889 results about "Orthogonal frequency code division multiplexing" patented technology

The invention provides a VDSL ultra-low time delay communication method and system, and relates to the technical field of communication, and the method comprises the steps: encrypting a clock synchronization channel through a quantum key distribution protocol, dynamically dividing micro time slot resources in an orthogonal frequency division multiplexing symbol period, and generating a dynamically adjusted micro time slot resource distribution result; calculating an optimal phase offset matrix of the metasurface intelligent reflecting surface through a depth deterministic strategy gradient algorithm to obtain an optimized electromagnetic wave propagation path; generating a global optimization check matrix by aggregating the locally trained lightweight error correction model gradient of each node to obtain a compensated data stream; and constructing a causal graph model dynamic pruning high-entropy path to minimize causal entropy, through multi-agent reinforcement learning, taking time delay-energy efficiency as a game target to decide an optimal modulation order and a subcarrier switching strategy, and obtaining an optimized stable communication link. According to the invention, high-reliability and low-delay communication basic support is provided for high-precision intelligent manufacturing.

The invention discloses a wide-narrow integrated ad hoc network method, and belongs to the technical field of network communication. The method comprises the following steps: a network node generates dynamic topology information based on a narrow-band communication module periodic broadcast state beacon; according to the link quality and the node load in the topological information, coordinating the resource allocation of broadband and narrowband channels by adopting a load-aware time slot allocation algorithm; data are classified according to service types, broadband data are modulated and transmitted by adopting orthogonal frequency division multiplexing, and narrowband control instructions are modulated and transmitted by adopting differential phase shift keying; when the link quality is deteriorated, the link is switched, and the transmitting power and the frequency band parameters are dynamically adjusted; and adaptive switching and data distribution of wide and narrow band communication modes are realized. According to the method, the problems of difficulty in topology maintenance and low bandwidth and narrowband resource allocation efficiency in a high-dynamic network scene are solved, the network adaptability, the anti-interference capability and the resource utilization rate are remarkably improved through a dynamic cooperative bandwidth and narrowband communication mode, and meanwhile, the protocol switching overhead and energy consumption are reduced.

The invention provides an optical-electric hybrid ultra-low time delay communication method and system, and relates to the technical field of communication, and the method comprises the steps: outputting a global synchronous clock signal with clock jitter less than 1ppm, dynamically dividing micro time slot resources in an orthogonal frequency division multiplexing symbol period, and generating a dynamically adjusted micro time slot resource distribution result; calculating an optimal phase offset matrix of the metasurface intelligent reflecting surface through a depth deterministic strategy gradient algorithm to obtain an optimized electromagnetic wave propagation path; generating a global optimization check matrix by aggregating the locally trained lightweight error correction model gradient of each node to obtain a compensated data stream; and constructing a causal graph model dynamic pruning high-entropy path to minimize causal entropy, through multi-agent reinforcement learning, taking time delay-energy efficiency as a game target to decide an optimal modulation order and a subcarrier switching strategy, and obtaining an optimized stable communication link. According to the invention, high-reliability and low-delay communication basic support is provided for high-precision intelligent manufacturing.

Methods and systems are disclosed for resource management on Sidelink for vehicle to everything (V2X) scenarios. Example methods and systems for a Resource Structure on Sidelink are disclosed. Control and data channels may be Frequency Division Multiplexed (FDMed) or Time Division Multiplexed (TDMed) with an Orthogonal Frequency Division Multiplexing (OFDM) waveform. Example methods and systems for a Resource Configuration on Sidelink are disclosed. The resource configuration may be statically configured or may be locally configured. Example methods and systems for Assisted Resource Allocation are disclosed. Assisted Sensing may be performed by a group lead or RSU and local scheduling may be performed by a group lead or RSU.

Systems, methods, and instrumentalities are described herein for adaptive waveform selection for wireless communication. In examples, the wireless transmit / receive unit (WTRU) may be configured with the orthogonal frequency-division multiplexing (OFDM) initially. If the WTRU, which may support dynamic waveform switch, receives system information blocks (SIBs) from multiple cells where at least one of them supports dynamic waveform switch, the WTRU may prioritize the initial access with the cell(s) that support dynamic waveform switch. If the WTRU supports dynamic waveform switch, the WTRU may send a physical uplink shared channel (RUSCH) in msg3 at a configured grant, which may be offset by a preconfigured number of slots with a waveform that is different from the preconfigured waveform type.

