256 results about "Carrier synchronization" patented technology

The invention provides a self-adaptive polarization modulation-based inter-satellite laser communication and signal scheduling method, which relates to the field of laser communication, and comprises the following steps of: acquiring polarization state information of emitted and received light beams, calculating a mismatch degree, generating a compensation parameter, constructing a polarization state prediction model by using a deep learning neural network for pre-correction, and calculating the mismatch degree; a polarization modulator is adopted to perform real-time modulation and establish a link quality evaluation model, carrier synchronization and channel compensation are realized based on an adaptive optical carrier recovery technology of coherent detection, a link state is monitored in real time, and a training data set is updated.

The invention provides a time division duplex multi-carrier synchronous transmission method based on 5G, which is used for solving the problems of inflexible carrier time slot allocation and inaccurate time delay compensation in synchronous transmission. By dynamically adjusting time slot allocation and working frequency bands of carriers in a network control center, the method optimizes network loads and reduces cross interference; the time delay of each carrier is compensated in real time by adopting a synchronous signal calibration algorithm, so that strict alignment of transmission time slots is ensured; the transmitting end dynamically adjusts the transmitting power according to link state information, and the receiving end reduces interference and signal attenuation through a multi-carrier cooperative interference management and multi-path delay compensation mechanism; and a receiving end performs joint decoding based on channel estimation and integrates demodulation signals of all carriers, so that the transmission efficiency and the signal quality of the 5G network are improved. The method is suitable for a base station system and a base station and repeater extension coverage system, and is especially suitable for a distributed wireless system including an optical fiber remote distributed system, a cable remote frequency shift repeater system and the like.

The invention relates to the technical field of high-frequency signal modulation, and discloses a high-frequency carrier synchronization signal modulation system. A carrier distortion compensation module of the system constructs a model based on a historical transmission data set, captures a phase jitter parameter, a spectrum leakage component and a modulation pulse sequence of a transmitting end carrier in real time, and outputs a reconstructed baseband parameter; the multi-dimensional distortion analysis module compares the reconstructed baseband parameter with a receiving end demodulation baseband parameter through composite difference detection, and generates a channel-level distortion coefficient tensor; the topological positioning network module is used for positioning signal out-of-step physical nodes and generating a probability distribution thermodynamic diagram by combining impedance characteristics of transmission nodes and signal path delay information; and the adaptive modulation strategy module starts a multi-band carrier injection mode for the high-probability out-of-step nodes according to the abnormal probability gradient of the thermodynamic diagram, and applies a phase disturbance test to adjacent transmission links. The system can improve the adaptability and accuracy of high-frequency carrier signal synchronous modulation.

The invention relates to a digital lock-in amplifier based on a frequency adaptive technology and a weak signal acquisition system and method, and the system comprises a front-end signal processing module which is used for obtaining a weak signal to be detected; the frequency self-adaptive tracking module is used for performing fast Fourier transform on the frequency of the weak signal to be measured to obtain the position of the maximum spectral line so as to synthesize a frequency control word, further generate a local reference signal and simultaneously adjust the coefficients of a low-pass filter and a loop filter and the series adjustment mode of a carrier synchronization ring; the multi-rate narrow-band low-pass filter module is used for multiplying the digital signal by a local reference signal and then carrying out filtering and down-sampling on a high-frequency signal to obtain a plurality of mutually orthogonal difference frequency components; the vector operation module is used for carrying out vector operation on the plurality of mutually orthogonal difference frequency components to obtain the phase and the amplitude in the weak signal to be measured; and the man-machine interaction module is used for displaying and storing the phase and the amplitude in the weak signal to be detected.

