49 results about "Cyclic prefix" patented technology

The present disclosure provides a method and apparatus for transmitting and receiving signals in a wireless communication system. According to the method and apparatus, a low-power wake-up signal (LP-WUS) may be received through a first receiver, and a second receiver may be triggered based on the reception of the LP-WUS. A length L_w of an on-off keying (OOK) symbol of the LP-WUS is determined based on (i) a length N_ofdm of an orthogonal frequency division multiplexing (OFDM) symbol, (ii) a length N_cp of a cyclic prefix (CP) duration of the OFDM symbol, and (iii) a number N of OOK symbols corresponding to the length of the OFDM symbol.

The application discloses a kind of underwater acoustic OFDM communication adaptive frequency domain equalization methods using Transform, it is related to underwater acoustic communication technical field, to solve the problems that existing underwater acoustic OFDM equalization method relies on cyclic prefix, is not sensitive to channel dynamic change, hard decision is prone to error propagation, the Transform framework containing only encoder is used in the present application, the soft decision of received symbol is completed by multi-head self-attention mechanism, and adaptive filtering is realized in combination with feedforward network;In the training phase, the loss function is calculated based on the network output and the true value, and the network parameters and the feedforward equalization filter coefficients are updated synchronously;In the inference phase, the network output is fed back to update the filter coefficients, and the real-time changes of the channel are adapted;The present application significantly reduces the probability of error propagation, and improves the communication reliability under complex underwater acoustic channel.

This invention discloses a waveform design method for integrated communication and sensing based on a multi-objective particle swarm optimization algorithm, relating to radar detection technology and communication technology. The method includes: constructing a multi-objective optimization problem for waveform parameter design using the subcarrier weight coefficients of the OQAM-OFDM integrated communication and sensing waveform as optimization variables; using the maximization of the sum of the signal-to-noise ratios (SNRs) of all subcarrier communication outputs as the optimization criterion for waveform parameter design; using the maximization of the sum of the SNRs of all range resolution units' sensing outputs as the optimization criterion for waveform parameter design; solving the multi-objective optimization problem for waveform parameter design using the multi-objective particle swarm optimization algorithm to obtain several non-dominated solutions for the subcarrier weight coefficients that simultaneously maximize both the communication output SNR and the sensing output SNR; and forming a Pareto front from these non-dominated solutions. The waveform designed in this invention can effectively resist multipath interference without using cyclic prefixes and blank guard intervals, exhibiting high resource utilization efficiency and excellent sensing and communication performance.

Systems and method provide for uplink carrier aggregation (UL CA) that is configured for a User Equipment (UE), and transmissions on multiple UL carriers by one power amplifier (PA). When a base station (e.g., a gNB) indicates the UE should switch its UL waveform from Cyclic-Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) to Discrete Fourier Transform Spread OFDM (DFT-S-OFDM) for Physical Uplink Shared Channel (PUSCH) transmission in one or more UL carriers, the base station expects that the UE transmit power on a particular carrier can be increased, the carrier for which a UL coverage issue (e.g., low signal strength, signal to noise ratio, interference, etc.) is found. UL waveform switching from CP-OFDM to DFT-S-OFDM can improve the lower bound of PCMAX, namely the total UE transmit power on UL carriers of intra-band CA.

The application provides a GMSK underwater acoustic communication method and system based on frequency domain equalization, and the method comprises the following steps: adding a cyclic prefix before a transmission signal sequence, adding a tail symbol after the transmission signal sequence, carrying out conversion and information-symbol mapping, modulating according to a GMSK signal modulation mode based on Laurent decomposition, obtaining a GMSK complex baseband signal, modulating the GMSK complex baseband signal to a carrier as a final transmission signal, and transmitting the final transmission signal to an underwater acoustic channel; receiving the transmission signal in the underwater acoustic channel, carrying out band-pass filtering, time-frequency two-dimensional synchronization, matched filtering, frequency domain equalization and iterative symbol detection on the received signal, obtaining a judged symbol, and completing the GMSK underwater acoustic communication based on the frequency domain equalization. The application has the advantages that the complexity of the symbol detection of the conventional frequency domain equalizer is reduced, and the communication performance is improved.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a network node may receive, in a first symbol, a second symbol, and a third symbol, a remote interference management reference signal (RIM-RS) that includes a cyclic prefix, a first sequence, and a second sequence identical to the first sequence. The network node may apply a circular shift in a time domain of one or more portions of the RIM-RS in one or more of the first symbol or the third symbol. Numerous other aspects are described.

