695 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.

In an example from the perspective of a first User Equipment (UE), in response to performing successful listen before talk (LBT), the first UE determines a channel occupancy time (COT). The first UE determines whether or not a second sidelink transmission, to be performed by a second UE, is within the COT. The first UE determines information, associated with LBT type and / or cyclic prefix (CP) extension, for inclusion in a first sidelink transmission in the COT, wherein whether the information includes first information associated with LBT type and / or CP extension or the information includes second information associated with LBT type and / or CP extension is based on the determination of whether or not the second sidelink transmission is within the COT. The UE transmits, to the second UE, the first sidelink transmission in the COT. The first sidelink transmission includes the information. The second sidelink transmission is associated with the first sidelink transmission.

A wireless communication method for use in a wireless terminal is disclosed. The method comprises performing a channel access procedure on a channel based on a transmission starting point for a sidelink transmission, wherein the transmission starting point is a cyclic prefix extension period before / preceding the first SL OFDM symbol of a SL slot configured for the sidelink transmission, and wherein the cyclic prefix extension period is determined based on a number of channel access procedures performed for the sidelink transmission.

A signal for wireless transmission is modulated by converting a serial sequence of symbols in the time domain into parallel symbol streams, transforming the parallel symbol streams into the frequency domain, mapping the resulting frequency domain signals onto subcarriers, converting the mapped signals into the time domain and converting the parallel time-domain signals into a serial signal. The serial signal is subjected to chirping and is transmitted to a receiver after adding a cyclic prefix (CP). The receiver removes the CP from the signal and, after de-chirping the prefix-less signal, converts the signal into parallel signals. The parallel signals are converted into the frequency domain for channel estimation, equalisation, and subcarrier mapping of detected symbols. The mapped symbols are transformed into the time domain before converting them into a serial stream of symbols.

The invention discloses a low-altitude target sensing method, a low-altitude target sensing device and a low-altitude target sensing system based on multi-base station cooperation. The low-altitude target sensing method comprises the following steps: performing down-conversion, cyclic prefix removal, discrete time sampling and DFT on a received time domain OFDM signal to obtain a frequency domain discrete signal observed quantity; smoothing the frequency domain discrete signal observed quantity into a plurality of sub-signal observed quantities by constructing a reconstruction rotation matrix and a reflection coefficient matrix; obtaining a parameter estimation result by using a four-dimensional joint ESPRIT algorithm; clustering the positioning estimation result of each ISAC base station by setting a threshold value; and based on the positioning estimation result of each ISAC base station, analyzing to obtain the real movement speed of the low-altitude target. Aiming at a one-transmitting-multiple-receiving multi-base-station cooperative sensing low-altitude target scene, multiple receiving stations cooperatively fuse the sensing data of each station, perform cooperative positioning on a low-altitude target, analyze the real three-dimensional speed of the target, fully utilize the observation information of each base station, and combine the good anti-interference performance and multi-carrier characteristics of OFDM signals, so that the multi-base-station cooperative sensing low-altitude target positioning method is realized. And multi-parameter joint estimation of the low-altitude target is realized.

A method by which a first device performs wireless communication and a device supporting same are provided. The method may comprise the steps of: acquiring information related to a resource for a sidelink-synchronization signal block (S-SSB); acquiring information about a first time domain for a first cyclic prefix extension (CPE) related to S-SSB transmission; performing the first CPE during the first time domain before the S-SSB transmission; and performing the S-SSB transmission on the basis of the resource.

Various aspects of the present disclosure relate to a UE that receives a resource allocation for wireless communication associated with using at least two antennas of the UE, and the wireless communication includes a respective signal associated with each respective antenna of the two antennas. The UE can multiplex a set of modulation symbols associated with the two antennas based on a cyclic-prefix orthogonal frequency-domain multiplex operation. The UE can then transmit the respective signal associated with each respective antenna of the two antennas based on the multiplexing, where a delay of a first signal associated with a first antenna relative to a second signal associated with a second antenna is based on the resource allocation for the wireless communication.

Wireless communications systems and methods related to use of cyclic prefix (CP) extensions for channel occupancy time (COT) sharing among sidelink user equipment devices (UEs) are provided. A first UE detects a first sidelink transmission in a COT, the COT for sharing with multiple sidelink UEs including the first sidelink UE. The first UE may determine a CP extension length for transmitting a second sidelink transmission after the first sidelink transmission, where a gap duration between the first sidelink transmission and the second sidelink transmission satisfies a listen-before-talk (LBT) gap time threshold. The first UE may apply a CP extension having the CP extension length to the second sidelink transmission and transmit, to a second sidelink UE, the second sidelink transmission with the CP extension.

