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

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.

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).

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.

A method is provided that is performed by a device comprising a digital baseband of a communication transmitter. The method includes setting (1102) a first portion of a plurality of elements in a time variant filter to zero to obtain a truncated time variant filter; and generating (1104) an approximate discrete Fourier transform spread-orthogonal frequency division multiplexing, DFTS-OFDM, waveform based on filtering data symbols in time domain with the truncated time variant filter.

Logic may generate or detect a communication as a punctured block of orthogonal frequency division multiplex (OFDM) symbols on a carrier with a channel bandwidth of 5 megahertz or less, the punctured block having a first set of highest frequency resource blocks (RBs) of the OFDM symbols punctured or having a second set of highest frequency RBs and lowest frequency RBs punctured. The punctured block may comprise a physical downlink control channel (PDCCH) block, a synchronization signal / physical broadcast channel (SS / PBCH) block, or a downlink bandwidth part (DL BWP) on a carrier with a channel bandwidth of 3 MHz, 5 MHz, or other channel bandwidth less than 5 MHz. And logic may cause transmission of or demodulate and decode the punctured block.

Disclosed are methods performed by a base station in a wireless communication system including identifying a number of orthogonal frequency division multiplexing (OFDM) symbols for a terminal; identifying downlink control information (DCI) format for the terminal; generating DCI for the terminal based on a resource allocation type and resource block group for data transmission of the terminal, wherein the resource allocation type is identified based on the DCI format; transmitting, to the terminal, the DCI; and transmitting, to the terminal, data corresponding to the DCI. The resource block group includes consecutive virtual resource blocks and a number of the consecutive virtual resource blocks is determined based on a size of a bandwidth and a configuration information by a higher layer signaling.

According to various embodiments of the present disclosure, provided is a method performed by a first device, the method comprising the steps of: mapping a codeword to a plurality of chips within at least one orthogonal frequency division multiplexing (OFDM) symbol of data; substituting or overriding a first chip or a last chip from among the plurality of chips with a value of another chip; and transmitting the data to a second device.

Various aspects of the present disclosure generally relate to wireless communication. A first device, such as a network node or a user equipment (UE), may transmit a reader-to-device (R2D) transmission to a second device, such as an ambient Internet of Things (A-IoT) device. The first device may be a reader and the second device may be a tag. The R2D transmission may include a start indicator, a clock acquisition, and a physical R2D channel (PRDCH) transmission. The PRDCH transmission may have at least two parts. A first part of the PRDCH transmission may support a different M value set as compared to a second part of the PRDCH transmission, where M is a number of chips in one orthogonal frequency division multiplexing (OFDM) symbol. The first part of the PRDCH transmission may support a lower M value as compared to the second part of the PRDCH transmission.

The invention discloses a subcarrier-level diversity combining method and subcarrier-level diversity combining equipment for multi-frequency diversity, and relates to the technical field of wireless communication. The method comprises the following steps: receiving a plurality of frequency points bearing the same service, and respectively carrying out orthogonal frequency division multiplexing demodulation on each frequency point to obtain a symbol estimation value; calculating a soft decision log-likelihood ratio and a reliability vector according to the symbol estimation value; aligning the time deviation, the carrier frequency deviation and the sampling rate deviation generated by frequency crossing of each frequency point based on each symbol estimation value; performing decorrelation processing on the aligned soft decision log-likelihood ratio to obtain a decorrelated soft decision log-likelihood ratio, and performing merging operation on the decorrelated soft decision log-likelihood ratio according to the aligned reliability vector to obtain a merged soft decision log-likelihood ratio; and decoding the merged soft decision log-likelihood ratio to obtain a decoding result, and adjusting the merging operation according to the decoding result. By implementing the technical scheme provided by the invention, the diversity combining accuracy can be improved.

