31 results about "Power line noise" patented technology

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.

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 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 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 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 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 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.

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.