311 results about "Cyclic prefix" patented technology

A wireless device transmits radio resource control (RRC) messages comprising capability parameters indicating support, for a layer 1 and / or layer 2 triggered mobility (LTM) procedure and within a measurement window, for synchronization signal block (SSB) based inter-frequency layer 1 reference signal received power (RSRP) measurement of a candidate cell with a received time difference, between the candidate cell and a serving cell, larger than a cyclic prefix (CP) length. The device receives RRC messages indicating a measurement window. The device receives a command indicating an uplink transmission of a L1 RSRP report of the candidate cell. The first cell and the candidate cell are inter-frequency configured. The device transmits the L1 RSRP report measured over one or more first SSBs of the candidate cell. The first SSBs are received: via the candidate cell with the received time difference being greater than the CP length, and within the measurement window.

The invention discloses an adaptive modulation anti-multipath unmanned aerial vehicle swarm communication method and system based on MIMO-OFDM, and relates to the technical field of wireless communication, and the method comprises the steps: receiving a down-conversion baseband; synchronization and compensation are carried out; removing a cyclic prefix and carrying out fast Fourier transform; estimating a channel and noise on the training and pilot frequency, and correcting a common phase; performing frequency domain equalization and soft decision, forward error correction and cyclic redundancy check according to the estimation to obtain a control parameter, decoding a payload according to the control parameter, and performing statistics to form a link quality indication; modulating coding, bandwidth and spatial mode, configuring mapping, power and weight, and packaging physical layer protocol data; carrier sensing conflict avoiding sending, confirmation and retry are adopted to generate media access statistics; and the routing selects the next-hop multi-hop forwarding according to the transmission quality, and performs end-to-end statistics and recharge. Through cooperation of hierarchical synchronization and phase correction with cyclic prefix and FFT, crosstalk is suppressed, channel noise scale optimization soft decision is robust, data decoupling is controlled, and end-to-end availability is improved through multi-hop self-healing recharge.

A wireless device receives one or more configuration parameters indicating cyclic prefix extension (CPE) starting positions for physical sidelink shared channel (PSSCH) transmissions and a plurality of priorities for the PSSCH transmissions. The CPE starting positions are configured for each priority. A plurality of CPE durations are based on the CPE starting positions. The wireless device receives a physical downlink control channel (PDCCH) indicating a starting symbol of a PSSCH transmission. The wireless device determines a first symbol based on a first CPE duration. The first symbol is before the first CPE duration from the starting symbol. The first CPE duration is based on a first CPE starting position that is pre-defined. The first symbol is after a processing time from the last symbol of the PDCCH. The wireless device transmits the PSSCH transmission and a CPE with a second CPE duration.

The invention belongs to the technical field of wireless communication, and particularly relates to a communication method and device based on MQAM-OFDM modulation, a medium and equipment, and the method comprises the steps: generating a random data source, carrying out MQAM modulation, generating a serial modulation signal, carrying out 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 a time domain OFDM symbol, and adding a cyclic prefix to obtain a sending signal; transmitting the sending signal based on a multipath channel model; receiving a sending signal and removing a 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 obtaining 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; and performing MQAM demodulation on the frequency domain symbol estimation value, and recovering the parallel data stream into the serial bit stream to complete data recovery.

One or more systems, devices, and / or methods may address signal design for ultra-low power receivers. Transmitter and receiver architectures capable of generating signals and waveforms supporting the operation of ultra-low-power receivers and compatible with OFDM-based signals are disclosed. In some cases, there may be procedures that address one or more of the following: device detection of an on-off keying (OOK) modulated sequence with redundant bits corresponding to OFDM symbols' cyclic prefix; device detection of an OOK modulated sequence with dynamic bit duration corresponding to long and short OFDM symbols; device reception of an OOK modulated DCI / message with redundant bits corresponding to OFDM symbols' cyclic prefix; and / or, device reception of an OOK modulated DCI / message with dynamic bit duration corresponding to long and short OFDM symbols.

The invention belongs to the technical field of wireless communication systems, and particularly relates to a GFDM waveform design method for a jungle communication system. The method mainly comprises two parts of performance test and waveform design, and in the GFDM jungle communication system, a receiving end tests the bit error rate and the symbol transmission rate of the GFDM jungle communication system according to a known pilot signal sent by a sending end; a utility function is confirmed, and waveform design parameters including a cyclic prefix and a roll-off coefficient are optimized step by step by applying a genetic algorithm; through careful construction and parameter optimization of each part, the invention aims to improve the overall performance of the jungle communication system, can give full play to the potential of the GFDM technology, and meets the diversified requirements of jungle communication.

