Methods, systems and devices for wireless communication are described. One example method includes mapping information bits to transmission resources in a two-dimensional delay-Doppler grid In this example, the two-dimensional delay-Doppler grid includes N Doppler elements along a Doppler dimension and M delay elements along a delay dimension, and N and M are positive integers. The example method continues with converting a result of the mapping to a signal waveform, and generating an orthogonal time frequency space (OTFS) waveform by spreading the signal waveform using a spreading scheme. In some examples, the signal waveform includes an ultra-wide band (UWB) waveform.

Methods, systems and devices for wireless communication are described. One method includes obtaining a two-dimensional delay-Doppler representation of a received wireless signal that is received over a wireless channel, determining an estimated channel response of the wireless channel from a portion of the delay-Doppler grid corresponding to a channel estimation portion, performing, using the estimated channel response, channel equalization in the delay-Doppler domain, generating, based on the channel equalization, a posteriori probability estimates of data symbols in the received wireless signal, wherein the a posteriori probability estimates are generated based on a priori feedback that is generated using an iterative process and further processing the a posteriori probability estimates of data symbols to recover information bits from the received wireless signal.

Computerized wireless transmitter/receiver system that automatically uses combinations of various methods, including transmitting data symbols by weighing or modulating a family of time shifted and frequency shifted waveforms bursts, pilot symbol methods, error detection methods, MIMO methods, and other methods, to automatically determine the structure of a data channel, and automatically compensate for signal distortions caused by various structural aspects of the data channel, as well as changes in channel structure. Often the data channel is a two or three dimensional space in which various wireless transmitters, receivers and signal reflectors are moving. The invention's modulation methods detect locations and speeds of various reflectors and other channel impairments. Error detection schemes, variation of modulation methods, and MIMO techniques further detect and compensate for impairments. The invention can automatically optimize its operational parameters, and produce a deterministic non-fading signal in environments in which other methods would likely degrade.

According to an exemplary embodiment, a method of making a Hermetic transform to mitigate noise comprises: receiving over a channel signal frames comprising predetermined data and gaps comprising noise; framing the predetermined data; constructing a set of linear equations which relate a transfer function matrix of the channel to the predetermined data; determining the transfer function matrix by inverting the linear equations using a first pseudo inverse matrix; incorporating transfer function matrix into linear equations for a hermetic transform; and determining the hermetic transform using a second pseudo inverse matrix based on the predetermined data and the noise.

A method for modulating data for transmission within a communication system. The method includes establishing a time-frequency shifting matrix of dimension N?N, wherein N is greater than one. The method further includes combining the time-frequency shifting matrix with a data frame to provide an intermediate data frame. A transformed data matrix is provided by permuting elements of the intermediate data frame. A modulated signal is generated in accordance with elements of the transformed data matrix.

A method of a receiver, which relates to a Doppler frequency compensation technique in a communication system, may comprise: performing a demodulation process so that a fractional part of a Doppler shift of a received signal is compensated; and de-spreading the received signal for which the fractional part of the Doppler shift compensated from a first two-dimensional domain to a second two-dimensional domain.

A method of performing fast orthogonal frequency division multiplexing (FOFDM) includes: receiving a symbol transmitted in a multi-carrier communication system, wherein the symbol represents at least part of a transmitted signal, wherein the symbol is modulated based on a discrete cosine transform (DCT) technique; and estimating the symbol by using a widely linear (WL) estimation technique to minimize a difference between the received symbol and the estimated symbol.

A method for processing a signal modulated with a variable carrier frequency includes calculating a coefficient for demodulation of the signal. The method also includes demodulating the signal by calculating discrete intermediate values utilizing the coefficient for a predefined maximum number of steps and calculating the signal with the aid of the intermediate values of the coefficient. The value of the coefficient is respectively calculated on the basis of carrier frequencies for each step.

An alternative method of data communications using orthogonal time frequency shifting (OTFS) wireless waveforms configured so as to transmit data in a manner that is relatively insensitive to communications channel distortions and frequency shifts. In contrast to prior methods taught by applicant, the present disclosure teaches an alternative modulation scheme that maps data symbols intended for data transmission onto a symplectic-like 2D Fourier transform which operates on a form of the original data symbols. This 2D Fourier transform in turn is passed through a filter bank of narrow band filters, and the output in turn used to modulate transmitted waveforms according to various time slices until the entire 2D Fourier transform has been transmitted. At the receiver, and inverse of this process can be used to both characterize the data channel and correct the received signals for channel distortions, thus receiving a clear form of the original data symbols.

Provided are a data sending method and apparatus, a data receiving method and apparatus, a data transmission system, and a storage medium. The data sending method includes: a first data stream is acquired, where the first data stream includes multiple coded data symbols; an N-dimensional orthogonal transformation is performed on the first data stream to obtain an orthogonally transformed first data stream, where N?2; a modulation processing is performed on the orthogonally transformed first data stream to obtain a first radio frequency signal; and the first radio frequency signal is sent.