Power line two-way power-frequency communication uplink signal detecting method

Abstract

The invention discloses a power line two-way power-frequency communication uplink signal detecting method. The method is characterized by including the steps of firstly, making background power-frequency signals of modulating signals cancelled out and enhancing the modulating signals through a weighted summation method in the two-way power-frequency communication uplink signal detecting process, conducting derivation on the enhanced modulating signals, and conducting empirical mode decomposition on the modulating signals through ensemble empirical mode decomposition; secondly, finding the order, where the frequency of 150 HZ to 500 HZ is located, in an n-order intrinsic mode function through correlation operation, finding the threshold value of a corresponding order through the intrinsic mode function of the order where the frequency of 150 HZ to 500 HZ is located, conducting threshold value denoising, and calculating the Hilbert marginal spectrum of the denoised signals through Hilbert conversion, and therefore the time domain where the modulating signals are located is detected, most noise and harmonic interference can be effectively removed, and the time domain where the modulating signals are located can be accurately detected. The method has the advantages of being scientific, reasonable, easy to implement, high in detection accuracy and the like.

Description

technical field [0001] The invention relates to a signal detection method for power line carrier communication, more specifically, a method for detecting uplink signals of power line two-way power frequency communication. Background technique [0002] The two-way power frequency communication system is a new communication system based on the power distribution network in recent years. The system uses the power line as the data transmission carrier and uses the zero-crossing modulation principle to realize signal modulation. The power frequency communication uplink signal is passed through the switch of the thyristor. Controlling the distorted current pulse signal generated near the zero-crossing point of the fundamental voltage signal is a time-varying signal whose frequency spectrum changes with time. Two-way power frequency communication uplink signal detection is to detect small signals in the background, the traditional detection method is the time domain detection metho...

AI Technical Summary

Problems solved by technology

Two-way power frequency communication uplink signal detection is to detect small signals in the background, the traditional detection method is the time domain detection method, this method will lose a lot of useful information, has certain requirements for the power grid, has certain limitations, the existing The time-domain detection method uses the most common wavelet transform signal detection algorithm. When this method performs time-frequency analysis on modulated signals, it will be affected by the selection of wavelet bases, resulting in the inability to perform accurate time-frequency analysis.

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