Cognitive Sub-Channel Selection for OFDMA Interference

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Solution Overview

Problem

Conventional Orthogonal Frequency Division Multiplexing (OFDM) technologies are limited by the restriction to using contiguous sub-channels, which can lead to unsuitable channels due to interference, resulting in lower data rates and increased power consumption in wireless and wired communication between computing devices.

Innovation Solution

A cognitive process is employed to select suitable sub-channels from anywhere in the frequency spectrum, including contiguous and non-contiguous channels, based on measurements and previous information to improve communication efficiency and reduce power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If contiguous sub-channels are used in OFDM, then channel allocation is simplified, but data rates decrease and power consumption increases due to interference from unsuitable channels

Engineering Contradiction:
Improvechannel allocation complexityVSAvoiddata rate
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The frequency spectrum is divided into multiple independent sub-channels that can be selectively allocated. Instead of using contiguous blocks, the system segments the spectrum and allows non-contiguous sub-channel selection based on interference conditions, enabling optimal data transmission paths while maintaining allocation simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sub-channel allocation becomes dynamic rather than static. The system continuously monitors interference levels and adaptively selects suitable sub-channels for each transmission, allowing the channel configuration to change based on real-time spectrum conditions, thereby maximizing data rates without proportionally increasing complexity.

Inventive Principle:
Principle #15Dynamics

2Device complexity

If contiguous sub-channels are used in OFDM, then channel allocation is simplified, but power consumption increases due to interference from unsuitable channels

Engineering Contradiction:
Improvechannel allocation complexityVSAvoidpower consumption
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The frequency spectrum is divided into multiple independent sub-channels that can be selectively allocated. Instead of using contiguous blocks, the system segments the spectrum and allows non-contiguous sub-channel selection based on interference conditions, enabling optimal data transmission paths while maintaining allocation simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sub-channel allocation becomes dynamic rather than static. The system continuously monitors interference levels and adaptively selects suitable sub-channels for each transmission, allowing the channel configuration to change based on real-time spectrum conditions, thereby maximizing data rates without proportionally increasing complexity.

Inventive Principle:
Principle #15Dynamics

3Productivity

If non-contiguous sub-channels are selected from anywhere in the frequency spectrum, then data rates increase and power consumption decreases, but channel allocation complexity increases

Engineering Contradiction:
Improvedata rateVSAvoidchannel allocation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system implements feedback mechanisms where transmission results and interference levels are monitored and used to inform future sub-channel selections. This feedback loop enables the system to learn from past transmissions and optimize channel allocation, reducing the effective complexity of managing non-contiguous sub-channels while maintaining high data rates.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes key parameters such as sub-channel frequency positions, bandwidth allocations, and modulation schemes based on measured interference conditions. By dynamically adjusting these parameters, the system optimizes data transmission efficiency without requiring complex manual configuration, as the parameters are automatically adapted to spectrum conditions.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS10581655B2Cognitive multi-user OFDMA
Publication Date: 2020.03.03 MICROSOFT TECHNOLOGY LICENSING LLC
  • US10581655B2 patent drawing
  • US10581655B2 patent drawing
  • US10581655B2 patent drawing

AI summary

A computing device operating according to a frequency division multiplexed protocol in which communication occurs over a signal formed from a plurality of sub-channels selected from anywhere in a frequency spectrum. A computing device may select sub-channels cognitively by using information about sub-channels previously deemed suitable or unsuitable by that computing device or other computing devices. A described technique for determining sub-channel suitability includes analyzing radio frequency energy in the sub-channel to detect signals generated by another computing device or high noise levels. Information may also be used to cognitively select sub-channels to be analyzed, such as by first selecting for analysis previously-used sub-channels.