The invention discloses an inverter parallel single bus active carrier phase synchronization method. A host sends a carrier synchronization signal to a slave through a synchronization signal line at a carrier counting zero point; the slave reads numerical values in the basic calibration register, the time deviation register and the period register while receiving the carrier synchronization signal, and calculates a deviation value delta psi of carrier phases of the current slave and the host; and compensating the period deviation in the period register through the deviation value delta psi, so that the carrier counting zero point of the slave is aligned with the carrier counting zero point of the host. An existing hardware system does not need to be expanded, extra hardware cost is not increased, and the hardware size is not expanded. And the carrier wave difference of different master and slave controllers can be dynamically compensated according to an established parallel operation system. The carrier synchronization of the host and the slave is realized in a carrier phase deviation period, the synchronization speed is high, the precision is high, the synchronization can be locked after synchronization, and the condition of carrier synchronization failure in the operation process is avoided. And the stability is excellent.

The invention relates to the technical field of wireless communication, and discloses a communication equipment command and dispatch system based on artificial intelligence, the system maps the state of communication equipment into a standardized carrier phase disturbance mode, and after the disturbance mode is adaptively adjusted in combination with channel noise perception and conflict arbitration logic, the communication equipment is commanded and dispatched. Controlling the radio frequency front end to carry out injection; the adjacent communication equipment directly detects the disturbance mode to trigger the cooperative scheduling action by monitoring the physical error signal of the carrier synchronization loop of the adjacent communication equipment, and the implicit cooperative mode based on the physical layer beacon is constructed, so that the complex high-level signaling interaction required by the traditional scheduling is avoided, and the scheduling efficiency is improved. According to the method, the millisecond level, determined by a software protocol, of the collaborative response time between the devices is substituted into the microsecond level determined by the hardware physical layer response entscheid, the system can still maintain reliable transmission of scheduling instructions when facing high-density concurrent conflicts and strong channel noise, and a technical implementation path is provided for ultra-low-delay and high-reliability communication.

The invention discloses a time division duplex multi-carrier synchronous transmission method based on 5G, which relates to the technical field of communication, and comprises the following steps of: establishing a carrier mapping table, respectively mapping a plurality of logic carriers to predefined physical resource blocks, and marking uplink and downlink switching time slots according to a time division mode; after a user terminal receives a synchronization signal, alignment is carried out through a high-precision local clock and the reference time of a main base station, and a synchronization reference point is recorded with a nanosecond-level time resolution. According to the invention, through the dynamic synchronization control and frequency domain interference suppression technology, the synchronization stability and the data transmission reliability in a high-speed scene are significantly improved; a synchronous load scoring mechanism is introduced to realize efficient scheduling and conflict avoidance of synchronous resources in a multi-user concurrent environment; and in combination with interference weight estimation and an adaptive filtering strategy, the anti-interference capability and environment adaptability of the system are effectively enhanced, and the requirements of key services such as the Internet of Vehicles and industrial control on low-delay and high-reliability communication are comprehensively met.

The invention provides a DFT precoding FBMC system carrier synchronization method oriented to air-ground communication. The method comprises the following steps: acquiring FBMC symbol data to be transmitted; a special CAZAC sequence with the length of M / 4 is constructed, four synchronous sequence symbols are constructed, and corresponding sending signals of a time domain are output after the four synchronous sequence symbols and other data symbols are subjected to conjugate symmetry module, pre-FFT, IFFT subcarrier modulation and PPN multi-phase filtering; the method comprises the following steps: constructing a local sequence at a receiver end, respectively taking two continuous parts with the length of M / 4 from a received special time domain sequence signal, and respectively correlating the two continuous parts with corresponding parts of the local sequence to obtain a correlation result; and conjugating the correlation result of the first part of sequence, multiplying the conjugate with the correlation result of the second part of sequence to obtain a frequency offset measurement function, obtaining decimal frequency offset estimation according to the frequency offset measurement function, and carrying out carrier frequency offset compensation by using a frequency offset estimation value. According to the method, a synchronous training sequence design method is provided, and carrier frequency offset is estimated and corrected by using time domain signal construction characteristics of a training sequence.