The embodiment of the invention provides a synchronization signal transmission method, device and system, which are used for realizing synchronization signals compatible with different types of terminal devices. The method comprises: determining a synchronization signal comprising a plurality of subsequences, each of the plurality of subsequences being mapped to a subcarrier of orthogonal frequency division multiplexing (OFDM), the bandwidth of the synchronization signal being greater than or equal to the bandwidth of any one of the plurality of subsequences; and sending a synchronization signal to the terminal device, wherein the synchronization signal is used for the terminal device to execute downlink synchronization.

Apparatuses and methods for channel state information (CSI) processing for CSI reporting. A method performed by a UE includes receiving a configuration about a CSI report. The configuration includes information about a parameter codebookType set to ‘typeI-MultiPanel-r19’ or ‘typeII-Doppler-r19’. The method further includes based on the configuration, processing the CSI report and determining the CSI report. Processing of the CSI report occupies OCPU CSI processing units (CPUs) for a number of orthogonal frequency division multiplexing (OFDM) symbols. The method further includes transmitting the CSI report.

The invention discloses a sparse Bayesian parameter estimation method based on a Markov chain Monte Carlo (MCMC). The sparse Bayesian parameter estimation method is suitable for super-resolution target number detection and high-precision target parameter estimation in a communication perception integration (ISAC) scene. The method comprises the following steps: a base station transmits an orthogonal frequency division multiplexing (OFDM) signal and receives a target reflection echo; performing frequency domain transformation on the echo signal and constructing a high-dimensional observation vector; target parameters are modeled as random variables including path complex gain, time delay, Doppler frequency shift and angle, and a learnable parameterized sensing matrix is constructed; the sparse Bayesian framework is combined with MCMC sampling, the parameters are iteratively updated through random small-batch gradient optimization and the Metropolis-Hastings criterion, and finally the estimation result of the target parameters is output. According to the method, the precision limitation of a traditional gridding method is broken through, super-resolution parameter estimation is achieved, meanwhile, the calculation complexity and the storage overhead are remarkably reduced, and the method is suitable for the high-precision sensing requirement in a 6G communication system.

The invention relates to the technical field of backscatter communication, and discloses a single-receiver WiFi backscatter method based on frequency domain cyclic shift. The method comprises the following steps: a transmitting end modulates data onto N frequency domain subcarriers, converts the N frequency domain subcarriers into N time domain samples through inverse fast Fourier transform, and forms an orthogonal frequency division multiplexing WiFi signal taking an OFDM symbol as a basic unit after adding a cyclic prefix; the label receives the WiFi signal, and performs sub-symbol-level modulation on an OFDM symbol in the WiFi signal based on a modulation technology of frequency domain cyclic shift; and the receiver determines the cyclic shift value of the frequency domain subcarrier through the frequency domain invariance of the OFDM symbol, and demodulates the received reflected signal to recover the label data. According to the invention, sub-symbol-level label data modulation is realized, the data transmission efficiency is improved, only a single symbol bandwidth is needed, and the waste of spectrum resources is avoided.

The invention discloses a signal transmission method and device based on orthogonal matrix precoding. The method comprises the steps that four chaotic sequences X, Y, Z and W are generated through a four-dimensional chaotic model according to a key initial value; performing bit interleaving on the original data by using X and W to obtain first data; performing serial-to-parallel conversion and QPSK mapping to obtain a mapping signal; scrambling the subcarriers and symbols of the mapping signals by using Y and Z to obtain encrypted data; carrying out IFFT (Inverse Fast Fourier Transform) on the encrypted data, adding a cyclic prefix, and carrying out parallel-serial conversion to obtain an encrypted data stream; performing binary conversion and serial-parallel conversion on the key initial value to obtain a square matrix K, and shaping the square matrix K by using a public key to obtain a key matrix; performing serial-to-parallel conversion, QPSK mapping, IFFT, cyclic prefix addition and parallel-to-serial conversion on the key matrix to obtain a key stream; and performing linear superposition on the encrypted data stream and the key stream through power distribution to obtain a power division multiplexing orthogonal frequency division multiplexing signal, and transmitting the power division multiplexing orthogonal frequency division multiplexing signal.

The invention relates to the technical field of wireless semantic communication, and discloses a semantic information transmission method, device and equipment and a storage medium, a sending end extracts features of to-be-transmitted data, and matches the features with vectors in a preset discrete vector codebook to obtain discrete feature vectors; and determining an orthogonal frequency division multiplexing time-frequency resource distribution grid according to the feature importance weights of the discrete feature vector and the initial feature vector, generating a sending signal, and transmitting the sending signal to a receiving end. And the receiving end inputs the semantic feature vector obtained after processing the received signal into the vector quantization variational self-decoder, and the semantic feature vector is matched with the vector in the discrete vector codebook again to correct the transmission error, thereby obtaining the reconstructed data to be transmitted. Discretization processing of the features is achieved through a discrete vector codebook, important semantic feature bits are quantized according to the importance weight of each feature and then distributed to orthogonal frequency division multiplexing for transmission, so that key semantic information is protected, and anti-interference transmission of the semantic information is achieved.

