service requirements without redesigning the entire system.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If multiple CQI tables and calculation methods are introduced to meet URLLC requirements, then the reliability and adaptability improve, but the device complexity and processing overhead increase

Engineering Contradiction:
ImproveCQI calculation flexibilityVSAvoidCQI table management complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent creates a universal CQI reporting framework that can serve both conventional services (using first CQI table with 10% BLER) and URLLC services (using second CQI table with 1% or lower BLER). The same user equipment and base station infrastructure handle both types of services by selectively applying different CQI tables or offset values, avoiding the need for separate systems.

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

Solution Approach 2:

The base station acts as an intermediary that receives service type information, determines the appropriate CQI table or offset value, and instructs the user equipment accordingly. This centralized control simplifies the user equipment's task to merely follow instructions rather than independently managing multiple CQI tables, reducing device complexity while maintaining system adaptability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3439355B1User device and reporting method
Publication Date: 2022.10.26 NTT DOCOMO INC
  • EP3439355B1 patent drawingFigure 1(a)~1(c)
  • EP3439355B1 patent drawingFigure 2~3
  • EP3439355B1 patent drawingFigure 4~5

AI summary

Provided is a user equipment in a radio communication system including a base station and the user equipment. The user equipment includes: a reception unit that receives an instruction related to a calculation method of a channel quality indicator, which is to be reported to the base station, from the base station; and a reporting unit that reports an index of a channel quality indicator, which is calculated in accordance with the instruction related to the calculation method of the channel quality indicator, to the base station.