30results about "Modulation depth measurements" patented technology

Disclosed is a unique system and method for recognizing the type of modulation embedded in an unknown complex baseband signal, comprising a receiver section for extracting the complex baseband signal from a modulated signal having a carrier frequency, and comprising an orderly series of signal processing functions for (a) estimating the bandwidth of the unknown signal, (b) removing the out-of-band noise and correcting gross carrier frequency errors, (c) discriminating between constant envelope and irregular envelope signals, (d) estimating and correcting residual carrier frequency errors, (e) classifying a constant envelope signal into one of the following modulation formats: {Continuous Wave (CW), Frequency Modulation (FM), Frequency Shift Keying (FSK)}, and (f) classifying an irregular envelope signal into one of the following modulation formats: {Amplitude Modulation (AM), Double Sideband Suppressed Carrier (DSB-SC), Binary Shift Keying (BPSK), Quaternary Phase Shift Keying (QPSK), π / 4-shifted QPSK, M-ary PSK (MPSK), and OTHER classes}.

A method and device are provided for an improved system and method of estimating the noise floor of a wideband signal without full knowledge of the nature of the narrowband signals contained therein, and provides digital characteristics to allow real-time signal processing with low levels of computational complexity. The method and device require very little a priori knowledge of the nature of the signals, allow both robust performance in non-ideal environments, and automated maximum sensitivity threshold setting.

A logical channel is configured to match a modulation profile of an active channel. A network element is assigned to the logical channel and a ping request is sent to the network element. A response from the network element is measured, such as measuring the MER. The modulation profile is increased in the logical channel and another ping request is sent to the network element. The response is measured again, and the process is repeated until a non-linearity is detected in the response. The acceptable modulation profiles are indicated before the non-linearity is detected in the response.

Measurement of a characteristic of a digital modulation signal transmission circuit is calculated using only a distorted digital modulation signal from the transmission circuit. A measurement and processing circuit receives and demodulates the distorted digital modulation signal from the transmission circuit, separates known and unknown data from the demodulated signal, and estimates ideal symbols for the unknown data using known information derived from the known data, such as modulation format information and pilot signals. Then the measurement and processing circuit calculates the characteristic, such as transmission circuit linearity, between the distorted digital modulation signal and a calculated ideal digital modulation signal based on the ideal symbols and known information. The characteristic measurement is displayed graphically.

An electromagnetic wave analyzer that accurately calculates electromagnetic waves emanating from a given wave source, without the need for assessing accuracy in other than the wave source domain. An analysis condition receiver receives analysis conditions including position parameters specifying observation points, as well as frequency parameters specifying frequencies to be analyzed. Upon receipt of analysis conditions, a Fourier transform processor transforms time-series electromagnetic current data to produce frequency-specific electromagnetic current data for each frequency specified by the frequency parameters. Based on the frequency-specific electromagnetic current data, an electromagnetic field calculator calculates the electric field at each observation point specified by the position parameters, by integrating electric fields produced by electric and magnetic currents in each small volume of the electromagnetic wave source.

A frequency hopping communication device has a memory for storing modulation coefficients related to the frequency hopping frequency of a carrier. Whenever the subsequent frequency hopping frequency is determined, the central processing unit (CPU) reads out one of the modulation coefficients according to the subsequent frequency hopping frequency from the memory, and supplies it to the Gaussian filter. The Gaussian filter stores the read modulation coefficient in the register, and then multiplies the supplied transmit data signal by the read modulation coefficient stored in the register to generate a modulated signal. Therefore, the modulating signal has a voltage amplitude that depends on the carrier frequency. The voltage controlled oscillator modulates a carrier with a subsequent hopping frequency with the modulation signal from the Gaussian filter and generates a transmit signal. Therefore, the transmitted signal has an approximately uniform frequency offset independent of the carrier frequency.

Outputs of a linear RF detector and a logarithmic RF detector are multiplexed individually to a single digitizer or simultaneously to a respective digitizers. A process generates a composite waveform from the resulting digitized data, either at a later time in the former case or in real-time in the latter case. To achieve simultaneous routing, several routing relays are arranged in a specialized configuration between the outputs of the RF detectors and the inputs of the digitizers.

The method provides an amplitude-modulated signal accompanying phase modulation measurement method based on vector analysis, and a mainly used device is a vector signal analyzer. Traditionally, measurement accompanying phase modulation utilizes a frequency spectrum analysis method with more limitations and complex computation. The method reasonably sets the parameters of the vector signal analyzerso as to measure amplitude-modulated signal by a vector demodulation way, has wide applicability and clear and simple mathematic relation.

In described examples of a method (100) of measuring phase noise (PN), a PLL frequency synthesizer includes a first phase frequency detector (PFD) receiving (101) a reference frequency signal coupled to a first charge pump (CP) coupled to a VCO having an output fed back to the first PFD through a feedback divider that provides a divided frequency signal to the first PFD. The first PED outputs an error signal. PN measurement circuitry includes a replica CP coupled to an output of a second PFD or the first PFD. The error signal is received at the replica CP, or the divided frequency signal and reference frequency signal are received at the second PFD. The replica CP outputs a scaled phase error current, which is current-to-voltage converted and amplified (102) to provide an amplified phase error voltage, and digitized (103) to provide a digital phase error signal. The digital phase error signal is frequency analyzed (104) to generate a PN measurement.

