67 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 present invention discloses a GPS interference phased array monitoring and direction-finding antenna system for the 1575 frequency band, relating to the technical field of smart antennas. The system comprises a data integration module for integrating satellite ephemeris, carrier attitude, and airspace coverage data using a weighted averaging method to generate an environmental parameter set; a prediction and calibration module for inputting the environmental parameter set into a bidirectional LSTM network to obtain a phase drift prediction value, and performing nonlinear calibration on the phase drift prediction value using a Kalman-particle hybrid filtering algorithm, while simultaneously monitoring IQ signals using a closed-loop feedback mechanism; and a beamforming module for performing orthogonal modulation and radio frequency up-conversion processing on the IQ signals, and generating a Butler matrix beam using a hybrid topology beam space transformation algorithm. The present invention utilizes a bidirectional LSTM network in combination with a Kalman-particle hybrid filtering algorithm to accurately predict and calibrate phase drift caused by factors such as carrier vibration in real time.

The present invention discloses a secure communication method and system based on chaotic prediction and interleaving coding in a reserve pool. The chaotic encryption module includes a light source output by a first continuous wave laser (CW), which is modulated by a parallel quadrature modulator (IQM) to convert the signal output by an arbitrary waveform generator (AWG) for transmission. The signal is pseudo-randomly interleaved and encoded. The transmitted signal is loaded onto a chaotic carrier through a first optical coupler (FC) to achieve chaotic hiding. The chaotic optical carrier is then transmitted through an information transmission module. The chaotic optical carrier is predicted in advance by the reserve pool in the chaotic decryption module and modulated onto the continuous optical carrier output by a second continuous wave laser (CW) through a Mach-Zehnder modulator (MZM). The signal is then decrypted by a 90° mixer to initially restore the original transmitted signal. Finally, the resulting signal is processed by a local oscillator (LO) and a coherent receiver, and digital information processing (DSP) is performed to compensate, recover, and decrypt the digital signal, thereby realizing chaotic secure coherent optical communication.

To provide an orthogonal modulation device, a method for spurious correction, and a method for correcting orthogonal modulation that can measure spurious components of a modulated wave with high accuracy without being limited by circuit configuration.SOLUTION: In a quantum computer 10, an orthogonal modulation device 12 includes a modulation unit 17 and a measurement unit 18. The modulation unit 17 includes: a first orthogonal modulation unit 21 configured to output a TX1 signal orthogonally modulated; and a second orthogonal modulation unit 22 configured to output a TX2 signal orthogonally modulated. The TX1 signal and the TX2 signal each include a desired wave of the same frequency. When the image components and local leakage of the TX1 signal and the TX2 signal are measured by the measurement unit 18, the TX1 signal and the TX2 signal are adjusted such that the desired wave of the TX1 signal and the desired wave of the TX2 signal have the same amplitude and are in opposite phase to each other, and the image components and local leakage are measured from a composite wave of the TX1 signal and the TX2 signal. A downconverter 53 of the measurement unit 18 includes a mixer 53a and a third local oscillator 53b composed of a fractional-N PLL circuit.SELECTED DRAWING: Figure 1

A balanced power amplifier includes a first power amplifier configured to apply a first gain having a first predetermined magnitude and a first programmable phase adjustable phase to generate a first amplified signal, the first programmable phase being adjustable to either a first phase or to a second phase that is 180° phase shifted relative to the first phase; a second power amplifier configured to apply a second gain having a second predetermined magnitude and a second programmable phase to generate a second amplified signal, the second programmable phase being adjustable to either the first phase or to the second phase; and a 90° hybrid coupler configured to receive the first amplified signal and the second amplified signal and generate and output a first output signal or a second output signal based on a combination of the first amplified signal and the second amplified signal.