The invention discloses a carrier synchronization method and device, an inverter and a storage medium, and relates to the technical field of carrier control, and the method comprises the steps: transmitting a host competition signal to a carrier bus in a system when a slave inverter in an inverter parallel system cannot acquire a carrier signal transmitted by a master inverter in the system and reaches a first preset duration, and then transmitting the host competition signal to the carrier bus in the system; all slave inverters in the system respond to the host competition signal to send a first identification number to the bus, and monitor a bus identification number transmitted in the bus at the same time, when a certain slave inverter finds that the first identification number sent by the slave inverter is matched with the bus identification number, it is confirmed that host competition succeeds, and the slave inverters send the first identification number to the bus. The main inverter sends carrier signals to the bus, the other slave inverters acquire the carrier signals to perform carrier synchronization, and the slave inverters establish a master-slave structure of the system through competition of the host, so that the carrier synchronization function of the system is established or recovered, the carrier synchronization stability of the system is improved, and the circulating current of the system can be efficiently inhibited.

The invention discloses a communication-detection integrated sonar signal design method and device based on multi-pulse composite modulation, and the method comprises the steps: dividing a total frame period into a detection sub-frame and a communication sub-frame, enabling the detection sub-frame to achieve the high-resolution distance measurement through employing a bidirectional linear frequency modulation (BILFM) signal, a communication sub-frame adopts a multi-frequency multi-phase composite modulation (MTPM) signal to realize high-bit-rate data transmission; after band filtering, orthogonal demodulation, low-pass filtering and down-sampling preprocessing are carried out on detection sub-frame echoes, distance and speed information is extracted by adopting fast-time low-sampling two-dimensional fast Fourier transform (2D-FFT), unambiguous Doppler frequency is recovered by utilizing the Chinese remainder theorem (CRT), and accurate speed measurement of long-distance and high-speed targets is realized; a communication subframe receiving signal is subjected to IQ demodulation after down-conversion, Costas loop carrier synchronization and matched filtering, and multi-frequency multi-phase coded data are extracted. According to the method, the time-frequency collaborative design of detection and communication is realized, the distance resolution and the speed measurement range are considered, and the signal bandwidth utilization rate and the underwater information transmission reliability are remarkably improved while the system complexity is kept low. The device comprises a processor and a memory, and an executable program for implementing the method is stored in the memory. The technology can be widely applied to the fields of unmanned underwater vehicles, ocean monitoring, underwater sensing networks and the like.

The invention discloses a multi-converter carrier synchronization control method, device and system. The method comprises the following steps: triangular carrier signals with the same frequency and phase are stored in each controlled converter; when the controlled converter receives data sent by a data sender, a carrier synchronization signal is extracted from the received data; judging a phase relationship between the extracted carrier synchronization signal and a triangular carrier signal in the controlled converter; adjusting the peak value of the triangular carrier signal according to the judgment result of the phase relationship to realize phase consistency, if the phase of the triangular carrier signal is judged to be ahead of the carrier synchronization signal, controlling to adjust the peak value of the triangular carrier signal to be an increased preset value, and if the phase of the triangular carrier signal is judged to be lagged behind the carrier synchronization signal, controlling to adjust the peak value of the triangular carrier signal to be an increased preset value. And controlling the peak value of the triangular carrier signal to be adjusted to a reduced preset value. The method has the advantages of simple implementation method, low execution cost and complexity, high stability and reliability, strong anti-interference performance and the like.

The invention discloses a synchronous circuit and method of an energy storage inverter parallel operation system, and belongs to the field of photovoltaic technology. The circuit comprises a CAN bus; the plurality of synchronous communication components are respectively arranged in each energy storage inverter of the energy storage inverter parallel operation system; the synchronous communication component comprises an ePWM module, and the ePWM module comprises corresponding time base counter registers; one of the energy storage inverters is a host, and the rest of the energy storage inverters are slaves; a main synchronous communication component in the host is used for sending a kth-phase carrier synchronization signal to the CAN bus when a count value of a time base counter register corresponding to the kth phase in the main synchronous communication component is 0; the slave synchronization communication component in each slave is used for setting the count value of the time base counter register corresponding to the kth phase in the slave to be 0 when receiving the kth phase carrier synchronization signal, and k is a positive integer. According to the embodiment of the invention, synchronous operation among the energy storage inverters can be realized, and the operation reliability and safety of the parallel operation system are ensured.

