27 results about "Quadrature modulator" patented technology

The invention provides an all-digital beamforming transmitter and an all-digital beamforming transmitting method based on a digital radio frequency technology. The all-digital beam forming transmitter provided by the invention comprises a plurality of baseband signal generators, a quadrature modulator, an adder, a 1-bit increment integral modulator, a digital-to-analog converter, a radio frequency front end and an antenna which are connected in sequence, each baseband signal generator is connected with one path of quadrature modulator and one antenna, one path of quadrature modulator comprises a plurality of quadrature modulators, and each baseband signal generator generates a pair of baseband signals; the number of the quadrature modulators in the one-path quadrature modulator is the same as the number of the adders, the number of the 1-bit incremental integral modulators, the number of the digital-to-analog converters, the number of the radio frequency front ends and the number of the antennas; the number of the baseband signal generators is the same as the number of wave beams formed by the antenna, and the number of the baseband signal generators is different from the number of the quadrature modulators in one path of quadrature modulator.

The invention discloses a physical layer security waveform generation method. The method comprises the following steps: step 1, acquiring and constructing a symbol related prime number set and a chip related prime number set; 2, respectively processing the symbol related prime number set and the chip related prime number set to obtain a symbol vector and a chip vector; step 3, carrying out point multiplication operation on the symbol vector and the chip vector to obtain a signal vector; step 4, filtering the signal vector as input through a baseband shaping filter; and 5, moving a filtered result to a corresponding frequency point through a quadrature modulator to obtain a final result. According to the method, the concealment characteristic of the waveform and the security characteristic of the transmission information are obtained based on the change of the waveform parameters of the physical layer during randomization, the short-time stable data transmission rate can be obtained, and the actual requirements of a wireless communication system are met.

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.

The invention discloses a radar interference and safety communication integrated system based on photonics, which comprises an optical signal generation unit, an arbitrary waveform generator module, a signal integrated processing unit and a signal transmission unit, and is characterized in that the optical signal generation unit is used for generating carrier suppression double-sideband optical signals; the arbitrary waveform generator module is used for generating a driving signal for driving the in-phase quadrature modulator module, and the driving signal comprises an encrypted OFDM signal and an LFM signal for radar interference; the signal integrated processing unit is used for combining the driving signal and the carrier suppression double-sideband optical signal, and generating and outputting an integrated optical signal; and the signal transmission unit is used for converting the optical signal into an electric signal to realize signal transmission. According to the technical scheme, radar interference and safe communication can be achieved in the same transmission system at the same time, and due to photon transmission, the transmission system is wide in bandwidth, low in loss and high in anti-electromagnetic interference capacity.

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 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.

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.

A chaotic encryption module is characterized in that a light source output by a first continuous wave laser (CW) is modulated by a parallel quadrature modulator (IQM), so that a signal output by an arbitrary waveform generator (AWG) is converted and transmitted, and pseudo-random interleaving coding of the signal is realized; a transmitted signal is loaded to a chaos carrier through a first optical coupler FC to realize chaos hiding, then the chaos optical carrier predicted in advance by a storage pool is utilized in a chaos decryption module through an information transmission module, and the chaos optical carrier is modulated to a continuous optical carrier output by a second continuous wave laser CW through a Mach-Zehnder modulator MZM. And the 90-degree frequency mixer carries out decryption so as to preliminarily recover an original transmission signal. And finally, the obtained signal is processed by a local oscillator (LO) and a coherent receiver, and digital information processing (DSP) is carried out to realize compensation, recovery and decryption of the digital signal, so that chaotic secrecy coherent optical communication is realized.

According to one aspect of the present disclosure, there is provided a device that includes: a first quadrature modulator configured to receive an in-phase portion of a baseband signal and a quadrature portion of the baseband signal, and to produce a first portion of an output signal according to the in-phase and quadrature portions of the baseband signal; a second quadrature modulator configured to receive a first modified signal and a second modified signal, and to produce a second portion of the output signal according to the first and second modified signals; an output circuit configured to sum the first and second portions of the output signal, and to transmit the output signal to an antenna; and a mode selection circuit configured to turn on the first quadrature modulator, to receive a control signal, and to determine whether to turn on the second quadrature modulator according to the control 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 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.

