1080 results about "Down conversion" patented technology

The invention discloses an adaptive modulation anti-multipath unmanned aerial vehicle swarm communication method and system based on MIMO-OFDM, and relates to the technical field of wireless communication, and the method comprises the steps: receiving a down-conversion baseband; synchronization and compensation are carried out; removing a cyclic prefix and carrying out fast Fourier transform; estimating a channel and noise on the training and pilot frequency, and correcting a common phase; performing frequency domain equalization and soft decision, forward error correction and cyclic redundancy check according to the estimation to obtain a control parameter, decoding a payload according to the control parameter, and performing statistics to form a link quality indication; modulating coding, bandwidth and spatial mode, configuring mapping, power and weight, and packaging physical layer protocol data; carrier sensing conflict avoiding sending, confirmation and retry are adopted to generate media access statistics; and the routing selects the next-hop multi-hop forwarding according to the transmission quality, and performs end-to-end statistics and recharge. Through cooperation of hierarchical synchronization and phase correction with cyclic prefix and FFT, crosstalk is suppressed, channel noise scale optimization soft decision is robust, data decoupling is controlled, and end-to-end availability is improved through multi-hop self-healing recharge.

The invention discloses an RFSOC-based FAST core array distributed collaborative observation and data fusion method and system, and the method comprises the steps: S1, system initialization: a master node RFSOC generates a global clock, achieves the phase synchronization of multiple board cards through an SYSREF differential signal, and completes the calibration of a three-stage clock tree; s2, signal acquisition and preprocessing: directly sampling a 3-8GHz radio frequency signal through an ADC (Analog to Digital Converter), and performing digital down-conversion to obtain a baseband signal; s3, intelligent resource scheduling: identifying a signal type based on an ESN (Echo State Neural Network), and dynamically allocating FPGA logic resources through an improved ant colony algorithm; s4, heterogeneous calculation acceleration: executing a 128-channel digital beam forming pipeline on the FPGA; s5, cross-domain data fusion; s6, collaborative observation planning; and S7, outputting data. The method is suitable for multi-beam synthesis, cross-region joint observation and mass data real-time processing scenes, and provides key technical support for solving the frontier scientific problems such as rapid radio storm origin and black hole activity monitoring.

The invention relates to the technical field of ground resistance detection, in particular to a single-core cable ground resistance detection method capable of resisting strong power frequency interference. High-frequency signals are injected in a non-contact mode through a coupling type capacitor clamp, background voltage and current signals are collected firstly, and injection frequency far away from power frequency and harmonic waves is selected through Fourier analysis; cancelling background noise by adopting a normalized least mean square adaptive filter to generate an enhanced signal; the signal is down-converted to a base band through digital quadrature demodulation, a Kalman filter estimates the amplitude and the phase in real time, and the state and noise parameters are periodically calibrated through a compressed sensing algorithm; and finally, loop impedance is calculated according to the voltage and current amplitudes and the phase difference to obtain grounding resistance. The method has the advantages of being non-contact, high in safety, strong in anti-interference capability, high in measurement precision and the like, and is suitable for monitoring the grounding state of the cable in a complex electromagnetic environment.

The invention relates to the technical field of signal analysis, in particular to a GNSS (Global Navigation Satellite System) detection method and system based on machine learning, and the method comprises the steps: receiving a navigation radio-frequency signal containing reality and deception, and carrying out the down-conversion of an RF (Radio Frequency) front end to obtain intermediate-frequency data; gNSS signal capture is completed by searching correlation peaks in frequency and code phases based on intermediate frequency data; in the capturing stage, a motion state, a correlation peak number, a noise value, capturing parameters and peak + / -1 chip sampling features are extracted and input into a machine learning classification model to judge whether cheating exists or not; if so, separating the deception signal from the real signal, and respectively sending the deception signal and the real signal into independent tracking channels; measuring an array element carrier relative phase by an array antenna, establishing a phase center model, and correcting to obtain an effective phase center and a differential baseline; according to the method, a deception azimuth angle and a pitch angle are obtained, a beam weight is calculated, a deception direction is subjected to null setting, a real direction is subjected to main lobe protection, and a weight value is fed back in real time to improve a signal carrier-to-noise ratio and locking stability. According to the invention, the problem that the existing commercial GNSS signal is low in power and easy to be interfered by deception is solved.

