Patents
Literature
Patsnap Eureka AI that helps you search prior art, draft patents, and assess FTO risks, powered by patent and scientific literature data.

441 results about "Spread spectrum" patented technology

In telecommunication and radio communication, spread-spectrum techniques are methods by which a signal (e.g., an electrical, electromagnetic, or acoustic signal) generated with a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth. These techniques are used for a variety of reasons, including the establishment of secure communications, increasing resistance to natural interference, noise and jamming, to prevent detection, and to limit power flux density (e.g., in satellite down links).

Data and clock recovery circuit, receiving apparatus, vehicle-mounted device, and vehicle

A data and clock recovery circuit, a receiving apparatus, a circuit system, a vehicle-mounted device, a vehicle, and a data and clock recovery method are provided. The data and clock recovery circuit includes a sampler, a phase detector, a multi-order filter, a frequency change detection circuit, and a selector. The sampler is configured to sample an input signal based on a multi-order filtered signal to generate a sampled signal. The phase detector is configured to determine a phase difference in the sampled signal based on the sampled signal. The multi-order filter is configured to generate the multi-order filtered signal based on the phase difference. The frequency change detection circuit is configured to determine a frequency change direction of a spread spectrum clock in the input signal by using the phase difference.
Owner:HUAWEI TECH CO LTD

Self-adaptive calibration method for ultrasonic wind speed sensor of power transmission tower

The invention relates to the technical field of power transmission line safety monitoring, and particularly discloses a self-adaptive calibration method for an ultrasonic wind speed sensor, which comprises the following steps of: arranging an orthogonal ultrasonic probe array at the top of a tower, and compensating probe offset caused by swinging of a tower body in real time through GNSS / IMU (Global Navigation Satellite System / Inertial Measurement Unit) fusion positioning; integrating a temperature, humidity and pressure sensor and vibration spectrum analysis to construct an environmental parameter compensation model; double-frequency ultrasonic waves are adopted to detect the ice accumulation thickness of the protective cover and correct the sound path distance; deploying a lightweight LSTM model at an edge computing unit to realize minute-level dynamic parameter adjustment; electromagnetic interference is suppressed by combining linear frequency modulation spread spectrum and beam forming technologies; and establishing a three-height-layer wind speed gradient model to generate a galloping early warning. The problem of measurement distortion caused by tower deformation, icing and parameter solidification of a traditional sensor is solved, all-working-condition operation from-40 DEG C to 60 DEG C is supported, and the monitoring reliability in a strong electromagnetic environment is remarkably improved.
Owner:ELECTRIC POWER SCI RES INST OF STATE GRID XINJIANG ELECTRIC POWER CO LTD

Satellite communication anti-interference transmission method based on frequency hopping and spread spectrum fusion algorithm

InactiveCN121643877ARadio transmissionFrequency-hopping spread spectrumInterference (communication)
The invention relates to the technical field of communication, in particular to a satellite communication anti-interference transmission method based on a frequency hopping and spread spectrum fusion algorithm. According to the method, interference power is collected at multiple nodes, multiple sub-carrier frequencies and multiple moments to construct an interference observation tensor, interference features are extracted through low-rank tensor decomposition, and interference of each sub-carrier frequency in a future frequency hopping time slot is predicted; calculating a signal to interference plus noise ratio and capacity according to predicted interference in combination with transmitting power and noise, constructing a utility function containing a service weight and a balance coefficient, and distributing working sub-carrier frequency to each satellite communication node under concurrency constraint to generate a frequency hopping sequence; a transmitting end performs channel coding, modulation and spectrum spreading on service data and transmits the service data according to a frequency hopping sequence, and a receiving end completes synchronization, de-spreading and decoding and performs weighting processing by utilizing predicted interference. The method improves the spectrum utilization rate and the interference suppression capability, and enhances the satellite communication reliability.
Owner:XIAN TIANYUNTU COMMUNICATION TECHNOLOGY CO LTD

