507results about "Carrier regulation" patented technology

The invention relates to a channel estimation method based on frequency domain deviation compensation and dynamic DCT denoising, and belongs to the technical field of wireless communication. The method comprises the following steps: establishing a wireless channel model and an OFDM system model; estimating the frequency offset in the received signal by using the phase rotation characteristic of the pilot signal; calculating a preliminary channel frequency domain response # imgabs2 # at a pilot frequency position through a least square criterion based on the compensation signal # imgabs1 #; obtaining a receiving pilot frequency signal # imgabs4 # according to the sending pilot frequency Xp and the roughly estimated channel frequency response # imgabs3 #; estimating a current signal-to-noise ratio SNRest based on the pilot frequency signal # imgabs5 # and a noise power ratio; and establishing an adaptive DCT denoising strategy based on a signal-to-noise ratio threshold, and selecting different denoising strategies according to different signal-to-noise ratios to perform denoising processing on # imgabs6 # to obtain final channel estimation # imgabs7 #. The adaptive denoising strategy design of the invention effectively balances the relationship between noise suppression and channel structure fidelity, and improves the precision and stability of overall channel estimation.

The invention relates to the technical field of ecological system service function evaluation. The invention relates to a frequency offset correction algorithm in HPLC (High Performance Liquid Chromatography) + HRF (High Radio Frequency) dual-mode communication. The method comprises the following steps: S1, collecting phase sequence data from an HPLC communication link, collecting frequency offset estimation data and corresponding confidence data from an HRF communication link, and adaptively adjusting a preset detection threshold value of the phase sequence data according to the confidence data; s2, performing pulse abnormal sample point detection and elimination on the phase sequence data according to the adjusted preset detection threshold value; according to the method, the detection threshold is dynamically adjusted through the confidence data, so that the anomaly detection process can be matched with the current interference environment in real time, the integrity of the phase sequence data is maintained, and the problem of insufficient adaptability of a fixed detection threshold in an electromagnetic interference dynamic change scene is solved; and a more reliable phase data basis is provided for subsequent interpolation compensation and frequency offset estimation, so that the frequency offset correction precision of the dual-mode communication system is improved.

The invention discloses a satellite signal distortion compensation and data reconstruction method, system and device and a medium, and belongs to the technical field of satellite communication, and the method comprises the steps: obtaining and processing a satellite communication time domain signal, obtaining a time-frequency graph and a local feature vector, calculating the local feature vector through an encoder, obtaining a global feature, and carrying out the calculation of the global feature; splicing the global feature and the local feature vector to generate a fusion feature vector, and recovering the resolution of the time-frequency graph based on an end-to-end compensation network; and inputting a time-frequency graph and the fusion feature vector to obtain a phase compensation factor, compensating the time-frequency graph by using the phase compensation factor, reconstructing a time-domain signal through inverse short-time Fourier transform, splicing the fusion feature vector and a combined data type label, and inputting the spliced fusion feature vector and combined data type label into a trained neural network to realize semantic reconstruction. The method solves the problem of joint compensation of signal amplitude and phase, guarantees data integrity, gets rid of dependence on complex physical parameter estimation, and can quickly adapt to ionosphere change and multipath effect environment.

The embodiment of the invention provides a time-space synchronization method and device, electronic equipment and a medium, which are used for solving the problem of inaccuracy of a local clock in related technologies. In the embodiment of the invention, the electronic equipment combines the average deviation pseudo-range, the RTT jitter and the target frequency offset into the multi-dimensional observation vector, so that the error source of clock synchronization is fully covered. The time deviation and the frequency deviation of the clock are accurately and effectively determined through a Kalman filtering algorithm, recursive processing of observation vectors and dynamic estimation of the time deviation and the frequency deviation of the clock, and high-precision synchronization of the local clock in a complex environment is achieved in combination with the optimization capability of the Kalman filtering algorithm. And the time of the local clock is the time determined according to the time of the multiple clocks, so that the clocks are more accurate.