The invention relates to the technical field of signal processing, in particular to an intelligent blind equalization method and device for large-scale carrier frequency deviation, and the method comprises the steps: carrying out the down-conversion of an original received signal of a preset modulation type, so as to sample an original complex sampling point sequence with large-scale carrier frequency deviation; performing local information exchange, parameter correction and splicing on the original complex sampling point sequence to obtain a compensated complex sampling point sequence; performing pre-extraction and channel amplification on the compensated complex sampling point sequence to obtain pre-extraction features containing implicit channel state information, and further extracting spatial information and time sequence dependence in the pre-extraction features to balance multipath fading of the original complex sampling point sequence and obtain balanced output; and demodulating the original bit information of the original complex sampling point sequence according to the balanced output. Therefore, the problem that a blind equalization method in the related technology cannot effectively adapt to a time-varying multipath channel and a scene with large-scale carrier frequency deviation is solved.

The invention discloses a broadband digital beam forming method based on a Farrow filter, and the method comprises the following steps: carrying out the DDC down-conversion and phase shift processing of a signal after the analog-to-digital conversion of a broadband signal is completed through an ADC; calculating the delay inequality of each array element signal relative to a reference array element, and decomposing the delay inequality into an integer sampling period and a fractional delay component; a fourth-order Lagrange type Farrow filter oriented to FPGA / DSP optimization is adopted to carry out fractional time delay compensation, and coefficients of the Farrow filter are dynamically adjusted through a polynomial expansion formula; and finally, performing complex weighted synthesis on each channel filtering signal to generate a directional wave beam. According to the method, high-precision fractional delay adjustment is achieved, the Farrow filter is adopted, the tedious process of recalculating coefficients can be omitted, only the P value is changed, and high-precision beam direction control can be achieved under the condition of low calculation amount.

The invention discloses a broadband noise generation method based on predistortion calibration, and relates to the technical field of communication, and the method comprises the steps: S1, setting a flatness threshold value, and screening out an original noise signal needing to be calibrated; s2, generating an inverse filter coefficient and a filter suppression coefficient for the original noise signal; s3, performing frequency response compensation by using an inverse filter coefficient, performing band-pass filtering by using a filter suppression coefficient, performing down-conversion to a baseband, and reducing a sampling rate; and S4, comparing the processed signal with a flatness threshold value, and if the processed signal does not exceed the flatness threshold value, indicating that signal calibration is completed, otherwise, entering calibration again. By introducing a pre-distortion calibration mechanism, the inverse filter coefficient is calculated in real time to compensate the system frequency response, the spectrum distortion caused by a fixed filter is effectively eliminated, and the method has the advantages of realizing dynamic and adaptive filter adjustment, effectively reducing the manual participation frequency and improving the continuous operation capability and the test efficiency of the system.

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 relates to a method for realizing multi-channel ADC (Analog to Digital Converter) data synchronization processing based on an FPGA (Field Programmable Gate Array), which comprises the following steps that: the FPGA receives a clock frequency generated by an external clock generator and takes the clock frequency as a working clock of the FPGA; a plurality of groups of same-frequency clocks and same-phase clocks are generated in the FPGA and are respectively used as working clocks of the ADC chips; the FPGA receives sampling data of each ADC, an enable signal is set, and when the enable signal is effective, digital down-conversion, decimation filtering and FIR filtering are carried out on each sampling data; and after FIR filtering is completed, another enable signal ENend is generated, and data are further stored or transmitted to an upper computer. According to the method and the device for realizing the multi-channel ADC data synchronous processing based on the FPGA, the processor and the computer readable storage medium thereof, synchronous start and stop of the processing flow are controlled through the enable signals ENstart and ENend, synchronous processing of the multi-channel ADC data is ensured, accuracy and effectiveness are improved, and the method and the device have a wide application range.

The invention provides a satellite communication system with multi-mode capability and a communication method, and belongs to the technical field of satellite communication. A signal processing module of the system comprises a load control unit and a baseband processing unit, the load control unit is responsible for beam correlation calculation, transmission rate control, antenna channel power-on and power-off control and the like, the baseband processing unit is used for processing uplink and downlink signals, and the downlink supports multiple modes. The frequency conversion processing module is provided with an upper frequency conversion channel and a lower frequency conversion channel which respectively process transmitted and received signals. And the wide-beam receiving antenna is responsible for receiving uplink data. The phased array transmitting antenna is responsible for transmitting downlink data, is high in gain and fast in pointing adjustment, and supports multiple modes. According to the communication method, satellite transmitting and receiving are started by default, and transmitting serves as a beacon to assist a user in capturing. According to the invention, the working modes can be flexibly switched, the telemetering downloading capability and the information broadcasting efficiency are improved, and diversified communication requirements are met.

