304results about "Frequency-modulated carrier systems" patented technology

The invention discloses a distribution network power line anti-interference communication method based on adaptive filtering, and belongs to the technical field of distribution network power line communication. According to the method, a communication signal adopting a frequency shift keying modulation mode is acquired from a power line coupler of a distribution network through a signal acquisition module, the communication signal is preprocessed by using a digital signal processing unit, spectral analysis is performed on the preprocessed signal, and characteristic parameters of interference noise are extracted; a coefficient vector of a finite impulse response adaptive filter is initialized based on the characteristic parameters, the order of the filter is in direct proportion to the reciprocal of the dominant interference frequency, fine adjustment is carried out based on noise energy distribution through a table look-up method or a linear mapping relation, and the weight coefficient of the filter is adjusted in real time in the communication process. The adjustment step length is dynamically adjusted according to the real-time estimated signal-to-noise ratio, and finally, the processed signal is output through the adaptive filter and data demodulation is carried out. The method is mainly used for improving the anti-interference capability and the communication reliability of the power private line communication of the distribution network.

A device for transmission of wireless power according to an embodiment of the present specification comprises: a power conversion circuit for transmitting the wireless power to a wireless power receiving device; and a communication / control circuit for communicating with the wireless power receiving device and controlling the wireless power, wherein the communication / control circuit transmits a response to a reception data packet received from the wireless power receiving device or a transmission data packet transmitted to the wireless power receiving device on the basis of a timeout period, and the timeout period is changed according to a communication speed between the communication / control circuit and the wireless power receiving device.

Embodiments of the present disclosure provides a method for wireless communication and an apparatus, which can enable paging for ambient internet of things (IoT) devices. The method for wireless communication includes receiving, by a first communication device, a paging message. Optionally, the first communication device is an ambient IoT device or a zero-power device.

The invention discloses a data scrambling method and device, a data descrambling method and device, equipment and a storage medium, and belongs to the technical field of communication. The data scrambling method executed by the first device comprises the steps that the first device determines a first transmission state from a plurality of transmission states of data transmission, the plurality of transmission states and a plurality of scrambling modes have a corresponding relation, and the scrambling mode corresponding to the transmission state is associated with data modulation adopted by the transmission state; the first device determines a first scrambling mode corresponding to the first transmission state; and the first device scrambles the first data to be transmitted in the first transmission state by using the first scrambling mode to obtain the second data. In the embodiment of the invention, the data transmission has a plurality of transmission states, and the plurality of transmission states have corresponding scrambling modes, so that the first data can be scrambled by using the corresponding first scrambling mode based on the current first transmission state, and the flexibility is high.

The invention provides a handheld radio multi-mode signal rapid detection method and system, and relates to the technical field of radio, and the method comprises the steps: collecting a radio frequency signal, and carrying out the down-conversion to obtain a baseband signal; digitally sampling to obtain a digital signal sample; time domain and frequency domain features are extracted through convolution kernels of different scales based on a deep learning network; determining a modulation mode and selecting a demodulation scheme, and automatically switching to an alternative scheme when the performance of a main demodulation scheme is poor; and comparing the demodulated signal with a signal feature library to determine and display the signal type. According to the invention, the multi-mode signal detection efficiency and accuracy are improved, and the equipment complexity is reduced.

A system and a method includes receiving, by an ambient Internet of Things (A-IoT) device, an energizing signal; receiving, by the A-IoT device, a paging message from a network node, the paging message including one or more configuration parameters, determining a resource for a random access transmission from the A-IoT device using the one or more configuration parameters in the paging message, and transmitting, by the A-IoT device, a random access transmission to the network node in response to the paging message

Various embodiments of this disclosure relate to generation and reception of signals comprising cyclically shifted basis functions. A device may obtain a set of modulation symbols and modulate a plurality of basis functions based on the set of modulation symbols to generate a signal. The plurality of basis functions may comprise cyclically shifted versions of a basis function and a periodic autocorrelation function of the basis function may comprise an ideal (e.g., perfect) periodic autocorrelation function.

The invention discloses a circuit and a method for demodulating current received by an instrument bus host, and relates to the technical field of instruments. The current demodulation circuit comprises an adder, the first input end of the adder is connected with an instrument bus MBUS to receive MBUS signals, the second input end of the adder receives reference voltage signals, and the output end of the adder outputs summing voltage signals; the resistor and capacitor charging and discharging device is connected with the output end of the summator so as to process the summing voltage signal; and the reverse input end of the comparator receives the MBUS signal, and the positive input end of the comparator receives the summing voltage signal processed by the resistor-capacitor charging and discharging device so as to determine the logic level corresponding to the MBUS signal based on the signal level of the output end of the comparator. According to the invention, the problem that the MBUS host receiving circuit cannot be compatible with all MBUS meters is solved.