The invention discloses an HRF signal synchronization method, device and system of a dual-mode carrier communication system, and belongs to the technical field of power line carrier communication. The method comprises the following steps: dividing a frequency offset range into a plurality of frequency offset hypothesis intervals based on an allowable maximum residual frequency offset range; performing frequency offset pre-compensation on the received signal according to each frequency offset hypothesis interval to obtain multiple paths of frequency offset compensation signals, and performing cross-correlation processing on the multiple paths of frequency offset compensation signals and a local reference sequence to obtain multiple paths of cross-correlation value sequences; in any cross-correlation value sequence, performing self-correlation processing on cross-correlation values of adjacent symbol intervals to obtain a corresponding self-correlation sequence; correlation peak values corresponding to the frequency offset hypotheses are extracted from the multiple paths of self-correlation sequences respectively, the maximum correlation peak value is determined from the correlation peak values, and if the maximum correlation peak value is larger than a synchronization judgment threshold value, the corresponding position is determined to be the synchronization position. According to the invention, high-precision wireless signal synchronization is realized, and high-quality signal transmission is ensured.

The present invention discloses a hierarchical synchronous reception method for weak spread spectrum signals. Based on the long coherent accumulation mechanism, the method utilizes the difference in sensitivity of different spread spectrum code lengths to frequency deviation, and realizes efficient synchronous reception of signals by hierarchically capturing the code phase and compensating for the frequency deviation in steps. Compared with the traditional two-dimensional joint search (code phase and frequency) method, the present invention optimizes the search process into a one-dimensional search, avoiding the exhaustive search in the frequency dimension, thereby significantly reducing the computational complexity and improving the processing efficiency. The present invention adopts a strategy of capturing the code phase step by step, combined with a coarse estimation and fine estimation scheme of the frequency deviation, to ensure high capture sensitivity and synchronization accuracy. Especially in low signal-to-noise ratio environments and complex channel conditions, the present invention can effectively improve the reception reliability of spread spectrum signals. The method and system have the advantages of low computational complexity, simple hardware implementation, and strong adaptability, and provide an innovative solution for the reception and processing of weak spread spectrum signals.

The invention discloses a short burst SOQPSK carrier synchronization method based on an RPT-Net network. The short burst SOQPSK carrier synchronization method comprises the following steps: preprocessing a signal, and merging time domain data of the signal and quartic data into input data; a multi-level residual convolutional network is adopted to extract cross-symbol local phase features, fine phase changes in SOQPSK signals are captured through layer-by-layer stacked convolution operation, the gradient degradation problem of a deep network is relieved in combination with a residual connection mechanism, and the local characterization capacity for phase jump and frequency offset disturbance is enhanced; through a phase perception position coding module, the time domain signal is converted into a complex number form, an instantaneous phase is extracted, orthogonal basis coding is constructed to represent phase change, and deep fusion with position coding is carried out; a Transform coding layer is introduced, a multi-head self-attention mechanism is utilized to capture a long-distance symbol dependency relationship, global phase consistency constraint is optimized, long-term influence of frequency offset on signals is captured, and time sequence error propagation is effectively inhibited.

The invention discloses a Doppler frequency offset estimation method and electronic equipment, and relates to the technical field of communication, and the method comprises the step that the electronic equipment communicates with a low-orbit satellite in a discontinuous reception (DRX) mode. Wherein in a discontinuous reception (DRX) mode, the electronic equipment enters a wake-up period when the wake-up moment arrives, the electronic equipment communicates with a low-orbit satellite in the wake-up period, the electronic equipment enters a sleep period when the sleep moment arrives, and the electronic equipment stops communicating with the low-orbit satellite in the sleep period. When the wake-up moment arrives, the electronic device obtains at least one historical Doppler frequency offset value; and the electronic equipment determines a Doppler frequency offset value corresponding to the wake-up moment based on the historical Doppler frequency offset value. In the scheme, the Doppler frequency offset value at the wake-up moment is estimated through the historical Doppler frequency offset value, and the electronic equipment can calculate the Doppler frequency offset value at the current wake-up moment, so that frequency offset compensation can be carried out in time at the current wake-up moment, and the performance of frequency offset compensation is optimized.

The invention relates to the technical field of audio equipment testing, and discloses a parallel burning and Bluetooth testing frequency calibration method of a special chip for audio equipment. The method comprises the following steps of: establishing an independent serial communication channel with a plurality of chip chips through a computer control unit, and synchronously transmitting a firmware data packet to each chip storage unit; the high-precision radio frequency detection device is started to scan Bluetooth signal frequency offset values of all chips, and detection data is fed back to the computer control unit in real time; screening unqualified chips according to a preset frequency offset threshold, starting a dynamic frequency calibration program for the unqualified chips, and modifying internal capacitance parameters of the chips through a serial communication channel; repeatedly executing the frequency offset detection and capacitance parameter adjustment step until the frequency offset values of all the chips reach a standard range; and after completing the frequency offset calibration, executing a multi-channel Bluetooth performance test and outputting a test result report. According to the method, the chip firmware burning and Bluetooth test frequency calibration efficiency can be improved, the chip performance is guaranteed, and the method is adaptive to the batch production requirement.