Some aspects of the present disclosure provide methods and devices that enable a framework for selection or configuration, or both, of a waveform for use in integrated sensing and communications (ISAC). Use of the framework provides a new waveform, based in part on various criteria, which provides a trade-off among different ISAC requirements. Therefore, when different criteria are important for a particular implementation, a waveform that best meets the requirement of those criteria may be used. The various criteria may include factors such as hardware constraints at the UE, radio frequency (RF) chirp generation or detections capability at the UE, spectral emission or leakage such as OOBE, sensing performance, and sensing complexity. In some embodiments, a cyclic prefix (CP) is provided to use the chirp-based sensing waveforms as a demodulated reference signal (DMRS). In some embodiments, the CP enables alignment with a communication signal frame.

An example user equipment (UE) device for wireless communication includes a communication interface; and one or more processors coupled to the communication interface, wherein the one or more processors are configured to: select a first cyclic prefix extension (CPE) for a transmission over a shared sidelink band via the communication interface; perform a listen before talk (LBT) procedure on the shared sidelink band; in response to the LBT procedure, determine that the shared sidelink band is LBT-blocked; in response to the shared sidelink band being LBT-blocked, select a second CPE larger than the first CPE; and transmit the second CPE and the transmission over the shared sidelink band via the communication interface.

The invention provides a synchronization adjustment method and system, computer equipment and a storage medium, and relates to the technical field of communication, and the method comprises the steps: obtaining synchronization information and an air interface signal of a current cell where a terminal is located; generating a first time domain signal based on the synchronization information; performing down-sampling processing on the air interface signal to obtain a second time domain signal; performing correlation calculation on the first time domain signal and the second time domain signal to obtain a correlation value sequence; and carrying out weight gravity center estimation on a peak value in the correlation value sequence, determining a timing offset, and adjusting a windowing position according to the timing offset to complete synchronous adjustment. According to the synchronization information disclosed by the invention, the accurate timing position is obtained by carrying out weight-based correlation calculation on the synchronization information and the air interface signal, so that the time drift error of the terminal in the signal receiving process is counteracted. The method is especially suitable for scenes with wide coverage and multipath delay exceeding the cyclic prefix length, can significantly reduce inter-symbol interference, and improves the synchronization precision and overall demodulation performance of a terminal receiver.

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.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a network node, a configuration that indicates one or more cyclic prefix extension (CPE) starting positions. The UE may transmit a sidelink transmission using a selected CPE starting position, of the one or more CPE starting positions, based at least in part on the configuration received from the network node. Numerous other aspects are described.

Methods, systems, and apparatuses are provided for listen-before-talk (LBT) mode for random access response (RAR) in a wireless communication system so that RAR indication of channel access type and cyclic prefix (CP) extension can be more efficient. A method of a User Equipment (UE) can comprise initiating a random access procedure, receiving a RAR, wherein the RAR comprises a channel access type indication, and determining whether to perform LBT for a Msg3 based on the channel access type indication in RAR.

The invention discloses an OFDM (Orthogonal Frequency Division Multiplexing) signal time-frequency collaborative equalization distortion suppression method, and belongs to the field of wireless communication. According to the invention, the problems of high complexity and poor transmission reliability of the existing short cyclic prefix method are solved. According to the invention, an OFDM system based on time domain oversampling and frequency domain interpolation equalization is adopted at a receiving end, and the oversampling algorithm can enhance the power of useful signals by properly broadening an equalization frequency band, so that the equalization effect is enhanced; according to the frequency domain interpolation equalization algorithm, weighted interpolation processing is carried out on frequency domain receiving signals, so that spectrum details can be better captured, and compensation and correction of an energy migration phenomenon generated by spectral lines in a frequency band due to a channel effect are realized. Through time-frequency cooperative processing at a receiving end, interference can be efficiently suppressed, stable and reliable demodulation precision and communication quality can be ensured, frequency spectrum resource loss caused by additional extension of a cyclic prefix can be avoided, and the frequency spectrum utilization efficiency of the system is further remarkably improved. The method can be applied to the field of wireless communication.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first user equipment (UE) may receive first sidelink control information (SCI) indicating a first reserved resource for a second UE. The UE may receive second SCI indicating a second reserved resource for a third UE. The UE may generate an indication of inconsistent cyclic prefix extensions (CPEs) based at least in part on a first CPE of the first reserved resource and a second CPE of the second reserved resource. The UE may transmit the indication to one or more of the second UE or the third UE. Numerous other aspects are described.