The invention discloses a sensing signal transmission method and device, equipment, a medium and a product. The method is applied to first equipment and comprises the following steps: acquiring a first sensing signal and a target prefix length; intercepting a cyclic prefix signal with a target cyclic prefix length from the first sensing signal; splicing the cyclic prefix signal and the first sensing signal to obtain a second sensing signal, the second sensing signal occupying a plurality of OFDM symbols; and sending a second sensing signal to a second device, so that the second device obtains the target cyclic prefix length, and splitting a cyclic prefix signal of the target cyclic prefix length from the second sensing signal to obtain a first sensing signal. By adjusting the length of the cyclic prefix signal, the device can sense a long-distance target, the problem of inter-symbol interference is solved, the sensing performance is improved, and the sensing coverage distance can be effectively improved.

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.

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 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.

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.

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.

In an aspect, a sidelink network device may determine a first cyclic prefix extension (CPE) for transmitting a set of one or more consecutive sidelink positioning reference signals (SL-PRS) in a slot of a resource pool that supports SL-PRS transmissions in a shared radio band, wherein the set of one or more consecutive SL-PRS are preceded by a transmission gap in the slot, and wherein the first CPE has a duration equal to or less than a single symbol duration and the duration is determined independent of other CPEs in the slot. The sidelink network device may transmit the set of one or more consecutive SL-PRS in the slot of the resource pool that supports transmission of SL-PRS in the shared radio band, wherein the first CPE is included after the transmission gap in the slot.

The invention provides a data transmission method and device and a storage medium, relates to the technical field of communication, and is used for improving spectrum efficiency. The method comprises the following steps: dividing data to be transmitted into N first sequences; in the N first sequences, M first sequences respectively correspond to a single-carrier sub-band, K first sequences respectively correspond to a multi-carrier sub-band, N is a positive integer, M is a positive integer smaller than N, and K is equal to N-M; based on the N first sequences, N second sequences are obtained, and the N second sequences comprise sequences obtained after Fourier inverse transformation and cyclic prefix adding operation are sequentially carried out on the first sequences corresponding to the multi-carrier sub-bands, and sequences obtained after cyclic prefix adding operation is not carried out on the first sequences corresponding to the single-carrier sub-bands; obtaining a time domain data sequence based on the N second sequences; and transmitting the time domain data sequence on the transmission resource of the data to be transmitted.

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 discloses an OTFS waveform modulation method based on DFrFT time-frequency analysis, solves the problems of fixed time-frequency resolution, signal fuzziness and cross term interference existing in Heisenberg (Wigner) transformation in an OTFS system in a high dynamic scene, and belongs to the technical field of information and communication. The method provided by the invention comprises the following steps of: modulating sending data to obtain a DD domain signal, firstly performing inverse symplectic Fourier transform on the DD domain signal, then converting the DD domain signal into a time domain signal block through IDFrFT transform, adding a cyclic prefix (CP) to the time domain signal block, performing row-column transform, and then transmitting the time domain signal block; a cyclic prefix (CP) is removed from a signal received by a receiving end, the signal is converted into a time domain signal block subjected to parallel processing, a time-frequency domain signal is obtained after the time domain signal block is subjected to DFrFT transformation, then the time-frequency domain signal is mapped back to a DD domain through the Sextile Fourier transform, a DD domain signal is obtained, the DD domain signal # imgabs0 # is demodulated, and recovered sending data are obtained. The IDFrFT provided by the invention obviously reduces the calculation complexity.

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.

The embodiment of the invention provides a communication method, a communication device and a storage medium, relates to the technical field of communication, and is used for improving the precision of channel estimation, and the communication method comprises the steps: obtaining a to-be-transmitted first data sequence and a first reference sequence, adding a cyclic prefix sequence and a cyclic suffix sequence to the first reference sequence to obtain a second reference sequence, and placing the latter part of the second reference sequence in front of the first data sequence, and placing the former part of the second reference sequence in back of the first data sequence to obtain a second data sequence, processing the second data sequence to obtain a third data sequence, and sending the third data sequence.

The invention relates to the technical field of signal demodulation, and discloses an OFDM (Orthogonal Frequency Division Multiplexing) signal demodulation method of a signal analyzer. According to the invention, through joint optimization of a synchronous detection and frequency offset compensation mechanism, the symbol positioning precision in a low signal-to-noise ratio environment is improved, and subcarrier interference caused by a cyclic prefix pseudo peak value and frequency offset phase ambiguity is effectively suppressed; a time-frequency two-dimensional adaptive interpolation strategy is adopted to enhance the robustness of channel estimation to non-uniform pilot frequency distribution and a fast time-varying channel, and data subcarrier response distortion is reduced; in combination with minimum mean square error equalization and dynamic noise reduction processing, inter-symbol interference and a noise accumulation effect are greatly weakened, and the bit error rate performance of a high-noise scene is improved; the error control technology is updated through a closed-loop channel, a demodulation error propagation path is blocked, and cooperative improvement of system demodulation stability and precision in a complex multi-path environment is achieved.