Methods, systems, and devices for wireless communications are described. A transmitter may modulate a set of bits into an on-off keying (OOK) sample sequence for wireless transmission to a receiver in a set of frequency resources. The transmitter may apply a transform (e.g., a discrete Fourier transform (DFT)) to the OOK sample sequence to generate a frequency domain representation of the OOK sample sequence. In some cases. the transmitter may, using an orthogonal frequency division multiplexing (OFDM) waveform generator, generate an OFDM waveform based on mapping the frequency domain representation of the OOK sample sequence to a set of resource elements of the set of frequency resources. In some cases. the transmitter may transmit the OFDM waveform to the receiver via the set of frequency resources.

The invention relates to the field of underwater acoustic communication and detection, in particular to a waveform optimization method and system for an underwater acoustic detection and communication integrated system. According to the method, a constant modulus phase is taken as a constraint, a reserved subcarrier phase is taken as an optimization variable, and a multi-objective function for joint optimization of a peak-to-average power ratio and a non-periodic autocorrelation integral sidelobe ratio is constructed; a population is initialized, an objective function is evaluated, and a parent population is obtained through non-dominated sorting and crowding distance calculation; generating filial generations through selection, crossover and variation, combining the filial generations with the parent generations, and updating sorting and crowding distance to maintain population diversity; introducing a local gradient descent refinement mechanism, carrying out gradient iteration adjustment on an optimized individual under a constant modulus phase condition, and adaptively adjusting a crossover probability, a mutation probability and a phase variation scale according to a diversity evaluation result; and outputting a Pareto optimal solution set after the maximum number of iterations is reached, and obtaining an optimized sounding and communication integrated orthogonal frequency division multiplexing signal, so that the underwater communication and detection comprehensive performance can be effectively improved.

Conventional Orthogonal frequency division multiplexing (OFDM) is unable to retain its orthogonality and suffers loss in performance in high Doppler circumstances. The present disclosure converts a signal received in delay-time domain into delay-Doppler domain and extracts a guard band region from the received converted signal. A 2-dimensional fast Fourier transform is performed on guard band region extracted from received converted signal. A 2-dimensional fast Fourier transform of the received converted signal is divided with the 2-dimensional fast Fourier transform of transmitted signal to extract phase information. A dictionary is created using a pre-defined set of values of delay and Doppler. A sparse recovery problem is formed for received converted signal using an orthogonal matching pursuit algorithm. One or more parameters are estimated by identifying one or more locations pertaining to the one or more columns corresponding to L significant non-zero locations comprised in sparse vector of sparse recovery problem.

The disclosure deals with system and method for discerning the radius maximizing reliability for binary modulation on conjugate-reciprocal zeros (BMOCZ) implemented with both a maximum likelihood (ML) and direct zero-testing (DiZeT) decoder. The optimal radius for BMOCZ is disclosed to be a function of the employed decoder. The radius maximizing the minimum distance between polynomial zeros does not maximize the minimum distance of the final code. While maximizing zero separation offers an almost optimal solution for the DiZeT decoder, the ML decoder outperforms the DiZeT decoder in both additive white Gaussian noise (AWGN) and fading channels when the radius is chosen to maximize codeword separation. Different sequence-to-subcarrier mappings for BMOCZ-based orthogonal frequency division multiplexing (OFDM) are analyzed to highlight a flexible time-frequency mapping approach that avoids distortion introduced by a frequency-selective channel at the expense of higher peak-to-average power ratio (PAPR).

The invention discloses a symbol processing method, a communication device and a communication system, and relates to the technical field of communication. The method comprises: a first communication device generating a first time slot, the first time slot comprising a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols, the plurality of OFDM symbols comprising a first OFDM symbol and a second OFDM symbol, the first OFDM symbol being the first OFDM symbol in the plurality of OFDM symbols, the first OFDM symbol comprising a first cyclic prefix (CP), the second OFDM symbol comprising a second CP, the length of the first CP being greater than the length of the second CP, the length of the first CP being greater than the length of the second CP, and the length of the second CP being greater than the length of the second CP; the length of the first CP is greater than a first value, and the first value corresponds to a subcarrier interval; a first communication device sends a first time slot, and correspondingly, a second communication device receives the first time slot. By adopting the embodiment of the invention, the signal loss can be reduced, and the demodulation performance is ensured.

