36 results about "Multi carrier modulation" patented technology

The invention provides a multi-carrier modulation and calculation method for cross-water-air communication. Signals which are subjected to 8B / 10B coding serial-parallel conversion and modulation are sent out through an underwater acoustic transducer, vibration of the water surface is triggered, and after a millimeter wave radar is used for extracting and resolving water surface vibration signals, transmitted information is obtained. According to the invention, the number of coexisting carriers can be reduced, and the power of a single carrier is improved, thereby increasing the transmission distance. The preamble and the prefix are used, so that a receiving end can obtain the time when information arrives and compensate for amplitude attenuation and frequency change generated in the process that sound signals are propagated in water, and therefore the error rate is reduced.

The invention discloses a multi-time slot MAMP receiver and coding method for an MIMO multicarrier modulation system, comprising a time domain linear estimation module gamma l (.) and a symbol domain nonlinear estimation module phi l (.), where l represents the number of iterations; the time domain linear estimation module adopts a matched filter to recover the received time domain signal to obtain an estimated value of the time domain signal; transforming the estimated value into a symbol domain through unitary transformation; and the symbol domain nonlinear estimation module calculates a log-likelihood ratio of each symbol and calculates an estimated value of each symbol through estimation of the symbol domain returned by the time domain linear estimation module. According to the method, the optimal MSE detection performance can be realized with extremely low complexity in a multi-time-slot transmission scene.

The invention provides a multi-carrier modulation-based common-inductance integrated waveform design method and system, and belongs to the technical field of multi-carrier communication. The method comprises the following steps: constructing a mapping relationship between different service types and waveform parameters; determining a waveform parameter of the subcarrier according to the current service type and the performance index requirement corresponding to the service type, and adjusting the waveform parameter; determining the total number of subcarriers according to the network mode and the service type; performing state detection on the communication channel by taking the total number of the subcarriers as the maximum number of the subcarriers so as to adjust waveform parameters of the subcarriers; and based on the adjusted waveform parameters of the subcarriers, synthesizing a flux-inductance integrated waveform. According to the invention, analysis of communication and sensing tasks can be carried out at the same time based on the same hardware, and dynamic adjustment of subcarrier related parameters and number is realized so as to meet the requirements of different application scenarios on transmission waveforms.

The invention provides a phase-sensitive optical time domain reflectometer system and method, and the system comprises a first polarization-maintaining coupler which is used for dividing laser generated by a DC laser, and obtaining first laser and second laser; the optical fiber measurement front-end module is used for processing the random signal through pulse shaping and multi-carrier modulation technologies to generate an electric signal, and sequentially performing modulation, amplification, Rayleigh scattering and amplification on the first laser after the electric signal is generated to obtain amplified Rayleigh backscattered light; the second polarization-maintaining coupler is used for dividing the second laser to obtain third laser and local oscillation light; the delay optical fiber is used for processing the third laser to obtain delay light; the third polarization-maintaining coupler is used for combining the delayed light and the amplified Rayleigh backscattered light to obtain combined light; the receiver is used for processing the combined light and the local oscillation light to obtain multiple paths of target electric signals; and the oscilloscope is used for processing multiple paths of target electric signals through low-pass and high-pass filters and a phase noise compensation algorithm so as to determine power and phase distribution. The system cost can be reduced.

A wireless communication method and a device are provided. The wireless communication method includes: a first communication device receives a carrier signal generated based on multi-carrier modulation, wherein the carrier signal is used for power supply to the first communication device, and / or the carrier signal is used for the first communication device to generate a backscattered signal by modulation.

A system and method for monitoring by optical fiber for the measurement of vibrations an object / structure includes the optical fiber associated with the object / structure and one end connected to a circulator and a terminated opposite end, a source of symbols emitting sequence of NS input signals and configured to generate an input vector, a multi-carrier OFDM modulation block adapted to modulate a light beam emitted by a laser source by an OFDM modulating signal to determine a sensing signal with NC subcarriers, the modulating signal OFDM being generated on the basis of the input vector; the circulator adapted to send the sensing signal to the optical fiber and to receive a backscattered signal; an OFDM demodulation block; and a processing unit that processes the output and input vectors, on the basis of respective Nc reference vectors of the optical fiber, generating a deformation vector.