The invention discloses a quadrature demodulation method, system, device and medium, and relates to the technical field of decoding, and the quadrature demodulation method comprises the following steps: processing a sinusoidal signal and a cosine signal through a quadrature DSM modulator, and carrying out down-conversion processing on a signal output by the quadrature DSM modulator to obtain an intermediate frequency signal; obtaining an orthogonal tracking signal, and calculating an intermediate frequency conjugate signal corresponding to the intermediate frequency signal and an orthogonal conjugate signal corresponding to the orthogonal tracking signal; determining a first product of the intermediate frequency signal and the orthogonal conjugate signal, and determining a second product of the orthogonal tracking signal and the intermediate frequency conjugate signal; and taking the difference between the first product and the second product as an orthogonal demodulation result. The technical scheme of the invention aims to solve the technical problem of low signal-to-noise ratio of useful signals in the existing demodulation technology.

The present application provides a fully digital beamforming transmitter and a transmission method based on digital radio frequency technology. The fully digital beamforming transmitter provided in the present application includes a plurality of baseband signal generators, orthogonal modulators, adders, 1-bit incremental integral modulators, digital-to-analog converters, radio frequency front ends and antennas connected in sequence; each baseband signal generator is connected to one orthogonal modulator and one antenna, one orthogonal modulator includes a plurality of orthogonal modulators, and each baseband signal generator generates a pair of baseband signals; the number of orthogonal modulators in the one orthogonal modulator is the same as the number of adders, the number of 1-bit incremental integral modulators, the number of digital-to-analog converters, the number of radio frequency front ends and the number of antennas; the number of baseband signal generators is the same as the number of beams formed by the antenna, and the number of baseband signal generators is different from the number of orthogonal modulators in one orthogonal modulator.

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.

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.

The invention belongs to the technical field of communication and signal processing, and particularly relates to a GMSK quadrature modulator which comprises a quadrature modulation baseband generator composed of a bidirectional counter, a four-curve data table, an in-phase component processor and a quadrature component processor, and a binary code element sequence and a system clock are input into the quadrature modulation baseband generator. A system clock carries out frequency division to generate a code element frequency multiplication clock to drive the bidirectional counter to carry out oscillation reciprocating counting, the in-phase component processor and the orthogonal component processor carry out processing to generate curve selection types and curve symbols, output of the bidirectional counter is used as a curve look-up table address, and a pre-stored four-curve data table looks up to generate an orthogonal modulation baseband signal. The signal is input into a digital up-conversion (DUC) circuit to generate a GMSK modulation signal. Compared with the prior art, the method saves more resources, is high in precision and small in stray, and is very suitable for design and implementation of an embedded system or a programmable device.

An over-the-air measurement system for testing a device under test is provided. The over-the-air measurement system includes at least two quadrature modulators and at least two antennas. Each of the antennas is connected to a dedicated quadrature modulator, thereby establishing at least two measurement modules. The at least two quadrature modulators are rotated with respect to each other, thereby providing different measurement polarizations of the at least two measurement modules with respect to a common reference plane.

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 invention relates to the field of clock synchronization, in particular to a broadband arbitrary reference adaptive clock synchronization device. An input signal is amplified and shaped to generate two paths of signals, one path of signals is sent to an FPGA, the other path of signals is sent to an orthogonal power divider and then is mixed with a local oscillator signal through an orthogonal modulator to obtain a frequency mixing signal, the frequency mixing signal passes through a fixed frequency divider to obtain a frequency division signal, the frequency division signal and a DDS output signal are subjected to phase discrimination to generate error voltage, and the error voltage passes through a low-pass filter to control a crystal oscillator. The output of the crystal oscillator passes through the coupler to generate two paths of signals, one path is used as a global system clock, the other path passes through the fixed frequency multiplier to obtain a frequency-doubled signal, the frequency-doubled signal passes through the filter amplifier to the power divider, the power divider divides the frequency-doubled signal into two paths of signals, one path is used as a reference clock, and the other path is used as a reference clock; a corresponding frequency point generation output signal is generated under the control of the FPGA, and the other path of signal is used as a local oscillator signal of the quadrature modulator after passing through the amplifier. The invention is applicable to the self-adaptive clock synchronization device.