A power conversion apparatus includes an AC-DC conversion circuit, a power controller, and a circulating current controller. The power controller is configured to control the AC-DC conversion circuit to convert a received alternating current into a first direct current and output the first direct current. The circulating current controller is configured to send a synchronization signal to another power conversion apparatus through a controller area network (CAN) bus. The synchronization signal is used to synchronize a carrier of the another power conversion apparatus with a carrier of the power conversion apparatus.

The invention discloses a carrier signal processing method and device based on an OFDM (Orthogonal Frequency Division Multiplexing) system and electronic equipment, and belongs to the technical field of communication. The carrier signal processing method comprises the following steps: acquiring signal energy of a current sampling point in a current signal segment in a digital signal; performing amplitude suppression processing on the signal energy of the current sampling point based on a comparison result of the signal energy of the current sampling point and reference energy; the reference energy is determined based on average signal energy of historical sampling points respectively corresponding to a plurality of historical signal segments in the digital signal, and the number of the sampling points of each signal segment in the digital signal is the same; and executing carrier synchronization processing based on the signal energy of the current sampling point after the amplitude suppression processing. According to the invention, filtering of impulse or impulse noise sampling points is realized, the accuracy of signal synchronization is improved, and the reliability of an OFDM system is improved.

The invention discloses a carrier synchronization control method with multiple converters connected in parallel, electronic equipment and a storage medium, each converter corresponds to a control unit, each control unit is integrated with a corresponding accumulation counter, one converter is used as a host, the other converters are used as slaves, the method is applied to any slave, and the control unit is integrated with a corresponding accumulation counter. Comprising the following steps: receiving a preset low-frequency synchronization signal generated and sent by a host; capturing a rising edge or a falling edge of the low-frequency synchronizing signal; when the rising edge or the falling edge of the low-frequency synchronization signal is captured every time, collecting the current carrier value and the maximum carrier value of the carrier signal output by the corresponding control unit; and according to the current carrier value and the maximum carrier value, adjusting the carrier count value of the corresponding accumulation counter, so that the carrier signal of the slave computer and the carrier signal of the host computer are synchronized in phase. According to the invention, a low-frequency signal is used as a synchronization mechanism, so that normal operation and efficient output of the multi-machine parallel system are ensured, and the high-frequency synchronization precision is improved.

The invention discloses a short burst SOQPSK carrier synchronization method based on an RPT-Net network. The short burst SOQPSK carrier synchronization method comprises the following steps: preprocessing a signal, and merging time domain data of the signal and quartic data into input data; a multi-level residual convolutional network is adopted to extract cross-symbol local phase features, fine phase changes in SOQPSK signals are captured through layer-by-layer stacked convolution operation, the gradient degradation problem of a deep network is relieved in combination with a residual connection mechanism, and the local characterization capacity for phase jump and frequency offset disturbance is enhanced; through a phase perception position coding module, the time domain signal is converted into a complex number form, an instantaneous phase is extracted, orthogonal basis coding is constructed to represent phase change, and deep fusion with position coding is carried out; a Transform coding layer is introduced, a multi-head self-attention mechanism is utilized to capture a long-distance symbol dependency relationship, global phase consistency constraint is optimized, long-term influence of frequency offset on signals is captured, and time sequence error propagation is effectively inhibited.

The invention discloses a carrier synchronization method for a parallel converter sharing an AC / DC bus, and the method comprises the steps: employing a layout of one main device, one standby device and multiple slave devices, enabling the main device to transmit a synchronization signal when the main device is normal, and enabling the standby device and the slave devices to receive the synchronization signal; arranging an optical fiber transmitter and an optical fiber receiver on each device; the carrier synchronization method of the multiple parallel converters comprises the following steps: in a normal mode, when carrier counting of an EPWM1 register in a main equipment DSP reaches 0, a synchronization signal is generated, and carriers in an EPWM2-EPWM6 register in the main equipment DSP receive the synchronization signal internally; the synchronizing signal is led to a GPIO pin through an Output X-BAR register in the DSP of the master device, then an electric signal is converted into an optical signal through an optical fiber transmitter in the master device, and the optical signal is sent to the standby device and the slave device.

