201 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 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 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 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 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.

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 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 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 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.

The present invention discloses a detection and synchronization method and system for M110-39T based on signal time-frequency characteristics, belonging to the field of short-wave communication technology. It includes: using a frequency-domain peak template to perform a sliding search on the signal to complete signal presence detection and carrier synchronization, where the frequency-domain peak template is constructed comprehensively based on the first-stage pre-synchronization code and Doppler tone of the M110-39T signal; using a time-domain phase template to perform a sliding search on the signal to complete signal coarse timing synchronization, where the time-domain phase template is constructed based on the second-stage pre-synchronization code of the M110-39T signal; adopting a cyclic prefix sliding correlation method to perform symbol synchronization on the data segment of the M110-39T signal. The present invention effectively utilizes various time-domain and frequency-domain characteristics to capture the pre-synchronization code, realizes accurate detection and synchronization of M110-39T in a short-wave time-varying channel, provides input parameters for signal demodulation, can adapt to the fading and changeable short-wave channel, and can cope with the scenario of large frequency offset, and has good robustness and practicability.

The invention discloses an encryption burst communication receiving method based on an FPGA, and belongs to the technical field of burst communication. According to the invention, the problems of poor synchronization performance and poor anti-interference capability at the receiving end in the existing method are solved. According to the method, the carrier synchronization range is expanded by introducing the pilot frequency to enable the synchronization heads to be '1', the limitation that a conventional frequency offset estimation algorithm can only work under the condition that the Doppler frequency shift is smaller than 0.5 times of the symbol rate is broken through, and the capacity of the system for adapting to the high-dynamic environment is improved. A spreading code continuous tracking working mode is designed, coarse estimation and synchronization are carried out in a frame header part, spreading codes are still adopted in an information part, and continuous tracking is carried out, so that the system can adjust the phase of the spreading codes in real time in the whole frame to solve the problem of phase error accumulation caused by adopting a low-precision clock; the problems that when one frame of data at the sending end is long, the synchronization performance is reduced when a low-precision clock is adopted, and even effective synchronization cannot be achieved are solved. The method can be applied to the field of burst communication.

The invention provides a signal-to-noise ratio estimation method and device suitable for PSK (Phase Shift Keying) modulation. The method comprises the following steps: calculating the average power of an input signal sequence; estimating the average power of the pilot frequency sequence; and calculating a signal-to-noise ratio. According to the method, the influence degree of noise on the distance between the PSK modulation signal and the original point in the constellation diagram is estimated, a traditional method for calculating the signal-to-noise ratio by estimating the deviation degree of the actual signal from the ideal signal due to the influence of noise is replaced, high accuracy can still be kept when the signal is influenced by Doppler frequency deviation and sampling deviation, the method is more suitable for an actual communication system, and compared with the prior art, the method has the advantages of simple operation and low cost. In an actual communication system, signal-to-noise ratio estimation is usually carried out after signal timing synchronization and carrier synchronization processing, however, the signal-to-noise ratio calculation method provided by the invention can be used for estimating the signal-to-noise ratio after synchronization before synchronization according to PSK modulation characteristics, and has certain application advantages in scenes such as switching modulation waveforms according to the signal-to-noise ratio.

The invention belongs to the technical field of inverter parallel carrier synchronization, and relates to an inverter multi-machine parallel wireless carrier synchronization method, a control device and a system. The method is applied to a control device of each inverter in a multi-inverter parallel wireless carrier synchronization system, and comprises the following steps of: acquiring a power grid voltage, and calculating a zero-crossing signal period based on a difference between timestamps of two continuous zero-crossing moments of the power grid voltage so as to obtain a carrier reference period; calculating the cycle ratio of the carrier reference cycle to the current carrier cycle of the inverter, and rounding off the cycle ratio to obtain the number of carrier cycles which should be generated by the inverter in the carrier reference cycle; calculating a single theoretical carrier period of the inverter based on the carrier reference period and the number of carrier periods which should be generated by the inverter in the carrier reference period, and rounding off the single theoretical carrier period to obtain a target carrier period of the inverter; and carrying out phase modulation on the carrier wave of the inverter based on the target carrier wave period, so that the carrier wave of the inverter is synchronized with the power grid reference.