System and method for an over-the-air computation (AirComp) scheme for federated edge learning (FEEL) doesn't require channel state information (CSI) at the edge devices (EDs) or edge server(ES). The disclosure adopts the majority vote (MV) principle and defines multiple subcarriers and orthogonal frequency division multiplexing (OFDM) symbols for voting options, which reduces to frequency-shift keying (FSK) over OFDM subcarriers as a special case. Thus, FSK-based over-the-air computation is provided for federated edge learning without channel state information. Since the votes from EDs are separated on orthogonal resources, the scheme eliminates the need for truncated-channel inversion (TCI) at the EDs and allows the ES to detect MV with a non-coherent detector.

Systems include a receiver configured to detect signals corresponding to a stream of digital symbols, a signal demodulator coupled to the receiver and configured to process an incoming stream of digital symbols, and a computing device connected to the receiver and to the signal demodulator, and featuring a set of software instructions that, when executed by the computing device, causes the computing device to determine an estimated time delay associated with the stream of digital symbols, transmit control instructions to the signal demodulator to configure the signal demodulator according to the estimated time delay, and process at least a second subset of the stream of digital symbols using the configured signal demodulator.

A signal folding device receives an input signal, and performs frequency modulation on a plurality of first analog signals based on the input signal to obtain a plurality of modulated first analog signals, where a frequency difference between two adjacent first analog signals in the plurality of modulated first analog signals is the same. The signal folding device may filter the plurality of modulated first analog signals based on a specified bandwidth to obtain a second analog signal, and demodulate the second analog signal to obtain an output signal. The output signal is a folded signal of the input signal within a target amplitude, and the second analog signal is an analog signal within the bandwidth.

This application belongs to the communication field, and discloses a communication method, an apparatus, a system, and a storage medium. The method includes: A first node generates a first signal to be sent to a second node, where a first frequency resource is used for the first signal; the first frequency resource is adjacent to a second frequency resource; the second frequency resource is used for transmitting a signal to be sent to the second node and the signal transmitted on the second frequency resource is different from the first signal, or the second frequency resource is not used for transmitting a signal; and a width of the second frequency resource is greater than or equal to a width of the first frequency resource. The first node sends the first signal. This application can reduce communication costs.

Methods, systems, and devices for wireless communications are described. A first wireless device may identify a set of data resource elements for transmitting data in one or more symbols periods. The first wireless device may generate, for the one or more symbol periods based on the set of data resource elements, a sequence of a set of pilot resource elements associated with the set of data resource elements, the sequence of the set of pilot resource elements including a demodulation reference signal. The first wireless device may transmit, to a second wireless device in the one or more symbol periods, the set of data resource elements and the set of pilot resource elements. The second wireless device may decode a first subset of the set of pilot resource elements based on a second subset of the set of pilot resource elements to determine the demodulation reference signal.

The present disclosure provides a method and apparatus for transmitting and receiving signals in a wireless communication system. According to the method and apparatus, a low-power wake-up signal (LP-WUS) may be received through a first receiver, and a second receiver may be triggered based on the reception of the LP-WUS. A length L_w of an on-off keying (OOK) symbol of the LP-WUS is determined based on (i) a length N_ofdm of an orthogonal frequency division multiplexing (OFDM) symbol, (ii) a length N_cp of a cyclic prefix (CP) duration of the OFDM symbol, and (iii) a number N of OOK symbols corresponding to the length of the OFDM symbol.

The invention provides an industrial field instrument communication system, an industrial field instrument and a communication method thereof. The industrial field instrument communication system comprises: a processing unit for processing sensor data and generating a main process variable; the analog output module is connected with the processing unit and used for converting the main process variable into an analog current signal of a first specification and outputting the analog current signal to a two-wire system current loop; the HART modulation-demodulation module is used for superposing a low-frequency FSK digital signal on the analog current signal; the digital communication module is connected with the processing unit and comprises a physical layer adaptation unit, and the physical layer adaptation unit is used for supporting at least two Ethernet physical layer standards with different electrical specifications and rates; wherein the analog current signal and the Ethernet digital communication signal of the digital communication module can be simultaneously and independently transmitted on respective physical media. The industrial field instrument communication system disclosed by the invention can be compatible with Ethernet communication while reserving the existing infrastructure.

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.

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.

Systems include a receiver configured to detect signals corresponding to a stream of digital symbols, a signal demodulator coupled to the receiver and configured to process an incoming stream of digital symbols, and a computing device connected to the receiver and to the signal demodulator, and featuring a set of software instructions that, when executed by the computing device, causes the computing device to determine an estimated time delay associated with the stream of digital symbols, transmit control instructions to the signal demodulator to configure the signal demodulator according to the estimated time delay, and process at least a second subset of the stream of digital symbols using the configured signal demodulator.