A system (800) for determining frequency separation for preventing intermodulation distortion signal interference is provided. The system (800) includes a sensor assembly (810) and a meter verification module (820) communicatively coupled to the sensor assembly (810). The meter verification module (820) is configured to determine a frequency of a first signal to be applied to a sensor assembly (810) of a vibration meter, and to set a demodulation window around the frequency of the first signal. The meter qualification module (820) is also configured to determine a frequency of the second signal to be applied to the sensor assembly such that a frequency of an intermodulation distortion signal generated by the first signal and the second signal is outside the demodulation window.

The present invention proposes a short time interval modulation domain measurement sequence design method, including: measurement data output time arrangement unit, each data effective serial parallel structure unit, measurement effective feedback signal generation unit, operation processing unit; the measurement data output time The arrangement unit arranges the data of various parameters in one measurement of each measurement unit in chronological order, and designs each data effective serial-parallel structural unit according to this order; the effective serial-parallel structural unit of each data is the output of each measurement parameter Construct a series-parallel process based on the contextual relationship, select the moment when the last measurement data is output as the end of an effective measurement process; the measurement effective feedback signal generation unit uses the feedback signal to start the measurement unit; the operation processing unit is responsible for the realization of the algorithm The data measured by the two channels of the high and low gates are seamlessly integrated, and the measured data is read through the high-speed interface, and is responsible for the final calculation, processing and display of the data.

Outputs of a linear RF detector and a logarithmic RF detector are multiplexed individually to a single digitizer or simultaneously to a respective digitizers. A process generates a composite waveform from the resulting digitized data, either at a later time in the former case or in real-time in the latter case. To achieve simultaneous routing, several routing relays are arranged in a specialized configuration between the outputs of the RF detectors and the inputs of the digitizers.

The present invention discloses a method and a system for metering a digital demodulating error parameter based on an amplitude modulation method or a phase modulation method, wherein the metering method can comprise the following steps: generating an amplitude modulation (AM) signal the carrier frequency of which is the summation or the subtraction of a first frequency and a second frequency and the amplitude modulation frequency of which is a third frequency and an amplitude modulation depth D, wherein the first frequency is larger than the second frequency; the second frequency is over 30 times than the third frequency; VSA sample sequence persistence length is equal to integral multiple of amplitude period; using the generated AM signal as an equivalent digital modulation signal input to the input end of a VSA, wherein the carrier frequency of the VSA is set to be the first frequency; a demodulating mode is set to be MPSK; the symbol rate is set to be M times of the second frequency; and the error parameter of the equivalent MPSK signal is calculated. The error parameter which is generated by the method and used for correcting the equivalent digital modulation signal of the VSA can be precisely set and calculated, thus the invention can simultaneously solve two problems of the parameter traceability of the digital demodulating error parameter and error setting.

The present invention proposes a wide-band large dynamic signal high-precision measurement device and method, which solves the current commonly used frequency domain analysis method, which does not have a setting method for adaptively configuring demodulation channel state parameters according to the signal to be measured, and lacks flexibility. , the test accuracy is not high, and it does not meet the requirements of metrological testing. The high-precision measurement device and method for wide-band large dynamic signals of the present invention utilize the pre-tested signal characteristic parameters of the test device to optimize the configuration of the channel gain value and demodulation bandwidth value of the test device by creating an automatic rule processor to achieve wide-band High-precision measurement of large dynamic signals.

In the described example of the method (100) of measuring phase noise (PN), the PLL frequency synthesizer comprises a first phase frequency detector (PFD) receiving (101) a reference frequency signal, the first phase frequency detector ( PFD) is coupled to a first charge pump (CP) coupled to a VCO having an output fed back to the first PFD through a feedback divider that provides a divided signal to the first PFD. The first PFD outputs an error signal. The PN measurement circuitry includes a replica CP coupled to the output of the second PFD or the first PFD. The error signal is received at the replica CP, or the frequency-divided signal and the reference frequency signal are received at the second PFD. The replica CP outputs a scaled phase error current, which is current-voltage converted and amplified (102) to provide an amplified phase error voltage, and digitized (103) to provide a digital phase error signal. Frequency analysis (104) is performed on the digital phase error signal to generate a PN measurement.

The method provides an amplitude-modulated signal accompanying phase modulation measurement method based on vector analysis, and a mainly used device is a vector signal analyzer. Traditionally, measurement accompanying phase modulation utilizes a frequency spectrum analysis method with more limitations and complex computation. The method reasonably sets the parameters of the vector signal analyzer so as to measure amplitude-modulated signal by a vector demodulation way, has wide applicability and clear and simple mathematic relation.

The invention provides a short time interval modulation domain measure sequential design method; a measuring data output time arranging unit, each data valid series-parallel mechanism unit, a measuring valid feedback signal forming unit and an operation processing unit are provided; the measuring data output time arranging unit can arrange various parameter data according to the time sequence, wherein the parameter data is obtained in one measurement of each measuring unit, and each data valid series-parallel mechanism unit is designed according to said sequence; the data valid series-parallel mechanism units build a series-parallel process for the sequence relation of the outputted measuring parameters, and select the time of the last outputted measuring data as the end of a valid measuring process; the measuring valid feedback signal forming unit uses a feedback signal to start the measuring unit; the operation processing unit is used for realizing an algorithm, realizing gapless integration of the data measured by high-low gate two measuring channels, using a high speed interface to read the measured data, and carrying out final operation, processing and displaying of the data.