Encryption communication system and method based on cognitive multi-carrier spread spectrum

The invention discloses an encrypted communication system and method based on cognitive multi-carrier spread spectrum, and belongs to the field of covert communication. The encryption communication system comprises a transmitting device and a receiving device. The transmitting device comprises a data encryption module, a constellation encryption modulation module, a multi-carrier spread spectrum module, a frequency hopping module and a cognitive power distribution module. The receiving device comprises a band-pass filtering module, a de-hopping frequency module, a de-spreading module, a constellation decryption demodulation module, a data decryption module and a coherent combination module. The data encryption module is divided into an interleaving coding unit and a double-rule reversible cellular automaton encryption unit. The cognitive power distribution module continuously scans a wireless electromagnetic environment and carries out real-time spectrum analysis to give power spectrum density results sensed under all frequency hopping frequency sets. According to the invention, continuous detection and dynamic response to the spatial frequency spectrum state can be realized, and the communication concealment, the anti-interference performance and the resource utilization efficiency in a complex electromagnetic environment are remarkably improved by utilizing the frequency spectrum hole.
Owner:BEIJING INFORMATION SCI & TECH UNIV

Carrier tracking method suitable for multi-bit spread spectrum signal

The invention discloses a carrier tracking method suitable for a multi-bit spread spectrum signal, and relates to the technical field of multi-bit spread spectrum, the carrier tracking method comprises the steps of coarse frequency offset correction, multi-bit spread spectrum, average phase estimation and delay phase correction.The carrier tracking method comprises the steps that firstly, a sliding DFT algorithm is adopted to estimate frequency offset, and a coarse frequency offset available correction signal is obtained; secondly, adaptively selecting the number of available windows according to historical data corresponding to the current signal-to-noise ratio; the method comprises the following steps: firstly obtaining a window intermediate point spread spectrum period, then extracting a carrier phase estimation value of the window intermediate point spread spectrum period, finally delaying a correlation value by the spread spectrum period to realize time sequence alignment and eliminate phase deviation, and finally obtaining information bits corresponding to each spread spectrum period by extracting and correcting a real part of the correlation value, matching a local sequence number and mapping. According to the method, the phase estimation precision under the low signal-to-noise ratio can be improved, parameter self-adaption to high and low dynamic scenes of a satellite is realized, the coherent judgment performance is improved, and the hardware complexity is reduced.
Owner:NANJING TIANJI YIDA COMM TECH CO LTD

Measurement and control simulation equipment based on measurement and control and data transmission integrated system

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.
Owner:GUIZHOU AEROSPACE LINQUAN MOTOR CO LTD

Large-scale constellation multiple access measurement and control spread spectrum signal de-spreading bit width quantization method

The invention relates to the field of spaceflight measurement and control, and discloses a large-scale constellation multiple access measurement and control spread spectrum signal de-spreading bit width quantization method. Signal samples are counted, a noise deterioration factor and a bit width quantification model are respectively established, the de-spreading bit width is accurately expanded, and the optimal balance of resources and performance is realized. The method solves the problem that the detection range of strong and weak signals is limited when a single receiver detects multi-satellite same-frequency signals at the same time, remarkably improves the system capacity, and has the characteristics of quantizability, large dynamic range and multi-constellation adaptation.
Owner:THE 54TH RESEARCH INSTITUTE OF CHINA ELECTRONICS TECHNOLOGY GROUP CORPORATION

Frequency offset estimation method and device, electronic equipment and storage medium

