12 results about "Multi carrier modulation" patented technology

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.

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 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.

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.

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.