Terminal Channel State Reporting for Coverage Enhancement

Solution Overview

Problem

In LTE-A systems, user equipment (UE) with low cost/low specification, such as those used for metering or surveillance, face performance deterioration in poor propagation environments due to limited data transmission and high battery consumption, especially when operating with a fixed number of resource blocks (RBs).

Innovation Solution

A method for reporting channel state information (CSI) by a UE that hops in a specific number of resource blocks, involving random access procedures and aperiodic CSI reporting, where the number of repetitive transmissions is determined by various factors including predetermined values, scaling factors, and coverage enhancement levels to enhance coverage and diversity gain.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the UE uses maximum 6 RBs only irrespective of system bandwidth to lower cost and reduce battery consumption, then device cost and energy efficiency are improved, but transmission performance deteriorates in poor propagation environments

Engineering Contradiction:

Improvebattery consumptionVSAvoidtransmission performance

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements dynamic adjustment of the number of repetitive transmissions based on coverage enhancement levels. The UE adapts its transmission strategy by selecting different numbers of repetitive transmissions (e.g., 1, 2, 4, 8, 16, 32) according to the detected coverage enhancement level, allowing the system to optimize between battery consumption and transmission reliability in real-time varying channel conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of repetitive transmission count based on coverage enhancement levels. By mapping different coverage enhancement levels to specific numbers of repetitive transmissions, the system dynamically adjusts transmission parameters to maintain reliable communication in poor propagation environments while minimizing battery consumption in better conditions.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the UE increases coverage using repetition method in poor propagation environments, then coverage and reliability are improved, but battery consumption increases

Engineering Contradiction:

ImprovecoverageVSAvoidbattery consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic adjustment of the number of repetitive transmissions based on coverage enhancement levels. The UE adapts its transmission strategy by selecting different numbers of repetitive transmissions (e.g., 1, 2, 4, 8, 16, 32) according to the detected coverage enhancement level, allowing the system to optimize between battery consumption and transmission reliability in real-time varying channel conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of repetitive transmission count based on coverage enhancement levels. By mapping different coverage enhancement levels to specific numbers of repetitive transmissions, the system dynamically adjusts transmission parameters to maintain reliable communication in poor propagation environments while minimizing battery consumption in better conditions.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the UE changes band for repetition according to time to obtain diversity gain, then transmission performance is improved, but channel state measurement accuracy becomes critical

Engineering Contradiction:

Improvetransmission performanceVSAvoidchannel state information accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent performs channel state information measurement and reporting before actual data transmission. The UE measures the downlink channel state, calculates CSI including CQI, PMI, and RI, and reports this information to the base station in advance. This preliminary CSI acquisition enables the base station to make informed scheduling decisions and select appropriate modulation and coding schemes before transmission begins, ensuring accurate channel state measurement is available for optimal transmission configuration.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where the UE measures downlink channel state information and feeds this back to the base station. The base station uses this feedback to adjust transmission parameters, select appropriate coverage enhancement levels, and optimize the number of repetitive transmissions. This closed-loop feedback ensures that channel state information remains accurate and up-to-date for dynamic transmission optimization.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS9941948B2Method of reporting channel state and apparatus therefor

Publication Date: 2018.04.10 LG ELECTRONICS INC

AI summary

A method of reporting a channel state, which is reported by a terminal configured to transmit and receive data while hopping in a unit of the specific number of resource blocks (RBs) in a wireless communication system, includes receiving a random access response including an aperiodic channel state report request in response to a transmitted random access preamble, calculating channel state information according to the aperiodic channel state report request in consideration of the number of repetitive transmissions for the terminal, and reporting the calculated channel state information to a base station. In this case, the number of repetitive transmissions for the terminal may be determined by a predetermined or signaled value.