The invention discloses an interference communication integrated waveform generation method based on spectrum dispersion-multi-system phase shift keying. The problems of difficult communication information demodulation and high hardware implementation complexity in interference communication integration research are mainly solved. According to the scheme of the invention, the SMSP interference signal is formed by periodically expanding the chirp signal on the time domain, the communication information is modulated on the phase of the chirp signal, and the plurality of chirp signals carrying the communication information can cause dense false target interference at random positions on the radar, so that the interference and communication integrated signal is generated. At a communication receiving end, a first linear frequency modulation signal is adopted to perform carrier synchronization, so that the synchronization effect can be improved by using the high time width-bandwidth product characteristic of the linear frequency modulation signal, and communication information can be demodulated directly by using a coherent demodulation mode; at a radar receiving end, the signal can generate a radar interference effect with dense false target characteristics.

This invention discloses a power line carrier-synchronized 5G differential protection synchronization method for power distribution networks, comprising: a master carrier transmitter sending synchronization signal pulses, and a carrier receiver receiving the synchronization signal pulses simultaneously; the carrier receiver counting each time it receives a synchronization signal pulse; when the count value reaches a set value, the carrier receiver sending a synchronization signal to the data acquisition module of the intelligent power distribution terminal equipment; the data acquisition module receiving the synchronization signal and entering an interrupt to directly calibrate the AD sampling pulses, thereby achieving synchronization. This invention achieves a low-cost, high-synchronization, and delay-free differential protection function through power line carrier, enabling rapid fault location and timely repair in case of faults; it has broad feasibility and ease of use.

The invention discloses an angle error demodulation method for a burst communication signal, and relates to the field of satellite random access. According to the invention, angle error demodulation of burst communication signals is realized through synchronous sequence detection, open-loop AGC control and frequency domain angle error calculation. The arrival of a burst signal and the starting boundary of the signal are determined through synchronous sequence detection, signal power is quickly estimated through open-loop AGC control, AGC coefficient adjustment is carried out, a sum path signal is kept at a constant level, and angle error demodulation is directly carried out in a frequency domain through frequency domain angle error calculation on the basis that carrier synchronization does not need to be established. The method is suitable for angle error demodulation of burst signals with short signal duration and unfixed signal intervals, carrier synchronization does not need to be established, and the applicable signal modulation system is wide.

The present application belongs to the technical field of very low frequency fluctuation detection, and discloses a very low frequency station signal information extraction method and system based on a phase-locked loop. The present application amplifies and samples a wide frequency signal containing a very low frequency station transmitting signal, sets local MSK demodulation parameters, uses phase-locked loop technology to respectively perform carrier synchronization on the upper and lower frequencies of the MSK modulated signal transmitted by the target monitoring very low frequency station, extracts a baseband synchronization signal and a carrier synchronization signal from the phase-locked loops of the upper and lower frequencies, respectively, calculates the amplitude information of the upper and lower frequencies using the baseband synchronization signal, and further obtains the amplitude information of the target monitoring very low frequency station. The carrier synchronization signals of the upper and lower frequencies are used to extract the frequency of the carrier synchronization signal of the MSK modulated signal transmitted by the target monitoring very low frequency station, and further extract the phase offset information of the target monitoring very low frequency station. The present application can improve the accuracy of very low frequency station signal information extraction.

The invention discloses a generator parallel operation control method and system based on carrier synchronization, and belongs to the technical field of power electronic conversion. A generator parallel operation control method based on carrier synchronization is characterized in that the method is applied to a system comprising a synchronous enabling unit, a synchronous signal transmitter and a plurality of parallel converters connected with the synchronous enabling unit and the synchronous signal transmitter respectively, and the method comprises the following steps: for each converter, determining a counting difference value and sending the synchronous enabling unit; the synchronous enabling unit feeds back an adjusting signal to the corresponding converter based on a comparison result of the difference value sent by the carrier wave processor of each converter and a count value threshold until the difference values sent by the carrier wave processors of all converters are smaller than the count value threshold; then, synchronous enable signals are sent to the converters respectively; and each converter drives the IGBT to realize current conversion based on the synchronous enable signal. According to the method, synchronous impact and circulation are reduced by simulating dynamic approximation of a carrier and an actual carrier.