987 results about "Pulse-code modulation" patented technology

The present invention provides a method and apparatus of using light-emitting elements for illumination as well as communication of data, wherein potential flicker due to sub-fusion frequency data correlations can be reduced compared to prior art techniques, while reducing redundancy in the data transmission. The intensity of the illumination from the light-emitting elements is controlled by a dimming signal such as a pulse width modulation (PWM) signal or a pulse code modulation (PCM) signal, for example. An amplitude-modulated data signal is then superimposed on the dimming signal for communication of data. The dimming signal thus acts as a carrier signal for the data signal. A sensing means is then used to receive the data signal by detecting all or part of the illumination from the light-emitting elements. The data signal can subsequently be extracted from the detected illumination.

A multidrop network of multichannel, addressable sensing modules (ASM's), to be embedded within a composite structure, remotely powered, and interrogated by a personal computer through a non-contacting inductive link. Each ASM contains a microprocessor with non-volatile memory, multiplexer, programmable gain and filter instrumentation amplifier, and sigma delta analog to digital converter (all housed in two thin surface mount packages). An embedded mothernode includes circuitry for power and data reception (into the structure), and data transmission (back out of the structure). The external interrogation system communicates into the network of ASM's by modulating the AC waveform that delivers power to the embedded electronics. Once addressed, each ASM powers up its programmable (gain & filter) sensing channels (3 full differential or 5 pseudo differential) and data conversion elements. Sensed data are pulse code modulated, including error checking, which serially modulate an RF carrier for wireless transmission out of the composite to the interrogating computer. These advanced, micro-miniature sensing networks may be applied to a wide variety of military, medical, & civil structures.

A method and device are disclosed which receives packets streamed over a packet network, decodes the packets received to generate a decoded signal stream and filters the decoded signal stream to generate a pulse code modulated (PCM) signal stream. The PCM signal stream may be tailored to conform to the target destination transport requirements, including call channels established over circuit-switched networks, whether wired or wireless, without modifying the capabilities associated with the network infrastructure or the client phone.

The present invention provides a method and apparatus of using light-emitting elements for illumination as well as communication of data, wherein potential flicker due to sub-fusion frequency data correlations can be reduced compared to prior art techniques, while reducing redundancy in the data transmission. The intensity of the illumination from the light-emitting elements is controlled by a dimming signal such as a pulse width modulation (PWM) signal or a pulse code modulation (PCM) signal, for example. An amplitude-modulated data signal is then superimposed on the dimming signal for communication of data. The dimming signal thus acts as a carrier signal for the data signal. A sensing means is then used to receive the data signal by detecting all or part of the illumination from the light-emitting elements. The data signal can subsequently be extracted from the detected illumination.

Various embodiments are disclosed for improved scanning ladar transmission, including but not limited to an example embodiment where a scanning ladar transmission system employs pulse modulation.

The invention provides an electrocardiogram signal compression and de-compression system. The invention uses the sign characteristics of the coefficients of the discrete cosine transform type IV and the characteristics of quantization of spectrum to perform the differential pulse code modulation of the spectrum for preserving the high frequency characteristics of the spectrum of the discrete Fourier transform. The invention also uses the Huffman coding to increase the compression ratio. Different from the conventional compression technology, the invention uses the fact that the quantization values of the spectrum in the high frequency are almost the same to increase the compression ratio and preserve the characteristics of high frequency components of the spectrum.

Systems (400, 500, 600) and methods (300) for generating a chaotic amplitude modulated signal absent of cyclostationary features by preserving a constant variance. The methods involve: generating a PAM signal including pulse amplitude modulation having a periodically changing amplitude; generating a first part of a constant power envelope signal (FPCPES) by dividing the PAM signal by a square root of a magnitude of the PAM signal; generating a second part of the constant power envelope signal (SPCPES) having a magnitude equal to a square root of one minus the magnitude of the PAM signal; and generating first and second spreading sequences (FSS and SSS). The methods also involve combining the FPCPES with the FSS to generate a first product signal (FPS) and combining the SPCPES with the SSS to generate a second product signal (SPS). A constant power envelope signal is generated using the FPS and SPS.

A system (300, 500) for scrambling digital samples (115, 200, 250, 260, 270) of multimedia data, including audio and video data samples, such that the content of the samples is degraded but still recognizable, or otherwise provided at a desired quality level. The samples may be in any conceivable compressed or uncompressed digital format, including Pulse Code Modulation (PCM) samples, samples in floating point representation, samples in companding schemes (e.g., μ-law and A-law), and other compressed bit streams. The quality level may be associated with a particular signal to noise ratio, or quality level that is determined by objective and / or subjective tests, for example. A number of LSBs can be scrambled in successive samples in successive frames (FRAME A, FRAME B, FRAME C). Moreover, the parameters for scrambling may change from frame to frame. Furthermore, all or part of the scrambling key (310) can be embedded (340) in the scrambled data and recovered at a decoder (400, 600) to be used in descrambling. After descrambling, the scramble key is no longer recoverable because the scramble key itself is scrambled by the descrambler.