Disclosed are methods, systems, and computer-readable medium to perform operations including: generating a mapping pattern that comprises a length-4 frequency division orthogonal cover code (FD-OCC4), the mapping pattern for mapping demodulation reference signals (DMRS) in frequency to a plurality of resource elements in at least one orthogonal frequency-division multiplexing (OFDM) symbol, wherein the DMRS are associated with a plurality of DMRS ports; mapping, using the FD-OCC4, the DMRS to the plurality of resource elements in the at least one OFDM symbol; and transmitting a transmission comprising the at least one OFDM symbol.

The invention discloses a satellite communication waveform generation method and system based on coding orthogonal frequency division multiplexing and continuous phase modulation, and a storage medium. The satellite communication waveform generation method comprises the following steps: S1, performing low-density parity check coding on input data; s2, performing constellation mapping on the coded data to generate a symbol sequence; s3, performing multi-stage continuous phase modulation on the symbol sequence to obtain a modulated signal; s4, performing selective mapping processing on the modulated signal, and selecting an orthogonal frequency division multiplexing subcarrier signal with the lowest peak-to-average power ratio as a signal to be output; s5, performing inverse fast Fourier transform on the to-be-output signal, adding a cyclic prefix, and outputting a final signal; the method can suppress the peak-to-average power of the signal, and is high in processing efficiency and low in bit error rate.

An apparatus (10, 110) comprising: means for transmitting, to a second apparatus (120), first information (901) indicative of a capability of the apparatus to adapt at least one of: a design of a frequency-domain spectral shaping, FDSS, filter (902) for FDSS-based orthogonal frequency division multiplexing, OFDM, transmission, or a spectral extension parameter (903) for use in FDSS-based OFDM with spectral extension transmission; means for receiving, from the second apparatus based at least in part on the transmitted first information, second information (904), wherein the second information comprises information for configuring the apparatus to operate in an operational mode (906) for generating training data for training a machine learning, ML, based FDSS filter; and means for operating in the operational mode, wherein the operation in the operational mode is based at least in part in on the second information, and wherein operating in the operational mode comprises: transmitting, using at least a first configuration of the FDSS filter design (909) or a first spectral extension parameter (910), at least a first FDSS-based OFDM transmission (908) to the second apparatus.

Various embodiments of the present disclosure provide a method performed by a first device, the method comprising the steps of: for each of a plurality of orthogonal frequency division multiplexing (OFDM) symbols of data, mapping a first value of a last chip (M-1@n) of a current OFDM symbol to a first chip (0@n+1) of a next OFDM symbol; mapping a preset second value to the last chip (M-1@n) of the current OFDM symbol; and transmitting the data to a second device, wherein M is the number of chips in one OFDM symbol, and n corresponds to the current OFDM symbol.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive an indication of one or more waveforms supported by a base station, wherein the one or more waveforms include at least one of an orthogonal frequency division multiplexing (OFDM) waveform, a single carrier frequency domain (SC-FD) waveform, or a single carrier time domain (SC-TD) waveform. The UE may determine whether the UE is capable of communicating with the base station based at least in part on the indication. The UE may selectively communicate with the base station using at least one waveform of the one or more waveforms based at least in part on the determination. Numerous other aspects are provided.

The invention relates to the technical field of wireless communication, in particular to an intelligent lock anti-interference wireless communication method and system based on metamaterial resonance. The method comprises the steps that preset frequency-phase combination parameters of a metamaterial resonant antenna are initialized at an intelligent lock end, 128 kinds of orthogonal frequency division multiplexing waveforms are corresponding, and the metamaterial resonant antenna only responds to excitation signals containing preset frequency-phase combinations so as to filter interference signals of non-matched frequencies and phases. According to the invention, an anti-interference wireless communication system based on metamaterial resonance is constructed at the intelligent lock end, so that deep fusion of physical layer signal screening and a protocol layer security mechanism is realized. Specifically, a preset frequency-phase combination parameter of the metamaterial resonant antenna and a dynamic time-frequency coding hopping sequence form dual-frequency phase filtering, only a signal matched with the resonance characteristic of the current communication period is allowed to enter a demodulation process, and interference signals of non-matched frequencies and phases are effectively suppressed from a physical layer.