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 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 invention discloses an optical network communication perception integration method and system based on carrier assistance, and the method comprises the following steps: 1, a carrier generation module generates two linear frequency modulation optical signals with a constant frequency difference and the same phase, and the linear frequency modulation optical signals are divided into a perception carrier and a communication carrier according to the frequency through a fiber bragg grating 1; 2, a communication carrier is divided into two beams through an optical fiber coupler 1, one beam serves as a reference optical signal to be input into a sensing receiving module, the other beam serves as a carrier to be input into an in-phase quadrature modulator, and a communication electric signal generated by an arbitrary waveform generator is modulated on the carrier through the modulator to generate a communication optical signal; 3, the sensing carrier and the communication optical signal are input into an optical fiber coupler 2 to generate a communication and sensing integrated optical signal, and the communication and sensing integrated optical signal is input into an optical fiber link through a circulator; and 4, inputting a signal received by the optical fiber link into a communication receiving module, and inputting a backward optical signal output by the circulator into a sensing receiving module.

The invention discloses a broadband microwave vector signal source system and an implementation method thereof, relates to the technical field of microwave signals, and is characterized in that a digital technology and an analog technology are combined, a digital modulation signal is generated by utilizing an FPGA (Field Programmable Gate Array), and a fixed quadrature modulation analog output signal is generated through a DAC (Digital-to-Analog Converter) (containing a quadrature modulator); according to the broadband microwave vector signal source system, the frequency of the broadband microwave vector signal source system is reduced, the frequency of the broadband microwave vector signal source system is reduced, the frequency of the broadband microwave vector signal source system is increased, the frequency of the broadband microwave vector signal source system is increased, the frequency of the broadband microwave vector signal source system is increased, and the consistency of indexes is well guaranteed.

A radio frequency (RF) transceiver includes a reference signal source to generate a reference signal, a local RF source to generate a local RF signal, and a mixed signal phase / frequency detector to compare the reference signal to the local RF signal and generate a difference signal from the comparison, wherein the difference signal includes a modulation component and an error component. The transceiver further includes a receiver front end to receive an angle modulated RF signal and downconvert the angle modulated RF signal to a baseband signal, and a quadrature modulator configured to angle modulate the reference signal source with the baseband signal.

The invention provides a device and method for achieving 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 optical 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 an information bit number A, splicing check bits to form total information bits, and optimizing the distribution of the information bits and freezing bits according to an optical signal channel sorting result; the method comprises the following steps: performing polarization coding on a signal at a coding end, and mapping the signal into a 16QAM coding symbol sequence by adopting a Polar modulation technology; at a receiving end, LLR is calculated, when the list width reaches a set value, path metric values of all paths are calculated and trimming operation is executed, and after decoding is completed, CRC verification detection is used for L candidate paths. According to the invention, the transmission rates of different optical network units can be flexibly regulated and controlled.

The utility model provides a transmitting terminal unit and a multi-carrier wireless communication system, and the transmitting terminal unit comprises an optical comb signal generation module which is used for generating an optical comb signal and outputting the optical comb signal to a wavelength division multiplexer; the orthogonal frequency division multiplexer outputs signals to the first rectangular filter and the second rectangular filter, the first rectangular filter outputs signals to the first orthogonal modulator, the first orthogonal modulator outputs modulated signals to the first dual-port Mach-Zehnder modulator, and the second dual-port Mach-Zehnder modulator outputs modulated signals to the second dual-port Mach-Zehnder modulator. The first dual-port Mach-Zehnder modulator outputs a signal to the Gaussian filter; the second rectangular filter outputs a signal to a second quadrature modulator, the second quadrature modulator outputs the modulated signal to a second dual-port Mach-Zehnder modulator, and the second dual-port Mach-Zehnder modulator outputs a signal to a third rectangular filter; and the Gaussian filter output signal and the third rectangular filter output signal are used for outputting filtered signals to the first combiner. The multi-carrier wireless communication system is provided with the transmitting terminal unit. According to the utility model, the efficiency of optical signals can be improved.

In some implementations, a controller may apply a set of phase dithers to a first inner Mach-Zehnder (MZ) interferometer and a second inner MZ interferometer, the first inner MZ interferometer and the second inner MZ interferometer being included in an outer MZ interferometer, the set of phase dithers including a first in-phase dither state and a second in-phase dither state and including a first anti-phase dither state and a second anti-phase dither state. The controller may determine an initial error term based at least in part on the set of phase dithers. The controller may adjust, based on the initial error term, the outer MZ interferometer to a target phase associated with a target error term, wherein respective branches of at least one of the first MZ interferometer or the second MZ interferometer are adjusted differentially.