46 results about "Quadrature modulation" patented technology

The invention discloses a high-speed data transmission high-order modulation compensation power amplifier linear distortion system, and belongs to the technical field of satellite high-speed data transmission. The system comprises a data processing module, a constellation mapping module, a shaping filtering module, a quadrature modulation module, a radio frequency up-conversion module, a power amplifier output module, a weighting parameter calculation module and a mapping correction module. Phase point analysis is carried out on a power amplifier output signal through a frequency spectrograph, constellation points after power amplifier compression are obtained and are compared with standard mapping phase points to generate correction parameters, then a mapping correction module is used for carrying out weighted adjustment on constellation mapping, and peripheral phase point amplitude compression caused by power amplifier saturation is compensated. According to the method, phase point distribution can be corrected through digital preprocessing under the power amplifier saturation working condition, linear distortion of high-order modulation signals is effectively improved, the power amplifier backoff amount is reduced, the power amplifier efficiency is improved, and the method is suitable for a non-amplitude balance high-order modulation scene in a satellite high-speed data transmission system.

This invention belongs to the field of communication and signal processing technology, specifically relating to a GMSK quadrature modulator. It comprises a bidirectional counter, a four-curve data table, an in-phase component processor, and a quadrature component processor, forming a quadrature modulation baseband generator. A binary symbol sequence and a system clock are input to this generator. The system clock is divided to generate a symbol frequency multiplier clock, driving the bidirectional counter to oscillate and count repeatedly. The in-phase and quadrature component processors process and generate curve selection types and curve symbols. The output of the bidirectional counter is used as the curve lookup table address. A quadrature modulation baseband signal is generated by looking up the pre-stored four-curve data table, and then input to a digital up-converter (DUC) circuit to produce a GMSK modulated signal. Compared to existing technologies, this invention is more resource-efficient, has higher accuracy, and lower spurious emissions, making it highly suitable for embedded system or programmable device design and implementation.

A method of decoding information encoded in respective activation modes of an activated subset of antennas of a MIMO transmitter transmitting orthogonally modulated signal components, the method comprising: decoupling a real part and an imaginary part of a signal component of a received signal vector, respective channel matrices of real and virtual channels are received, determined, or estimated, and real and virtual signal components are represented as respective products of transmitted symbol components and activation unit vectors. The respective activation unit vectors of the decoupled real and imaginary parts are then represented with corresponding random variable vectors that are dependent on a probability quality function of the activation pattern available at the transmitter. Then, a Gaussian belief propagation-based messaging process is applied to the random variables to jointly estimate activation unit vectors of the respective real and imaginary parts of the received signal vector, and finally the activation unit vectors are decoded to obtain the information.

The application discloses a kind of triaxial SERF atom magnetometer quadrature double frequency modulation system and method, the system utilizes signal generation module to generate frequency f m The sine quadrature modulation signal of cosine is respectively driven SERF atom magnetometer X and Y axis magnetic field generating coil, and 2nf m Frequency sine signal of driving Z axis coil, through the integral filter of 3 groups of integral period integration, the open-loop magnetic field signal of X axis, Y axis and Z axis magnetic field component is obtained, and through control module, the driving current of three-axis magnetic field coil is controlled to generate compensation magnetic field, so that the open-loop magnetic field signal of X axis, Y axis and Z axis magnetic field component is zero, at this time, the magnetic field intensity of atom chamber is zero, and the compensation current output by control module is the X, Y and Z axis magnetic field intensity signal measured by triaxial SERF atom magnetometer.The system can directly extract triaxial magnetic field calculation signal from a laser signal, and eliminate the cross-coupling effect when triaxial magnetic field is calculated, improve the measurement range and quadrature of SERF atom magnetometer, with very high engineering application value.