This invention discloses a method and system for detecting low signal-to-noise ratio periodic linear frequency modulated (LFM) continuous wave signals, relating to the fields of radio target monitoring and spectrum management. The method includes: detecting periodic components in the data to be detected; if periodic components exist, recording period estimates based on these components; determining two adjacent observation windows based on the difference between the period estimates and the delay, and the delay itself; dividing the data to be detected into P consecutive groups of data using the period estimates; using a sampling point as the starting position of a step-size sliding observation window, performing piecewise discrete polynomial transformation and spectrum calculation on the data to be detected corresponding to each step-size sliding observation window, thereby detecting the periodic LFM continuous wave signal; when the detection result indicates the presence of a periodic LFM continuous wave signal, determining the modulation slope and modulation inflection point position of the signal. This invention effectively improves the detection capability for weak periodic LFM continuous wave signals.

A wireless communication system provides a baseband signal processing circuit configured to sample a baseband signal at twice a baseband frequency to produce an upsampled signal that provides a sequence of samples of the baseband signal at twice the baseband frequency; and combine each sample within the upsampled signal with a preceding sample within the upsampled signal to produce a modified baseband signal that provides a sequence of modified symbols at twice the baseband frequency; a modulator circuit coupled to modulate frequency of a carrier signal based upon symbol values of symbols within the modified baseband signal to produce a frequency modulated carrier signal; and an antenna coupled to transmit the modulated carrier signal.

The present disclosure discloses a method, apparatus, a device and a storage medium for signal demodulation. The method includes: acquiring at least two frames of message signals of a target balise; superimposing a current signal with a preset number of previous frames of signals adjacent to the current signal based on a synchronization algorithm to obtain a target signal, wherein the current signal is a message signal of any frame of the at least two frames of message signals of the target balise except the preset number of previous frames of message signals; and demodulating the target signal. By means of the solutions according to the present disclosure, it is possible to exploit the characteristics of the cyclical and repetitive transmission of the same message signal of the balise, and by accumulating currently received signal and signals received at the same position in previous frames after applying bit synchronization techniques, the signal-to-noise ratio is improved and the success rate of a signal being correctly demodulated is improved, i.e., the performance of BTM to receive messages of the balise is improved.

The invention discloses a signal transmission method and device, communication equipment and a readable storage medium, and belongs to the technical field of communication, and the signal transmission method comprises the steps that first equipment carries out backscattering modulation according to a to-be-transmitted information bit and a second signal to obtain a first signal; wherein the second signal is a carrier signal of the first signal; the first signal comprises at least one first signal unit, each first signal unit comprises two chirp spread spectrum CSS symbols, the average powers or reflection coefficients of the two CSS symbols are different, and other parameters, except the average powers and the reflection coefficients, of the two CSS symbols are the same; the information bits to be transmitted are modulated through the frequency of each CSS symbol in each first signal unit; and sending the first signal.

The application discloses a kind of detection communication integrated collision avoidance sonar signal design method and device, its method includes: modulating continuous frequency phase shift keying signal CFPSK, generates initial frequency and Chirp signal;Modulate continuous frequency phase shift keying signal, BPSK signal is modulated to Chirp by phase modulation two-way, then two-way signal is added, obtains final transmitting signal;After CFPSK signal is pulse width modulated, it is emitted by the transducer of collision avoidance sonar;Collecting collision avoidance sonar original echo signal, obtains original echo data;Original data collected is preprocessed, and two-way signal of virtual and real is obtained;Signal is compressed into short pulse bandwidth signal, generates the impulse response parameter of two groups of matched filters, each group is matched with virtual and real two-way signal to obtain four groups of matching results, and the final matching output is obtained from real number field to complex number field;The starting point of CFPSK signal is determined by detecting the peak position of matched filter output, and echo signal is accurately intercepted from received signal for communication decoding, and coherent detection is carried out on received signal and reference carrier.The application realizes the cooperative work of detection and communication function.

This innovation presents a novel method for both linear time-varying channel estimation and low complexity sensing in Orthogonal Frequency Division Multiplexing (OFDM) systems by leveraging repeated chirp signals (CS). By integrating chirps orthogonally within a single OFDM symbol in frequency domain, the method enables simultaneous estimation of channel coefficients, delay, and Doppler shifts while facilitating environmental sensing. The repetition of chirps in time creates a sparse distribution in the frequency domain, and the number of repeated chirps within each OFDM symbol determines the number of subcarriers allocated in the frequency domain, with the remaining subcarriers dedicated to OFDM data (D) which ensure seamless data (D) transmission, environmental sensing, and channel estimation.