According to the navigation and communication signal integration method provided by the invention, aiming at a conduction integration signal system application scene, the positioning precision and the anti-multipath capability are selected as evaluation indexes, and the navigation and communication integration signal precision and performance are analyzed and evaluated based on the performance theoretical limit. By combining the characteristics of a communication signal and a navigation signal, taking compatibility of the communication signal and the navigation signal as a starting point and adopting a burst multicarrier modulation mode, a navigation signal, namely a burst multicarrier signal (BCC signal) which can be broadcasted in a time slot of a communication channel and is compatible with multiple communication systems is constructed. Mi subcarriers are modulated on a single frequency point of a signal source i, the frequency interval between the subcarriers is fixed, the signal duration is adjustable, the subcarriers have burst characteristics, each subcarrier is modulated with the same pseudo code, meanwhile, the signal power of each subcarrier can be adjusted according to needs, and finally, the signals of the Mi subcarriers are combined together and transmitted out. Different pseudo codes are used for representing different signal sources.

The present invention discloses a low-complexity peak-to-average power ratio (PAPR) suppression method for multi-carrier modulation signals based on ADMM, belonging to the field of wireless communication. The method includes: introducing phase shifts to each sub-carrier in the signal transmission frequency domain of the multi-carrier modulation system; obtaining the time-domain waveform through oversampling and mathematically modeling the PAPR to obtain an optimization problem; in the Lagrangian function of the optimization problem, fixing the phase factor and the Lagrange multiplier, and then optimizing the optimization objective; fixing the optimization objective and the Lagrange multiplier of this optimization problem and using the fast Fourier transform (FFT) to optimize the phase factor; updating the Lagrange multiplier according to the optimized optimization objective, phase factor and constraint conditions, and iterating repeatedly until convergence, and optimizing the PAPR of the multi-carrier modulation through the optimized phase factor. The PAPR suppression method of the present invention has good PAPR optimization effect and low computational complexity.

The present invention discloses a multi - carrier modulation scheme for reconstructing orthogonal chirp multiplexing signals based on the KK relationship. By constructing a single - sideband OCDM modulation signal and using digital up - conversion technology, the real part and the imaginary part of the frequency - converted OCDM signal satisfy the Kramers - Kroning relationship. At the receiving end, a KK receiver is adopted to reconstruct the real - part and imaginary - part information of the OCDM signal, ultimately improving the receiving sensitivity of the communication system.

The invention discloses a filter bank multicarrier modulation and orthogonal time-frequency modulation combined system of a low-altitude communication sensing system, and the system is characterized in that an inverse symplectic Fourier transform module is used for receiving a first sending signal of a time delay-Doppler domain, and carrying out the inverse symplectic Fourier transform of the first sending signal, and obtaining a second sending signal of a time-frequency domain; the first multi-carrier modulation module is used for performing multi-carrier modulation on the second sending signal through the filter bank to obtain a receiving signal; the communication receiving end is used for acquiring a vector estimation signal of the received signal by adopting an iterative maximum ratio combination method on the received signal; the sensing receiving end is used for acquiring an optimal sensing target parameter of the received signal by adopting a two-stage mode search algorithm on the received signal; the second multicarrier modulation module is used for carrying out multicarrier modulation on the vector estimation value through a filter bank to obtain an estimation signal of a time-frequency domain; and the symplectic Fourier transform module is used for performing symplectic Fourier transform on the estimation signal to obtain a final signal vector estimation value.

The application discloses a kind of adaptive QAM and OFDM bimodulus intracorporeal ultrasonic communication system and method based on channel estimation, belong to intracorporeal ultrasonic communication technical field, the transmitting end is configured with single carrier QAM modulation mode and multicarrier OFDM modulation mode, real-time evaluation intracorporeal ultrasonic channel quality in receiving end, according to the optimal modulation mode of evaluation result, according to the optimal modulation mode generation mode switching instruction, the mode switching instruction is sent to transmitting end, transmitting end according to the mode switching instruction seamlessly switches between single carrier QAM modulation mode and multicarrier OFDM modulation mode, so that transmitting end works in optimal modulation mode, the system and method can dynamically select optimal modulation mode according to intracorporeal channel real-time quality parameter, while ensuring that mode switching is reliably synchronized.

The invention discloses an interference equalization method, device and equipment for multi-carrier modulation in a high-dynamic scene and a storage medium, and relates to the technical field of mobile communication, and the method comprises the steps: obtaining a time domain channel matrix of a time-frequency double-color dispersion channel, and determining an inversion core matrix in a minimum mean square error equalization matrix based on the time domain channel matrix; based on the sparsity structure of the inversion core matrix, decomposing the inversion core matrix to obtain a decomposition matrix; based on the time domain channel matrix, the inversion core matrix and the decomposition matrix, determining a multilayer linear equation set with minimum mean square error equalization; and solving the multi-layer linear equation set to obtain an equalization result. By means of the mode, the calculation complexity of the equalization process in the process of resisting inter-symbol interference and inter-carrier interference existing in multi-carrier modulation in a high dynamic scene is remarkably reduced, excellent performance is still kept under the extreme condition that no cyclic prefix exists or the length of the cyclic prefix is zero, and high scene adaptability and system practicability are embodied.