Embodiments of the present disclosure provide a wireless signal configuration method, a storage medium, and an electronic apparatus. The method comprises: configuring a wireless signal, wherein the wireless signal comprises a cyclic prefix part and a valid signal part, the valid signal part comprises N segments of unit valid signals of equal length in a time domain, the phase difference between adjacent unit valid signals is determined according to a set frequency domain comb offset K value so that the wireless signal is an N-comb signal after being transformed into a frequency domain, the valid signal part occupies a K-th comb, and N and K are integers greater than or equal to 1; and transmitting the wireless signal on an integrated sensing and communication device.

This invention relates to the field of baseband communication technology, specifically to a rapid detection method for mobile terminals involved in a case based on signal sensing. The method involves down-converting the captured air interface radio frequency signal into a baseband data stream, extracting the random access preamble sequence and removing the cyclic prefix during the physical layer synchronization phase, performing a Fast Fourier Transform on the preamble sequence to extract the carrier frequency offset estimate and the inter-symbol phase difference sequence, and combining them to generate a baseband physical layer feature vector. This feature vector is then subjected to a time-domain sliding cross-correlation operation with a pre-stored baseband fingerprint database of the involved terminal. When the cross-correlation peak exceeds the decision threshold and the frequency offset change rate is consistent, a detection trigger signal is output and the timestamp is locked. This invention bypasses the higher-layer signaling parsing and encryption cracking stages, directly using baseband waveform features at the physical layer to complete the matching judgment, eliminating the processing delay and decryption failure risk caused by the step-by-step parsing of the protocol stack, and achieving rapid detection of the involved mobile terminal.

The application discloses an OFDM signal interference detection method, device, equipment, medium and product. The method comprises the following steps: receiving an OFDM signal to be detected, each OFDM symbol in the OFDM signal to be detected contains a cyclic prefix with a length of L sampling points and useful symbol data with a length of N sampling points, and the cyclic prefix is obtained by copying a tail symbol with a length of L sampling points in the useful symbol; extracting cyclic prefix data and tail symbol data with a length of L sampling points of the OFDM signal to be detected, and determining a first noise power of the OFDM signal to be detected in the time domain according to the cyclic prefix data and the tail symbol data; determining a second noise power of the OFDM signal to be detected in the frequency domain; and determining whether the OFDM signal to be detected has interference according to the first noise power and the second noise power. The signal quality requirement is low, and the prior information of the interference is not required, so that the existence of the interference can be detected.

Disclosed are a wireless communication method and a communications device. One example method includes: transmitting sensing signals on a plurality of consecutive time domain symbols, wherein the plurality of time domain symbols comprise a first time domain symbol and N second time domain symbols located after the first time domain symbol, a signal in the second time domain symbol comprises the sensing signal, and at least one of a cyclic prefix determined based on the sensing signal or a cyclic postfix determined based on the sensing signal, signals in the plurality of time domain symbols are periodic and have a period equal to a length of the sensing signal in each time domain symbol, and N is a positive integer.

The application discloses a time-frequency collaborative equalization distortion suppression method for an OFDM signal, and belongs to the field of wireless communication. The application solves the problems of high complexity and poor transmission reliability of the existing short cyclic prefix method. The application adopts an OFDM system based on time domain oversampling and frequency domain interpolation equalization at a receiving end. The oversampling algorithm can enhance the power of useful signals by appropriately widening the equalization frequency band, thereby enhancing the equalization effect. The frequency domain interpolation equalization algorithm can better capture spectral details by performing weighted interpolation processing on the frequency domain receiving signals, thereby realizing compensation and correction of the energy migration phenomenon of spectral lines in the frequency band caused by the channel effect. Through time-frequency collaborative processing at the receiving end, the application can efficiently suppress interference, ensure stable and reliable demodulation accuracy and communication quality, avoid the spectral resource loss caused by the extra lengthening of the cyclic prefix, and further significantly improve the spectral utilization efficiency of the system. The application can be applied to the field of wireless communication.

