124results about How to "Accurate amplitude" patented technology

A high-band speech encoding apparatus and a high-band speech decoding apparatus that can reproduce high quality sound even at a low bitrate when wideband speech encoding and decoding using a bandwidth extension function, and a high-band speech encoding and decoding method performed by the apparatuses. The high-band speech encoding apparatus includes: a first encoding unit encoding a high-band speech signal based on a structure in which a harmonic structure and a stochastic structure are combined, if the high-band speech signal has a harmonic component; and a second encoding unit encoding a high-band speech signal based on a stochastic structure if the high-band speech signal has no harmonic components. The high-band speech decoding apparatus includes: a first decoding unit decoding a high-band speech signal based on a combination of a harmonic structure and a stochastic structure using received first decoding information; a second decoding unit decoding the high-band speech signal based on a stochastic structure using received second decoding information; and a switch outputting one of the decoded high-band speech signals received from the first and second decoding units according to received mode selection information.

An electric power steering apparatus includes: a rotation speed detecting unit which detects a rotation speed of the electric motor; a compensation current determining unit which determines an instruction value of a compensation current to flow through the electric motor to suppress torque ripples due to distortion of an induced electromotive force waveform of the electric motor in accordance with a load correspondence quantity as a physical quantity corresponding to a load of the electric motor and the rotation speed detected by the rotation speed detecting unit; a correcting unit which corrects the current target value on the basis of the compensation current instruction value; and a control unit which performs a feedback control on the electric motor so that a current having the current target value as corrected by the correcting unit flows through the electric motor.

An OFDM transceiver has a transmitter, a receiver, and a loopback switch. The loopback switch configured is for selectively establishing a physical connection between an output terminal of the transmitter and an input terminal of the receiver. The transmitter is configured for outputting to the output terminal an OFDM signal generated based on a local oscillator signal. The receiver is configured for demodulating the OFDM signal, received via the physical connection, using the local oscillator signal and determining amplitude and phase imbalance parameters based on performing frequency-domain estimation of amplitude and phase imbalances. Hence, the receiver is configured for performing imbalance compensation on a received wireless OFDM signal based on the determined amplitude and phase imbalance parameters. Hence, amplitude and phase imbalances can be estimated accurately despite channel fading and frequency variations encountered between the transmitter of the wireless OFDM signal and the receiver.

A transceiver system and method for transmission of information data over a communication line are described. The transceiver system comprises a transmitter and a receiver. The transmitter includes a synthesis filter bank and an overlapping unit downstream of said synthesis filter bank. The synthesis filter bank is configured for generating a set of wavelets and modulating thereof. The overlapping unit is configured for generating a multicarrier signal carrying the information data and providing thereof to the communication line. The receiver includes a separating unit and an analyzing filter bank downstream of the separating unit. The separating unit includes a separating shift register and a parallel register arranged downstream of said separating shift register. The analyzing filter bank includes an N-points FFT unit and a demodulator coupled to the N-points FFT unit. The method includes at the transmitter end the steps of providing a sequence of prototype wavelets by using N-points IFFT, modulating the sequence of the prototype wavelets by said information data, overlapping the modulated prototype wavelets to generate a multicarrier signal carrying the information data. The method includes at the transmitter end the steps of separating the overlapped wavelets from the received multicarrier signal distorted by a noise, analyzing the separated wavelets by using an N-points FFT, and demodulating spectral frequency amplitudes of the wavelets to provide the information data.

The invention discloses a method for network voltage amplitude, frequency and phase angle detection based on the one-phase phase-locked loop algorithm. According to the method, accurate amplitude, frequency and phase angle detection is achieved when direct current offset and harmonic waves exist in a one-phase power grid. The method comprises the steps that a network voltage signal is acquired and transmitted to a delay phase-shifting module; the delay phase-shifting module receives a network voltage frequency value obtained from the last cycle at the same time and outputs a network voltage delay signal; subtraction is carried out on the acquired network voltage signal and the network voltage delay signal to obtain a result, and the result is divided by 2 to obtain a network voltage signal free of direct current offset; the network voltage signal free of direct current offset is taken as an input signal of an enhanced phase-locked loop, and then the network voltage amplitude value, frequency value and phase angle value of the cycle are obtained. The method for network voltage amplitude, frequency and phase angle detection based on the one-phase phase-locked loop algorithm is suitable for the field of conversion of electrical energy.