A multi-static radar detection system for a vehicle includes one or more receivers for collecting multi-carrier modulation signals emitted by one or more transmitters that are positioned at base stations located in an environment surrounding the vehicle. The multi-carrier modulation signals include one or more types of reference signals. The multi-static radar detection system also includes one or more controllers in electronic communication with the one or more receivers. The one or more controllers execute instructions to collect, by the one or more receivers, a multi-carrier modulation signal emitted by the one or more transmitters. The one or more controllers determine a Doppler shift and a time delay of a respective object located within the environment surrounding the vehicle based on an interpolated time-frequency grid; and transform a value for the Doppler shift into a velocity value and a value for the time delay into a range value.

This invention relates to the field of smart meter communication data acquisition technology, and discloses a method for anti-interference data acquisition in smart meter communication based on multi-carrier modulation technology. The method includes using multi-carrier modulation to perform frequency division processing on the signal during data transmission, combining channel state perception and dynamic subcarrier allocation strategies to avoid interference frequency bands in real time, and enhancing data robustness through time-frequency joint coding. This application can effectively suppress narrowband interference and impulse noise, improving the communication reliability and data acquisition accuracy of smart meters in complex electromagnetic environments.

The invention discloses a signal recovery method assisted by spatial modulation and space-time codes, which comprises the following steps of: 1, performing spatial modulation on information bit stream groups according to the number of time slots and the number of carriers to obtain spatial modulation symbols; 2, mapping the spatial modulation symbols into a space-time coding structure; 3, performing orthogonal time-frequency-space multi-carrier modulation on the spatial modulation symbols with the same transmission period, and transmitting the data symbols on a plurality of transmitting antennas respectively; and step 4, carrying out signal detection recovery on the transmission data symbols obtained in the step 3 based on the special sparsity of the signal structure. The method is used for recovering various source end signals which cannot be directly measured, high transmission rate and high diversity gain are realized, and the problems of poor signal detection performance and relatively high calculation complexity in the signal recovery process of a multi-antenna multi-carrier system are solved.

The invention relates to a communication and navigation integrated signal processing method for a low-orbit satellite. The method comprises the following steps: step 1, establishing a system model and designing an ICAN waveform; step 2, transmitter ICAN resource mapping and communication-navigation joint modulation; step 3, receiver communication-navigation joint demodulation; step 4, calculating communication capacity and navigation positioning precision; 5, constructing a communication-navigation combined utility index and solving a waveform parameter; the method has the advantages that various multi-carrier modulation and pseudo-random codes can be well compatible, and time-frequency resources and hardware overhead are saved by providing a framework and a normal form of a communication and navigation integrated waveform; the communication-navigation combined utility index provided by the invention can directly reflect the integrated performance compared with the independent use of a single function index, and is more intuitive and efficient compared with separate measurement; by maximizing the proposed integrated utility index, the optimal waveform parameter can be obtained, and better communication and navigation performance can be obtained under limited time-frequency resources.

The application discloses a multi-carrier signal receiving method and system based on a layered power regulation neural network, relates to the technical field of communication signal processing, and comprises the following steps: acquiring a multi-carrier modulation signal, performing frequency domain transformation on the multi-carrier modulation signal to obtain a time-frequency grid representation, acquiring global power information and local power information based on the time-frequency grid representation, inputting the global power information and the local power information into a neural network model established in advance to obtain a processed neural network model, inputting the time-frequency grid representation into the processed neural network model to generate a feature representation used for symbol decision, performing symbol decision on the multi-carrier modulation signal based on the feature representation, and obtaining a signal decision result, so that the symbol error rate of the multi-carrier signal can be effectively reduced.