The invention discloses a parallel receiving method and system for high-speed 16 QAM (Quadrature Amplitude Modulation) data demodulation, and the method comprises the following steps: S1, carrying out the sampling of received intermediate-frequency 16 QAM data through a high-speed ADC (Analog to Digital Converter), and obtaining four paths of signals through the serial-to-parallel conversion function of the ADC; s2, converting the four paths of signals into 32 paths of parallel signals at a conversion rate of 1: 8 by using a serial-to-parallel converter special for the FPGA; and S3, carrying out digital orthogonal down-conversion on the 32 paths of parallel signals to obtain 16 paths of baseband signals of an I path and a Q path, and then sequentially carrying out matched filtering, timing synchronization, blind equalization, carrier synchronization, frame synchronization and 16QAM judgment decoding to complete parallel receiving. According to the invention, the requirement of high bit rate is met based on three key technologies of timing synchronization, blind equalization and carrier synchronization, and the receiving and demodulation recovery functions of high-speed data in a 16 QAM modulation mode can be effectively completed.

The invention discloses an interconnection-line-free carrier synchronization method and device, equipment and a storage medium, and relates to the technical field of power systems. The method comprises the following steps: acquiring a voltage signal of a grid-connected point, and determining a first interruption triggering moment according to the state of the voltage signal by using a logic state capturing unit; determining a clock reference moment corresponding to a target phase in voltage phases by using phase-locked loop software, and determining an optimal time interval according to the first interrupt trigger moment and the clock reference moment; and determining the moment of the second interruption triggering moment after the optimal time interval as a carrier synchronization reference moment, and carrying out carrier synchronization at the carrier synchronization reference moment. According to the technical scheme provided by the embodiment of the invention, the high-precision determination of the reference moment is realized through the combination of software and hardware, the realization is simple, the problem that the reference time of the carrier synchronization without the interconnection line is inaccurate is solved, the carrier synchronization effect is improved, and the parallel circulating current is inhibited.

The invention discloses a dynamic environment distributed coherent communication carrier synchronization method and device, and relates to a distributed coherent communication technology, and the method comprises the steps: dividing system time resources according to time slots after time synchronization; in the synchronous time slot Ti, 1, the master node sends synchronous reference signals to all the slave nodes; each slave node Sn measures a phase change value between two same pilot symbol sequences in the received signal, estimates to obtain frequency deviation, and calculates phase and amplitude estimated values; each slave node Sn analyzes a data symbol in the received synchronous reference waveform signal to obtain a coherent cooperative micro time slot; each slave node Sn respectively measures the frequency, the phase and the amplitude of the reference signal in each time slot Ti; and performing distributed coherent cooperative communication from the plurality of slave nodes Sn to the master node M within the time interval of the synchronous time slot Ti, 1 and the coherent cooperative time slot Ti, j. According to the invention, the problem of distributed carrier synchronization caused by a dynamic environment can be solved, and the adaptive capacity of a system to channel state change is improved.

The invention discloses a carrier synchronization method and system based on PWM period adjustment, and relates to the technical field of photovoltaic and energy storage, and the method comprises the steps: adjusting DSP interrupt logic, and adjusting a carrier counting limit value in real time; determining an annular band width according to the carrier counting limit value; and the DSP signal after the PWM period is adjusted is used as a trigger pulse of a driving circuit to be given to an inverter, so that a parallel operation synchronization function is realized. According to the carrier synchronization method based on PWM period adjustment, the carrier counting value and the carrier counting direction are read in real time through a program, and the carrier counting peak value is dynamically adjusted. According to the method, the problem that the output voltage and current waveforms of the inverter are abnormal due to carrier distortion can be well solved.