The invention relates to a low-orbit satellite short burst signal high-precision capturing method and device, equipment and a medium. The method comprises the following steps: sequentially carrying out digital down-conversion and L-time signal pseudo code rate down-sampling on a low earth orbit satellite short burst signal sequence sampled by an ADC (Analog to Digital Converter) to obtain a down-sampled signal sequence; performing pre-accumulation processing on the down-sampling signals of every adjacent L points in the down-sampling signal sequence, and performing coarse capture on the pre-accumulated signal sequence by adopting a PMF-FFT algorithm to obtain a coarse pseudo code phase and a coarse frequency offset value; and performing serial code phase search on the down-sampling signal sequence based on the coarse pseudo code phase and the coarse frequency offset value, optimizing to obtain a fine pseudo code phase, and optimizing the estimation precision of the coarse frequency offset value according to the fine pseudo code phase and a frequency offset estimation algorithm based on a phase relation to obtain a fine frequency offset value. By adopting the method, the acquisition precision and speed of the short burst signal of the low-orbit satellite can be improved.

A multi-channel analog-digital converter (ADC) subsystem for test device such as a spectrum analyzer may include multiple multi-channel ADCs to receive down-converted signals and convert the received signals to digital output signals, a field programmable gate array (FPGA) to select one or more ADCs based on a frequency, a bandwidth, and / or a signal type of each received signal and a characteristic of each ADC, and an ADC sample clock to provide a clock signal to the selected ADCs. Characteristics of the ADCs may include a resolution, a signal-to-noise-and-distortion ratio (SINAD), an effective number of bits (ENOB), a signal-to-noise ratio (SNR), a total harmonic distortion (THD), a total harmonic distortion plus noise (THD+N), and / or a spurious free dynamic range (SFDR).

The invention discloses a self-adaptive CPFSK multi-symbol incoherent demodulation method, and belongs to the field of communication signal processing. The implementation method comprises the following steps: initializing a receiving signal and the length of an observation window; performing orthogonal down-conversion on the received signal to obtain a baseband received signal; constructing a local template sequence according to the length of the observation window, and performing baseband modulation to generate a local baseband template signal; according to the baseband receiving signal and a local baseband template signal, constructing an incoherent judgment statistic, and selecting a candidate sequence; classifying the candidate sequences into credible sequences and uncredible sequences by comparing the judgment of the candidate sequences before and after about the same symbol; taking an intermediate symbol of the credible sequence as an incoherent judgment result, and adding one to the position of the symbol to be judged; for an untrusted sequence, the length of an observation window is expanded, a candidate sequence is selected again, an intermediate symbol is used as a new incoherent judgment result, the position of a symbol to be judged is increased by one, iteration is repeated, and self-adaptive multi-symbol incoherent demodulation is achieved.

The invention relates to the technical field of radio frequency, in particular to a radio frequency conversion assembly, and the assembly comprises a baseband processing unit which employs a millimeter wave SoC chip and is used for generating and processing an initial transmitting signal of 79-81GHz and an initial receiving signal of 79-81GHz; the frequency conversion unit comprises an up-conversion subunit and a down-conversion subunit, and the local oscillation synthesis unit is used for generating and providing a local oscillation signal with a fixed frequency; the mode switching and processing system is used for selectively performing down-conversion processing on the echo signal or a target radio frequency signal from an external non-cooperative irradiation source in two working modes and then transmitting the echo signal or the target radio frequency signal to the baseband processing unit; the working mode comprises an active mode and a passive mode.

The invention relates to the field of satellite ground station electromagnetic environment monitoring, in particular to a full-band satellite ground station electromagnetic environment monitoring system. Comprising a monitoring and direction-finding subsystem and an information processing subsystem, and an omnidirectional real-time monitoring device and a directional high-sensitivity monitoring device receive interference signals through corresponding monitoring antennas and direction-finding antennas and send the received interference signals to corresponding radio frequency receivers. The radio frequency receiver antenna processes the received signal, outputs an intermediate frequency signal, and sends the intermediate frequency signal to a corresponding signal processing unit; the signal processing unit is used for sampling an input signal, then carrying out down-conversion, filtering and extraction preprocessing operation according to a specified frequency, carrying out analysis and monitoring direction finding on preprocessed data, and transmitting monitoring direction finding data to the information processing subsystem; and the information processing subsystem receives monitoring results of the ground stations and performs fusion statistical processing. The method is suitable for satellite ground station electromagnetic environment monitoring.