A method of operating infrastructure equipment of a wireless communications network is provided. The method comprises transmitting, to a first communications device, an indication of time and frequency resources assigned for the first communications device to transmit a first uplink transmission as a first set of uplink repetitions to the infrastructure equipment. The first set of uplink repetitions comprises a first subset of the first set of uplink repetitions and a second subset of the first set of uplink repetitions. The method comprises transmitting, to the first communications device, an indication of an assigned Orthogonal Cover Code (OCC) for the first communications device to apply to the first set of uplink repetitions. The time and frequency resources for the first communications device to transmit the first uplink transmission, and the OCC for the first communications device to apply to the first set of uplink repetitions, are assigned such that the first communications device belongs to a first OCC group for transmitting the first subset of the first set of uplink repetitions and belongs to a second OCC group for transmitting the second subset of the first set of uplink repetitions. The first OCC group and the second OCC group comprise at least one other communications device. The at least one other communications device in the first OCC group is different from the at least one other communications device in the second OCC group.

Certain aspects of the present disclosure provide techniques for generating and processing a frequency multiplexed continuous wave (FMCW) based synchronization signal (SS). According to certain aspects, a method for wireless communication at a wireless node, comprising obtaining a synchronization signal comprising a first frequency modulated continuous waveform signal associated with a frequency that increases in time for a duration according to a first slope and a second FMCW signal that overlaps with the first FMCW signal, wherein the second FMCW signal is associated with a frequency that decreases in time for the duration according to a second slope that corresponds to a negative of the first slope; and performing frequency offset estimation based on the first and second FMCW signals.

Methods and systems for NN-based digital pre-distortion for digital envelope tracking power amplifiers. A computer-implemented method includes receiving a measure of a digital envelope at a digital pre-distortion module having a neural network (NN)-based digital pre-distortion structure for digital envelope tracking (DET), receiving a transmit signal at the digital pre-distortion module, inputting the measure of the digital envelope and the transmit signal into the NN-based digital pre-distortion structure to produce a pre-distorted transmit signal, adjusting nonlinearity compensation of a power amplifier based on the measure of the digital envelope, and using the adjusted nonlinearity compensation of the power amplifier to produce an output signal.

The invention relates to the technical field of signal processing, and discloses a velocity vector sensing method and device, equipment, a storage medium and a product, and the method comprises the steps: carrying out the down-conversion and matched filtering of a pilot signal transmitted by a user side, obtaining a target discrete signal sequence, carrying out the fast Fourier transform of the target discrete signal sequence, and obtaining a target discrete signal sequence; and determining a signal frequency sequence based on a discrete Fourier transform result, determining a frequency increase rate and a Doppler offset according to the signal frequency sequence, obtaining a signal propagation delay according to the discrete Fourier transform result, and further determining a velocity vector sensing result of the user side. According to the invention, hardware complexity and power consumption are reduced through down-conversion and matched filtering processing, and the signal-to-noise ratio is improved; according to the method, fast Fourier transform and inverse fast Fourier transform are combined, a signal frequency sequence, signal propagation time delay, frequency increase rate and Doppler offset are extracted, the velocity vector of a user side is sensed comprehensively, and the limitation that only part of parameters can be sensed in the prior art is overcome.

The invention provides a sodium ion energy storage SOC dynamic equalization and calibration method combined with carrier phase shift modulation, which comprises the following steps that: after an SOC acquisition module acquires voltage, current and temperature data of a sodium ion battery, a master control unit calculates an SOC value and constructs a global SOC deviation index, and when the SOC deviation index is greater than a preset threshold value, the SOC value is calculated by the master control unit; the main control unit sends a phase shift angle updating instruction to the carrier phase shift modulation module, so that the sodium ion battery with large SOC deviation preferentially participates in the equalization process, meanwhile, the carrier phase shift modulation module transfers energy of the sodium ion battery with high SOC to the sodium ion battery with low SOC, and when the equalization process is completed every time, the energy of the sodium ion battery with high SOC deviation is transferred to the sodium ion battery with low SOC. According to the method, the SOC value and the global SOC deviation index are calculated again until the global SOC deviation index is smaller than the preset threshold value, the problem that the performance of the battery pack is reduced due to SOC imbalance in a traditional method is solved by introducing a carrier phase-shifting modulation technology, and meanwhile, system parameters are optimized through a genetic algorithm, so that the efficiency and the accuracy of the equalization process are improved.