The problem of charge leakage in the AC compensation filter for the error amplifier of a pulse width modulation (PWM)-based DC—DC converter is effectively obviated by controllably sampling and storing the voltage across the AC compensation filter, in response to a transition of the operation of a DC power supply from run or active mode to quiescent or sleep mode. The sampled voltage is retained as a compensation voltage throughout the quiescent mode, so that it will be immediately available to the PWM circuitry at the termination of the quiescent interval. This serves to ensure a relatively smooth (low noise) power supply switch-over during a subsequent transition from quiescent to active mode.

Systems and methods for controlling amplification of a pair of pulse width modulated signals. In one embodiment, a system comprises an audio amplifier which is configured to receive a pulse code modulated (PCM) input signal, convert this signal to a pulse width modulated (PWM) signal in a controller, and amplify the PWM signal in an output stage. The controller separates the PWM signal into a high-side signal and a low-side signal. The controller incorporates digitally programmable delays into the processing paths for each of the high-side and low-side signals. The high-side and low-side signals are separately provided to the output stage. The separate high-side and low-side signals can be used to individually control (e.g., turn off) the high-side and low-side transistors. Circuitry is included to generate a short low-side pulse when both transistors are turned off in order to drain the gate charge from the high-side transistor.

A method of balancing the voltage of DC links in a cascaded multi-level converter (CMC) semiconductor circuit, including the steps of providing a plurality of H-bridge converters per phase in the CMC circuit and utilizing a three phase duty cycle value from the main controller to determine a normalized duty cycle value, a ceiling duty cycle value and a floor duty cycle value. The normalized duty cycle value and an output current of the CMC is used to determine the direction and polarity of a capacitor current, and utilizing the capacitor current to determine a plurality of output capacitor voltages. A voltage summation result and direction is obtained from a ceiling index pointer and a floor index pointer and the voltage summation result, direction from the ceiling index pointer and a floor index pointer are used to create a combined switching table for the H-bridge converters. A pulse width modulator is utilized to balance the voltage of the DC links and thereby eliminate DC-capacitor voltage imbalance.

The present invention provides a method and apparatus for scaling the average drive current supplied to a light-emitting element or string thereof by coupling a scaling signal to an original control signal thereby generating an effective control signal for control of the light-emitting element(s). The scaling signal can be a modulated signal, for example a Pulse Width Modulation (PWM) signal, Pulse Code Modulation (PCM) signal, or other signal and modifies the original control signal to produce an effective control signal. The effective control signal is subsequently used to control the supply of power to the light-emitting element(s) from a power source via a switching device. The effective control signal essentially modifies the ON time of the light-emitting element(s), thereby modifying the average drive current passing through the light-emitting element(s). The scaling signal is coupled to the original control signal by a coupling mechanism, thereby enabling the modification of the original control signal by the scaling signal forming the effective control signal.

A method and device are disclosed which receives packets streamed over a packet network, decodes the packets received to generate a decoded signal stream and filters the decoded signal stream to generate a pulse code modulated (PCM) signal stream. The PCM signal stream may be tailored to conform to the target destination transport requirements, including call channels established over circuit-switched networks, whether wired or wireless, without modifying the capabilities associated with the network infrastructure or the client phone.

There is provided herein a first preferred arrangement of the instant invention, wherein an electronic patient monitor utilizes a computer CPU as an alarm signal generator, which CPU is preferably directly connected to a power amplifier and / or a speaker without an intervening (or subsequent) conventional volume control. The alarm signal is preferably expressed as a series of square waves. The volume of the alarm signal as heard through the speaker is controlled by varying the width of the square waves that represent the alarm signal with the duty cycle of the square waves being shortened to reduce the output alarm volume and lengthened to increase it.

The invention discloses an intra-frame lossless compression coding method based on an HEVC (high efficiency video coding) frame, wherein the method is low in time complexity and high in prediction accuracy and increases compression ratio. By the aid of the HEVC frame, a coding unit can be adaptively divided according to image flatness, the best division scheme is determined, and the optimal prediction mode is selected. DPCM (differential pulse code modulation) differential codes are used for preliminary prediction, prediction errors are possibly large when only the differential codes are used for an area with complex texture, and accordingly, prediction values are corrected for the area by means of error compensation. By combining the two methods, reduction of time complexity and improvement of prediction accuracy can be effectively compromised. Distribution characteristics of residual errors depend on the prediction mode, so that the scanning sequence of the residual errors is determined according to the prediction mode, and entropy coding can be more effective.