The invention relates to the technical field of wireless communication, and particularly discloses an authorization-free random access method for the Internet of Things of a low-orbit satellite. Comprising the following steps: S01, a terminal generates a SC-IFDMA symbol modulated by BPSK, and a cyclic prefix is added to the SC-IFDMA symbol to generate a data signal; s02, the terminal selects a plurality of pilot frequency sequences from the pilot frequency sequence set to form a pilot frequency signal, forms a data packet by using the pilot frequency signal and the data signal, and sends the data packet to a satellite; s03, the satellite performs pilot frequency detection on the received data packet, compares the pilot frequency detection result with a detection threshold value, identifies a pilot frequency sequence selected by an active user, and performs cyclic prefix removal on the received data packet to obtain the data packet without the cyclic prefix; and step S04, the satellite carries out parameter estimation on the active user by using the received pilot signal and the detected pilot sequence set, ML detection decoding of the active user data signal is completed, and a decoded signal is obtained.

According to embodiments, a method performed by a radio unit (RU) may comprise an operation of receiving configuration information for a remote interference management (RIM)-reference signal (RS) from a distributed unit (DU). The method may comprise an operation of receiving a message containing bit data for the RIM-RS from the DU. The method may comprise an operation of generating a complex-valued symbol corresponding to the bit data for the RIM-RS. The method may comprise an operation of generating a RIM-RS signal by performing at least one of phase rotation or phase difference compensation for the complex-valued symbol on the basis of the configuration information. The method may comprise an operation of generating a baseband signal corresponding to the RIM-RS signal on the basis of an inverse fast fourier transform (IFFT) and cyclic prefix (CP) insertion of the RU.

The invention provides an information processing method and device, network equipment and a terminal, and relates to the technical field of communication. The method comprises the following steps that: network equipment determines the time domain length of a first cyclic prefix (CP) transmitted by a terminal signal according to transmission configuration related information of the terminal; the network equipment sends indication information to the terminal; wherein the indication information is used for indicating the time domain length of the first CP. According to the invention, the problem that the current CP time domain length configuration cannot meet more application scene requirements can be solved.

The invention discloses a multipath effect suppression method for 2.4 GHz radio frequency identification. The multipath effect suppression method comprises a transmitting end processing flow and a receiving end processing flow. A transmitting end carries out pulse code modulation on an analog signal to obtain a digital signal, blocks the digital signal after channel coding, and distributes the digital signal to subcarriers through quadrature amplitude modulation; and generating a time domain OFDM symbol through IFFT (Inverse Fast Fourier Transform), adding a cyclic prefix and a synchronization head, converting into an analog baseband signal, and performing up-conversion, filtering, amplification and radiation. The receiving end amplifies the signal, down-converts the signal to a baseband, filters the signal and converts the signal into a digital signal; the method comprises the following steps of: synchronizing header frame alignment, recovering a coding bit stream through FFT (Fast Fourier Transform) and QAM (Quadrature Amplitude Modulation) demodulation, carrying out CRC (Cyclic Redundancy Check) after decoding and merging, returning ACK (Acknowledgement Character) if According to the method, the multipath effect can be effectively inhibited, and the integrity of received data is improved.

The invention provides a communication method and device, and relates to the field of communication, in the method, under the condition that the sum of the cyclic prefix of a signal and the length of a symbol is not changed, a symbol structure with multiple cyclic prefix lengths exists, for example, the cyclic prefix length of a first symbol structure is not equal to the cyclic prefix length of a second symbol structure, and the sum of the cyclic prefix length of the first symbol structure is not equal to the cyclic prefix length of the second symbol structure. The symbol length of the first symbol structure is not equal to the symbol length of the second symbol structure, and the sum of the cyclic prefix length and the symbol length of the first symbol structure is equal to the sum of the cyclic prefix length and the symbol length of the second symbol structure, so that the cyclic prefix length can be dynamically adjusted under the condition that the subcarrier interval is not changed, and the performance of the device is improved. Therefore, the sensing distance is flexible and adjustable, and various scenes of practical application can be met.

Methods and apparatus for communicating zero-padded signals related to zero padding of a transmission symbol that is to be transmitted in a wireless communication network. Signaling indicative of such zero padding is communicated between communication devices, and a zero-padded transmission symbol to which the zero padding has been applied, as well as a cyclic prefix preceding the zero-padded transmission symbol, are transmitted by a transmitting device and received by a receiving device. In some embodiments, the zero padding includes both head zero padding at a head of the transmission symbol and tail zero padding at a tail of the transmission symbol. Zero padding may also be applied to a reference signal sequence upon which a reference signal for channel estimation is based.

The embodiment of the invention provides a time domain sampling point extension method and device, a storage medium and an electronic device. The method comprises the following steps: determining a weight matrix of a first communication symbol through a sensing symbol subsequent to the first communication symbol; adjusting the first communication symbol according to the weight matrix to generate a second communication symbol; and expanding the time domain sample point of the cyclic prefix of the sensing symbol according to the time domain sample point of the second communication symbol. By adopting the technical scheme, the problem that a solution of a cyclic prefix expanding method which is compatible with an existing frame structure of an NR system and flexibly supports various sensing distances is not provided in the related technology is solved.