31 results about "Power line noise" patented technology

The invention discloses a spot low-voltage power line carrier channel noise testing system and a method thereof. Noise testing of a time domain and a frequency domain is carried out through a specially-designed coupler and a high-speed and multichannel data acquisition card, time domain waveform display of noise signals is achieved through testing software in a laptop, fast Fourier transform algorithm (FFT) is carried out on time domain data through the software, and noise frequency domain waveform (power spectral density) is obtained. When the waveform is observed, computer date storage resources can be used at the same time to carry out long-time data storage and monitoring so that recording, analyzing and assessing on low-voltage power line noise characteristics can be achieved. Meanwhile, the spot low-voltage power line carrier channel noise testing system and the method thereof have the advantages of being flexible, convenient and fast, and suitable for various low-voltage power line environments.

The invention discloses an OFDM power-frequency synchronous power carrier communication and physical layer coded modulation method. The communication method comprises that P OFDM symbols are sent within 1 / 2 AC power-frequency period, and P represents a positive integer; the SNR of each subcarrier and the corresponding OFDM symbol is measured repeatedly; and according to a measured SNR sequence, a bit loading table is generated via a time domain and frequency domain 2D ToneMap and sent to achieve the channel adaptability and improve the reliability and communication speed of the whole communication system. The method of the invention has the advantages that the sparsity of period static characteristic and noises in the time and frequency domains of power line noises is utilized fully, the utilization rate (speed) of a PLC channel is improved, the transmission reliability and the system throughput are improved, and coding efficiency is high. The method can support an OFDM power-frequency synchronous continuous sending mode as well as a discontinuous sending mode.

The present invention relates to methods and apparatuses for sensing noise sources in a wireline communications environment such as a customer premises environment in a DSL system. In embodiments, the invention includes an additional sensor that is connected to power mains in a DSL customer premises environment either to characterize, at their source, noises coupling into the DSL lines, and / or to mitigate their impact into the DSL lines. One objective is associated with diagnostics that help to better characterize the noise signals themselves and derive correlation of signals sensed from the power mains and their possible projection onto the DSL line. Another objective makes use of these power line sensor signals to mitigate or to eliminate power line noises that make their way onto the DSL line. Example embodiments further include and exploit signals from additional secondary sensors such as secondary common mode, differential mode and phantom mode sensors.

The invention discloses a power line noise compression method based on compressive sensing. When a power line is unloaded, noise on the power line is subjected to strong electrical isolation and attenuation through a coupler; then, noise of a power line channel is acquired through noise acquisition equipment; the acquired noise of the power line channel is divided into background noise and random noise; then, characteristic data of the background noise are extracted in a time domain and stored; the random noise is compressively sensed in a frequency domain according to an observation matrix; and furthermore, main information obtained after the random noise is processed is stored. The invention further discloses a power line noise compression device based on compressive sensing. By means of the invention, when the power line is unloaded, the power line noise acquired from the power line in a coupled manner is effectively compressed and stored; therefore, the volume of data in need of being stored can be effectively reduced; and the relatively high compression removal rate can be achieved.

An efficient current feedback buffer is revealed. The buffer is useful in power supplies for a number of analog and digital devices, including CMOS voltage controlled ring oscillators, frequency synthesizers, delay locked loops, phase accumulators, and phase locked loops. The power supply and buffer maintains a low impedance output to the load, regulates the voltage output of the supply, and rejects power line noise.

The invention discloses an interference noise elimination method suitable for a power line carrier (PLC) communication network, which is mainly used for solving the impulse interference noise which appears randomly and has high energy causes performance attenuation of the whole communication system in the PLC network. The method mainly comprises two parts of receiver-side signal amplitude pretreatment and robust channel estimation. The initial filtering of the impulse interference noise is performed according to the statistical characteristics of received signals by the receiver-side signal amplitude pretreatment, and the influence on the residual noise is further weakened by the robust channel estimation. Compared with other conventional power line noise elimination algorithms, the method provided by the present invention is characterized by a relatively low complexity and being insensitive to noise change. The method eliminates the power line noise from the viewpoint of practical feasibility and effectiveness, so that the bit error rate is reduced during the power line carrier transmission, and the system reliability can be improved.

The invention belongs to the technical field of power frequency communication channel state analysis algorithms, and particularly relates to a method of evaluating the state of a power frequency communication channel. The method comprises steps: through acquiring data influencing the quality of the power frequency communication channel such as lengths of different power lines, the power line branch number, a branch length, load impedance characteristics, power line types and power line noise, a power frequency communication channel quality evaluation data storage and sharing platform is built; on the basis, the data are mined and calculated; and an Adaboost ensemble learning algorithm is used, through an expert analysis system and a neural network algorithm based on deep learning, the state of the power frequency communication channel under multiple parameters is evaluated comprehensively. Compared with the traditional simplex and fixed channel state evaluation method, the method of the invention can continuously learn and optimize the evaluation model according to changes of influence factors, and a more accurate channel state is obtained.