The invention discloses a frequency offset estimation method and device, electronic equipment and a storage medium, and relates to the technical field of communication. The method comprises the following steps: receiving a baseband spread spectrum signal from a low earth orbit satellite to obtain a received signal; performing segmented sweep frequency compensation on the received signal to obtain a compensated measured signal; despreading and descrambling the compensated measured signal by using prior information determined from the received signal, and completing coarse frequency offset estimation on the measured signal despread and descrambled for the first time; and de-spreading and descrambling the signal data after the coarse frequency offset estimation again, and finishing fine frequency offset estimation on the signal data after the second time of de-spreading and descrambling. According to the invention, prior information is introduced to directly lock and track a specified target beam signal, so that the directionality and efficiency of measurement are remarkably improved; by designing a low-complexity signal processing flow, the algorithm burden can be remarkably reduced, it is ensured that adjacent satellite beam frequency offset estimation is rapidly completed in service proceeding, and the real-time requirement of seamless switching is met.
Owner:CHINA SATELLITE NETWORK EXPLORATION CO LTD

Ultra-short baseline positioning method based on binary short baseline

The invention discloses an ultra-short baseline positioning method based on a binary short baseline, and belongs to the technical field of underwater acoustic target navigation positioning. The method comprises the following steps: S1, designing a spread spectrum underwater acoustic communication signal for underwater acoustic communication between an ultra-short baseline transceiver and a transponder; s2, solving ultra-short baseline time delay information by adopting a frequency domain correlation method, and obtaining high-precision time delay information through an interpolation method; s3, two sets of transceivers with known positions are installed at the ship end at a preset interval distance, and the two sets of transceivers form a binary short baseline framework; installing at least one group of transponders at the mobile terminal, and obtaining the distance information of the two groups of transceivers and the transponders and the initial position information of the mobile terminal; and S4, based on the two groups of distance information and the initial position information, performing binary short baseline positioning calculation by adopting an iterative optimization algorithm to obtain high-precision position information of the mobile terminal. The ultra-short baseline positioning method based on the binary short baseline is high in positioning precision and high in stability, and can still realize high-precision target positioning in a low signal-to-noise ratio environment.
Owner:崂山国家实验室

GPU chip detection method and related equipment

The invention discloses a GPU chip detection method and related equipment, and the method comprises the steps: injecting a low-duty-ratio pulse signal into a stream processor cluster, carrying out the linear frequency sweeping, and generating a frequency space phase resonance diagram; collecting error count and retransmission frequency data during ray tracing rendering, and determining a target focusing area; the target area flow processor is configured to be a phase emission array to generate a steerable electrothermal acoustic wave beam, and an air gap defect area is determined; inputting a spread spectrum signal, applying a random flipping sequence, and calculating air gap defect three-dimensional parameters through a multi-physics field inversion model; and adjusting clock frequency according to the air gap parameters, controlling offset beams, adjusting power consumption of a stream processor, and executing a test to judge the qualification of the GPU. According to the method, the nano air gap defect in the GPU structure can be effectively detected, and the accuracy and reliability of GPU quality detection are remarkably improved.
Owner:SHENZHEN LCD AUTOMATIC EQUIP

Chirp spread spectrum photon terahertz communication sensing integrated system

The invention discloses a chirp spread spectrum photon terahertz communication perception integrated system. The system comprises a coherent light source module used for generating two beams of coherent single-frequency optical carrier signals; the signal modulation module is used for generating a baseband chirp spread spectrum communication sensing integrated signal and modulating the signal to one beam to form a carrier signal; the integrated signal transmitting module is used for taking the other beam of single-frequency optical carrier signal as an optical local oscillator signal, and after the optical local oscillator signal is coupled with the carrier signal, a terahertz communication sensing integrated signal is generated and radiated through optical down-conversion; the communication receiving module is used for performing frequency conversion and demodulation on the received terahertz communication sensing integrated signal and recovering communication information in the signal; and the radar receiving module is used for performing de-chirp and target information estimation on the received terahertz communication sensing integrated signal. According to the system, the advantages of a photon terahertz architecture are fully exerted, and an ultra-wideband chirp spread spectrum integrated signal is generated, so that a communication sensing integrated system with high spread spectrum gain and high energy efficiency is realized.
Owner:ZHEJIANG UNIV