The invention relates to a digitally-controlled quadrature modulation laser single side band frequency shift and phase locking device and method, a field programmable logic gate array of the device is connected with four digital-to-analog converters, every two digital-to-analog converters are connected with a quadrature modulator, the two quadrature modulators are also connected to an optical quadrature modulator, and the optical quadrature modulator is connected with the four digital-to-analog converters. The output of the laser source realizes single side band frequency shift through an optical quadrature modulator, part of optical signals are converted into electric signals through a third beam splitter, and parameters of the optical modulator are adjusted in real time through a voltage control port. And the other path of laser is interfered with the frequency-shifted optical signal in the beam combiner through the first beam splitter, demodulated by the orthogonal down-conversion mixer, fed back with phase information, and transmitted back to the field programmable logic gate array through the three-channel analog-to-digital converter to form closed-loop control. According to the invention, the influence of sideband signals generated by adjustment is reduced; moreover, the frequency shift bandwidth can be higher, the influence of a spatial light path is reduced, and the stability is improved.

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.

The present invention discloses a pulse programming-based shortwave array signal phase-controlled synchronization method. This method can eliminate errors caused by layout and routing delays, clock offsets, and clock jitter through pulse programming, achieving precise array signal synchronization. The method's main implementation process includes: 1) Synchronous clock generation: Through input clock processing, master clock distribution, master clock deviation elimination, driving, and buffering, N+1 stable and synchronized master clocks are generated. Then, N+1 sub-clocks with different frequency synchronization are generated through clock derivation. 2) Programmable pulse generation: Upon receiving an external signal generation instruction, one pulse is generated based on the synchronized master clock. Then, pulse programming is used to generate pulses for other master and sub-clocks for synchronous triggering of array signal generation. 3) Array signal generation: Under the triggering of the sub-clock pulse, a low-rate baseband signal is obtained through modulation source acquisition and baseband signal generation. Under the triggering of the master clock pulse, the low-rate baseband signal is processed through baseband signal processing to obtain a high-rate baseband signal. A carrier signal corresponding to the initial phase is generated according to the array output phase requirement. Orthogonal modulation, amplitude adjustment, and digital-to-analog conversion are performed to obtain the array signal for transmission.

The present invention relates to the field of clock synchronization, and more specifically to a broadband arbitrary reference adaptive clock synchronization device. An input signal is amplified and shaped to generate two signals. One signal is sent to an FPGA, and the other is sent to an orthogonal power splitter. The mixed signal is then mixed with a local oscillator signal through an orthogonal modulator to generate a mixed signal. The mixed signal is then passed through a fixed frequency divider to generate a frequency-divided signal. This mixed signal is then phase-detected with a DDS output signal to generate an error voltage, which is then passed through a low-pass filter to control a crystal oscillator. The crystal oscillator's output is passed through a coupler to generate two signals. One signal serves as the global system clock, and the other signal is passed through a fixed frequency multiplier to obtain a multiplied signal. The multiplied signal passes through a filter amplifier and then to a power splitter. The power splitter splits the multiplied signal into two signals. One signal serves as the reference clock and generates a corresponding frequency point under the control of the FPGA to generate an output signal. The other signal is passed through an amplifier and serves as the local oscillator signal of the orthogonal modulator. The present invention is suitable for adaptive clock synchronization devices.

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.

The embodiment of the invention provides a signal modulation depth detection method, electronic equipment, a computer readable storage medium and a computer program product. The signal modulation depth detection method comprises the following steps: adjusting the bias voltage of an in-phase quadrature IQ modulator in an optical module to enable the phase difference of the IQ modulator to reach a target phase difference; loading a disturbance signal to the IQ modulator to enable the IQ modulator to be in a measurement state; stopping inputting the radio frequency signal to the IQ modulator, and acquiring a reference optical power signal from the output end of the IQ modulator; a radio frequency signal is input to the IQ modulator, and a measured optical power signal is acquired from the output end of the IQ modulator; and determining the signal modulation depth according to the reference optical power signal and the measurement optical power signal. According to the technical scheme, the modulation depth of the radio frequency signal can be simply, conveniently and accurately measured, so that the transmission quality of the signal can be well ensured.

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.