Uplink SDMA Scheduling via TXOP Start Frame

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Solution Overview

Problem

Current wireless communication systems face challenges in efficiently managing uplink transmissions in MIMO systems, particularly in achieving high data throughput while supporting both legacy and non-legacy devices, and effectively utilizing channel resources amidst interference.

Innovation Solution

The method involves an access point receiving request messages for transmission slots from stations and transmitting a TXOP start frame to indicate the start of SDMA transmissions, allowing multiple stations to transmit simultaneously using assigned spatial streams, thereby optimizing resource allocation and reducing interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple stations transmit simultaneously in uplink SDMA, then data throughput is improved, but interference management becomes more difficult

Engineering Contradiction:
Improvedata throughputVSAvoidinterference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system segments the uplink transmission resources by assigning different spatial streams to different stations. The access point receives request messages from multiple stations and allocates specific spatial streams to each station, allowing simultaneous transmissions while managing interference through spatial separation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements local quality by assigning different spatial characteristics to different transmission streams. Each station transmits on assigned spatial streams with specific beamforming characteristics, creating localized transmission quality that reduces interference to other stations while maintaining high throughput.

Inventive Principle:
Principle #3Local quality

2Productivity

If TXOP scheduling is implemented for uplink SDMA, then resource utilization is improved, but system complexity increases

Engineering Contradiction:
Improveresource utilizationVSAvoidscheduling system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The access point performs preliminary actions by receiving request messages from stations before the actual data transmission. The TXOP scheduling decision is made in advance, and the TXOP start frame is transmitted to indicate the scheduled transmission opportunity, allowing stations to prepare their transmissions efficiently.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The TXOP start frame serves as an intermediary mechanism between the access point's scheduling decision and the stations' transmission actions. This standardized frame format simplifies the scheduling system by providing a clear, structured way to communicate transmission opportunities without requiring complex real-time coordination.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Quantity of substance

If spatial streams are assigned to multiple stations, then channel capacity is improved, but spatial stream management becomes more complex

Engineering Contradiction:
Improvechannel capacityVSAvoidspatial stream management complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The system segments the available spatial streams and assigns specific streams to specific stations based on their transmission requests. The access point maintains tracking of which spatial streams are assigned to which stations, allowing efficient management of channel capacity without requiring complex real-time allocation during transmission.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2481252B1Uplink SDMA transmit opportunity scheduling
Publication Date: 2013.09.04 QUALCOMM INC
  • EP2481252B1 patent drawingFigure 1
  • EP2481252B1 patent drawingFigure 2
  • EP2481252B1 patent drawingFigure 3

AI summary

Certain aspects of the present disclosure present medium access control (MAC) protocols for uplink Spatial Division Multiple Access (SDMA) transmissions by one or more stations (STAs). An access point (AP) may receive one or more requests for uplink SDMA transmission from a plurality of stations. The access point may schedule the transmissions by sending a signal to the stations to notify them of the parameters of the uplink SDMA transmissions such as start time, duration of the transmission, spatial streams assigned to each station, and so on.