A base station, which includes a transceiver and a processor are configured to produce a signal for transmission in a time slot of a frame, wherein the time slots have variable lengths. The signal has a first portion and a second portion, the first portion and the second portion being located in defined time regions in the time slot, the first portion comprising data and a multiplexed first pilot multiplexed with the data, wherein the multiplexed first pilot is derived from a pseudo random sequence, the second portion comprising a pilot sequence and a cyclic prefix. The transceiver is configured to transmit the signal in the time slot.

The application belongs to the technical field of wireless communication, and particularly relates to a communication method, device, medium and equipment based on MQAM-OFDM modulation, which comprises the following steps: generating a random data source and performing MQAM modulation, generating a serial modulation signal, performing serial-parallel conversion and subcarrier mapping, and obtaining frequency domain subcarrier data; performing inverse fast Fourier transform on the frequency domain subcarrier data to generate time domain OFDM symbols, and adding a cyclic prefix to obtain a sending signal; transmitting the sending signal based on a multipath channel model; receiving the sending signal and removing the cyclic prefix part in the sending signal to obtain an effective OFDM signal; performing fast Fourier transform on the effective OFDM signal to recover frequency domain data and obtain a frequency domain receiving symbol sequence; performing channel estimation and equalization on the frequency domain receiving symbol sequence to obtain a frequency domain symbol estimation value; performing MQAM demodulation on the frequency domain symbol estimation value, and recovering parallel data streams into a serial bit stream, thereby completing data recovery.

Embodiments of the invention relate to transmission of OFDM symbols from a first communication device (100) to a second communication device (300). Each transmitted OFDM symbol comprises a cyclic prefix part and a data part in the time domain, and the cyclic prefix part comprises at least one sensor signal part. Based on the sensor signal part of the received OFDM symbol, the second communication device (300) may determine a sensing result for the second communication device (300) or a channel measurement of the radio channel. Furthermore, the invention also relates to corresponding methods and a computer program.

The present disclosure describes methods, system, and devices for configuring extended cyclic prefix (ECP) for broadcast and / or multicast transmission. One method includes determining, by a user equipment (UE), ECP resource for at least one of broadcast transmission and multicast transmission according to predefined resources; and receiving, by the UE from a base station, a broadcast transmission or multicast transmission in the ECP resource. Another method includes configuring, by a base station, ECP resource for at least one of broadcast transmission and multicast transmission according to predefined resources; and transmitting, by the base station to at least one UE, a broadcast transmission or multicast transmission in the ECP resource.

This invention discloses a low-storage, high-reliability transceiver cooperative interleaving transformation method for random multiplexing communication systems. The method includes: at the transmitter, mapping the bit stream to be transmitted into source domain information symbol vectors; interleaving and rearranging the symbol vectors using a low-storage interleaver; performing phase perturbation and multi-layer coupling transformation on the interleaved and rearranged transmitted signal to generate a high-reliability random multiplexing modulation signal and adding a cyclic prefix before sending it to the receiver; at the receiver, after receiving the signal, removing the cyclic prefix to obtain a time-domain observation signal vector; performing iterative signal detection using an HR-CD-MAMP detector matched to the transmitter's transformation to complete symbol estimation; and completing the interleaving and deinterleaving operations of the high-reliability transformation and inverse transformation in the iterative estimator using a low-storage interleaver corresponding to the synchronization parameters to recover the source domain symbol vectors; and recovering the binary bit stream from the obtained source domain symbol vectors through digital demapping.