Ka-band broadband filtering antenna

The invention discloses a Ka-band broadband filtering antenna, which comprises a probe, a ground paving layer, and a first horizontal dielectric plate, a first radiation patch, a second horizontal dielectric plate and a second radiation patch which are arranged on the ground paving layer, and is characterized in that the first radiation patch is provided with a c-shaped groove, the c-shaped groove is internally provided with a circular groove, and the circular groove is internally provided with a pair of branches; one ends of the two branches are combined to form a combined end connected to the first radiation patch, and the other ends of the two branches are parallel and have a gap to form a parallel opening end; and the center of the second radiation patch is close to the combined end of the two branches on the first radiation patch and far away from the parallel opening ends of the two branches on the first radiation patch. According to the invention, through collaborative design of slotting and branch knot loading, a filtering structure is innovatively constructed. The core innovation lies in the collaborative design of the two filtering structures and the spread spectrum structure, and the filtering frequency domain and the passband width are remarkably improved. The method can be widely applied to the fields of base stations, national defense and military industry and the like.
Owner:ZHEJIANG UNIV

Inaudible orthogonal signal communication

Methods are generally described for inaudible orthogonal signal communication. An example method includes determining, based on an input message, a series of symbols, where each symbol from the series of symbols represents a numerical value, wherein each symbol from the series of symbols corresponds to a band-limited white noise tone orthogonal to each other band-limited white noise tone corresponding to each other symbol. The example method also includes generating a sub-token comprising each symbol from the series of symbols, where each symbol overlaps in time with at least one other symbol. The example method also includes modulating a carrier wave with the sub-token to produce a signal audio waveform, where the modulation uses a spread spectrum technique, and providing the signal audio waveform to a television device, where the television emits the signal audio waveform as a low-amplitude audio signal.
Owner:AMAZON TECH INC

Broadband spread spectrum signal capturing device based on rapid lock judgment feedback mechanism

The invention discloses a broadband spread spectrum signal capturing device based on a rapid lock judgment feedback mechanism, and belongs to the technical field of spaceflight measurement and control communication. According to the method, a pseudo code parallel multi-channel capturing method and a carrier serial search capturing method are adopted, compromise processing is carried out between signal capturing time and consumed resources, and rapid carrier capturing can be completed through a rapid judgment locking feedback mechanism. According to the invention, rapid carrier capture of high-bandwidth spread spectrum signals can be completed under the condition of less resource consumption. According to the invention, the engineering realization occupies less chip resources, a low-performance processing chip can be adopted, the cost is saved, and the method is suitable for low-cost application scenarios. Through a rapid carrier wave lock judgment feedback mechanism, carrier wave serial search is combined with pseudo code parallel search, so that a corresponding carrier wave frequency is rapidly found during carrier wave frequency search, and a corresponding chip phase is found through pseudo code parallel search. The method is simple in design, easy in engineering realization and low in difficulty.
Owner:THE 54TH RESEARCH INSTITUTE OF CHINA ELECTRONICS TECHNOLOGY GROUP CORPORATION

Optical fiber optical frequency transmission relay system and method based on spread spectrum technology

The invention discloses an optical fiber optical frequency transmission relay system and method based on a spread spectrum technology. The relay system comprises a receiving module, a regenerative laser module and a sending module. The receiving module is used for demodulating the spread spectrum optical signal according to the second pseudo-random sequence to obtain a demodulated optical signal; the spread spectrum optical signal is a signal which is transmitted through an optical fiber link after a preceding stage performs spectrum spreading on the optical signal; the regeneration laser module is used for locking the frequency of the demodulation optical signal to generate a regeneration optical signal and splitting the regeneration optical signal to obtain a return optical signal and a transmission optical signal; the receiving module is also used for modulating the returned optical signal according to the second pseudo-random sequence and transmitting the modulated returned optical signal back to the preceding stage; and the sending module is used for demodulating the post-stage modulation return optical signal to obtain a demodulated return optical signal, carrying out noise suppression and spectrum spreading on the transmission optical signal according to the demodulated return optical signal and a third pseudo-random sequence, and then transmitting the transmission optical signal to the post-stage. By introducing the spread spectrum technology, the second-order Rayleigh scattering signals are filtered out, and the stability and reliability of the system are remarkably improved.
Owner:NAT TIME SERVICE CENT CHINESE ACAD OF SCI