The invention discloses a bimodal identity authentication method based on voice and ultrasonic signals. The method comprises the following steps: transmitting an orthogonal frequency division multiplexing modulated ultrasonic wave by using a built-in loudspeaker of equipment, and synchronously acquiring a mixed signal containing voice and ultrasonic reflection; after separation, converting the speech signal into a speech spectrogram, and carrying out vocal organ positioning, segmented de-trending and multi-scale spectrogram conversion on the ultrasonic signal to extract anti-interference pronunciation action features; the method comprises the following steps: respectively extracting depth features of voice and ultrasound through a double-flow neural network, and carrying out dynamic weighted fusion according to signal quality by adopting a quality sensing channel gating fusion module to generate an identity embedding vector irrelevant to speaking content; in the registration stage, a speaker template is constructed, and a personalized threshold value is calculated; and in the authentication stage, identity judgment is realized through cosine similarity comparison. According to the method, the robustness of the system in a noise environment and the defense capability of the system on spoofing attacks such as playback and synthesis are remarkably improved by fusing the voice content and the ultrasonic living body action characteristics.

A fault detection system for detecting a fault condition in a direct current (DC) system. The system may include a DC power transmitter to energize a cable and a DC power receiver connected to the cable. A signal generator at the receiver employs orthogonal frequency division multiplexing (OFDM) and combines symbols for messaging or data communications with redundant symbols dedicated to fault detection. At a signal receiver, the transmitted OFDM signal is used to measure changes in the channel transfer function by monitoring changes in a parameter of the received redundant symbols. The redundant symbols need not be decoded to detect a greater-than-threshold change in the transfer function that is indicative of a fault on the cable.

The present disclosure relates to a method for operating a terminal and a base station in a wireless communication system and an apparatus for supporting the same. As an example of the present disclosure, a method for operating a terminal in a wireless communication system may include: processing data symbols so that a first unique word (UW) discretely located in a frequency domain does not overlap with the data symbols; and transmitting a first unique word (UW)-orthogonal frequency division multiplexing (OFDM) symbol that adds the data symbols, which are processed not to overlap, and the first UW discretely located in the frequency domain.

The invention discloses a channel estimation method for a 5G-OFDM system based on deep learning, and the method comprises the steps: building an OFDM orthogonal frequency division multiplexing system, and forming a low-resolution channel matrix; establishing a deep learning neural network channel estimation model; the low-resolution channel matrix is input into a deep learning neural network channel estimation model to be processed, the deep learning neural network channel estimation model adopts an interpolation-free end-to-end learning framework, and feature extraction is directly conducted on channel response data which are not interpolated; and outputting a complete channel frequency response matrix through the deep learning neural network channel estimation model to realize channel estimation. Under a 3GPP TDL-A multipath channel, the model provided by the invention has excellent performance in a signal-to-noise ratio range of 1-30dB: compared with an existing deep learning model, the estimation precision has the advantage that the parameter quantity is reduced by 93% under similar precision; the reasoning time is only 12.44 ms, the speed is increased by 25.7% compared with that of an SRCNN, the model calculation amount is only 38.24 MMac, and the method is easy to deploy in a mobile terminal with limited resources.

The invention provides a filtering windowing method, device, equipment and medium in a uRLLC scene, and the method comprises the steps: extracting an orthogonal frequency division multiplexing symbol from time domain data; expanding each symbol to obtain an expanded sequence of each symbol; windowing the extended sequence of each symbol to obtain a windowing sequence of each symbol; and obtaining an output sequence after filtering processing according to the windowing sequence of each symbol. According to the method provided by the invention, the windowing sequence is obtained by windowing after the symbol is expanded, and the filtered output sequence is obtained according to the windowing sequence, so that the real-time requirement can be ensured, and the signal can have sharper attenuation in transition.

