MCM Packet Detection via Phase Difference Deviation

Solution Overview

Problem

Existing Multi-Carrier Modulation (MCM) receiving systems face challenges in cost-effective carrier detection, particularly in low-cost or low-power systems, where correlation-based methods are computationally intensive and unreliable due to varying packet amplitudes and noise levels, making them unsuitable for applications like power line communication.

Innovation Solution

A method for detecting packets in MCM systems by computing a deviation value based on phase differences between carriers in the preamble, which is compared to a threshold to determine packet detection, and optionally calculating a symbol offset to synchronize with the packet, independent of amplitude and noise variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If correlation-based carrier detection is used in MCM receiving systems, then packet detection capability is improved, but computational complexity and power consumption increase significantly

Engineering Contradiction:

Improvepacket detection capabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts only the essential phase difference information from the received signal, discarding amplitude information that contributes to computational complexity. By computing phase differences between adjacent carriers and comparing against a threshold, the system achieves reliable packet detection without the computationally intensive correlation operations required by conventional methods.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical/computational correlation-based detection system with a phase-difference-based detection system. This substitution eliminates the need for complex correlation calculations and threshold adjustments based on amplitude, significantly reducing power consumption while maintaining detection reliability in low-cost MCM receiving systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If correlation-based carrier detection is used in MCM receiving systems, then packet detection capability is improved, but device complexity increases

Engineering Contradiction:

Improvepacket detection capabilityVSAvoidprocessor complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts only the essential phase difference information from the received signal, discarding amplitude information that contributes to computational complexity. By computing phase differences between adjacent carriers and comparing against a threshold, the system achieves reliable packet detection without the computationally intensive correlation operations required by conventional methods.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical/computational correlation-based detection system with a phase-difference-based detection system. This substitution eliminates the need for complex correlation calculations and threshold adjustments based on amplitude, significantly reducing power consumption while maintaining detection reliability in low-cost MCM receiving systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If conventional detection methods are used, then packet detection can be performed, but the system is sensitive to amplitude variations and noise

Engineering Contradiction:

Improvedetection stabilityVSAvoidnoise sensitivity

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful effect of noise and amplitude variations into a beneficial feature by using phase differences as the detection metric. Since phase differences between adjacent carriers are independent of absolute amplitude and less affected by noise, the system achieves robust packet detection that is insensitive to amplitude fading and noise interference.

Inventive Principle:

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

Solution Approach 2:

The patent changes the detection parameter from amplitude-based correlation to phase-difference-based comparison. This parameter change makes the detection process independent of amplitude variations and more resistant to noise, as phase information is inherently more stable in noisy environments compared to amplitude information.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9614706B2Method and apparatus for multi-carrier modulation (MCM) packet detection based on phase differences

Publication Date: 2017.04.04 ECHELON CORP

AI summary

A method is disclosed for detecting packet at a receiving system in a Multi-Carrier Modulation (MCM) system. The method starts with receiving a signal at the receiving system. Then a deviation value of the signal is computed, where the deviation value is computed at least partially based on phase differences between some number of carriers in the preamble. The deviation value is compared with a threshold to determine whether a packet has been detected from the received signal. In response to the determination that a packet has been detected, a symbol offset is computed optionally, where the symbol offset indicates a number of sample points from a beginning of a symbol.