OTFS IoT Transmission for Low-Power Delay-Doppler Links

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Solution Overview

Problem

Existing wireless communication methods for IoT devices are power-intensive and prone to disruptions due to channel imperfections, requiring significant energy for mesh network maintenance and encoding, which is inefficient for devices with limited energy sources.

Innovation Solution

The implementation of orthogonal time frequency space (OTFS) modulation techniques, which allow IoT devices to transmit directly to a wireless base station with reduced energy consumption by mitigating channel state and compensating for impairments, and the use of a manager device for efficient address translation and device management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mesh network methods are used for IoT device communication, then network connectivity is established, but energy consumption increases significantly

Engineering Contradiction:
Improvenetwork connectivityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts the core communication function from the complex mesh network infrastructure, allowing IoT devices to communicate directly with base stations without requiring intermediate relay devices. This eliminates the need for mesh network maintenance and reduces energy consumption associated with multi-hop transmissions and network protocol overhead.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent transitions from traditional time-frequency domain communication to the delay-Doppler domain, enabling more efficient signal transmission that is inherently more robust to channel impairments. This dimensional change in the signal processing domain allows for direct communication with fewer repeaters and less energy expenditure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If conventional wireless methods are used, then communication is established, but disruptions occur due to channel imperfections requiring retransmission

Engineering Contradiction:
Improvecommunication efficiencyVSAvoidcommunication stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent transforms the communication signal into the delay-Doppler domain, where multipath fading and mobility-induced Doppler shifts are converted into manageable phase rotations rather than destructive interference. This allows receivers to accurately recover transmitted data even in challenging wireless environments, eliminating the need for retransmissions and improving communication reliability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent converts the harmful effects of multipath propagation and Doppler shifts into beneficial phase information in the delay-Doppler domain. What were previously sources of signal degradation become carriers of useful channel state information that can be exploited for improved communication performance and robustness.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If encoding and verification protocols are implemented to cope with channel disruptions, then communication reliability improves, but energy overhead increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidenergy overhead
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

By operating in the delay-Doppler domain, the patent achieves inherent robustness to channel impairments through the mathematical properties of the transformation. This built-in resilience eliminates the need for extensive error detection and correction protocols, reducing the energy overhead associated with encoding, verification, and retransmission while maintaining high communication reliability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3940975A1Orthogonal time frequency space modulation system for the internet of things
Publication Date: 2022.01.19 COHERE TECHNOLOGIES INC
  • EP3940975A1 patent drawingFigure 1
  • EP3940975A1 patent drawingFigure 2A
  • EP3940975A1 patent drawingFigure 2B

AI summary

A system and method of operating an Internet of Things (IOT) device and an IOT manager device. The method includes determining, during operation of the IOT device in a low power mode, an orthonormal time-frequency shifting (OTFS) transmission waveform using two-dimensional (2D) channel state information relevant to a delay-Doppler channel domain. The method further includes transmitting, during operation of the IOT device in a high power mode, the OTFS transmission waveform. The process of determining the OTFS transmission waveform may include, for example, receiving, from the IOT manager device, the 2D channel state information and storing it within a memory of the IOT device. Alternatively, at least one OTFS pilot transmission may be received from the IOT manager device and the 2D channel state information determined using the OTFS pilot transmission.