The present invention relates to a processing apparatus (10) for processing a physiological signal (21) using model subtraction, notch filtering and gating. The processing apparatus comprises a model subtraction unit (11) configured to receive the physiological signal (21) and to reduce a first unwanted signal component, such as an ECG contamination, in the physiological signal by subtracting from the physiological signal a model (31) of the 5 first unwanted signal component to obtain a residual signal (32); a filter unit (12) configured to receive the residual signal (32) and to reduce a second unwanted signal component, such as power line noise, in the residual signal by applying a notch filter to obtain a filtered signal (33); and a gating unit (13) configured to receive the filtered signal (33) and to apply gating to the filtered signal to obtain a gated signal (34). The present invention further relates to a 10 corresponding electromyography system and a method for processing a physiological signal using model subtraction, notch filtering and gating.

Increase power line noise immunity in an IC is provided by using decoupling capacitor structure in an area of the IC that is typically not used for routing, but filled with unconnected and non-functional metal squares (fills). In one embodiment, a method includes providing a circuit design layout; determining a density of a structure in an area of the circuit design layout; and in response to the density being less than a pre-determined density for the structure in the area, filling in a portion of the area with at least one capacitor structure until a combined density of the structure and the at least one capacitor structure in the area is about equal to the pre-determined density. Power line noise immunity is increased by increasing decoupling capacitance without enlarging the IC's total size by using a (fill) area that would normally be filled with unconnected and non-functional metal shapes.

The invention relates to a low-voltage power line noise recording and injecting system, and the system comprises a power line interface, a power module, a power line coupling filter, a power amplifier, an arbitrary waveform generator and a power line communication signal detecting and analyzing device. According to the system, on-site noise is recorded and stored, and on-site noise signals are restored through any signal generator in a laboratory, so that the working characteristics of the power line carrier communication module in an on-site noise environment are verified; high-voltage mainssupply is isolated through the power line coupling filter, so a measuring instrument is isolated from strong current, the safety of measuring equipment is ensured, noise outside a test frequency bandis filtered, useless signal interference is reduced, and the system provides a basis for an anti-interference test of the low-voltage carrier communication module.

An embodiment of the invention discloses a device for measuring impedance of a power line access point. The device comprises a PCB (printed circuit board), a signal collector, a PC, a signal transmitter and a coupler, the signal collector, the PC, the signal transmitter and the coupler are fixedly arranged on the PCB, the output end of the signal collector is electrically connected with the inputend of the PC, the output end of the PC is electrically connected with the input end of the signal transmitter, the output end of the signal transmitter is electrically connected with the input end ofthe coupler, the output end of the coupler is electrically connected with a power line, and the input end of the signal collector is electrically connected with the power line. By the device, the technical problem that conventional oscilloscopes and spectrometers do not have a long-time signal storage function generally, which goes against long-time recording and playback of power line noise is solved.

The invention discloses a low-frequency power line carrier topology identification method, which comprises the following steps of: 1, continuously carrying out continuous voltage sampling, and simultaneously carrying out parallel processing on sampling data at a previous moment in an assembly line mode; 2, performing high-density data analysis on the sampled data by adopting a method based on an FFT (Fast Fourier Transform) convolutional neural network; 3, averaging analysis results of the multiple sliding window data, and taking an averaged frequency spectrum module value as a judgment basis of a carrier signal; 4, step classification is carried out according to the frequency spectrum module value amplitude of the signals, and 16-bit modulation signal codes are output; the signal detection mode based on the FFT convolutional neural network can utilize the effective duration of the modulation signal to the maximum extent, and the interference of the power line noise on the modulation signal is reduced and the topology identification monitoring accuracy is improved by using the mode of combining the digital filter and the multi-sliding window FFT average.

The invention relates to a device and a method for testing the performance of an electromagnetic interference noise separator, and the device consists of a tested conducted noise separator, an in-phase power divider, an anti-phase power divider, a 50-ohm matching load and a dual-port network analyzer which are connected through a 50-ohm coaxial line. The tested conducted noise separator is provided with two input ports and two output ports and is used for inputting a power line noise signal and outputting a differential mode noise component and a common mode noise component, and the anti-phase power divider and the in-phase power divider are used for simulating the differential mode signal and the common mode signal. The method can be used for testing the performance of the conducted noise separator and also can be used for testing the performance of the filter, and carrying out common-mode and differential-mode separation and quantification on electromagnetic compatibility disturbance conducted noise in a product test process. Scientific and effective targeted guidance is provided for common-mode and differential-mode filter parameters designed for suppressing conducted noise in the electromagnetic compatibility rectification and optimization process.