Outdoor power equipment temperature abnormity monitoring method, device and equipment

The invention discloses an outdoor power equipment temperature abnormity monitoring method, device and equipment, and the method comprises the steps: carrying out the calibration processing of power equipment temperature data collected based on a dynamic collection frequency through employing a preset calibration algorithm, and obtaining the calibration temperature data; performing temperature anomaly analysis according to the calibration temperature data based on the temperature threshold, the trend threshold, the mutation mechanism and the baseline standard, and generating an anomaly analysis data packet; sending the abnormal analysis data packet to a relay gateway according to a spread spectrum technology and a check retransmission mechanism, so that the relay gateway performs data aggregation and protocol conversion processing based on an abnormal priority to obtain a transmission data packet; and triggering different temperature early warning mechanisms through the cloud platform according to the abnormality level in the received transmission data packet to realize temperature abnormality early warning. The technical problems of lack of timeliness, accuracy and remote control capability of monitoring due to lack of timeliness, weak data acquisition anti-interference capability and easy loss in the data transmission process in the prior art can be solved.
Owner:FOSHAN POWER SUPPLY BUREAU GUANGDONG POWER GRID

IRNSS navigation signal simulation generation method and system based on parameter compensation

The invention relates to an IRNSS navigation signal simulation generation method and system based on parameter compensation, and the method comprises the steps: receiving original signal data outputted by an IRNSS navigation receiver, and receiving a target machine position coordinate and a velocity vector; analyzing the navigation message to extract ephemeris parameters, and calculating the real-time position and velocity vector of the satellite; calculating a Doppler frequency compensation value and a pseudo code time delay compensation value; according to the pseudo code time delay compensation value and a preset target simulation coordinate, modifying a signal emission time field in the navigation message, generating a simulation navigation message frame, carrying out forward error correction coding processing, generating a coding symbol sequence, and carrying out modulo-two addition operation on the coding symbol sequence and a pre-generated PRN pseudo code sequence to obtain a baseband spread spectrum signal; generating an intermediate frequency carrier signal according to the Doppler frequency compensation value and the carrier phase; and modulating the baseband spread spectrum signal to the intermediate frequency carrier signal, and outputting an intermediate frequency analog signal. According to the invention, the concealment of signal simulation and the success rate of capturing the analog signal by the target receiver can be improved.
Owner:HANGZHOU LEIQING ELECTRONIC TECH DEV CO LTD

Electromagnetic compatibility integrated protection system for electric driving system of electric vehicle

The invention discloses an electromagnetic compatibility integrated protection system for an electric driving system of an electric vehicle, which relates to the technical field of electromagnetic compatibility protection and comprises a multi-dimensional parameter synchronous sampling module for acquiring an operation condition characteristic sequence of a target electric driving system in a preset time window; the space-time diagram isomorphic prediction module outputs a predicted interference frequency domain feature vector corresponding to the current control period; the collaborative anti-interference resolving module is used for respectively calculating a carrier frequency band spread spectrum instruction aiming at a bottom microcontroller and a reverse compensation injection current aiming at an active filtering loop; and the bottom hardware reconstruction execution module is used for updating a carrier frequency register of a pulse width modulation generator in the target electric driving system according to the carrier frequency band spread spectrum instruction and synchronously controlling the active filtering loop to output the reverse compensation injection current. According to the invention, the accurate pre-judgment capability of electromagnetic interference of the electric driving system of the electric vehicle and the long-term stability of full-life-cycle electromagnetic compatibility protection are improved.
Owner:LOTAN ELECTRONIC TECH (SHANGHAI) CO LTD