Embodiments of the present disclosure are related, in general to communication, but exclusively related to methods and systems methods for transmitting a waveform. The waveform is a pre-DFT RS and data multiplexed DFT-S-OFDM with excess bandwidth shaping and MIMO. Also, embodiments of the present disclosure relate to methods of detecting the received data. The method for transmitting a waveform, comprising generating, by one or more transmitters, at least one data sequence and at least one reference sequence (RS). Also, the method comprises time-multiplexing the at least one data sequence with the at least one RS, to generate a multiplexed sequence. Further, the method comprises generating a filtered-extended bandwidth DFT-s-OFDM symbol using the multiplexed sequence. The filtered-extended bandwidth DFT-s-OFDM symbol generated by the one or more transmitters is transmitted in an OFDM symbol.

The invention discloses a random access preamble and detection algorithm design based on low earth orbit satellite communication. Specifically, firstly, a novel lead code with a plurality of subsequences is provided, in order to enlarge the number of available lead codes in a wave beam, a ZCM sequence is introduced to form the subsequences, and orthogonal frequency division multiplexing is adopted for modulation and is sent to a channel. Subsequently, a timing advance (TA) detection algorithm is proposed. The first sub-sequence is used for decimal time delay detection, and the other sub-sequences are used for integer time delay detection. In addition, the peak detection ingeniously utilizes the variance of the power delay spectrum, so that the detection performance is improved. Finally, a simulation result shows that the lead code provided by the invention is almost not influenced by frequency offset, does not need pre-compensation, and is suitable for being applied to low-orbit satellite communication with relatively large frequency offset.

In some implementations, a non-terrestrial network (NTN) platform may transmit a radio frequency (RF) signal toward the earth, the RF signal including an orthogonal frequency division multiplexing (OFDM) waveform having a plurality of symbols, the plurality of symbols including a JCS symbol and one or more non-JCS symbols, where: the RF signal is incident on an area of the earth defining a coverage area, and the one or more non-JCS symbols are not incident on the area of the earth defining the coverage area; and the duration of the cyclic prefix (CP) of the JCS symbol is a function of the width of the coverage area. The NTN platform may receive one or more reflections of a JCS symbol at the NTN platform.

The invention relates to the technical field of communication, and discloses an anti-interference communication sensing integrated beam forming method and system. The method comprises the following steps: generating an integrated waveform based on an orthogonal signaling base and a random data symbol; the sensing ranging performance is evaluated through periodic and non-periodic autocorrelation functions, time-frequency resource allocation of the waveform is optimized based on the performance, and an optimized waveform is generated; obtaining channel state information, carrying out interference source identification, and calculating a beam forming weight according to an identification result; mapping the optimized waveform to a time-frequency resource lattice of a frame according to orthogonal frequency division multiplexing to generate a frame structure signal; inputting the frame structure signal into a multi-antenna array, and regulating and controlling the phase and amplitude of each antenna unit through a beam forming weight to form a directional beam with a main lobe aligned with a target and a null aligned with interference; the target and interference changes are monitored in real time, the beam forming weight and waveform time-frequency resource allocation are dynamically updated, the anti-interference capability is improved, and the communication perception integration performance is enhanced.

Provided are a communication method and a communication device, the method comprising: determining a transmission waveform of a signal, the transmission waveform being related to a threshold of a first parameter, the first parameter comprising: a modulation order and a roll-off factor, the transmission waveform is an orthogonal frequency division multiplexing QAM-DFTS-OFDM waveform of discrete Fourier transform spread spectrum of orthogonal amplitude modulation or an orthogonal frequency division multiplexing OQAM-DFTS-OFDM waveform of discrete Fourier transform spread spectrum of offset orthogonal amplitude modulation, and the roll-off factor is determined based on the transmission bandwidth and the number of symbols carried by the transmission waveform. And transmitting or acquiring the signal. In the method provided by the invention, the network equipment or the terminal equipment can determine the transmission waveform of the signal according to the set threshold value of the modulation order and the threshold value of the roll-off factor, so that the output power supporting higher power amplifiers can be obtained, and a larger signal coverage range can be obtained.

Various aspects of the present disclosure relate to orthogonal time domain reference signal transmission. A user equipment (UE) may receive signaling configuring a set of parameters corresponding to one or more orthogonal time domain reference signals (e.g., unique words (UWs) in a time domain). The UE supports multiple input multiple output (MIMO) transmission and reception using an orthogonal frequency division multiplexing (OFDM) waveform. The UE transmits or receives symbols in a time domain including the one or more orthogonal time domain reference signals based on the set of parameters and the OFDM waveform.