The application provides a device and a method for realizing PON rate adjustment based on Polar modulation, and relates to the technical field of passive optical networks.The device comprises a first external cavity laser, a second external cavity laser, a dual-polarization phase quadrature modulator, an arbitrary waveform generator, an erbium-doped fiber amplifier, a single-mode optical fiber, a variable optical attenuator, a coherent receiver and an oscilloscope.The method comprises the following steps: dynamically adjusting the number of information bits A, splicing check bits to form total information bits, optimizing the distribution of information bits and frozen bits according to the optical signal channel sorting result, performing polar encoding on the signal at the encoding end, and mapping the signal into a 16QAM code symbol sequence by using the Polar modulation technology; at the receiving end, calculating the LLR, calculating the path metric value of all paths and performing a pruning operation when the list width reaches a set value, and detecting the L candidate paths by using the CRC check after the decoding is completed.The application realizes flexible regulation and control of the transmission rate of different optical network units.

The application discloses a single-channel signal detection design method suitable for a multi-feed antenna, and relates to the field of satellite communication.The method comprises the following steps: S1, a modulator is used to perform orthogonal modulation on multiple-channel signals generated by the multi-feed source, and a combiner is used to form a combined signal; S2, the combined signal is converted into an L-band combined signal by a low-noise down converter (LNB); S3, the L-band combined signal is converted into a zero intermediate frequency baseband digital signal by a tracking receiver; S4, a baseband processing unit is used to complete frequency coarse estimation on the baseband digital signal by using a multi-path parallel frequency search method, so that signal detection is realized; and S5, the baseband processing unit is used to perform frequency coarse correction, FFT frequency offset estimation, phase-locked tracking and power estimation on the signal, so that signal tracking of the multi-feed antenna is completed.The application adopts a code domain synthesis scheme, has low requirements on the antenna feed part of the multi-feed source, can reduce the system cost by using a single-channel receiver, and can improve the reliability of the system.In addition, the multi-path parallel frequency search method is simple in calculation and high in detection precision, and is suitable for signal detection and tracking of a multi-feed antenna system which is cost-sensitive, low in complexity and high in precision.

A signal transmission link and method, a transceiver link, an integrated circuit, and an electromagnetic wave device are disclosed. The signal transmission link is applied in a radar system. The signal transmission link includes: a transmitting baseband digital module, a digital-to-analog converter (DAC) module, a transmitting local oscillator, and a transmitting quadrature modulator. The DAC module includes two identical DACs. The transmitting baseband digital module is configured to generate two orthogonal transmitting digital baseband signals and send the two orthogonal transmitting digital baseband signals to one DAC respectively. The DAC module is configured to convert the two orthogonal transmitting digital baseband signals into two transmitting analog baseband signals. The transmitting local oscillator is configured to provide a transmitting local oscillator signal. The transmitting quadrature modulator is configured to perform frequency shifting and phase shifting operations on the transmitting local oscillator signal based on the two transmitting analog baseband signals to form a predetermined phase-shifted FMCW radio frequency transmission signal.

Systems and methods for power budgeting within a coherent optical network are provided. A phase shift controller may be provided for controlling a phase shift (θ) between an in-phase (I) and quadrature (Q) branches of an optical IQ modulator to generate a complex IQ signal. The phase shift of the optical IQ modulator may be controlled between an orthogonal mode, such as a conventional QPSK mode, and a nonorthogonal mode, based on an operational state of the modulator. The nonorthogonal mode may include a high-suppression mode and a high-power mode.

A wireless RF connection provides relocatable transmitter and / or receiver antennas utilizing digital fiber optic connections to provide improved resilience of relocatable RF antennas. Improved robustness against suboptimal performance of various optical components is realized by the introduction of serial, bit stream transmission of in-phase and quadrature modulation data (I, Q data).

The invention discloses an NMOR atom magnetometer three-axis magnetic field measurement method based on dual-frequency quadrature modulation, and belongs to the technical field of three-axis magnetic field vector measurement, and the method comprises the steps: S1, tuning a laser frequency, generating a linear polarization laser through employing the frequency-tuned laser, and polarizing an atom ensemble through employing the linear polarization laser; s2, applying modulation magnetic fields with different frequencies to two orthogonal axes of the light polarization plane, performing dual-frequency orthogonal modulation, generating an optical rotation response signal, performing balance differential detection on the optical rotation response signal, and outputting a differential voltage signal; s3, synchronously demodulating the differential voltage signal to obtain a three-axis signal component; s4, performing in-situ calibration of a three-axis scale coefficient to obtain a scale coefficient; and S5, according to the scale coefficient, converting each axis signal component into a three-axis magnetic field amplitude, and outputting a three-axis magnetic field vector measurement result. The method is high in measurement precision and good in real-time performance, and can be widely applied to the technical fields of biological magnetic measurement, basic physics and the like.