The invention relates to the technical field of semiconductor radio frequency signal processing, and discloses a narrowband signal receiving system and method, and the system comprises a coarse frequency offset value capturing module, a carrier phase locking module, a digital domain carrier tracking module, a timing synchronization and multipath correction module, and a vector amplitude phase correction and equalization module. In the prior art, the technical problems of lock losing, judgment errors and high bit error rate caused by serious multipath interference and frequency offset drifting of narrow-band signals are difficult to solve in complex environments with multipath effect and high frequency offset, such as urban canyons, basements and warehouses. According to the invention, by introducing analog phase locking, digital fine tuning, dual-correlation symbol synchronization based on multi-path sensing and vector amplitude-phase combined compensation overall architecture with cooperation of analog and digital, the problems of synchronization failure and demodulation performance reduction caused by multi-path distortion in the prior art are avoided; and the sensitivity and the overall reliability of radio frequency signal receiving are remarkably improved.

The invention discloses a radio frequency fingerprint hiding method based on feature compensation. The method comprises the following steps: at a transmitter end, carrying out carrier frequency offset compensation, I / Q imbalance compensation and PA nonlinear distortion compensation on a to-be-transmitted signal in sequence by using a preset joint compensation model to obtain a transmitted signal after radio frequency fingerprint hiding; the joint compensation model is constructed by the following steps: carrying out carrier frequency offset estimation and compensation, I / Q imbalance estimation and compensation and PA nonlinear distortion estimation on a received signal of a receiver in sequence, and constructing the joint compensation model according to a carrier frequency offset estimation result, an I / Q imbalance estimation result and a PA nonlinear distortion estimation result. According to the method, a scientific and reasonable parameter estimation and compensation sequence is designed, an illegal receiver is effectively prevented from extracting radio frequency fingerprints from received signals, the classification precision of the RFFI technology can be effectively reduced, and the privacy protection and recognition resistance of a transmitter are remarkably enhanced.

The invention discloses a bionic signal demodulation method based on a DSCAF-Net. The method comprises the following steps: receiving a bionic signal, then carrying out signal preprocessing, constructing a double-flow feature tensor, executing sample-level randomization sorting, carrying out global normalization processing, carrying out one-hot coding on a category label, and dividing a preprocessed data set into a training set, a verification set and a test set; a double-flow neural network architecture is constructed, and data is split into two independent channels such as a training sequence and a data symbol sequence through a double-flow separation module. According to the invention, through signal preprocessing, double-flow neural network architecture design and an optimized training strategy, key problems in an existing bionic covert communication system are effectively solved, and bionic signal demodulation with low bit error rate, low delay and high real-time performance is expected to be realized under a complex underwater acoustic channel condition; and a new thought and technical support are provided for the development of a bionic covert communication system.

The invention discloses a closed-loop frequency offset adjustment method in a low-orbit satellite scene, and belongs to the technical field of wireless communication. A satellite side always carries out frequency offset feedback by taking a carrier center as an anchor point, and a satellite terminal always carries out Doppler compensation according to a PUSCH scheduling bandwidth center frequency point, so that low complexity, high frequency offset estimation precision, low PUSCH demodulation performance deterioration and a low-orbit satellite scene uplink closed-loop frequency offset maintenance function are realized.

Provided in the embodiments of the present disclosure are a carrier phase tracking method and device for an orthogonal frequency division multiplexing (OFDM) multi-carrier system. The method includes: performing frequency domain tracking on a received current OFDM symbol and determining a phase of each subcarrier; analyzing a phase curve of all subcarriers and determining an inter-symbol phase average offset, and the inter-symbol phase average offset is used to characterize an estimated value of a difference obtained by subtracting a second value from a first value, the first value is a carrier phase value of the current OFDM symbol, and the second value is an estimated value of a carrier phase of a previous OFDM symbol; and performing time domain tracking by using the inter-symbol phase average offset as an input phase and determining an estimated value of a carrier phase of the current OFDM symbol.