Various solutions for on-off keying (OOK) signal generation with respect to reader apparatus and an Internet of Things (IoT) device are described. A reader apparatus may generate an OOK signal with an orthogonal frequency-division multiplexing (OFDM) waveform, wherein a start of an OOK signal transmission is aligned with a boundary of a symbol of the OFDM waveform. The reader apparatus may transmit the OOK signal to an IoT device.

A modem is configurable on a satellite, user terminal or gateway generates a radio frequency (RF) signal using an orthogonal frequency division multiplexing (OFDM) protocol including a radio frame including one or more bursts. A burst of the one or more bursts includes a first portion including burst detection data, a second portion including channel characteristic estimation data, a third portion including payload data, and fourth and fifth portions including pilot data. The first portion in a time domain is included in the burst prior to the second, third, fourth, and fifth portions. The first portion can include a pseudo-random noise sequence inserted in the time domain. The same physical modem can be configured to transmit signals on an uplink or downlink between a user terminal and a satellite or on the uplink or downlink between the satellite and the gateway.

This disclosure provides a sounding reference signal (SRS) transmission method and apparatus. The method includes: A terminal device receives a cyclic shift offset value sent by a network device; determines a target SRS pattern from M SRS patterns based on the cyclic shift offset value, where the M SRS patterns correspond to N candidate cyclic shift offset values, each SRS pattern in the M SRS patterns includes a quantity of orthogonal frequency division multiplexing (OFDM) symbols and a quantity of SRS combs that are occupied by at least two SRS ports, the at least two SRS ports belong to a same SRS resource, N is greater than or equal to M, and M is an integer not less than 2; and sends an SRS based on the target SRS pattern.

The embodiment of the invention discloses a communication method and device and a readable storage medium, relates to the technical field of communication, and can flexibly configure an SRS (Sounding Reference Signal). The method comprises: transmitting first indication information, the first indication information being used for indicating a plurality of discontinuous orthogonal frequency division multiplexing (OFDM) symbols, the plurality of OFDM symbols being used for a terminal device to send an SRS signal to a network device, the plurality of OFDM symbols corresponding to the same SRS bandwidth and the same antenna port of the terminal device.

Various solutions for Internet of Things (IoT) signal transmission with respect to reader apparatus and an IoT device are described. A reader apparatus may transmit a message to an IoT device through an in-band frequency or a guard band frequency in a frequency spectrum for an orthogonal frequency division multiplexing (OFDM) signal. A start of the transmission is aligned with a boundary of an OFDM symbol of the OFDM signal. The reader apparatus may receive a backscattered IoT signal from the IoT device through the in-band frequency or the guard band frequency.

Certain aspects of the present disclosure provide techniques for method for wireless communications by a user equipment (UE) generally including receiving a plurality of code blocks (CBs) from a network in one or more orthogonal frequency division multiplexed (OFDM) symbols and decoding the CBs using an iterative process performed on each OFDM symbol, wherein the iterative process involves data aided channel estimation and each iteration of the process involves demodulation and decoding.

The invention discloses a communication method and a related device, and the method comprises the steps: determining a synchronization signal, and transmitting the synchronization signal to a label on a first time domain resource and a first frequency domain resource. The first time domain resource comprises M orthogonal frequency division multiplexing (OFDM) symbols, the first frequency domain resource comprises N * 12 subcarriers, and both M and N are positive integers. Wherein the modulation mode of the synchronization signal is on-off keying (OOK), the synchronization signal comprises a first signal and a second signal, the first signal indicates that the second signal is behind the first signal and the second signal is adjacent to the first signal, and the second signal is used for time calibration; the duration T1 of the first signal and the duration T2 of the second signal are both fixed values, and the sum of T1 and T2 is equal to the duration of M OFDM symbols. According to the invention, the method can be compatible with the design of a synchronization signal of a label (namely a passive label or a semi-passive label) under different downlink signal bandwidths, and facilitates the improvement of the communication performance.

Methods, systems, and devices for wireless communications are described. In some examples, a transmitting device associated with one or more non-coherent demodulation reference signal ports may transmit data including a phase change estimation reference signal with multiple reference signal groups. In some examples, multiple different phase change estimation reference signal ports may be code-division multiplexed to transmit the phase change estimation reference signal in the same set of reference signal groups using a different orthogonal cover code for each phase change estimation reference signal port. In some other examples, the different phase change estimation reference signal ports may be used for transmitting the phase change estimation reference signal in the different time-division multiplexed sets of reference signal groups. In such cases, by assigning two phase change estimation reference signal ports to two TDM sets, the two phase change estimation reference signal ports may be time-division multiplexed.