Downlink Grant CSI Feedback Resource Allocation

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Solution Overview

Problem

Current wireless communication systems face inefficiencies in uplink resource indication for channel state information (CSI) feedback, particularly in heterogeneous networks with mixed eNB deployments, leading to suboptimal performance and interference management challenges.

Innovation Solution

The solution involves using a downlink grant-triggered CSI transmission mechanism, where additional bits in the downlink grant are used to trigger CSI feedback, allowing for efficient resource allocation and reducing uplink overhead, especially in cloud RAN operations with multiple cooperating cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional uplink resource indication methods are used for CSI feedback, then the system maintains compatibility with existing protocols, but uplink overhead increases and resource allocation efficiency decreases

Engineering Contradiction:

Improveresource allocation efficiencyVSAvoiduplink overhead

Core Design Contradiction:

ProductivityVSLoss of substance

Solution Approach 1:

The downlink grant message is enhanced to serve dual purposes: traditional downlink scheduling and CSI feedback resource indication. By incorporating a CSI request field and uplink resource indication field into the existing downlink grant structure, the system eliminates the need for separate uplink grants, thereby reducing uplink overhead while improving resource allocation efficiency.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The CSI feedback resource indication functionality is extracted from the traditional uplink grant mechanism and integrated into the downlink grant message. This extraction allows the system to indicate uplink resources for CSI feedback through downlink signaling, reducing the need for separate uplink resource allocation messages and thereby reducing uplink overhead.

Inventive Principle:

Principle #2Taking out (Extraction)

2Device complexity

If separate uplink grants are used for CSI feedback allocation, then resource allocation is explicit and clear, but downlink control overhead and signaling complexity increase

Engineering Contradiction:

Improvesignaling complexityVSAvoidcontrol overhead

Core Design Contradiction:

Device complexityVSLoss of information

Solution Approach 1:

The patent merges the CSI feedback resource indication function with the downlink grant message. By combining these two previously separate signaling mechanisms into a single downlink grant, the system reduces downlink control overhead and signaling complexity while maintaining explicit resource allocation for CSI feedback.

Inventive Principle:

Principle #5Merging (Combining)

3Productivity

If downlink grant-triggered CSI transmission is implemented, then uplink resource allocation efficiency improves, but compatibility with legacy systems decreases

Engineering Contradiction:

Improveuplink resource allocation efficiencyVSAvoidsystem compatibility

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic fields (CSI request field and uplink resource indication field) into the downlink grant message that can be configured based on system needs. These dynamic elements allow the system to adapt between legacy and enhanced modes, maintaining compatibility while enabling improved uplink resource allocation efficiency when needed.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP2949068B1Efficient uplink resource indication for CSI feedback

Publication Date: 2021.03.17 QUALCOMM INC

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Figure 3A~3B

AI summary

Channel state information (CSI) feedback reporting is disclosed for multi-cell downlink cooperation networks. In such networks, when a user equipment (UE) has little uplink data traffic, CSI feedback is triggered by the serving base station through a downlink grant to the UE. The UE detects the CSI feedback trigger placed by the base station in the downlink grant and selects a set of uplink resources based, at least in part, on the downlink grant.