A base station, according to one embodiment of the present disclosure, may: transmit configuration information including at least one of information on a first period in which at least one of reception or transmission of orthogonal frequency division multiplexing (OFDM) signals is performed or information on a second period in which at least one of reception or transmission of at least one low-power (LP) signal is performed; receive a wake-up signal (WUS) from a terminal in the second period; and terminate the second period and start the first period on the basis of the reception of the WUS.

Apparatuses and methods for generating on-off keying (OOK) signal based on orthogonal frequency-division multiplexing (OFDM) waveform. A method for an Internet of Things (IoT) device to communicate with a reader includes receiving a preamble signal that includes a start indicator part (SIP) and a clock acquisition part (CAP), receiving a physical reader-to-device channel (PRDCH), and receiving a postamble signal. The preamble signal, the PRDCH, and the postamble signal are OOK modulated based on an OFDM waveform. The preamble signal is followed by the PRDCH without a gap. The PRDCH is followed by the postamble signal without a gap. When the postamble signal ends in during an OFDM symbol duration, a padding signal is included from the end of the postamble signal for a remainder of the OFDM symbol duration.

A computer-implemented method for enabling a base station (BS) to provide configuration commands wirelessly to a reconfigurable intelligence surface (RIS) includes establishing a new codebook for each configuration from a previous set of configurations. The method further includes generating an RIS control message based on embedding amplitude-modulated (AM) signals into Orthogonal Frequency-Division Multiplexing (OFDM) signals using the new codebook and providing the RIS control message to the RIS to control the RIS. The method can be used to optimize and / or allow enhanced decision making for controlling the RIS using the BS. For instance, the method can synchronize its radio scheduler decisions and the optimization of the RIS configuration seamlessly and / or disguise RIS control messages into New Radio OFDM symbols. In some embodiments, machine learning (ML) and / or artificial intelligence (AI) techniques (e.g., a neural network (NN)) can be used.

This terminal includes: a control unit for determining at least one of an intra-symbol orthogonal cover code (OCC) spreading in the frequency domain and an inter-symbol OCC spreading in the time domain, applied to a physical uplink shared channel (PUSCH) modulated by discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) or OFDM; and a transmission unit for transmitting the PUSCH to which the OCC is applied to a base station. The control unit multiplexes uplink control information (UCI) before executing spreading for OCC application.

Systems, methods, devices, and means for multipath mitigation, interference cancellation and multilateration in a cellular network supporting accurate and resilient position, navigation, and timing (PNT) services are described. The techniques described herein include operations directed to processing positioning reference signals (PRSs) to determine time of arrival (TOA) measurements for determining user equipment (UE) position in the presence of multipath noise and interferences. Example operations associated with processing PRSs includes receiving one or more PRSs in accordance with a comb pattern via resources defined by a set of orthogonal frequency division multiplexing (OFDM) symbols and a set of subcarriers. The example operations include generating a single OFDM symbol comprising the set of subcarriers based on combining the set of OFDM symbols into the single OFDM symbol. The example operations further include performing a multipath mitigation operation using the single OFDM symbol.

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

A method, network node and wireless device (WD) for phase noise mitigation are disclosed. According to one aspect, a method in a network node includes receiving an orthogonal frequency division multiplex (OFDM) signal provided over a radio frequency (RF) channel that includes at least one guard band, the OFDM signal including at least one pilot signal. The method also includes mitigating phase noise based at least in part on the at least one pilot signal and further based on observations of signal content of the at least one guard band.

Provided in the embodiments of the present application are a transmission method and apparatus. The method includes: resource configuration information of a first sounding reference signal (SRS), which is from a network device, is received; and according to the resource configuration information, antenna ports of a first SRS resource on at least two orthogonal frequency division multiplexing (OFDM) symbols are transmitted. The antenna ports, which are transmitted on the OFDM symbols, are different from each other.