The invention belongs to the technical field of wireless multi-carrier communication and signal processing, and particularly discloses an LDPC (Low Density Parity Check) assistance-based iterative channel estimation method, which comprises the following steps of: performing LDPC low density parity check code coding, offset quadrature amplitude modulation and filter group multi-carrier modulation on information at a transmitting end; at a receiving end, initial channel estimation is calculated based on pilot symbols, interpolation is carried out, and initial channel estimation values at all data symbol positions are obtained; performing hard decision re-modulation reconstruction to obtain a reconstructed symbol after the data symbol is subjected to balanced demodulation by using the demodulation signal; calculating the updated channel estimation according to the receiving symbol and the reconstruction symbol; and combining the initial channel frequency response estimation value at the pilot frequency position and the updated channel estimation value at the data symbol position, carrying out Gaussian filtering processing on the combined channel estimation value, and outputting a final full frequency domain channel estimation value. According to the invention, the channel estimation accuracy of the FBMC-OQAM system can be effectively improved.

The application provides a kind of multi-carrier modulation and solution method for cross water acoustic communication. The signal after 8B / 10B encoding string parallel conversion and modulation is sent out through underwater acoustic transducer, which causes the vibration of water surface. After the vibration signal of water surface is extracted and solved by using millimeter wave radar, the transmitted information is obtained. The application can reduce the number of simultaneously existing carriers, increase the power of a single carrier and thus increase the transmission distance. The use of preamble and prefix enables the receiving end to obtain the time of information arrival and compensate for the amplitude attenuation and frequency change generated during the propagation of acoustic signals in water, thereby reducing the bit error rate.

The present invention relates to a high-dynamic anti-interference method based on random discrete time-frequency phase distribution, which is suitable for the transmission of high-dynamic anti-interference signals and belongs to the field of satellite communication technology. The method designs the time-frequency phase distribution range and distribution granularity of the random discrete carrier frequency according to the usage scenario, uses carriers in the three dimensions of time, frequency, and phase to perform multi-carrier modulation on the transmitting end signal, and synthesizes the signals on multiple carriers into one carrier at the receiving end to demodulate the information data. Analysis results show that the signal capture method designed by the present invention has excellent anti-interference and anti-interception performance, and the receiving terminal has the characteristics of fast capture speed and easy engineering implementation.

The invention discloses a power line PLC communication adaptive optimization method based on a multi-carrier signal, and relates to the technical field of power line communication optimization, and the method comprises the steps: carrying out fusion alignment processing on an adaptive candidate frequency band set and a power line interference mean value spectrum, generating an interference constraint frequency band vector set, carrying out interference sensing clustering, and generating a clustering optimal carrier group set; executing a dynamic link analysis operation on the path optimization guide set, dynamically constructing a wireless networking forwarding path, and outputting a multi-carrier networking diagram in combination with optimal carrier distribution information matched with each hop link; and extracting a carrier distribution result, link state characteristics and interference association information from the multi-carrier networking diagram, and generating a multi-carrier modulation control parameter set. By constructing the scheduling priority graph based on the signal-to-noise ratio and the interference condition and combining the frequency domain sparsity rule, the adaptive candidate frequency band set is screened out, and efficient screening and utilization of spectrum resources in the interference environment are achieved.

The present invention relates to a capacity-approaching multicarrier modulation and coding system and method. A multicarrier transmitter apparatus is disclosed. The apparatus includes an outer encoder, a shell mapper, and an inner encoder. The outer encoder is configured to receive a signal, perform error correction on the received signal using an outer code, and generate an outer encoder signal. The shell mapper is configured to perform constellation shaping on a subset of bits from the outer encoder signal and generate one or more constellation-shaped bits. The inner encoder is configured to perform inner error correction / coding on a second subset of bits from the outer encoder signal using the inner code and generate an inner correction signal.

The invention relates to a high-dynamic anti-interference method based on random discrete time-frequency phase distribution, is suitable for transmission of high-dynamic anti-interference signals, and belongs to the technical field of satellite communication. The method comprises the following steps: designing a time-frequency phase distribution range and distribution granularity of random discrete carrier frequency according to a use scene, carrying out multi-carrier modulation on a signal at a sending end by using carriers in three dimensions of time, frequency and phase, and synthesizing the signals on a plurality of carriers on one carrier at a receiving end to demodulate information data. An analysis result shows that the signal capturing method designed by the invention has good anti-interference and anti-interception performance, and the receiving terminal has the characteristics of high capturing speed and easiness in engineering realization.

A Channel Estimation mechanism in an FBMC or other multicarrier modulation based communication channel offering a plurality of sub-carriers, comprises transmitting pilot symbols based on the Zadoff Chu or other Constant Amplitude Zero Auto-Correlation sequence on non-adjacent (for example alternating) sub-channels. In multi-user scenarios, pilot symbols from each user device are transmitted on the same selected sub-channels, but subjected to a circular shift. These mechanisms obviating the need for Guard bands between each user devices pilot symbols, and the need for the including of a noise correlation matrix.