This invention belongs to the field of optical communication technology and discloses a coherent optical communication system driven by an integrated electro-optic frequency comb, comprising: a continuous wave laser (1), an electro-optic frequency comb chip (2), a radio frequency signal source (3), a radio frequency signal distribution module (4), a first fiber amplifier (5), an arbitrary waveform generator (6), a dual-polarization in-phase quadrature modulator (7), a second fiber amplifier (8), a single-mode fiber (9), a third fiber amplifier (10), a tunable bandpass filter (11), a local oscillator continuous wave laser (12), a coherent receiver (13), and an offline digital signal processing module (14); wherein, the electro-optic frequency comb chip (2) is loaded with a radio frequency signal and can perform electro-optic modulation on the continuous wave optical signal to generate a broadband, flat-top electro-optic frequency comb. By integrating an electro-optic frequency comb chip into the coherent optical communication system, this invention can significantly improve the system integration and greatly reduce the system cost.

A wireless RF connection provides relocatable transmitter and / or receiver antennas utilizing digital fiber optic connections to provide improved resilience of relocatable RF antennas. Improved robustness against suboptimal performance of various optical components is realized by the introduction of serial, bit stream transmission of in-phase and quadrature modulation data (I, Q data).

This invention relates to the field of satellite communication technology, and provides an inter-satellite transmission signal system, a signal system, and a signal processing method. The inter-satellite transmission signal system includes M GEO satellites, M signal modulation units, and M signal demodulation units. Each GEO satellite includes one signal modulation unit and one signal demodulation unit. Two inter-satellite signal paths exist between any two adjacent GEO satellites; one path is used to transmit a first signal, and the other path is used to receive a second signal. The signal modulation units are used to perform orthogonal modulation on the communication signals and telemetry and control signals; the signal demodulation units are used to perform orthogonal demodulation on the modulated signals. The system described in this invention improves the versatility and interchangeability of the system structure, and the signal system can integrate communication and telemetry and control signals for information processing, improving the integration level of the signal system and thus improving the utilization rate of transmission channels and power resources.

The present application relates to a kind of methods for measuring the amplitude-frequency and phase-frequency response of radio frequency cavity, comprising: the digital radio frequency low level system generates sawtooth wave pulse frequency signal, and generates frequency control word;The digital radio frequency low level system generates sine data sequence and cosine data sequence according to the frequency control word, and the sine data sequence and the cosine data sequence are quadrature modulated, the output of the quadrature modulation is converted to digital-analog after output to the power source, and then the power amplifier is carried out power amplification and the directional coupler coupling after generation radio frequency signal input to the radio frequency cavity;The digital radio frequency low level system obtains the cavity pressure signal of the radio frequency cavity, and the forward voltage signal and reverse voltage signal of the directional coupler;The digital radio frequency low level system carries out real-time signal processing according to the cavity pressure signal, the forward voltage signal and the reverse voltage signal, and obtains the amplitude-frequency and phase-frequency response curve of the radio frequency cavity.

A transformer circuit (10) for output synthesis combines in-phase output signals (RF_I, RF_IB), which are obtained by modulating an in-phase baseband signal with a first local oscillator signal, with quadrature output signals (RF_Q, RF_QB), which are obtained by modulating a quadrature baseband signal with a second local oscillator signal orthogonal to the first local oscillator signal. An output inductor (21) comprises a wiring section (211) adjacent to a first input inductor (11), a wiring section (212) adjacent to a second input inductor (12), and connection wiring (CN) connecting the wiring sections (211, 212). Output terminals (RF, RFB) are provided at locations other than the connection wiring (CN) and wiring on the side continuous with the connection wiring (CN) for the wiring sections (211, 212).