The present application belongs to the technical field of communications. Disclosed are a signal transmission method and apparatus, and a communication device and a readable storage medium. The signal transmission method in the embodiments of the present application comprises: a first device modulating an information bit to be transmitted, so as to obtain a first signal, wherein the first signal is obtained by adding a first part and a second part, the first part is a signal obtained by performing frequency shifting of a first frequency and filtering on a second signal, the second part is a signal obtained by performing frequency shifting of a second frequency and filtering on the second signal, the frequency shift directions of the first part and the second part are opposite, the sum of the first frequency and the second frequency is equal to the bandwidth size of the second signal, the first frequency and the second frequency form a frequency pair associated with said information bit and used for frequency shifting, and the first signal is a backscatter modulation signal of the second signal; and sending the first signal.

The invention relates to a well-ground two-way communication method and device based on mixed dipole cooperation, and the device comprises an uplink communication device which is configured to carry out the coding and modulation of collected underground data through an underground transmitting device, transmits a modulated first time-varying electromagnetic field signal to a ground medium, and at the same time, transmits a second time-varying electromagnetic field signal to a ground medium; receiving the first time-varying electromagnetic field signal by using a first magnetometer, and decoding the received first time-varying electromagnetic field signal to realize underground data uploading communication; and the downlink communication device is configured to code and modulate a control instruction to be downloaded by using the ground transmitting device, transmit a modulated second time-varying electromagnetic field signal to the earth medium, receive the second time-varying electromagnetic field signal by using a second magnetometer, decode the received second time-varying electromagnetic field signal, and transmit the decoded second time-varying electromagnetic field signal to the ground medium. And control instruction downloading communication is realized. The method can be widely applied to the technical fields of oil and gas well engineering, measurement and control while drilling and underground communication.

The invention relates to the technical field of radar remote sensing measurement, in particular to a method and a system for measuring snow thickness by using a dual-carrier-frequency interference radar. The method comprises the following steps: generating a linear frequency modulation signal, respectively modulating the linear frequency modulation signal to a first carrier frequency channel and a second carrier frequency channel, and synchronously transmitting the linear frequency modulation signal to a snow area; synchronously receiving echo signals of the two channels, and respectively carrying out carrier frequency removal and dechirp processing on the echo signals of the two channels to obtain baseband echo signals of the two channels; respectively converting the baseband echo signals of the two channels into a frequency domain, executing high-order phase removal processing, and then converting the baseband echo signals back to a time domain to obtain high-order phase removal time domain echo signals of the two channels; performing interference operation on the high-order phase removed time domain echo signals of the two channels to obtain an interference baseband signal between the two channels; and carrying out distance compression on the interference baseband signal to obtain an echo frequency spectrum and then carrying out parameter estimation so as to output a measurement result of the snow thickness corresponding to the distance difference between the snow surface and the underlying interface.

The application discloses a digital SPWM modulation method, comprising the following steps: 1) sampling a modulation wave to obtain a sampling value x As input data, the discrete lead transfer function is used to obtain the estimated value at the nearest peak of the lead; the modulation wave is sampled to obtain a sampling value; as input data, the discrete lag transfer function is used to obtain the estimated value at the nearest peak of the lag; 2) using the estimated values at the nearest peaks before and after the sampling value and the current sampling value, the intersection of the modulation wave and the carrier wave is solved by using the similar relationship of the triangle; 3) using the period of the carrier wave and the intersection relationship, the duty ratio in the carrier wave period is solved. The modulation method has small calculation amount compared with the natural sampling method and high accuracy compared with the symmetrical method.

The application provides a blind demodulation analysis method of a signal, a chip, a remote control device and a storage medium. The method comprises the following steps: determining the center frequency of a target signal through a bandwidth scanning strategy; performing mixing processing and analog-to-digital conversion on the target signal to obtain an I-path intermediate frequency digital signal and a Q-path intermediate frequency digital signal, so as to determine the amplitude of the target signal; determining the modulation mode of the target signal according to the change of the amplitude of the target signal within a preset time length; if it is determined that the modulation mode is OOK, determining the amplitude mean value of the target signal, and demodulating the target signal according to the size relationship between the amplitude of the target signal and the amplitude mean value to obtain a baseband signal; if it is determined that the modulation mode is 2FSK, determining the frequency offset estimation mean value and the frequency offset of the target signal, and demodulating the target signal according to the size relationship among the frequency of the target signal, the center frequency of the target signal and the frequency offset estimation mean value to obtain the baseband signal; and performing frequency measurement on the baseband signal to determine the symbol rate.