LoRa-based covert communication method and system

The invention relates to the technical field of low-power wide area network communication and information hiding, and discloses a LoRa-based covert communication method, which comprises the following steps of: at a transmitting end, generating a key-driven perturbation sequence according to covert information to be transmitted, constraining perturbation parameters through an undetectable controller, and transmitting the perturbation sequence to a receiving end; performing symbol-level perturbation modulation on the linear frequency modulation slope of the LoRa signal, and embedding a low-speed synchronous beacon in a preamble symbol counting tolerance range; at a receiving end, conventional data is demodulated through a standard LoRa receiving process, a frequency offset residual error, a phase residual error and a symbol fitting error after de-spreading are extracted in parallel, related detection is carried out by using a key consistent with a sending end, and hidden information is extracted from a residual error domain; the undetectability controller dynamically adjusts perturbation magnitude and embedding density based on a distribution difference metric. The objective of the invention is to solve the problem that communication reliability and hidden undetectability are difficult to guarantee at the same time in a LoRa system.
Owner:JIANGSU UNIV OF SCI & TECH

Emergency LoRa communication method based on multi-band cooperation and dynamic resource modulation

The invention relates to the technical field of wireless communication, in particular to an emergency LoRa communication method based on multi-band cooperation and dynamic resource modulation. The method comprises the following steps: S1, dynamically acquiring communication environment information, channel quality information and network load information; s2, dynamically analyzing and selecting an initial target spreading factor based on the information; s3, setting a preset factor optimization target by taking the minimum bit error rate as a target, and dynamically adjusting and obtaining a current optimal spreading factor; and S4, based on the current optimal spread spectrum factor, performing dynamic allocation of spectrum resources by adopting a dynamic channel allocation mechanism and a reinforcement learning algorithm of adaptive network load balance, and learning a network state in real time through the reinforcement learning algorithm so as to dynamically select an optimal channel allocation strategy to perform emergency communication. According to the method, communication parameters can be adaptively adjusted, the network efficiency and reliability are remarkably improved, the system capacity, the real-time performance and the robustness in a mobile scene are enhanced, and reliable communication guarantee is provided for rescue in an extreme environment.
Owner:HANGZHOU EBOYLAMP ELECTRONICS CO LTD

EMI filtering method based on dual-frequency spread spectrum and dual-frequency recombination common-mode noise cancellation waveform

The invention belongs to the technical field of EMI (Electro-Magnetic Interference) suppression, and relates to an EMI filtering method based on dual-frequency spread spectrum and dual-frequency recombination common-mode noise cancellation waveform, which comprises the following steps of: selecting a frequency as a composition frequency; enabling the EUT to work normally by taking a selected frequency as a switching PWM frequency, and obtaining common-mode noise amplitude data of multiple times of the frequency; acquiring a common-mode voltage amplitude, and calculating an amplitude transformation ratio and an amplitude of an injected offset waveform; acquiring a common-mode voltage amplitude, and calculating the phase of the injected offset waveform; injection offset waveform data is obtained through calculation, and the common-mode voltage is offset; according to the invention, common-mode noise is taken as a main scene, and common-mode suppression can be realized while the size is reduced.
Owner:XI AN JIAOTONG UNIV

A multi-service communication release response integrated time synchronization submersible system and method

This invention relates to a multi-mode communication release-response integrated time-synchronized underwater mooring system and method, and relates to the fields of underwater acoustic communication networks and underwater positioning and navigation technology. The purpose of this invention is to solve the problems of poor reusability of existing underwater mooring systems in complex and diverse application scenarios, the insynchrony of time among mooring nodes making it impossible to coordinate data aggregation or communication reporting tasks at precise times, resulting in single-function underwater mooring equipment, low resource utilization, and large reference time errors. The system includes multiple dual-master control mooring communication units and an external battery compartment, integrating spread spectrum communication, OFDM communication, multiple orthogonal response, atomic clock timekeeping, release control, and positioning functions; it achieves time synchronization and local timekeeping through 1PPS signals and GPRMC information or absolute time information; after deployment, each node completes multi-mode signal reception and response according to a preset mode, and serves as a positioning anchor point to achieve platform positioning through a long baseline positioning algorithm; after the task is completed, it is released and surfaced under control.
Owner:HARBIN ENG UNIV

