Partial CSI Feedback Chains for Massive MIMO Overhead Reduction

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Solution Overview

Problem

In wireless communication systems, especially massive MIMO systems, the increased CSI overhead poses a challenge in efficiently reporting channel state information (CSI) from user equipment to base stations, necessitating a method to manage and reduce this overhead effectively.

Innovation Solution

The method involves configuring two feedback chains for channel state information-reference signals (CSI-RS) and generating partial CSIs, with periodic and aperiodic reporting through these chains, allowing for flexible and dynamic feedback periods and offsets, enabling efficient CSI reporting by categorizing CSI into partial CSIs and reporting them through individual chains.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complete CSI is reported in massive MIMO systems, then channel state information accuracy is improved, but CSI overhead increases

Engineering Contradiction:

Improvechannel state information accuracyVSAvoidCSI overhead

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent divides complete CSI into multiple partial CSIs, each corresponding to different feedback chains. This segmentation allows the system to report only necessary partial CSIs based on channel conditions, reducing overall CSI overhead while maintaining essential channel state information accuracy for massive MIMO operations

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements partial CSI reporting where only selected partial CSIs are reported based on channel conditions and feedback chain configurations, rather than reporting complete CSI. This partial action approach reduces CSI overhead significantly while still providing sufficient channel state information for effective massive MIMO communication

Inventive Principle:

Principle #16Partial or excessive action

2Adaptability or versatility

If flexible feedback periods and offsets are implemented, then adaptability is improved, but device complexity increases

Engineering Contradiction:

Improvefeedback flexibilityVSAvoidfeedback chain configuration

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces dynamic feedback mechanisms where feedback periods and offsets can be flexibly adjusted based on channel conditions and traffic requirements. The system dynamically selects which partial CSIs to report through different feedback chains, providing adaptability while managing complexity through structured feedback chain configurations

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes feedback parameters such as reporting periods and offsets dynamically based on system conditions. By allowing these parameters to vary, the system achieves high adaptability in massive MIMO operations while the structured approach to parameter management keeps device complexity within acceptable limits

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10505612B2Method for feeding back partial CSIs from user equipment in wireless communication system and an apparatus for the same

Publication Date: 2019.12.10 LG ELECTRONICS INC

AI summary

A method for reporting channel state information (CSI) from a user equipment to a base station in a wireless communication system is disclosed. The method comprises the steps of configuring a first feedback chain corresponding to a first channel state information-reference signal (CSI-RS) and a second feedback chain corresponding to a second CSI-RS through higher layer signaling; generating a first partial CSI and a second partial CSI corresponding to each of the feedback chains by using the first and second CSI-RSs received from the base station; periodically reporting the first partial CSI to the base station in accordance with the first feedback chain; and aperiodically reporting the second partial CSI to the base station in accordance with the second feedback chain.