The embodiment of the invention provides a wireless communication method and equipment, which introduces a carrier signal generated based on multicarrier modulation, can support a carrier signal and an energy supply signal for zero power consumption communication in a multicarrier system, reduces the complexity of a transmitter introduced for supporting zero power consumption communication, and improves the communication performance. And the compatibility with other equipment can also be maintained. The wireless communication method comprises the following steps: a first communication device receives a carrier signal generated based on multi-carrier modulation; wherein the carrier signal is used for supplying energy to the first communication device, and / or the carrier signal is used for the first communication device to generate a backscattering signal through modulation.

The invention relates to the technical field of underwater robots, in particular to an underwater robot based on optical imaging and multicarrier modulation communication technology, which comprises an optical imaging module, a multicarrier modulation communication module, a communication module and a control module, the multi-carrier signal modulation module is used for modulating optical image data into multi-carrier signals and realizing remote transmission, and the data processing module is used for carrying out preprocessing, coding and decoding coordination and physical and underwater acoustic engineering interdisciplinary cross fusion on the image data and combining innovative ideas and technologies in different fields; the underwater optical vision imaging technology and the acoustic multi-carrier modulation technology are applied to the automatic underwater robot, the image capturing accuracy and the wireless real-time communication stability of the automatic underwater robot are improved, a camera basic imaging model is optimized through significance analysis of underwater imaging, meanwhile, the laser scanning technology is tried to be applied, and the image capturing accuracy is improved. And the fixed-point image capturing capability with higher precision is obtained.

A system and a method are provided in which a user equipment (UE) obtains a set of coefficients and a set of subcarriers from a location management function (LMF), and measures carrier phases on subcarriers, from the set of subcarriers, of a received reference signal transmitted with multi-carrier modulation. The UE determines a virtual carrier phase generated from the measured carrier phases and corresponding coefficients, from the set of coefficients. The UE reports the virtual carrier phase to the LMF.

The invention discloses an OTFS peak-to-average ratio suppression method based on data symbol block optimization selection, and belongs to the technical field of communication multi-carrier modulation. The grey wolf optimization algorithm is introduced through effective discrete coding and decoding to solve the discrete combination optimization problem, meanwhile, crossover and mutation operation is introduced to improve the global search ability of the optimization algorithm, and neighborhood search operation is introduced to further enhance the local search ability of the optimization algorithm. Aiming at the problem that the peak-to-average ratio of a transmitted signal is relatively high and is easy to exceed the linear range of a power amplifier to cause nonlinear distortion of the signal, OTFS frame data symbol block selection is optimized to obtain a better sub-block division scheme, so that better OTFS signal peak-to-average ratio suppression performance is realized, the signal works within the linear range of the power amplifier, and the signal performance is improved. And the transmission reliability of communication is ensured.

A Channel Estimation mechanism in an FBMC or other multicarrier modulation based communication channel offering a plurality of sub-carriers, comprises transmitting pilot symbols based on the Zadoff Chu or other Constant Amplitude Zero Auto-Correlation sequence on non-adjacent (for example alternating) sub-channels. In multi-user scenarios, pilot symbols from each user device are transmitted on the same selected sub-channels, but subjected to a circular shift. These mechanisms obviating the need for Guard bands between each user devices pilot symbols, and the need for the including of a noise correlation matrix.

The invention discloses a secure sparse code multiple access transmission method and receiving method based on path superposition shaping, and belongs to the technical field of communication, and the transmission method comprises the steps: carrying out serial-parallel conversion and forward error correction coding according to an original data stream of each user to obtain a parallel coding data stream; performing constellation mapping by querying a preset user codebook to obtain a constellation point sequence corresponding to each user, performing superposition by taking constellation point groups in the user codebook as paths through group operation according to the sparse matrix, and performing probability shaping to obtain superposed constellation point paths to form sparse code division multiple access (SCMA) symbols; performing disturbance encryption according to the four-dimensional hyper-chaos model to obtain an encrypted signal, and performing multicarrier modulation, inverse fast Fourier transform and parallel-serial conversion processing in sequence to obtain a signal to be transmitted; according to the method, the problems that the spectrum efficiency is limited due to non-uniform distribution of constellation points in the traditional sparse code multiple access technology, wireless signals are easy to eavesdrop in the transmission process, and the iterative detection complexity of a receiving end is high are solved.