The invention discloses a low-orbit satellite Doppler frequency offset pre-compensation dynamic optimization algorithm, which comprises the steps of multipath signal separation and path identification: identifying a line-of-sight path and at least one non-line-of-sight reflection path through power delay spectrum analysis of satellite receiving signals, wherein the signal power of the non-line-of-sight reflection path is not lower than-10dB of the line-of-sight path power; and reflection path geometric parameter extraction: based on time delay information of each path in the power time delay spectrum, reversely deducing propagation distances corresponding to a line-of-sight path and a non-line-of-sight reflection path, calculating a direct distance between the satellite and the terminal and a total distance of a reflection path from the satellite to a reflection point and then to the terminal by combining satellite orbit parameters and real-time position information of the terminal, and calculating geometric parameters of the reflection path. According to the method, the multi-path scene compensation precision is improved, the limitation that only the sight distance path is compensated traditionally is broken through by independently identifying the non-sight distance reflection path and establishing the exclusive frequency offset model, the frequency offset superposition error caused by multi-path propagation is solved, and the demodulation error rate in a complex environment is remarkably reduced.

This application provides a frequency offset correction method and a communication apparatus, and relates to the field of wireless communication technologies. The method includes: A second device performs down-conversion by using a first local oscillator signal, to receive a first reference signal from a first device, and adjusts the first local oscillator signal based on a receiving result of the first reference signal, to obtain a second local oscillator signal, where a frequency offset of the second local oscillator signal is less than a frequency offset of the first local oscillator signal. The second device performs down-conversion by using the second local oscillator signal, to receive a first data signal from the first device, where a guard band of the first reference signal is greater than a guard band of the first data signal.

The invention provides a frequency offset processing method and a frequency offset processing device for OFDM (Orthogonal Frequency Division Multiplexing) signals, which can be applied to the technical field of signal processing. The method comprises: processing an initial OFDM signal to obtain a processed OFDM signal, the processed OFDM signal comprising a master synchronization sequence and a plurality of OFDM symbols, each OFDM symbol comprising a plurality of pilot symbols; determining a first frequency adjustment value according to the spectral line position of the high-order spectrum of the primary synchronization sequence; adjusting and processing the frequency of the OFDM signal to obtain an intermediate OFDM signal; for each intermediate OFDM symbol, determining a first phase adjustment value corresponding to each intermediate OFDM symbol according to respective phases of the plurality of intermediate pilot symbols and phases of theoretical pilot symbols corresponding to the plurality of intermediate pilot symbols; and adjusting the phase of the intermediate OFDM signal to obtain a target OFDM signal, the target OFDM signal comprising a plurality of target OFDM symbols.

The invention discloses a Doppler frequency shift compensation method, a Doppler frequency shift compensation device and electronic equipment. The method comprises: a user equipment receiving a first message issued by a satellite, the first message carrying a first compensation value corresponding to a Doppler frequency shift between the satellite and the user equipment, and the first compensation value being used for pre-compensating a downlink signal sent by the satellite; in response to the first message, determining the distance between the user equipment and the beam center position of the satellite; and under the condition that the distance is greater than a preset threshold value, performing post-compensation on the frequency deviation of the received downlink signal according to the first compensation value. According to the invention, the technical problem that the accuracy of satellite compensation and the power consumption of terminal compensation cannot be effectively balanced in a Doppler frequency offset compensation scheme adopted by the related technology by adopting a sending end compensation or receiving end compensation mode is solved.

The invention discloses a hierarchical optimization search underwater acoustic Doppler estimation method and system, and the method comprises the steps: S1, a receiving end receives an OFDM signal frame, carries out the preliminary frequency offset scanning, and obtains a preliminary Doppler frequency offset value f corresponding to the maximum value of a correlation index and a coarse Doppler estimation interval [f-1, f + 1]; s2, randomly generating a group of initial particles in the coarse Doppler estimation interval [f-1, f + 1], each initial particle representing a candidate frequency offset value; and S3, calculating the amplitude of the mutual ambiguity function of each initial particle as a fitness function for continuous iteration until a convergence condition is met, and obtaining a fine Doppler frequency offset f1. The problem of high calculation complexity can be effectively solved under the condition that Doppler estimation precision is guaranteed.