An OFDM receiver is configured for suppressing pilot energy, and DC energy, from received I and Q components prior to estimating amplitude and phase imbalances of the received I and Q components. Hence, amplitude and phase imbalances can be estimated accurately despite channel fading and frequency variations between the transmitter and receiver.

In a vehicle parking system, when a selected shift position is changed between Park and a shift position other than Park, if both an electric motor of an electric parking lock mechanism and an electric motor of an electric parking brake mechanism are operated, these electric motors are started in such a manner that the times at which striking currents supplied to these electric motors reach their peaks are staggered.

The invention belongs to the technical field of microwave linearization, and particularly relates to an amplitude and phase tunable type pre-distortion linearizer. According to the pre-distortion linearizer, based on the diode pre-distortion linearization working mechanism, by means of the vector superposition principle, pre-distortion nonlinear compensation with different amplitude and phase requirements is obtained through phase change, and the defect of traditional series-connection and parallel-connection transmission type simulation pre-distortion circuits that only pre-distortion signals suitable for solid-state power amplifiers can be generated and the defect of reflection type pre-distortion circuits that only pre-distortion signals suitable for microwave traveling-wave tube power amplifiers can be generated mostly are overcome; meanwhile, the capacity of control, over the amplitude expansion and phase expansion degrees of generated non-linear signals, of a microwave pre-distortion circuit is improved, and accurate strong-nonlinearity amplitude and phase compensation can be achieved.

The invention discloses a method for calculating the amplitude and phase of an alternating-voltage signal based on an iteration Fourier transform and belongs to the technical field of electric power supply. The method comprises the following steps of: determining a sampling frequency and initializing parameters; determining an alternating voltage frequency to be extracted; calculating a sine function and a cosine function; sampling an alternating voltage value; judging a sampling sequence and calculating an alternating voltage sub-harmonic cosine amplitude and a cosine amplitude; and obtaining an alternating voltage sub-harmonic voltage amplitude and the phase. The method disclosed by the invention utilizes sampling data of each time to carry out primary addition and subtraction calculation to obtain accurate fundamental wave voltage amplitude and phase; and compared with the traditional Fourier transform, a lot of calculation processes are reduced; and the requirements of the rapidness and the accuracy of signal detection of an electric power system are met.

A method of processing a received communication signal comprises calculating a traffic-to-pilot scaling factor by relating data correlations determined from despread traffic values obtained from the received communication signal-to-noise correlations determined from despread pilot values obtained from the received communication signal, and generating traffic symbol estimates by combining corresponding ones of the despread traffic values using combining weights calculated from the data correlations. Generating combining weights in this manner provides, among other things, Minimum Mean Square Error (MMSE) estimations for the received traffic symbols that inherently are properly scaled in amplitude relative to symbol values in a reference modulation constellation. By obtaining proper scaling as part of combining weight generation, the receiver need not make an explicit estimate of symbol power to obtain proper soft value information, and the estimated traffic symbols may be compared directly with the reference constellation.

A receiving device is provided that includes a radio receiving unit to receive radio signals transmitted from multiple transmitting antennas by multiple receiving antennas and output received signals being digital signals, a frequency control unit to detect and correct a frequency error contained in the received signals, a channel estimation unit to estimate a channel matrix of which each element corresponds to respective pair of each transmitting antenna and each receiving antenna, an equalization unit to equalize the received signals by using the estimated channel matrix, a demodulation and decoding unit to demodulate and decode the equalized received signals, and an error estimation unit to estimate a channel variation component indicating temporal variation of characteristics of each channel and a phase error component remaining in the received signals based on the channel matrix, the received signals, and a decoding result or an equalization result.

The invention discloses a laser phased array multi-beam forming system and method. The system specifically comprises a laser, a polarization splitting prism, a beam expander, a first liquid crystal optical phased array, a 4f optical system and a second liquid crystal optical phased array. An outgoing laser beam of the laser sequentially passes through the polarization splitting prism, the beam expander, the first liquid crystal optical phased array, the 4f optical system and the second liquid crystal optical phased array; the mode of cascading the two liquid crystal optical phased arrays is adopted for achieving forming and deflection of any multi-beam, one phased array is adopted as an amplitude modulator, the other phased array is adopted as a phase modulator, and the 4f system is used for precisely aligning phase shifting units of the two phased arrays. The mode of precise control over the amplitudes of the liquid crystal optical phased arrays and phase modulation is adopted, and forming and random pointing of any number of wave beams can be achieved.

