Segmented CSI Feedback Protocol for VHT Wireless Systems

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Solution Overview

Problem

Current wireless communication systems face challenges in efficiently communicating Channel State Information (CSI) feedback, particularly in MIMO systems with multiple user terminals sharing a single access point, where CSI feedback can be large and exceed the limitations of single MPDU or PPDU sizes, leading to fragmentation and inefficiencies in data transmission.

Innovation Solution

The proposed solution involves a protocol for segmented CSI feedback transmission, using Null Data Packet Announcement (NDPA) and CSI Poll messages to manage and segment CSI feedback into multiple MPDUs or PPDUs, allowing for efficient communication of CSI reports through low-overhead frame formats and segmentation, accommodating large CSI feedback sizes within the constraints of MPDU and PPDU sizes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If CSI feedback is transmitted using single MPDU or PPDU, then transmission simplicity is maintained, but large CSI feedback data cannot be accommodated

Engineering Contradiction:
ImproveCSI feedback data sizeVSAvoidtransmission protocol complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent segments large CSI feedback data into multiple smaller PPDUs, each fitting within standard size limits. The segmentation is achieved by dividing the CSI feedback report into multiple segments, with each segment transmitted in a separate PPDU. This allows large CSI feedback data to be transmitted while maintaining compliance with standard PPDU size constraints and avoiding the need for custom oversized frame structures.

Inventive Principle:
Principle #1Segmentation

2Quantity of substance

If CSI feedback is segmented into multiple MPDUs or PPDUs, then large CSI feedback data can be accommodated, but transmission overhead and complexity increase

Engineering Contradiction:
ImproveCSI feedback data sizeVSAvoidtransmission time
Core Design Contradiction:
Quantity of substanceVSLoss of time

Solution Approach 1:

The patent performs preliminary actions by establishing segmentation rules and identifiers before actual CSI feedback transmission. The Access Point sends a Null Data Packet Announcement (NDPA) frame that pre-notifies Stations about upcoming CSI feedback requirements and segmentation parameters. This preliminary notification allows Stations to prepare their CSI feedback data in the correct segmented format, reducing transmission delays and coordination overhead during actual feedback transmission.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If multiple STAs share a single channel sounding packet, then resource efficiency is improved, but CSI feedback coordination becomes more complex

Engineering Contradiction:
Improvechannel resource efficiencyVSAvoidCSI feedback coordination
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies local quality by assigning station-specific parameters and identifiers within the shared channel sounding packet. Each STA receives customized feedback requirements and transmission parameters tailored to its specific channel conditions and capabilities, while still participating in the shared sounding process. This allows efficient resource utilization through sharing while maintaining individualized coordination for each STA.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3661086B1Protocol for channel state information feedback
Publication Date: 2021.10.20 QUALCOMM INC
  • EP3661086B1 patent drawingFigure 1
  • EP3661086B1 patent drawingFigure 2
  • EP3661086B1 patent drawingFigure 3

AI summary

Certain aspects of the present disclosure relate to a low-overhead method for communicating Channel State Information (CSI) feedback in Very High Throughput (VHT) wireless communications systems. The present disclosure also provides packet formats for Null Data Packet Announcement (NDPA), CSI Poll and CSI feedback. In some cases, the CSI feedback may be too large to be carried in a single Media Access Control (MAC) protocol data unit (MPDU) or a Physical Layer (PHY) protocol data unit (PPDU), and a proposed protocol for CSI feedback segmentation can be then utilized.