The present application discloses a frequency-domain carrier synchronization method and apparatus based on sparse pilot frequency, which relates to the technical field of carrier frequency synchronization. The method includes: the transmitting end generates a data sequence and an original UW sequence; the transmitting end inserts the original UW sequence into the data sequence in an equally spaced postposition manner to obtain a first data transmission frame, and sends the first data transmission frame to the receiving end; the receiving end detects the received second data transmission frame to determine the maximum peak position of the frequency-domain signal; the receiving end determines a frequency offset estimation value according to the maximum peak position of the frequency-domain signal; the receiving end performs deviation correction on the second data transmission frame based on the frequency offset estimation value to obtain the first data transmission frame. This method comprehensively considers the influencing factors in the actual communication transmission process, and improves the anti-interference performance and the accuracy of frequency offset estimation.

This application provides an inverter carrier synchronization system, belonging to the field of inverter control technology. The system includes multiple inverter devices connected via cascaded communication. Each inverter device includes a CPLD unit, a drive unit connected to the CPLD unit, a fault output unit, and a fault identification unit. The CPLD unit generates or forwards a carrier synchronization signal. The first contact of the relay in the fault output unit outputs a fault status signal to the next-level inverter device. The first-level inverter device acts as the master, and the fault status signal output by any normal inverter device is low. When any inverter device loses power or malfunctions, its relay disconnects, causing the output fault status signal to be high. Upon detecting the high-level fault status signal, the next-level inverter device automatically switches to become the master of the downstream inverter device. This system effectively suppresses high-frequency circulating currents in the system, improving system operating efficiency and stability.

The invention relates to a burst communication adaptive carrier synchronization method based on FFT. The method comprises the following steps: carrying out a first round of nonlinear transformation on a captured first sequence, then sequentially carrying out Fourier transformation, selecting even number spectrums from a plurality of amplitude spectrums, screening position indexes of spectral lines corresponding to a first peak value and a second peak value of each spectrum in the even number spectrums, and forming a position index set; solving an intersection of all position index sets of the even number spectrum, selecting a position index element with the highest overlapping degree, and determining a frequency offset coarse estimation value according to the position index element; obtaining a first peak value, a second peak value and a third peak value corresponding to the position index element from the plurality of amplitude spectrums, and then carrying out weighted averaging to obtain a final position index element; according to the final position index element, calculating to obtain a frequency offset precise estimation value; summing the coarse frequency offset estimation value and the fine frequency offset estimation value to obtain a frequency offset estimation overall value; and realizing carrier synchronization according to the frequency offset estimation overall value of the current round.

The invention discloses a communication physical link multi-protocol sharing method during parallel operation of energy storage converters. The method is based on two general physical links, and efficient sharing of multiple protocols is achieved through the steps of hardware standardization integration, protocol intelligent adaptation, automatic switching of a drive circuit and the links, protocol signal two-way transmission, real-time state monitoring and the like. A unified adaptation platform is built on the hardware level, a multi-protocol special drive circuit and a high-performance MCU are integrated, the protocol level supports dynamic switching and parallel work of multiple protocols such as CAN, I2C, RS485, RJ45 and carrier synchronization signals, and scene changes can be responded without changing hardware. And during operation, through a full-dimension state monitoring and redundancy protection mechanism, transmission stability and rapid fault recovery are guaranteed. Redundant configuration of a special link and a driving circuit is reduced, the space utilization rate of a circuit board and the flexibility of the system are improved, and the diversified communication requirements of large-scale parallel connection of the energy storage converter can be quickly met.

The invention provides a fast differential frame synchronization method under a burst transmission system, which comprises the following steps: a receiver reduces the sampling rate of a burst transmission sequence to four times of a symbol rate, detects the timing error of a down-sampling sequence, calculates an integer parameter and a fraction parameter based on a timing error result, and performs frame synchronization according to the integer parameter and the fraction parameter; then, a cubic interpolation filter is used for calibrating timing errors and recovering a correct data sequence, a differential frame synchronization method which is insensitive to signal amplitude and suitable for any phase deviation is used for searching a frame header position, and whether the size of a correlation peak value is larger than a set threshold value or not is judged; if yes, timing synchronization and frame synchronization are completed; and if not, returning to continue to calculate the timing error. The method is suitable for a burst transmission system, is different from a traditional frame synchronization method, does not need to carry out frequency difference estimation, amplitude control and carrier synchronization in advance, and can quickly realize timing synchronization and frame synchronization, so that the synchronization time is shortened.