The invention relates to a method for detecting a noise signal power of a power line. The method comprises the following steps: step a, on the basis of a frequency difference between a power frequencyand that of a carrier signal needing to be tested, carrying out coupling of a power frequency signal and a tested signal; step b, transmitting a coupled power line signal to a band-pass filtering unit; step c, processing the filtered signal by using a carrier signal power testing unit; step d, generating a local oscillator signal needed by a mixing unit in the carrier signal power testing unit byusing a program-controlled local oscillator unit; step e, transmitting a filtered intermediate-frequency signal to an AD sampling unit for detection; and step f, sending AD data generated by the AD sampling unit to a DSP unit for FFT operation. With the obtained power information, noise time domain information, and frequency domain information of the noise, graphic displaying of waveform data andspectrum data of the collected current power line signal is realized and the noise signal in the power line is analyzed deeply and conveniently, so that the accuracy of terminal communication is enhanced and reliability is improved; and targeted advice is provided for selection of a terminal product.

The invention discloses a method for calculating the topological structure relationship of low-voltage power line branches based on the distribution characteristics of the radiation signal intensity of low-voltage power line carrier communication. The invention is based on the strength of the radiation signal intensity of low-voltage power line carrier communication collected by each branch node. Since the carrier signal attenuation characteristics of low-voltage power line carrier communication and power line noise characteristics interfere with the data of carrier communication radiation signals, it is impossible to use the method of carrier communication radiation signal strength to calculate the topological relationship. According to the characteristics, the method of accurately calculating the belonging branch of the terminal meter is given. According to the relationship between the carrier communication radiation signal strength between the branch nodes, the connection relationship between the calculation branch and the branch is given. Based on the relationship between the terminal smart meter and the branch and the relationship between the branches The connection relationship between them can accurately draw the topology relationship of low-voltage power line branches.

The invention discloses a method for calculating a low-voltage power line branch topological structure relationship based on low-voltage power line carrier communication radiation signal intensity distribution characteristics, which is based on low-voltage power line carrier communication radiation signal intensity acquired by each branch node. The innovativeness of the method is to solve the problem that the topological relation cannot be calculated in a carrier communication radiation signal intensity mode due to interference of low-voltage power line carrier communication carrier signal attenuation characteristics and power line noise characteristics on carrier communication radiation signal data. The method for accurately calculating the affiliated branch of the tail-end electric meteris provided according to the radiation signal distribution characteristics of the intelligent electric meter at the tail end of each branch on each branch node, the connection relationship between the branches is calculated according to the carrier communication radiation signal intensity relationship between the branch nodes, and a low-voltage power line branch topological structure relationshipaccurately drawn based on the connection relationship between the tail-end intelligent electric meter and the branches and the connection relationship between the branches.

The invention relates to an improved electrocardiosignal noise reduction method based on singular spectrum analysis. The method specifically comprises the following steps: selecting a proper window length for electrocardiosignals to construct a track matrix, and carrying out singular value decomposition; calculating a signal reconstruction component corresponding to each singular value, and removing a trend term from the first reconstruction component by adopting a low-order polynomial fitting method; adopting a wave trap to remove power frequency interference in each reconstruction component; calculating an absolute value of a correlation coefficient between the reconstruction components and comparing the absolute value with a threshold value to select an effective signal component; and finally, superposing the effective signal components to obtain a denoised electrocardiosignal. The method is driven by data, does not need reference input, is suitable for removing Gaussian white noise, baseline drift, myoelectricity interference, power line noise and other noise, and can improve the subsequent signal analysis effect. According to the method, the signal distortion degree is small, noise reduction can be well achieved under the condition of the low signal-to-noise ratio, and the method can be popularized to noise reduction of one-way or multi-way other physiological signals.

The invention discloses an OFDM power-frequency synchronous power carrier communication and physical layer coded modulation method. The communication method comprises that P OFDM symbols are sent within 1 / 2 AC power-frequency period, and P represents a positive integer; the SNR of each subcarrier and the corresponding OFDM symbol is measured repeatedly; and according to a measured SNR sequence, a bit loading table is generated via a time domain and frequency domain 2D ToneMap and sent to achieve the channel adaptability and improve the reliability and communication speed of the whole communication system. The method of the invention has the advantages that the sparsity of period static characteristic and noises in the time and frequency domains of power line noises is utilized fully, the utilization rate (speed) of a PLC channel is improved, the transmission reliability and the system throughput are improved, and coding efficiency is high. The method can support an OFDM power-frequency synchronous continuous sending mode as well as a discontinuous sending mode.

