21 results about "Multi carrier modulation" patented technology

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.

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 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 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 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.

The application discloses an adaptive OFDM variable bandwidth signal sensing and receiving method, and belongs to the technical field of wireless communication. The application solves the problem that data loss exists and high real-time data transmission cannot be met by using a traditional multi-carrier modulation method. The sending end of the application can sense a channel matrix of the surrounding environment and sends a dynamic adjustable subcarrier number to adapt to the channel. The receiving end judges the boundary of the signal bandwidth by a threshold method to sense the variable subcarrier number to ensure that data is not lost. A plurality of subcarriers are taken as a resource block, the subcarrier number of each resource block is fixed as a constant, and when a part of the missing signal is received at the receiving end, the correct subcarrier number is obtained by taking the resource block as the minimum unit, so that data loss is ensured, the integrity of data is improved, and the stability of the system is improved. The sending end sends the adjustable subcarrier number to resist the deteriorated channel, the channel capacity can be improved, and the application is very suitable for high real-time data transmission scenes. The application can be applied to the technical field of wireless communication.

There is provided a filter unit for wideband multicarrier FDD operation. The filter unit comprises an MXT, at least one isolator, and a filter bank. The MXT and the filter bank are connected via the at least one isolator. The MXT is configured to receive a TX wideband multicarrier signal as provided by at least one PA, and to 5 provide a first BP filtered TX wideband multicarrier signal to the at least one isolator. The MXT comprises at least one first BP filter structure for first BP filtering of the TX wideband multicarrier signal. The at least one isolator is configured to receive the first BP filtered TX wideband multicarrier signal from the MXT and provide the first BP filtered TX wideband multicarrier signal to the filter bank. The filter bank is 10 configured to receive the first BP filtered TX wideband multicarrier signal from the at least one isolator, and to provide a second BP filtered TX wideband multicarrier signal towards an antenna port. The filter bank comprises at least one more second BP filter structure than there are first BP filter structures for second BP filtering of the first BP filtered TX wideband multicarrier signal to provide the second BP filtered 15 TX wideband multicarrier signal.

Provided are wireless communication methods and communication devices. A wireless communication method comprises: a first device sending a first frame for providing energy to a second device, wherein a first field in the first frame satisfies one or more of the following: using multi-carrier modulation; being used for determining the frame type of the first frame; and the format of the first field being used for determining the field length of the first field. In an embodiment of the present application, a first device sends a first frame for providing energy to a second device, wherein a first field in the first frame satisfies one or more of the following: using multi-carrier modulation; being used for determining the frame type of the first frame; and the format of the first field being used for determining the field length of the first field. Compared with a conventional solution in which a signal for providing energy to a second device is not specified, the present solution facilitates increasing the possibility that a first device provides energy to a second device.

The invention discloses an IRS-assisted IFDM-NOMA and rate maximization design method, which relates to the technical field of multicarrier modulation, and comprises the following steps: constructing a downlink communication link of an MU-MISO-IFDM-NOMA system based on IRS assistance; the transmitting end generates and processes the IFDM modulation signal to obtain a final transmission signal and distributes the final transmission signal to the T antennas for transmission; establishing a millimeter wave communication channel model; k single-antenna user equipment is arranged at a receiving end, and after the user equipment carries out de-interleaving conversion on a received signal, the problems of multiple user equipment and rate maximization of an IRS-assisted MU-MISO-IFDM-NOMA system in a millimeter wave communication environment are constructed and solved. By the adoption of the method, the optimal parameter configuration when multiple users and the rate of the system reach the maximum in the millimeter wave mobile communication scene is obtained, and corresponding technical support is provided for IFDM system communication in the millimeter wave scene.

This invention discloses an OTFS peak-to-average power ratio (PAPR) suppression method through optimized selection of data symbol blocks, belonging to the field of communication multi-carrier modulation technology. This invention introduces the Grey Wolf optimization algorithm into effective discrete encoding and decoding to solve discrete combinatorial optimization problems. It also introduces crossover and mutation operations to improve the global search capability of the optimization algorithm, and introduces neighborhood search operations to further enhance the local search capability. Addressing the problem of high PPR of transmitted signals easily exceeding the linear range of power amplifiers and causing nonlinear signal distortion, this invention optimizes the selection of OTFS frame data symbol blocks to obtain a better sub-block partitioning scheme, thereby achieving better OTFS signal PPR suppression performance. This ensures the signal operates within the linear range of the power amplifier, guaranteeing reliable communication transmission.