The invention discloses a carrier synchronization control method, which is applied to an energy storage converter and comprises the following steps: recording a first timestamp corresponding to a slave carrier wave starting point of a local machine; judging whether a first broadcast message sent by the host at the host carrier starting point is obtained within a first preset time or not; if not, determining that the host has a fault, and if the local meets a preset condition, switching the local to be a new host of the system; if so, determining that the acquisition time of the first broadcast message is a second timestamp; based on second preset time, the first timestamp and the second timestamp, calculating a time deviation between the carrier starting point of the local computer and the carrier starting point of the host computer; and adjusting the carrier starting point of the local machine to be synchronized with the carrier starting point of the host based on the time deviation. The carrier synchronization can be realized without adding extra equipment, and when the host fails, the slave can compete for the new host, so that the cost of the energy storage system can be reduced, and the stability of the system is improved.

The embodiment of the invention provides a carrier synchronization method, system and device, and relates to the technical field of communication, the method is applied to a non-ground network node, and comprises the following steps: obtaining a first uplink transmission signal sent by a mobile terminal, the first uplink transmission signal is an uplink transmission signal obtained by pre-compensating a to-be-transmitted uplink transmission signal; frequency offset compensation and phase correction are carried out on the first uplink transmission signal based on a locally stored second uplink transmission signal, a synchronous demodulation signal is obtained, and the second uplink transmission signal comprises an uplink transmission signal sent by the mobile terminal and acquired in a previous time slot. According to the embodiment of the invention, carrier synchronization in a high-dynamic and low-signal-to-noise-ratio scene is realized.

The invention discloses a 32APSK parallel demodulation method and system, and the method comprises the steps: receiving a radio-frequency signal through an antenna, carrying out the frequency conversion processing through a receiving channel, converting the radio-frequency signal into an intermediate-frequency signal, carrying out the digital-to-analog conversion, obtaining an intermediate-frequency digital signal, carrying out the grouping according to a fixed length, and obtaining a data package with a fixed length, mixing the intermediate frequency digital signal in the data packet with two paths of in-phase orthogonal carriers to obtain a mixed signal, and filtering the mixed signal through a low-pass filter to generate an in-phase baseband signal and an orthogonal baseband signal; in-phase baseband signals and orthogonal baseband signals are sequentially subjected to resampling, frequency offset estimation, carrier synchronization, coherent demodulation and judgment to obtain judged signals, and finally equalization processing is carried out to remove inter-symbol interference. The method has the advantages of low data dependence and high degree of parallelism, symbol synchronization and carrier synchronization are realized by using an open loop after I and Q signals are acquired, the degree of parallelism is high, and the method is suitable for a GPU platform and 32 APSK signal demodulation at any rate.

The invention discloses a high-order QAM (Quadrature Amplitude Modulation) signal demodulation carrier synchronization design method based on secondary loop filtering, which relates to the field of signal processing, gives consideration to steady-state phase difference and capture bandwidth of carrier synchronization, covers various application scenes and provides good demodulation performance. According to the technical scheme, the method comprises the steps that a first loop is designed and mainly comprises a carrier compensator, a digital frequency discriminator, a numerical control oscillator, a first-stage digital loop filter and a frequency locking detector; the two-stage digital loop mainly comprises a carrier compensator, a digital phase discriminator, a numerical control oscillator, a two-stage digital loop filter and a phase locking detector. After the two stages of loops are connected in series, the first-stage loop carries out synchronous compensation on large frequency offset of signals, and the second-stage loop carries out synchronous compensation on small residual frequency offset and phase offset of the signals. The design is monitored through a locking detector, and carrier synchronization of high-order QAM signal demodulation is achieved.