The invention relates to a method for estimating a power line system channel by using a neural network, and belongs to the technical field of communication. The method comprises the following steps of: firstly, performing channel estimation in a neural network DnLSTM by using preamble orthogonal frequency division multiplexing (OFDM) symbol data; then, a neural network DnLSTM is adopted to generate a channel characteristic matrix of each symbol in frame control and frame load, and the channel characteristic matrix is used for channel equalization; and carrying out signal demodulation on the frame control and frame load symbols after channel equalization to obtain a log likelihood estimation value LLR of data carried by each OFDM symbol. According to the method for demodulating the communication signal by adopting the deep neural network, the robustness is good, specific algorithm processing does not need to be carried out on specific noise on the power line, and different power line noise environments are self-adapted through a large amount of training.

The invention discloses an RC electronic arc extinguisher. The RC arc extinguisher includes a capacitor and a resistor; the capacitor and the resistor are connected in series, and the capacitor and the resistor are packaged in a packaging body; a capacitor and a resistor The resonant circuit composed of it can effectively filter out interference and absorb quasi-waves, has a certain safety guarantee function and excellent anti-pulsation ability, integrated design, easy to use and install, and improves reliability; suitable for power cross-line noise reduction routes, CNC machine tools, AC and DC occasions such as audio equipment.

The invention discloses an HPLC-oriented power line noise suppression method, and relates to the technical field of power communication. Based on a self-adaptive power line noise suppressor, pre-noise N'(n) is extracted from a power line according to preset pre-time, self-adaptive noise suppression is carried out on a power line signal d(n) through the pre-noise N'(n), a noise reduction signal e(n) is obtained, and the self-adaptive power line noise suppressor comprises a self-adaptive filter and a subtracter which are electrically connected with each other; and through the adaptive power line noise suppressor, pre-noise N'(n) is extracted to carry out adaptive noise suppression on a power line signal d (n), a noise reduction signal e(n) and the like are obtained, the working efficiency of power line noise suppression is high, and the effect is good.

The invention discloses power line carrier communication equipment, which comprises a carrier receiving module, a carrier transmitting module, a coupling transformer and a control chip, the input end of the carrier receiving module is connected with the power line through the coupling transformer, and the output end is connected with the control chip; the input end of the carrier transmitting module is connected with the control chip, and the output end is connected with the power line through the coupling transformer; and the control chip realizes data interaction with the power line through the carrier receiving module and the carrier transmitting module based on a G3-PLC standard. The invention further discloses a power line carrier communication system. By adopting a G3-PLC standard power line carrier communication mode, normal communication between the power system and the terminals is realized, interactive communication between the multiple terminals and the power system during charging is ensured, and the system has strong anti-interference capability and power line noise resistance, and interactive data communication across transformers can be realized.

A pairing apparatus according to an exemplary embodiment of the present invention includes: a noise filtering part for filtering a noise on a power line; and a processor for pairing with a pairing target device and performing an authentication by generating a secret key using the filtered noise and by using the generated secret key.

A processing apparatus for processing a physiological signal using model subtraction, notch filtering and gating. The processing apparatus comprises a model subtraction circuit configured to receive the physiological signal and to reduce a first unwanted signal component, such as an ECG contamination, in the physiological signal by subtracting from the physiological signal a model of the first unwanted signal component to obtain a residual signal; a filter circuit configured to receive the residual signal and to reduce a second unwanted signal component, such as power line noise, in the residual signal by applying a notch filter to obtain a filtered signal; and a gating circuit configured to receive the filtered signal and to apply gating to the filtered signal to obtain a gated signal. The processing apparatus further relates to a corresponding electromyography system and a method for processing a physiological signal using model subtraction, notch filtering and gating.

The invention discloses a low-frequency power line carrier topology identification method, which includes the following steps: Step 1: Continuously perform continuous voltage sampling, and simultaneously process the sampled data at the previous moment in parallel in a pipeline; Step 2: Use FFT-based convolution The neural network method performs high-density data analysis on the sampling data; step 3: average the analysis results of multiple sliding window data, and use the averaged spectrum modulus as the basis for judging the carrier signal; Stepwise classification of value and amplitude, and output 16-bit modulation signal code; the signal detection method based on FFT convolutional neural network in the present invention can maximize the effective duration of modulation signal, and use digital filter and multi-sliding window FFT average phase The combined method improves the accuracy of topology identification and monitoring while reducing the interference of power line noise on the modulation signal.