An apparatus configured to: receive a downlink signal; determine whether a TA stored at the apparatus is valid based, at least partially, on a reception timing of the received downlink signal and a delay spread value; and initiate small data transmission with a pre-configured uplink resource based, at least partially, on the determination that the TA is valid. An apparatus configured to: transmit, to a UE, a configuration comprising information related to TA validation for the UE, wherein the information comprises at least one of: an indication of a value configured to indicate a fraction of a cyclic prefix length of a symbol for reception of an uplink transmission from the UE, or a delay spread value; transmit a downlink signal; and receive a SDT based, at least partially, on the fraction of the length of the cyclic prefix, the transmitted downlink signal, and the delay spread value.

Disclosed are techniques for performing wireless communication. In some aspects, a first user equipment (UE) may determine that one or more physical sidelink feedback channel (PSFCH) instances are scheduled during a channel occupancy time (COT) corresponding to a sidelink transmission by the first UE to a second UE. In some examples, the first UE may transmit a COT maintenance signal during the one or more PSFCH instances, wherein at least one PSFCH symbol in the COT maintenance signal has a cyclic prefix extension.

A method according to an embodiment of the present specification comprises a step of transmitting a signal to a second device on the basis of repetition. The repetition is performed on the basis of a cyclic prefix (CP) handling method.

The invention relates to the technical field of wireless optical communication, and discloses a multi-carrier wireless optical communication physical layer security authentication system and method.The receiving end of the system comprises a multi-receiver joint judgment module, a data gating module, an information sink and at least three receivers; each receiver comprises an optical detector, a cyclic prefix removal module, an FFT (Fast Fourier Transform) module, a receiving end key update storage and watermark generation module, a channel estimation and watermark extraction module, a subcarrier authentication module, a multi-carrier self-adaptive decision judgment module and a multi-carrier integration module; oFDM frequency domain channel response is used as an implicit fingerprint, a self-adaptive switching decision strategy is executed according to the average signal-to-noise ratio, fine recognition of legal device position features is achieved without ranging hardware, IM / DD can be adapted, the problem of imitation attack and replay attack authentication of attackers is effectively solved from the physical mechanism, and the method has the advantages of being high in practicability and high in practicability. And the accuracy and robustness of physical layer authentication are obviously improved.

Embodiments of the present application provide a random access method. In the method, the compensation amount of a transmission time of a random access preamble is related to the length of a cyclic prefix in a format corresponding to the random access preamble, thereby expanding available resources of a terminal device.

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 invention discloses a multi-user frequency conversion photoelectric fusion transmission method and system under a high bandwidth, and relates to the technical field of communication, and the method comprises the steps: obtaining a user original data stream, carrying out the encryption and up-conversion of the user original data stream, obtaining encrypted data, and enabling the user original data stream to correspond to the communication content of a user; performing optical fiber channel transmission on the encrypted data, performing demodulation, cyclic prefix removal and down-conversion on the transmitted encrypted data to obtain recovered user original data, and decrypting the recovered user original data to obtain communication content of the user; parallel transmission of data can be realized, and the transmission rate and the transmission capacity of the system are obviously improved.

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.

Methods, systems, and devices for wireless communications are described. Various aspects generally relate to wireless communication and more particularly to packet designs for energy harvesting (EH) -capable devices that include a radio frequency (RF) on signal. Some aspects more specifically relate to timing and durations of RF on signals relative to other portions of the packet. The RF on signal may outside of a preamble of the packet, inside of the preamble of the packet, outside of a start indicator of the packet, or part of the start indicator of the packet. In some examples, the preamble may be aligned with a beginning of a symbol, or aligned with an end of a symbol. In some examples, a length of the RF on signal may be independent of a duration of a physical reader-to-device channel message in the packet. In some examples, the packet may include a cyclic prefix.

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.