The application discloses a self-evolution underwater communication method and system for an underwater acoustic dynamic heterogeneous channel. A hyperbolic frequency modulation acoustic signal is used by a sending end underwater acoustic node to extract time domain multipath and frequency domain Doppler characteristics of an underwater acoustic medium, and a joint entropy value is constructed to initialize acoustic wave transmission waveform parameters. An error code rate is monitored by a receiving end, and an energy efficiency fitness function value is calculated by combining an underwater acoustic transducer and a physical layer total energy consumption to perform feedback. According to the function value change trend, a directional update rule is used by the sending end to perform joint iteration on a subcarrier spacing, a cyclic prefix and a pilot insertion density. When the channel is reliable but the energy efficiency decreases, a low energy consumption disturbance operation of reducing the pilot insertion density or shortening the cyclic prefix is forced to be performed to reduce the invalid acoustic wave radiation time of the transducer. Through entropy value decoupling and energy efficiency evaluation, the application solves the acoustic energy waste problem caused by excessive protection of a traditional communication method, and significantly prolongs the endurance of an underwater node.

This invention provides a wireless signal configuration method, storage medium, and electronic device. The method includes: configuring a wireless signal, the wireless signal comprising a cyclic prefix portion and a valid signal portion, wherein the valid signal portion comprises N segments of equal length in the time domain, the phase difference between adjacent valid signal segments is determined according to a set frequency domain combing offset K value such that the wireless signal, after transformation to the frequency domain, is an N-combed signal, the valid signal portion occupies the Kth comb, and N and K are integers greater than or equal to 1; and transmitting the wireless signal in a sensing integrated device. This invention solves the problem that existing signal design schemes cannot effectively suppress interference generated by networking, and also improves the anti-interference capability of networking.

The disclosure relates to a method for 5G or 6G communication system. This disclosure provides apparatuses and methods for data-aided CP-OFDM communications in wireless communication systems. In one embodiment, the method may include receiving, a signal including data transmitted over a band channel from a second electronic device; and generating, information about the transmitted data using an artificial intelligence (AI) model trained to generate information about input bits.

This invention provides an OFDM chaotic communication method, apparatus, device, and medium with reference signal multiplexing. The bit stream to be transmitted is divided into b... k Reference bit and b i Index bits, each reference bit triggers a generator group consisting of two heterogeneous chaotic mappings based on its 0 or 1 value, generating b. k A set of chaotic sequences of length β constitutes a reference sequence set R; b i The index bits are divided into G groups. Each group selects one chaotic sequence from R using an index selector as the data carrier sequence. The R and G data carrier sequences are then superimposed using OFDM modulation to form the transmitted signal. At the receiving end, the signal undergoes cyclic prefix removal, serial-to-parallel conversion, and FFT to separate the reference and index data portions. Finally, a deep neural network demodulation model recovers the data. k Reference bits and reconstruct R, then use the reconstructed R to perform cross-correlation detection on the index data to recover b. i Index bits. This allows the reference signal to synchronously complete reference transmission and user information transmission on the same time, frequency, and power resources, eliminating the pure overhead of the reference signal.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless communication device may generate a chirp signal associated with performing radio frequency (RF) sensing, wherein the chirp signal has a waveform that is compatible with a cyclic prefix (CP) orthogonal frequency division multiplexing (OFDM) waveform used for communication. The wireless communication device may transmit the chirp signal in association with performing RF sensing. Numerous other aspects are described.

This invention discloses a neural network equalization method embedding signal-related noise variance. The method includes: removing the cyclic prefix from the received time-domain signal, performing a fast Fourier transform, and removing Hermitian symmetry to obtain N frequency-domain signals; obtaining the photon count variance detected by a single SPAD in the nth sampling period based on the N frequency-domain signals, and then obtaining the photon count variance detected by the array; modeling the time-domain signal equalization as a DNN-SDN network, using the photon count variance as the input data of the DNN-SDN network; after offline training of the DNN-SDN network, deploying the network in a receiver for signal equalization. This invention can effectively suppress signal distortion caused by SPAD nonlinearity and underwater channel attenuation, thereby significantly reducing the bit error rate, increasing the communication distance of optical signals, and simplifying the complexity of the receiver.