The invention relates to a time domain broadband adaptive beam forming method and system based on Chebyshev weighting, and belongs to the field of array signal processing. Aiming at the technical problems of poor real-time performance and high sidelobe of the existing broadband beam forming, the method comprises the following steps of: dividing a received broadband signal into a plurality of sub-bands, obtaining an optimal weight vector for each sub-band by adopting a minimum linear constraint iterative algorithm after down-conversion, constructing an expected response of an FIR filter according to each weight, obtaining a filter coefficient through L2 norm convex optimization, and finally obtaining a high sidelobe beam according to the expected response of the FIR filter. And performing time domain weighting on each array element signal by using a filter bank, and outputting a directional beam. According to the method, the calculated amount is low, a main lobe and interference null can be formed in real time in a broadband, and a certain side lobe height is kept.

The utility model discloses a vehicle-mounted quick-charging USB charging module, and belongs to the technical field of charging modules. The technical problems that no input protection exists in the charging process, and when positive and negative electrodes of an input end are reversely connected, a fast charging module is damaged are solved. According to the technical scheme, the power supply comprises a power supply input end, a rectification filtering module, a step-down conversion module and an output interface, the power supply input end is used for obtaining external alternating current and inputting the external alternating current to the rectification filtering module, the rectification filtering module is used for outputting first direct current, and the step-down conversion module receives the first direct current for power supply; the step-down conversion module is connected with the output interface for providing charging power; the charging module has the advantages that the positive electrode and the negative electrode do not need to be considered when the charging module is installed, the installation reliability of assembly connection is improved, and the charging module is provided with multiple interfaces and is convenient to adapt.

The invention relates to a multiband radio frequency signal transmitting and receiving method, belongs to the technical field of microwave integrated circuits, and solves the problem that multiband integrated broadband transmitting and receiving are difficult to realize in an existing radio frequency transmitting and receiving mode. The method is divided into a multiband radio frequency signal receiving / transmitting method. The receiving method comprises the following steps of: performing up-conversion on a received radio frequency input signal to a K wave band through first-stage frequency mixing, performing down-conversion on the received radio frequency input signal to an S / C wave band through second-stage frequency mixing, performing down-conversion on the received radio frequency input signal to an L wave band intermediate frequency through third-stage frequency mixing, and generating a first L wave band intermediate frequency output signal; the transmitting method comprises the steps that an obtained second L-band intermediate-frequency output signal is subjected to fourth-stage frequency mixing up-conversion to the S / C band, is subjected to fifth-stage frequency mixing up-conversion to the K band and is subjected to sixth-stage frequency mixing down-conversion to the S / C / X / Ku band, and a radio-frequency output signal is generated; the first-stage frequency mixing up-conversion and the sixth-stage frequency mixing down-conversion are realized by the same bidirectional microwave link working in up-conversion and down-conversion regulation and control states respectively.

The invention particularly relates to a method for quickly capturing high-dynamic and low-carrier-to-noise-ratio signals, which comprises the following steps of: preprocessing input digital intermediate-frequency signals, performing correlation operation on stored local pseudo code data and baseband data after down-conversion, and accumulating correlation results of which the length is a set value; if the local code phase is aligned with the pseudo code phase modulated by the baseband data, a peak value is obtained through FFT, the index of the peak value indicates the Doppler frequency, and the number of FFT calculation times indicates the code phase; calculating a module value based on a real part and an imaginary part output by the FFT; judging whether capturing succeeds or not based on the maximum module value, and obtaining the Doppler frequency of rough capturing if capturing succeeds; and refining the roughly captured Doppler frequency to obtain a refined Doppler frequency. According to the method, the Doppler frequency and the code phase are accurately searched in a short time, and the method is suitable for capturing high-dynamic weak signals.

A radar system employs a self-test to determine time synchronization of cascaded radar transceiver integrated circuits (ICs) in the radar system that are used in a motor vehicle. To effectively detect information in the environment, the radar system periodically executes the self-test operation by sending a trigger signal to at least one follower radar transceiver IC. Moreover, the leader radar transceiver IC generates a chirp signal at a set frequency and transmits this. In response to receiving the trigger signal, the at least one follower radar transceiver IC receives the chirp signal transmitted from leader and generates its own local chirp signal with the set frequency, but also includes a frequency offset. The local chirp signal is then used to down-convert the received signal into an intermediate frequency (IF) signal. The IF signal is filtered, analog-to-digital converted, and processed to determine a beat frequency. The beat frequency is compared to the frequency offset to determine the level of synchronization between the leader radar transceiver IC and the at least one follower radar transceiver IC.