Provided are a method for a first device to communicate wirelessly and a device for supporting same. The method may comprise the steps of: acquiring information related to a plurality of cyclic prefix extension (CPE) starting candidate positions; selecting a CPE starting position from among the plurality of CPE starting candidate positions on the basis of the priority of sidelink (SL) transmission; and transmitting SL on the basis of the CPE starting position.

This application provides a wireless communication method and apparatus. The method includes: determining N first symbols in a first slot, where N is a positive real number greater than 1 and less than M, M is a quantity of symbols included in the first slot, M is a positive integer, a frequency domain resource corresponding to the first slot is an unlicensed spectrum, and the first symbols are unoccupied symbols in the first slot; and sending a first signal to a terminal device on the N first symbols. The first signal includes at least one of the following: a symbol copied from a second slot, a to-be-sent first transport block, or a cyclic prefix extension. The second slot is a next slot of the first slot. According to the disclosure, a channel resource in an unlicensed spectrum can be effectively occupied, thereby reducing waste of channel resources.

The invention provides an SSB time-frequency synchronization method and device, and relates to the technical field of mobile communication. The method comprises the following steps: receiving a synchronization signal block SSB signal sent by a base station; processing the SSB signal to obtain a target time domain sequence generated after processing, and performing sliding correlation on the target time domain sequence to obtain a time domain correlation value sequence; acquiring a peak value of the time domain correlation value sequence, and performing time synchronization of the SSB signal based on time offset corresponding to the peak value; after the time synchronization of the SSB signal is completed, obtaining a cyclic prefix (CP) removal sequence corresponding to the time domain sequence of the SSB signal, and obtaining a pre-frequency offset PSS time domain sequence generated after a primary synchronization signal PSS time domain sequence is subjected to multiple times of frequency offset adjustment; performing correlation calculation based on the CP-removed sequence and the pre-frequency offset PSS time domain sequence to determine a target estimated frequency offset; and completing frequency synchronization of the SSB signal based on the target estimation frequency offset. According to the invention, the PSS can be locked quickly and accurately to realize time-frequency synchronization.

An apparatus may be a wireless device or UE that may be configured to transmit an SRS using a first CP length configuration, wherein the first CP length configuration is different from a second CP length configuration associated with communication. The apparatus may also be configured to receive a reflected SRS based on transmitting the SRS and / or receive an indication of at least one value associated with a corresponding at least one object in an environment of the wireless device based on the SRS. The apparatus may be a network device configured to receive a reflected SRS using a first CP length configuration. The apparatus may also be configured to transmit to the wireless device an indication of at least one value associated with a corresponding at least one object in an environment of the wireless device based on the reflected SRS.

The invention discloses a clutter cancellation method for a common inductance comb regulation and control multiplexing signal, and relates to the technical field of radars, and the method comprises the steps: at a transmitting end, coupling a common inductance integrated signal of multi-carrier comb regulation and control multiplexing to a reference receiving channel, and forming a reference signal; at a receiving end, K periodic reference data and echo data are respectively taken from the reference signal and the echo, and K reference pulses and echo pulses of the radar are demodulated; connecting end to end to form a long-time filtering reference signal and a filtering preprocessing signal; a filtering weight vector is obtained through normalization minimum mean square processing to complete long-time assistance; c-NLMS processing is carried out on the reference pulse and the echo pulse in the same period, and short-time cancellation is completed; and converting a short-time cancellation result to a distance Doppler domain to obtain a distance Doppler map after clutter cancellation. According to the method, a mobile communication cyclic prefix signal structure is fully utilized, rapid steady-state cancellation of short pulses is realized, and the Doppler dispersion effect of strong ground clutters is greatly inhibited.

The embodiment of the invention provides a voltage regulation circuit, a chip and electronic equipment. The circuit comprises a power amplification module, and the power supply input end of the power amplification module is used for being externally connected with a first power supply; the power amplification module is used for amplifying the input first signal; the first signal comprises a cyclic prefix (CP) signal and an effective data signal; the first end of the first energy storage module is electrically connected with the power supply input end of the power amplification module, and the second end of the first energy storage module is electrically connected with the grounding end; the first energy storage module is used for providing stable power supply voltage for the power amplification module; and the resonance voltage regulation module is electrically connected with the power supply input end of the power amplification module, and the resonance voltage regulation module is used for obtaining the target voltage and regulating the voltage at the power supply input end of the power amplification module to the target voltage in the first time. The efficiency of the power amplifier is improved.