The invention discloses a method for calculating the amplitude and phase of alternating current based on iterative Fourier transform, and belongs to the technical field of power supply. The method comprises the following steps of: determining sampling frequency, and initializing parameters; determining the frequency of the alternating current to be extracted; calculating a sine function and a cosine function; sampling an alternating current value; judging a sampling number, and calculating the cosine amplitude and sine amplitude of sub-harmonics of the alternating current; and obtaining the amplitude and phase of sub-harmonic current of the alternating current. Accurate fundamental current amplitude and phase can be obtained by performing addition and subtraction once on data obtained by the sampling of each time; and compared with the conventional Fourier-transform-based method, the method has the advantages that calculation processes are greatly reduced, and requirements for the high speed and accuracy of signal detection in a power system can be met.

A distributed optical detection system comprising: a broadband optical source; and a phase and amplitude receiver for measuring phases and amplitudes of distributed backscattered signals from a sensing medium. Methods of quantitatively sensing optical path length changes along a sensing medium in a distributed manner are also disclosed.

The invention provides a method for estimating film thickness based on an even function seismic response. The method comprises the steps of carrying out 90-degree phase shifting on a zero-phase odd function seismic response to form the even function seismic response, carrying out matching pursuit time-frequency analysis on the even function seismic response to obtain a peak amplitude and peak frequency, and estimating the film thickness through the combination of the peak amplitude and peak frequency. A device with the method used comprises a preprocessing module used for carrying out 90-degree phase shifting on the zero-phase odd function seismic response to form the even function seismic response, a matching pursuit time-frequency analysis module used for carrying out analysis on the even function seismic response to obtain the peak amplitude and peak frequency, and a film thickness obtaining module used for estimating the film thickness through the combination of the peak amplitude and peak frequency. According to the method and device for estimating the film thickness based on the even function seismic response, the equivalence between 90-degree phase shifting and film odd-even relation conversion is verified, the advantage of an even function on film thickness estimation is determined, and prediction of the film thickness is facilitated through the combination of the peak amplitude and peak frequency.

The invention discloses an IQ imbalance estimation and compensation method applicable to an OFDM-WLAN radio frequency testing system. The IQ imbalance estimation and compensation method comprises the steps of firstly obtaining coarse estimation of an IQ imbalance parameter by utilizing a long training sequence of a WLAN signal based on the smoothness characteristic of a channel impact response; then carrying out iterative operation by using pilot frequency information in a symbol based on a minimum mean square error criterion so as to obtain more precise amplitude and phase error estimation; and carrying out united balancing of the IQ imbalance and a channel for a signal based on the estimation result. The IQ imbalance estimation and compensation method is applicable to the condition that a channel has frequency selectivity; and compared with the traditional LMS algorithm, the IQ imbalance estimation and compensation method speeds up the convergence speed of the algorithm greatly as an initial value approximate to a steady-state solution can be obtained only by adding a small amount of computation, also can obtain a good estimation and compensation effect in the presence of a relatively small number of the symbols, and has very strong practicability.

A computer implemented method including a numerical model of a region of the earth modeling the acoustic behavior of that region. The method implements an acoustic wave propagator allowing the simulation of the propagation of pure P-waves in transversal isotropic media. The propagator can be applied to applications such as seismic forward modeling, reverse time migration and other two-way wave-equation based applications.

Upon data recording, a data recording unit inserts revise bytes as a predetermined specific code train into at least two or more portions including the head and last portions of data and records the data onto a medium. Upon data reproduction, a data reproducing unit separates a head reproduced signal by using clocks and, thereafter, executes a clock extraction and an amplitude correction by using a signal corresponding to the revise bytes as a specific code train. In principle, an RLL code for the clock extraction and gain tracking is eliminated and, in place of the RLL code, the revise bytes comprising the specific code train are inserted into the data and the data is recorded onto the medium.

The invention provides a wearable respiration measurement device and a respiration measurement method. The wearable respiration measurement device comprises a respiration sensor and a chest belt connected with the respiration sensor, wherein the chest belt is used for binding the respiration sensor onto the chest of a user; the respiration sensor is composed of a packaging case and a pressure detecting unit arranged inside the packaging case; the pressure detecting unit is composed of a substrate, a piezoelectric sensing element, a single processing device, a pressing unit and a first deformation piece. Through the micro-pressure model technology, the wearable respiration measurement device can convert tension generated by the chest during respiration into transverse force perpendicular tothe chest, and by precisely collecting micro pressure sensors, can obtain precise respiration frequency and amplitude through circuit processing.