Disclosed is a method of and apparatus for managing and redeeming bar-coded coupons that are displayed from a light emitting display surface of an information storage and display device, such as a cell-phone, a smart-phone, or a data communication device. The linear (1D) bar code symbols, associated with bar-coded store coupons, are displayed on the light emitting display surface using in a pulse code modulation (PCM) format, wherein a substantial portion of the pixels on the light emitting display surface are energized and de-energized to emit red-wavelengths of light energy, at a rate which temporally corresponds to the spatial frequency of the bars and spaces of the linear bar code symbol, so that a laser scanning bar code symbol reading device is capable of reading the PCM formatted bar code symbol displayed from the light emitting display surface.

A DC (direct current) converter includes a PWM (pulse width modulation) pulse generation unit outputting a PWM pulse signal whose duty ratio is controlled in accordance with an output voltage, a PFM (pulse frequency modulation) pulse generation unit outputting a PFM pulse signal whose pulse output interval is controlled in accordance with an output voltage, a selection circuit selecting and outputting any one of the PWM pulse signal and the PFM pulse signal in response to a selection signal, a drive circuit unit driving a load and generating an output voltage on the basis of a signal outputted from the selection circuit, and a switching control unit outputting the selection signal. When the selection signal is in a second state, the switching control unit detects a fact that the number of pulses of the PFM pulse signal in a measurement period increases to or above a set value of the maximum number of pulses, and switches the selection signal to a first state.

A visible light communication system and method for transmitting and receiving an information symbol in a visible light communication system for a Color Code Modulation (CCM) scheme using a chromaticity diagram. The method includes determining a first coordinates value corresponding to an information symbol to be transmitted on the chromaticity diagram; determining a first color ratio corresponding to the first coordinates value; determining a second coordinates value corresponding to a compensation symbol for compensating for the first color ratio into a color white and determining a second color ratio corresponding to the second coordinates value; and emitting a visible ray corresponding to each of the first color ratio and second color ratio. The first and second coordinates values are located on a line on the chromaticity diagram.

The invention discloses a dual-redundancy attitude control system of a coaxial unmanned helicopter, which consists of a serial communication module, a PCM (Pulse-Code Modulation) decoding module, an AD acquisition module, a PWM (Pulse-Width Modulation) output module and a CPU control module. The serial communication module, the PCM decoding module and the AD acquisition module are used as system input, the CUP control module carries out improved digital PID control, and the PWM output module carries out output in the form of PWM pulses, and thus, the control of a backward-stage high power valve is realized. A debug method comprises the following fives steps of: firstly, connecting a defined I / O port to a high or low-level end according to a parameter debug object; secondly, adjusting a potentiometer to provide initial parameters for Kp and Kd and controlling the backward-stage high power valve; thirdly, keeping a neutral position of Futaba unchangeable, adjusting the potentiometer so that a steering engine achieves a critical state of self-excitation vibration; fourthly, operating the Futaba to output a signal exceeding a pulse threshold; and fifthly, operating the Futaba to return to a central position. The method realizes the debug and the storage of relevant parameters, decreases interference and improves the system stability and the response speed.

A game console capable of communicating with other game consoles over a link or network is provided with a headphone and microphone for each player who will engage in voice communication. Verbal communications directed to one or more other players are converted to pulse code modulated (PCM) digital data and are encoded and compressed in real-time, producing data packets that are transmitted to another game console. The compressed data packets are decompressed and decoded, producing PCM data that are converted to an analog signal that drives a headphone of the intended recipient. Players can selectively mute voice communications to and from a specific other player. The PCM data can be encoded in a round-robin fashion that reduces the number of encoders required. A predefined level of computing resources is used for voice communication to avoid aversely affecting the quality of game play.

Methods and systems for processing an analog signal that is generated by a high energy photon detector in response to a high energy photon interaction. A digital edge is generated representing the time of the interaction along a first path, and the energy of the interaction is encoded as a delay from the digital edge along a second path. The generated digital edge and the delay encode the time and energy of the analog signal using pulse width modulation.