The invention discloses a common radio frequency single-channel monopulse tracking method based on time modulation, and the method comprises the steps: designing a multi-order quadrature modulation waveform according to a time modulation principle with Fourier transform as a core; the optimized weight vector is adopted to adjust excitation of a time modulation array element so as to suppress interference caused by an unexpected target; establishing a corresponding relation between the phase delay and the steering factor so as to meet phase compensation required by beam scanning; more harmonic components are introduced, and the available bandwidth is controlled while beams are synthesized on any multiple pairs of selected sidebands; and performing monopulse tracking on a target in the space by using the sum and difference beams which are synthesized at the same time. According to the method, beam steering and simultaneous synthesis of multiple groups of sum-difference beam pairs can be realized without a plurality of independent beam forming networks by utilizing the mapping relation between the time modulation parameters and the radiation characteristics, the problems of complex structure and insufficient flexibility of the existing method are solved, and the conciseness and engineering applicability of a monopulse tracking system are remarkably improved.

The invention discloses a photo-thermal spectrum device and method based on orthogonal pseudo-random code modulation, and the device comprises a control and signal processing unit, a pseudo-random code generator, a laser driver, a tunable laser, a collimator, an air chamber, a focusing lens, a quartz tuning fork, a pre-amplifier, a data collector, and a related demodulator. A pseudo-random code sequence with good self-correlation and cross-correlation characteristics is used for carrying out binary orthogonal modulation on laser intensity, and weak photo-thermal signals are extracted from strong noise through a correlation demodulation technology. The method has the advantages that the method is insensitive to narrow-band noise due to the broadband modulation characteristic, any noise irrelevant to pseudo-random codes can be effectively suppressed by relevant calculation, and the method has extremely high anti-interference capability; related processing is equivalent to long-time energy accumulation, and the noise bandwidth can be compressed; the broadband characteristic of the pseudo-random code enables the pseudo-random code to cover the drift range of the resonant frequency of the quartz tuning fork, and the system is higher in adaptability to environmental changes and higher in stability.

The invention discloses a light-induced thermoelastic multi-component gas detection device and method based on quadrature modulation, which adopts a technical path combining double-path quadrature phase modulation and single-path quadrature demodulation, that is, two tunable lasers are respectively driven by sinusoidal signals with the same modulation frequency but orthogonal phases; the two laser beams are combined by the wavelength division multiplexer, collimated by the collimator, acted by the gas chamber and the gas and focused by the lens and then radiated to the surface of the quartz tuning fork, a piezoelectric signal generated by the quartz tuning fork comprises excitation mixing information of the two gases, and the signal is amplified by the preamplifier and then sent to the lock-in amplifier; and the phase-locked amplifier synchronously calculates two components X and Y which are orthogonal to each other according to a reference signal with the same frequency as the laser modulation signal, and the two components respectively and independently correspond to the concentration information of the two target gases, so that real-time, synchronous and crosstalk-free measurement of the two-component gases is realized.

A transmitter includes: processing circuitry which, in operation, performs correction processing on a first signal of a pair of transmission signals mapped to frequency resources symmetric with respect to a center frequency by using a second signal of the pair of transmission signals; and a quadrature modulator which, in operation, performs quadrature modulation on the pair of transmission signals after the correction processing.

The application provides a signal processing method, device, equipment, medium and product, and belongs to the technical field of signal processing. Data flow of a digital baseband signal is separated into a first signal and a second signal, then a first modulation signal and a second modulation signal are respectively generated by combining a first digital carrier and a second digital carrier which are strictly orthogonal through a multiplier in a digital domain, signal synthesis operation is performed by a digital adder to output a first complex signal, and finally the synthesized single data flow is sent into a single digital-to-analog converter to be converted into a first analog signal. In this process, the link which is prone to defects in the orthogonal modulation process is all transferred to the digital domain which is composed of absolute accurate 0 and 1. Since there is no physical direct current bias in the digital domain, and the digital multiplication operation eliminates the parasitic capacitance crosstalk under the high-frequency electromagnetic field, the local oscillator leakage generated when operating with the carrier is directly avoided in the data bottom logic, and the radio frequency signal distortion is avoided.