The invention relates to the technical field of satellite communication, and discloses a low-orbit satellite communication Doppler frequency offset processing method, system and device and a medium, and the method comprises the steps: separating a pilot signal from a received signal; taking the Doppler frequency as a first system state, taking the received signal as first observation data, and performing Doppler frequency offset estimation on the pilot signal by adopting a frequency offset estimation algorithm to obtain a frequency offset estimation value; taking the Doppler frequency as a second system state, taking the frequency offset estimation value as second observation data, and adopting a frequency offset tracking algorithm to perform Doppler frequency offset tracking on the pilot signal to obtain a frequency offset tracking value; and performing frequency offset compensation on the received signal according to the frequency offset tracking value to obtain the received signal after frequency offset compensation. According to the method, the Doppler frequency offset is subjected to streaming processing through Bayesian filtering in the estimation and tracking stages, the complexity of data storage and calculation is effectively reduced, the data updating rate is increased, and therefore the accuracy of low-orbit satellite data is effectively improved.

The invention discloses a Doppler frequency offset compensation method and device, electronic equipment and a storage medium, and relates to the technical field of satellite communication. The method comprises the following steps: determining an included angle between a movement direction of a satellite and a beam center direction according to a satellite ephemeris, attitude information and beam information of the satellite; calculating a frequency offset pre-compensation value of the beam center point according to the included angle; wherein the wave beam central point is a central point of a wave beam of the satellite in a wave beam coverage range of the ground, and is used for reducing the calculation complexity of Doppler frequency offset compensation.

The invention provides a PUSCH signal demodulation method and device, a program product, electronic equipment and a storage medium, and is applied to the technical field of communication, and the PUSCH signal demodulation method comprises the steps: in a certain time slot, receiving a radio frequency signal and obtaining a baseband signal through frequency reduction, a single frequency domain signal corresponding to each terminal in the time slot is obtained according to the baseband signal, and at least one terminal in the time slot sends a PUSCH signal; for a certain terminal, determining a first frequency parameter corresponding to the current demodulation of the terminal, and if the current demodulation of the terminal is not the first demodulation, calculating the first frequency parameter according to a second frequency parameter corresponding to the last demodulation of the terminal and a first frequency offset value; calculating a corresponding phase compensation factor of the terminal in the time slot according to the first frequency parameter; and demodulating the PUSCH signal corresponding to the terminal based on the phase compensation factor corresponding to the terminal and the single frequency domain signal.

This disclosure provides a method and system for jointly estimating the LO leakage and quadrature error parameters of a transmitter RF front-end (e.g., a direct upconversion transmitter RF front-end). The proposed method utilizes a PN sequence inserted at the transmitter baseband. On the receiver side, an RX accumulator is implemented to sum the receiver signal to utilize the despreading gain from the same PN sequence from the transmitter side. Through the despreading process, the receiver-transmitter channel can be estimated and used to extract the quadrature error parameters. The estimated channel can also be used to eliminate user data interference presented in the RX accumulator output, which can be further used to calculate the LO leakage.

The invention discloses a Bluetooth chip without a crystal oscillator and a frequency offset estimation method and device thereof. The method comprises the following steps: entering a query scanning state before establishing communication connection with host equipment; searching an ID packet broadcasted and sent by the host equipment in the query state in the query scanning state; when an ID packet is received, the information transmission duration of the ID packet is multiplexed, and the first sampling period number of the information transmission duration is counted; determining the actual output frequency of the PLL unit according to the first sampling period number; and obtaining a frequency offset value of the Bluetooth chip without the crystal oscillator by using the difference between the actual output frequency and the ideal output frequency of the PLL unit. Therefore, the frequency offset estimation of the Bluetooth chip without the crystal oscillator is realized.

A communication frame for an OTFS transmission system includes at least one first-type and at least one second-type block. At least the first-type block includes data signals two-dimensionally arranged along the delay domain and the Doppler domain of which at least one has a superimposed pilot signal. The second-type block includes data signals two-dimensionally arranged along the delay domain and the Doppler domain which may or may not have superimposed pilot signals. At least one second-type block is preceded and followed, in the delay-domain, by first-type blocks, the first-type blocks preceding and following a second-type block having at least one identical data symbol and associated superimposed identical pilot symbol at an identical location in the two-dimensional arrangement. An OTFS transmitter generates and transmits the communication frame, and a receiver uses its properties for compensating oscillator frequency offset and channel estimation.