This application relates to a broadband reception method, design, and medium based on a LoS-MIMO channel, and pertains to the field of wireless communication. The aim of this application is to address the limitation of high-speed transmission in practical applications of LoS-MIMO systems. The receiving end of this application acquires the received signal and obtains multiple serial time-domain received signals after down-conversion; it performs timing synchronization on the time-domain received signals to determine the start position of OFDM symbols; it converts each received signal into multiple parallel low-speed data streams; it calculates and accumulates the local carrier frequency offset correlation value of the low-speed data using a cyclic prefix, and estimates the carrier frequency offset value based on the accumulation result; it uses the estimated value to perform phase compensation on each parallel low-speed data stream and removes the cyclic prefix, performing OFDM symbol demapping; it performs channel estimation and equalization based on the frequency-domain OFDM symbols, and performs inverse discrete Fourier transform and recovery processing on the equalized signal to obtain the original bitstream.

The application discloses a communication method, a communication device and a storage medium. The method comprises: performing uplink transmission based on configuration uplink transmission indication information; and adding a bias before a cyclic prefix of a first symbol of CG-PUSCH before first uplink transmission (S10). Therefore, resource conflicts between different users can be avoided by cyclic prefix extension, and / or DCI overhead can be saved.

The application provides an OFDM chaotic communication method and device for reference signal multiplexing, equipment and medium. A to-be-transmitted bit stream is divided into b k reference bits and b i index bits, each reference bit is mapped according to a 0 or 1 value to trigger a generator group composed of two heterogeneous chaotic mappings, to generate b k chaotic sequences with a length of β to form a reference sequence set R; b i index bits are evenly divided into G groups, each group selects one chaotic sequence from R as a data-carrying sequence through an index selector; R and the G data-carrying sequences are superimposed through OFDM modulation to form a transmission signal. The receiving end separates the reference and index data parts through de-cyclic prefix, serial-parallel conversion and FFT, restores b k reference bits through a deep neural network demodulation model, and reconstructs R, and then performs cross-correlation detection on the index data with the reconstructed R to restore b i index bits. Thus, the reference signal synchronously completes reference transmission and user information transmission on the same time-frequency and power resources, and eliminates the pure overhead of the reference signal.

Methods, systems, and devices for wireless communications are described. In some systems, a network entity may map on-off keying (OOK) symbols of an OOK sequence to an orthogonal frequency division multiplexing (OFDM) waveform including at least one OFDM symbol with a cyclic prefix. Each OOK symbol of the OOK sequence may be mapped to at least one segment of an integer quantity of segments of the OFDM waveform based on an OOK data rate. A duration of each segment of the integer quantity of segments of the OFDM waveform may be based on the OOK data rate and a ratio between a duration of the cyclic prefix and a duration of a remainder of the OFDM symbol. The network entity may transmit the OFDM waveform via a set of frequency resources. A user equipment (UE) may receive and decode the OFDM waveform to obtain the OOK sequence.

This invention discloses a probabilistic shaping encryption method, decryption method, encryption system, and decryption system based on symbol-level chaotic tags in the field of optical communication transmission technology. The method includes: performing serial-to-parallel conversion on the signal to be transmitted to obtain a parallel signal; generating a first chaotic encryption sequence, a second chaotic encryption sequence, and a third chaotic encryption sequence using a three-dimensional chaotic system; performing symbol-level chaotic tag conversion on the parallel signal using the first chaotic encryption sequence to obtain a symbol-level encrypted signal; performing asymmetric polygon constellation mapping on the symbol-level encrypted signal to obtain an 8QAM constellation; performing symbol masking and subcarrier masking on the second and third chaotic encryption sequences to obtain a first scrambling matrix and a second scrambling matrix; scrambling the 8QAM constellation using the first and second scrambling matrices, performing an inverse Fourier transform, and adding a cyclic prefix to obtain an encrypted transmittable signal.