Distributed Resource Unit Uplink Using CSD to Prevent Beamforming

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Solution Overview

Problem

Existing wireless communication systems face challenges in preventing unintentional beamforming when multiple stations transmit simultaneously, leading to interference and reduced communication efficiency.

Innovation Solution

Implementing cyclic shift diversity (CSD) phase shifts and dividing uplink bandwidth into odd and even subcarriers, with each station using a different CSD value for transmission to prevent unintentional beamforming.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If multiple stations transmit simultaneously using the same CSD value, then transmission simplicity is maintained, but unintentional beamforming interference occurs

Engineering Contradiction:
Improvetransmission simplicityVSAvoidunintentional beamforming interference
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by assigning different CSD values to different stations based on their specific characteristics or identifiers. Each station receives a unique CSD value tailored to its position or ID, which prevents unintentional beamforming interference while maintaining the simplicity of simultaneous transmissions. This localized differentiation resolves the contradiction by making each transmission distinct without complicating the overall transmission process.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the CSD parameter dynamically based on station characteristics. By varying the CSD value as a parameter that depends on station ID or position, the system prevents beamforming interference while maintaining transmission simplicity. This parameter change approach allows multiple stations to transmit simultaneously without creating harmful interference patterns.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a single CSD value is used for all stations, then system complexity is minimized, but communication reliability decreases due to interference

Engineering Contradiction:
Improvesystem complexityVSAvoidcommunication reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements local quality by assigning unique CSD values to each station based on their identifiers or positions. This localized differentiation ensures that each station's transmission is distinct, preventing interference and improving reliability without significantly increasing system complexity. The CSD values are determined by simple functions of station ID or position, maintaining ease of implementation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses copying by deriving CSD values from station identifiers or positions through deterministic functions. Each station's CSD value is copied from its unique identifier, ensuring consistency and reliability while avoiding the need for complex centralized coordination. This copying approach maintains system simplicity while achieving reliable communications.

Inventive Principle:
Principle #26Copying

3Object-affected harmful factors

If stations use different CSD values, then unintentional beamforming is prevented, but transmission differentiation complexity increases

Engineering Contradiction:
Improveunintentional beamforming preventionVSAvoidtransmission differentiation complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by making the CSD value a function of station characteristics such as ID or position. This simple parameter transformation provides sufficient differentiation to prevent beamforming interference without requiring complex transmission processing. The CSD values are computed using straightforward mathematical operations on station identifiers.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses segmentation by dividing the set of available CSD values into different groups or patterns that can be assigned to different stations. This segmentation allows for systematic differentiation while maintaining simplicity in the assignment process. The CSD values are segmented based on station characteristics, providing clear differentiation without excessive complexity.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4686112A1Short training field transmission via distributed resource units
Publication Date: 2026.01.28 COMCAST CABLE COMM LLC
  • EP4686112A1 patent drawingFigure 1
  • EP4686112A1 patent drawingFigure 2
  • EP4686112A1 patent drawingFigure 3

AI summary

A station may receive a trigger frame from an access point. The station may divide an uplink bandwidth into multiple portions (e.g., odd and even subcarriers) based on the trigger frame. The same cyclic shift diversity value may be used for: a first spatial stream with a first portion of subcarriers, and a second spatial stream using a second portion of the subcarriers, which may reduce unintentional beamforming.