To improve the performance of radio communication.SOLUTION: The transmitter includes a processing circuit that uses one of the transmission signals mapped to the symmetric frequency resources with respect to the center frequency to perform correction processing on the other of the transmission signals mapped to the symmetric frequency resources, and a quadrature modulator that performs quadrature modulation on the transmission signal after the correction processing.SELECTED DRAWING: Figure 5

The utility model provides an S-band radar broadband radio frequency transceiver, which belongs to the technical field of radars and adopts the technical scheme that the S-band radar broadband radio frequency transceiver comprises a broadband transceiver unit, a power supply module and a transceiver control module, the signal transmitting end is electrically connected with the output end of the broadband transceiving unit; the signal receiving end is electrically connected with the input end of the broadband transceiving unit; the reference output end, the first clock output end, the second clock output end and the intermediate frequency output end are electrically connected with the output end of the broadband transceiving unit; the broadband transmit-receive unit comprises a synthesis module. According to the device, channel local oscillation and transmitting signals are synthesized based on the broadband phase locking technology and quadrature modulation, the receiving and transmitting antennas are gated by using the low-loss multi-channel radio frequency switches in turn, and the device has the advantages of ultra wide band, dense frequency hopping, large dynamic, multiple channels, low weight and low cost.

A stylus receiving circuit receives a vector data signal emitted by a stylus, the vector data signal carrying vector data, the vector data including in-phase data and quadrature data, the stylus receiving circuit comprising: an integrating delta-sigma analog-to-digital converter converting the vector data signal into a one-bit bit stream using integrating delta-sigma operation; and a first logic gate circuit and a second logic gate circuit, the first logic gate circuit performing logical and quadrature operation on the one-bit bit stream and an in-phase modulated carrier signal to generate demodulated in-phase data, the second logic gate circuit performing logical and quadrature operation on the one-bit bit stream and a quadrature modulated carrier signal to generate demodulated quadrature data, whereby demodulated vector data is obtained.

The invention relates to multi-spoke beamforming for low-power wide-area satellites and ground networks. Wireless communication methods and apparatus enable communication between a plurality of endpoints and a satellite or ground gateway integrated with a plurality of rectangular antenna arrays. The wireless communication method utilizes orthogonally modulated data symbols. The approach allows the use of multiple compact rectangular antenna arrays to increase network capacity and reduce endpoint power consumption.

This application discloses a broadband vector signal generator, including a multi-channel phase-locked loop (PLL) module, a baseband processing module, and a radio frequency (RF) processing module. The generator performs PLL on a synchronization reference signal to obtain five clock signals; acquires waveform data; performs digital-to-analog conversion on the waveform data based on a first clock signal to obtain two baseband signals; divides a third clock signal to obtain a frequency-divided signal; uses a second clock signal or the frequency-divided signal as a quadrature modulation local oscillator signal to orthogonally modulate the two baseband signals to obtain a quadrature modulation signal; performs power control on the quadrature modulation signal to obtain a first RF signal, a first control signal, and a second control signal; uses a fourth clock signal as an up-converted local oscillator signal to up-convert the first control signal to obtain a second RF signal; and uses a fifth clock signal as a down-converted local oscillator signal to down-convert the second control signal to obtain a third RF signal. This broadband vector signal generator can achieve wide bandwidth and high linearity.

The application discloses a high-speed data transmission high-order modulation compensation power amplifier linear distortion system and belongs to the technical field of satellite high-speed data transmission. The system comprises a data processing module, a constellation mapping module, a shaping filter module, a quadrature modulation module, a radio frequency up-conversion module, a power amplifier output module, a calculation weighting parameter module and a mapping correction module. The power amplifier output signal is analyzed by a spectrum analyzer, the constellation points after compression of the power amplifier are acquired, the correction parameters are generated by comparison with standard mapping phase points, the constellation mapping is adjusted by the mapping correction module, and the amplitude compression of the peripheral phase points caused by the saturation of the power amplifier is compensated. The application can correct the phase point distribution by digital preprocessing under the working condition of the saturation of the power amplifier, effectively improve the linear distortion of the high-order modulation signal, reduce the power amplifier backoff amount, improve the power amplifier efficiency, and be suitable for the high-order modulation scene of non-amplitude balance in the satellite high-speed data transmission system.