The invention discloses a millimeter wave transceiver and a state monitoring method, and belongs to the technical field of millimeter wave communication. Comprising a transceiver circuit, and the transceiver circuit is arranged on a transceiver structure. The transceiver circuit comprises an EMI circuit, a power supply system, a heat dissipation system, an up-conversion assembly, a local oscillator assembly, a down-conversion assembly, a one-to-four filtering power divider and a monitoring system. And the monitoring system is used for controlling the working states of each circuit, assembly, system and device, executing an intermediate frequency signal processing flow when receiving an intermediate frequency signal, and executing a millimeter wave signal processing flow when receiving a millimeter wave signal. The millimeter wave transceiver integrates various components, improves the integration level of the millimeter wave transceiver through a tiled layout mode and a modular design, improves the aesthetic property and safety of a product, and is extremely high in product integration level, small in size, light in weight, low in hardware cost, high in product reliability, short in later maintenance time and low in maintenance cost.

The invention discloses a multipath effect suppression method for 2.4 GHz radio frequency identification. The multipath effect suppression method comprises a transmitting end processing flow and a receiving end processing flow. A transmitting end carries out pulse code modulation on an analog signal to obtain a digital signal, blocks the digital signal after channel coding, and distributes the digital signal to subcarriers through quadrature amplitude modulation; and generating a time domain OFDM symbol through IFFT (Inverse Fast Fourier Transform), adding a cyclic prefix and a synchronization head, converting into an analog baseband signal, and performing up-conversion, filtering, amplification and radiation. The receiving end amplifies the signal, down-converts the signal to a baseband, filters the signal and converts the signal into a digital signal; the method comprises the following steps of: synchronizing header frame alignment, recovering a coding bit stream through FFT (Fast Fourier Transform) and QAM (Quadrature Amplitude Modulation) demodulation, carrying out CRC (Cyclic Redundancy Check) after decoding and merging, returning ACK (Acknowledgement Character) if According to the method, the multipath effect can be effectively inhibited, and the integrity of received data is improved.

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 relates to a radio frequency transceiving multichannel amplitude-phase calibration system, which comprises a radio frequency receiver, a radio frequency transmitter, a data converter, an FPGA (Field Programmable Gate Array) processor and a clock network, wherein the radio frequency receiver adopts a zero intermediate frequency architecture and is used for receiving a multichannel radio frequency signal and down-converting the multichannel radio frequency signal into an analog baseband signal; the radio frequency transmitter adopts a zero intermediate frequency architecture and is used for up-converting the analog baseband signal into a radio frequency signal and transmitting the radio frequency signal; the data converter is connected with the radio frequency receiver and the radio frequency transmitter and is used for realizing conversion between an analog signal and a digital signal; the FPGA processor is connected with the data converter through a JESD204B interface and is used for aligning the data of each receiving and transmitting channel; and the clock network consists of a clock chip with JESD204B characteristics and a clock Buffer, and is used for providing a synchronous clock and an SYSREF signal for the whole system and supporting an SYNC synchronous trigger signal. By adopting the method, the problem of multi-channel amplitude-phase consistency can be solved.

A receiver includes an antenna block configured to transduce impinging electromagnetic signals into electrical signals; a signal conditioning block configured to condition electrical signals received from the antenna block; and a down-converter block configured to down-convert conditioned electrical signals received from the signal conditioning block. The down-converter block comprises a plurality of signal channels. The receiver further includes a plurality of analog-to-digital converters (ADCs) respectively connected to the signal channels of the down-converter block; and a field-programmable gate array (FPGA). The FPGA is configured to program the down-converter block by selecting a set of mixer frequencies and a set of bandwidths designed to remove interference signals in each signal channel. The selections are calculated to mitigate reductions in dynamic range in the ADCs due to interference. The FPGA is further configured to process digital signals received from the ADCs after the down-converter block has removed the interference signals.