A circuit and a method for performing pulse width modulation are provided. A pulse density modulator (PDM) is applied to receive the least N bits of the input data and to generate a pulse density modulation signal. The number of pulse of the pulse density modulation signal in 2^N frames correspond to a value of the least N bits of the input data. An adder is applied to generate a PWM data by adding a value of the most M bits of the input data to a value of the pulse density modulation signal generated by the PDM. A pulse width modulator is applied to generate a PWM signal dithering in 2^N frames according to the PWM data generated by the adder, so as to improve the audio quality of pulse width modulation and the Electro-Magnetic Interference (EMI) phenomenon.

A video encoder includes a mode decision module that determines a final macroblock cost for each macroblock of the plurality of macroblocks based on costs associated with a plurality of motion vectors. An intra pulse code modulation (IPCM) module, when enabled, selects an IPCM mode when the final macroblock cost compares unfavorably to an IPCM threshold. A reconstruction module generates residual pixel values for each macroblock of the plurality of macroblocks and a transform and quantization module, transforms and quantizes the residual pixel values when the IPCM mode is not selected.

In a display device capable of low power and multi-color displaying without raising a frame rate due to increase of display gradations in number by combining a gradation representation through a FRC and a gradation representation system using a pulse width modulation or pulse height modulation method, the gradation representation is executed by a method of pulse width or pulse height modulation in one frame using lower significant N bits to a video signal of M bits, and the display of the gradations is performed by the FRC of the present invention using more significant M−N bits and further using 2M−N−1 frames, and thus the number of the frames required for FRC is reduced to decrease a frame frequency to thereby realize a gradation display with reduction of electric power and suppression of flickers.

The invention relates to a self-adapting pulse code modulation method, which comprises the following steps: firstly, locally allocating the corresponding relationship between the indicated value, the modulation mode and the transmission code rate of the communication channel quality by a base station, secondly, transmitting down-bound data to a mobile terminal according the locally allocated corresponding relationship to select the corresponding modulation method and the transmission code rate after the base station receives the indicated value of the communication channel quality of the current time of the communication channel, namely the indicated value is transmitted by the mobile terminal. The self-adapting pulse code modulation method of the invention correspondingly selects the appropriate transmission code rate when selecting the appropriate modulation mode through the CQI, thereby the throughput of the system can reach the maximum value and the coding performance can be better.

A transmitter and transceiver for an optical communication channel may include a data encoder, a partial response (PR) precoder, a pulse filter, and an electrical-to-optical converter to transmit a spread pulse signal over an optical communication channel. The data encoder to encode the transmit data into coded data. The precoder to correlate bits of the coded data together into a precoded signal at the output of the precoder. The pulse filter to spread out the pulses in the precoded signal into a spread-pulse signal at the output of the pulse-shaping filter. The electrical-to-optical converter to convert an electrical spread-pulse signal into light pulses at its optical output. A transceiver may further include an optical-to-electrical converter, an automatic gain controller, a matched filter, a PR finite impulse response equalizing filter, a maximum likelihood sequence estimation detector, and a data decoder in order to decode and recover the data.

The invention relates to a method and a device for detecting an insulator through a multi-rotor unmanned aerial vehicle. The device comprises a multi-rotor unmanned aerial vehicle, as well as an onboard control computer of a flight control system, a positioning device, an unmanned aerial vehicle steering engine controller, a height measuring device, a speed measuring device, a high-definition camera, an unmanned aerial vehicle PCM (Pulse-Code Modulation) remote control receiver, an onboard wireless communication unit and a lifting device which are arranged on the multi-rotor unmanned aerial vehicle; the lifting device drives a probing lower pole to move; the onboard wireless communication unit communicates with a ground station; the unmanned aerial vehicle steering engine controller controls a servo steering engine; the servo steering engine controls a multi-rotor module; a probing upper pole and the probing lower pole are respectively connected with respective voltage sensors; the two voltage sensors are connected with an A / D (Analogue-to-Digital) conversion unit, a DSP (Digital Signal Processor) unit and the onboard control computer of the flight control system. The method and the device provided by the invention can be used for knowing and control the operation condition of a circuit insulator in time; the risk when a detector climbs up to carry out near-distance electrified operation can be further avoided; and meanwhile, the detection efficiency can be improved.

A method of and apparatus for encoding and decoding a signal by illumination change compensated motion estimation are provided. The apparatus for encoding a signal by illumination change compensated motion estimation includes: an illumination change compensation unit performing compensation for an illumination change by performing a differential calculation between each pixel value of a current block and the means pixel value of a reference block indicated by a motion vector of the current block and the mean pixel value of the reference block; a residual signals generation unit generating residual signals based on the blocks in which illumination change compensation is performed; and an illumination changed amount prediction unit performing differential pulse code modulation (DPCM) based on the illumination change amount prediction value by reflecting the closeness between neighboring blocks in which illumination change occurs.