A shared codebook multiple access transmission method without user identification approaching the theoretical capacity in finite fields

The present invention discloses a method for multiple access transmission with a shared codebook without user identification (URA) that approaches the theoretical capacity under a finite field. The source data of each user terminal is encoded according to the encoding method proposed by the present invention, and the signal is transmitted according to the disclosed sending method. The multi-user signal is dispersed in several subframes. The disclosed encoding and sending methods can construct subframe signals with strong noise resistance. The disclosed decoding method completes the detection and estimation of the active sequence codeword channel state information based on the signal transmission energy and noise statistical information estimation and the pre-stored spread spectrum sequence codebook, and performs soft demodulation and decoding on the state information of the subframe time slot. In addition, the recovered information obtained by parity check is reused for serial interference elimination, and this iterative operation can improve system performance. Under a finite field, the above scheme improves the user capacity of multi-antenna multiple access and approaches the theoretical capacity of multi-antenna without user identification shared codebook multiple access.
Owner:SOUTHEAST UNIV

Downhole fault detection in well system using spread spectrum time domain reflectometry (SSTDR)

Systems, methods, and apparatus, including computer programs encoded on computer-readable media, for downhole fault detection in a well system are disclosed. A spread spectrum time domain reflectometry (SSTDR) apparatus of the well system may transmit an SSTDR signal downhole via a well electrical cable of the well system and receive a reflected SSTDR signal. The SSTDR apparatus may determine whether a downhole fault exists in the well electrical cable or in a well device based on a signal analysis of the reflected SSTDR signal and the transmitted SSTDR signal. The SSTDR apparatus may also use historical SSTDR data and a machine learning algorithm for downhole fault detection and analysis. When a downhole fault is detected, the SSTDR apparatus also may determine a type of the downhole fault and a location of the downhole fault, such as the depth downhole of the downhole fault.
Owner:HALLIBURTON ENERGY SERVICES INC

Spread spectrum and time-digital conversion coordinated underwater communication measurement system and method

PendingCN121333407ATelemetry/telecontrol selection arrangementsFree-space transmissionUnderwater wireless optical communicationsSpread spectrum
The invention relates to a spread spectrum and time-digital conversion cooperative underwater communication measurement system and method, belongs to the technical field of underwater wireless optical communication, and solves the technical problems of limited communication rate and insufficient positioning precision in an underwater complex environment. The measurement system comprises a master-end underwater wireless optical communication machine and a slave-end underwater wireless optical communication machine, each of the master-end underwater wireless optical communication machine and the slave-end underwater wireless optical communication machine comprises an optical transmitting unit, an optical receiving unit, a signal processing unit, an upper computer and a shell. And the optical transmitting unit, the optical receiving unit and the upper computer are respectively connected with the signal processing unit. The optical transmitting unit, the optical receiving unit and the signal processing unit are arranged in the shell, and the upper computer is arranged outside the shell. The measurement method comprises the steps of system initialization and link establishment, communication and time service synchronization, distance measurement signal triggering and transmitting, and distance calculation and display. The method is used for underwater robot collaborative operation, ocean monitoring and deep sea detection.
Owner:XIAN INST OF OPTICS & PRECISION MECHANICS CHINESE ACAD OF SCI

System, method, device, processor and storage medium thereof for realizing bidirectional radio frequency signal source output of millimeter wave vector network analyzer

