480 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 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.

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.

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 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 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 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 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 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.

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.

An apparatus and system to enable URLLC PUSCH repetitions in the unlicensed spectrum are described. The number of consecutive PUSCH repetitions indicated in the RRC parameter is reinterpreted as the number of transmission occasions over which the UE is able to attempt CCA. An orphan symbol is used to provide a DMRS transmission or cyclic prefix of the PUSCH transmission causing the orphan symbol. Whether a CG-UCI is piggybacked in a PUSCH transmission, and whether DCI-DFI is used, is dependent on whether cg-RetransmissionTimer is configured.

Aspects relate to enhancing communication between network entities and ambient IoT devices using a cyclic prefix (CP) transparent on-off keying (OOK) waveform. An ambient IoT device may be configured to receive an OOK orthogonal frequency-division multiplexing (OFDM) waveform that includes a CP. The ambient IoT device may be configured to sample symbols of the received OOK OFDM waveform at a pre-defined sampling rate. The pre-defined sampling rate may be based upon a pre-defined duration of the symbols of the received OOK OFDM waveform. In particular, the pre-defined duration of each of the symbols of the received OOK OFDM waveform may be defined such that a last OOK OFDM symbol duration is set to be the same as a first OOK OFDM symbol duration, in which, the first OOK OFDM symbol includes the CP.

A user equipment (UE) is configured to establish a connection to a fifth generation (5G) new radio (NR) network, wherein the connection is configured to utilize cyclic prefix (CP)-orthogonal frequency division multiplexing (OFDM) waveform and demodulation reference signal (DMRS) type 1, receive a DMRS port indication configured to indicate one or more DMRS ports assigned to the UE, wherein single symbol DMRS type 1 is configured to support up to eight DMRS ports and two symbol DMRS type 1 is configured to support up to sixteen DMRS ports and perform a transmission operation or a reception operation using the one or more DMRS ports assigned to the UE.

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.

The present application relates to the technical field of communications, and provides a sensed target identification method and apparatus, a sensing device, and a storage medium. An implementation solution is: sending a sensing reference signal to a sensing and communication environment, wherein a comb factor of the sensing reference signal is greater than a set value, an OFDM symbol in the sensing reference signal comprises NS time-domain sample points, and a cyclic prefix in the sensing reference signal comprises NCP time-domain sample points; detecting the sensing and communication environment to obtain a sensing echo signal, wherein the sensing echo signal is a signal reflected from the sensing reference signal by a sensed target in the sensing and communication environment; performing radio-frequency preprocessing on the sensing echo signal to obtain a first baseband signal, and deleting the first NS / 2 time-domain sample points and the last NCP time-domain sample points in the first baseband signal to obtain a second baseband signal; and identifying a distance between the sensed target and a sensing device on the basis of the second baseband signal. In this way, the sensing ranging range can be expanded, and it can be ensured that time-frequency resources of original systems are not wasted.

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.

The invention discloses a sensing target identification method and device, sensing equipment and a storage medium, and relates to the technical field of communication. According to the implementation scheme, a sensing reference signal is sent to a sensing environment; wherein the comb factor of the sensing reference signal is greater than a set value, an OFDM symbol in the sensing reference signal comprises NS time domain sampling points, and a cyclic prefix in the sensing reference signal comprises NCP time domain sampling points; detecting the sensing environment to obtain a sensing echo signal; wherein the sensing echo signal is a signal reflected by the sensing reference signal through a sensing target in the sensing environment; performing radio frequency preprocessing on the sensing echo signal to obtain a first baseband signal; deleting the foremost # imgabs0 # time domain sample points and the rearmost NCP time domain sample points in the first baseband signal to obtain a second baseband signal; a distance between the sensing target and the sensing device is identified based on the second baseband signal. Therefore, not only can the sensing ranging range be increased, but also the time-frequency resources of the original system can be ensured not to be wasted.

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.

There is provided a method of switching between Discrete Fourier Transform spread Orthogonal Frequency Division Multiplexing (DFT-S-OFDM) and Cyclic Prefix-Orthogonal Frequency Division Multiplexing (CP-OFDM) in a mobile communication system. The method is performed by a g NodeB (gNB), and includes (a) preparing a Medium Access Control (MAC) layer communication message that specifies which of DFT-S-OFDM or CP-OFDM will be used for an uplink (UL) waveform, and (b) dynamically transmitting the message to user equipment. There is also provided an apparatus that performs the method, and a storage device that contains instructions that cause a processor to perform the method.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may transmit uplink signaling via a cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) waveform or a discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) waveform. A configured resource muting pattern may be based on or may reuse a phase tracking reference signal (PTRS) frequency pattern. The resource muting pattern may mute every other resource element (RE) of an uplink symbol or uplink subband of subband full duplex (SBFD) symbols, and the transmitting UE may perform uplink rate matching (e.g., applying a zero power PTRS pattern and inserting the zero power REs after a DFT spread operation, oversampling after a DFT-s-OFDM procedure and doubling a size of an IFFT, or repeating an input sequence to a DFT and doubling a size of the IFFT, power boosting, updating a power control calculation, etc.).