The application discloses a physical layer security waveform generation method, comprising the following steps: step 1, obtaining and constructing a symbol-related prime set and a chip-related prime set; step 2, processing the symbol-related prime set and the chip-related prime set respectively to obtain a symbol vector and a chip vector; step 3, performing point multiplication operation on the symbol vector and the chip vector to obtain a signal vector; step 4, filtering the signal vector as an input through a baseband shaping filter; and step 5, moving the filtered result to a corresponding frequency point through a quadrature modulator to obtain a final result. The method obtains the concealment characteristics of the waveform and the security characteristics of the transmission information based on randomization time-varying physical layer waveform parameters, and can obtain a short-time stable data transmission rate, thereby meeting the actual requirements of a wireless communication system.

The present application relates to the technical field of control board signal processing, and provides a method for improving the anti-interference capability of a control board, frequency characteristics of each motor control signal in the control board are collected, a frequency spectrum is obtained by performing Fourier analysis on the frequency characteristics, and the control signals are divided into a high-frequency signal group and a low-frequency signal group according to the frequency spectrum; time slot allocation is performed on the control signals in the high-frequency signal group, the transmission cycle of the high-frequency signal group is divided into N time slots, and each control signal occupies one time slot; based on the frequency characteristics of the low-frequency signal group, an orthogonal modulation base vector is constructed, and the control signals of the low-frequency signal group are mapped onto the orthogonal modulation base vector; and according to the time slot allocation scheme and the orthogonal modulation base vector, the signal transmission timing of the control board is reconstructed, so that the control signals of the high-frequency signal group and the low-frequency signal group do not interfere with each other. The technical problem that the control precision is reduced due to mutual interference of the control signals when the control board is in operation with multiple motors is solved.

The invention discloses an optical communication multi-system modulation method and system based on power optimization, and relates to the technical field of satellite optical communication, and the method comprises the steps that an optical power control unit carries out the power distribution of a laser signal outputted by a laser based on a target modulation format and a target multiplexing mode, and carries out the modulation of the optical communication based on a power distribution result; the laser signal is input to the in-phase quadrature modulation unit; the in-phase quadrature modulation unit determines a modulation parameter based on a target modulation format and the target multiplexing mode, modulates a laser signal input by the optical power control unit based on the modulation parameter to obtain a polarization modulation optical signal, and inputs the polarization modulation optical signal to the polarization multiplexing unit; and the polarization multiplexing unit processes the polarization modulation optical signal to obtain a target modulation optical signal. Through the mode, on the basis of supporting multi-system modulation, optical power distribution can be carried out according to different modulation formats and different multiplexing modes, the loss of optical power is reduced, the utilization rate of the optical power is improved, and the signal-to-noise ratio is improved.

This invention discloses an optoelectronic fusion millimeter-wave ultra-wideband image suppression receiver device, applied in the field of ultra-wideband communication and radio frequency reception technology. It addresses the problem that existing receiver technologies cannot meet the requirements of multi-band, high-fidelity ultra-wideband reception applications. This invention achieves continuous tuning of the local oscillator frequency from several GHz to hundreds of GHz by independently setting an optically generated local oscillator module with wide tuning capability, adapting to multi-band reception requirements. The multi-wavelength parallel processing capability of the optical comb technology allows for baseband signal extraction without complex channelization. Furthermore, by increasing the signal amplitude through intermediate frequency conversion, it effectively adapts to the driving requirements of electro-optic modulators. Combined with orthogonal mixing and electro-optic quadrature modulation architecture, it achieves excellent image suppression performance. This invention simultaneously solves four core problems: difficulty in adapting large instantaneous bandwidth modulation drives, poor high-frequency local oscillator phase noise performance, poor image suppression effect, and insufficient multi-band adaptability. It has significant engineering application value and technological innovation.