This invention relates to a system for realizing bidirectional RF signal source output of a millimeter-wave vector network analyzer. The system includes a vector network analyzer main unit, a main unit port output channel, a rear panel output channel, and a signal switching and control unit. The vector network analyzer main unit has a built-in main RF signal source, and the RF signal output from the main RF signal source is output from the front test port of the vector network analyzer main unit. The rear panel output channel outputs the RF signal output from the main RF signal source from the rear auxiliary RF port of the vector network analyzer main unit. The system, method, apparatus, processor, and computer-readable storage medium of this invention for realizing bidirectional RF signal source output of a millimeter-wave vector network analyzer improve high-frequency measurement performance. By using the spread spectrum module as a remote test head closer to the DUT, it reduces the loss and error of long cables, increases testing flexibility, and enables switchable RF signal source output paths, meeting the needs of various testing scenarios.
Owner:TRANSCOM INSTR

Systems and methods for enhanced multipath identification

Some implementations herein relate to a device that receives and processes multiple spread spectrum signals corresponding to multiple linear frequency modulated (LFM) signals, including multipath LFM signals having directly and indirectly received signal components. Based on the transmission times and transmission locations of the multiple spread spectrum signals and the multiple LFM signals, the device can estimate the location of the device, the time the device was at a location, the arrival times of the directly and indirectly received signal components, and the time difference of arrival between the arrival times of the directly and indirectly received signal components. Based on the transmission locations, the device location, and the time difference of arrival, the device can estimate a range to a surface relative to the device location.
Owner:TRUSTPOINT INC

Cable aging on-line monitoring method and device based on spread spectrum time domain reflection method

PendingCN122449285ATime domainFeature vector
The application provides a cable aging online monitoring method and device based on a spread spectrum time domain reflection method, which comprises the following steps: establishing a frequency-variable distribution parameter model based on the physical structure of a cable, performing background noise spectrum scanning on the cable to identify a spectrum hole, and taking the spectrum hole as a working frequency band of a detection signal; generating a detection signal matched with the working frequency band, and injecting the detection signal into a live cable; collecting echo signals of the cable, performing adaptive signal decomposition on the echo signals to obtain purified echoes, performing cross-correlation operation on the purified echoes and the detection signal, and extracting reflection response features; performing phase dispersion compensation on the reflection response features to obtain dispersion-corrected reflection responses; extracting multi-dimensional feature vectors of the dispersion-corrected reflection responses, inputting the multi-dimensional feature vectors into a physical information neural network, and inversely obtaining insulation aging quantitative indexes and cable aging grades of each position of the cable.
Owner:SHANGHAI NUCLEAR ENGINEERING RESEARCH & DESIGN INSTITUTE CO LTD

Spread spectrum receiver and test method

The invention relates to a spread spectrum receiver and a test method. A method of characterizing a LoRa modulated signal or any such signal having multiple chirps as symbols. It foresees: sampling and storing the signal, determining the phase of at least one chirp in the signal, and determining a timing error and / or a frequency error based on the phase, the timing error being extracted by the height of the discontinuity jump in the phase at the cyclic shift position, and the frequency error being obtained by the slope of the phase. The method can be applied to a dedicated receiver for characterizing a LoRa transmitter.
Owner:SEMTECH CORP

An information sensing and transmission system for a new energy base

PendingCN122395284AData packPropagation delay
The application discloses a new energy base-oriented information sensing and transmission system and relates to the technical field of power Internet of Things.The system comprises an edge convergence gateway and a plurality of sensing terminal nodes.The edge convergence gateway constructs a dynamic topology according to micro-meteorological vector data, selects a cluster head node at the upstream of physical field propagation, calculates and issues a theoretical envelope delay parameter, and the sensing terminal node uses a perturbation signal modulated by an orthogonal pseudo-random spread spectrum code and the parameter to complete phase alignment, uses the parameter to perform space-time compensation and predicted waveform construction on received cluster head reference data, calculates a numerical residual error between a local waveform and a predicted waveform, quantitatively encodes sparse residual errors to generate an upper report data packet.The application eliminates the physical field propagation delay caused by spatial distribution, effectively reduces the differential data energy, and solves the problem of real-time and efficient transmission of high-frequency waveforms under limited bandwidth.
Owner:HUANENG ZHANHUA NEW ENERGY LTD CO