The invention discloses an embedded special high-frequency low-level control system, which comprises a digital signal processing board card, an ADC / DAC sub-board card and a radio frequency front-end board card, the radio frequency front-end board card comprises two paths of up-conversion channels and six paths of down-conversion channels; the digital signal processing board card comprises an FPGA (Field Programmable Gate Array); wherein the radio frequency front-end board card is used for dividing an input reference line RF signal into four paths of RF reference signals and generating an LO signal; the ADC / DAC sub board card is used for ADC analog-to-digital conversion and DAC digital-to-analog conversion; the main functions of the digital signal processing board card comprise clock distribution of RF reference signals, a motor drive and piezo ceramic drive circuit, a data acquisition and logic control algorithm of an FPGA logic unit PL part, an embedded ARM system of an FPGA processor unit PS part, EPICS-IOC application of a low-level system, network data communication and the like.

The invention relates to a 92GHz MIMO roadside radar radio frequency system based on a frequency conversion assembly, and the radar radio frequency system comprises a baseband processing layer which comprises at least two cascaded millimeter wave system-level SoC chips; the frequency conversion layer is a frequency conversion module FCM, and the FCM comprises a local oscillator synthesis unit, an upper mixer group and a lower mixer group; the local oscillation synthesis unit is used for generating a 13GHz local oscillation signal; the input end of the upper mixer group is connected with the output end of the baseband processing layer, the local oscillation end of the upper mixer group is connected with the local oscillation synthesis unit, the output end of the lower mixer group is connected with the input end of the baseband processing layer, and the local oscillation end of the lower mixer group is connected with the local oscillation synthesis unit; and the down-conversion layer is used for down-converting 92-94 GHz echo signals received by the antenna array to 79-81 GHz and then outputting the echo signals to the baseband processing layer. According to the invention, 92-94 GHz frequency conversion can be realized.

The invention relates to the field of communication, in particular to a spread frequency hopping signal capturing method based on Doppler and spread frequency hopping pseudo code search. Comprising the following steps: step 1, down-conversion; step 2, searching for a large step frequency; step 3, caching the data at regular time; step 4, de-hopping; step 5, downsampling; step 6, searching for a small step frequency; step 7, sliding correlation; step 8, interpolation: performing high-power interpolation processing on the sliding correlation output sequence; step 9, phase rotation: carrying out phase rotation processing on the data segments before coherent accumulation; step 10, performing coherent accumulation during a frequency hopping cycle; step 11, carrying out incoherent accumulation between symbols; and step 12, inter-symbol capture judgment. According to the invention, the bandwidth of the data to be processed is effectively reduced, and the purposes of saving hardware resources and improving the capture accuracy of the spread frequency hopping signals are achieved.

A measurement and control simulation device based on a measurement and control data transmission integrated system comprises an upper computer display control test module, a PC host module, a signal processing master controller module, an isolation DC / DC module, a down-conversion module, a filtering module, an isolator module and an outer end face interface module. The system has the characteristics of multiple modulation systems, a spread spectrum function, controllable output power, Doppler frequency change and the like, can be used for simulating a star chain control system link test in a ground test system, and fully improves the index assessment performance during system docking; meanwhile, the design of a down-conversion link meets the requirements for the strength and sensitivity of the received signal, the stability and accuracy of the radio-frequency signal after frequency conversion in a low-power injection state are remarkably improved, and a new scheme is provided for a high-frequency conversion mode. Besides, the display control module of the equipment has the functions of multiplexing, reconstruction, multi-data interaction and the like, so that multifunctional and multi-task full-system test coverage can be realized, the cost investment of test systems such as spacecrafts and the like is greatly reduced, and the multifunctional index test coverage efficiency is improved.

The invention relates to the technical field of data processing, and discloses an integrated reconnaissance interference method and system based on a transmit-receive cancellation technology, and the method comprises the steps: receiving a mixed signal containing a target radar signal and a leakage interference signal through a receiving channel, and obtaining a first digital signal after down-conversion and analog-to-digital conversion, the leakage interference signal is a signal leaked from the transmitting channel to the receiving channel; acquiring a second digital signal corresponding to an interference signal generated in the transmitting channel, and transmitting the interference signal through an antenna after digital-to-analog conversion and up-conversion; taking the second digital signal as a reference signal, performing adaptive cancellation processing on the first digital signal through an adaptive filter to suppress a leakage interference signal component in the first digital signal, and generating a cancelled signal; wherein in the adaptive cancellation processing process, the digital processing unit adaptively updates the cancellation filtering weight of the adaptive filter according to the reference signal and the cancelled signal.