Wireless communication techniques for transmitting and receiving reference signals is described. The reference signals may include pilot signals that are transmitted using transmission resources that are separate from data transmission resources. Pilot signals are continuously transmitted from a base station to user equipment being served. Pilot signals are generated from delay-Doppler domain signals that are processed to obtain time-frequency signals that occupy a two-dimensional lattice in the time frequency domain that is non-overlapping with a lattice corresponding to data signal transmissions.

Techniques for performing channel estimation in an orthogonal time, frequency and space (OTFS) communication system include receiving a wireless signal comprising a data signal portion and a pilot signal portion in which the pilot signal portion includes multiple pilot signals multiplexed together in the OTFS domain, performing two-dimensional channel estimation in a time-frequency domain based on a minimum mean square error (MMSE) optimization criterion, and recovering information bits using a channel estimate obtained from the two-dimensional channel estimation.

Systems and methods for transmitting data using various Modulation on Zeros schemes are described. In many embodiments, a communication system is utilized that includes a transmitter having a modulator that modulates a plurality of information bits to encode the bits in the zeros of the z-transform of a discrete-time baseband signal. In addition, the communication system includes a receiver having a decoder configured to decode a plurality of bits of information from the samples of a received signal by: determining a plurality of zeros of a z-transform of a received discrete-time baseband signal based upon samples from a received continuous-time signal, identifying zeros that encode the plurality of information bits, and outputting a plurality of decoded information bits based upon the identified zeros.

An operation method of a first communication node may include: mapping data symbols to be transmitted to a second communication node of the communication system to resources in a first two-dimensional (2D) domain; pre-processing the data symbols mapped to the resources in the first 2D domain to spread the data symbols on resources in a second 2D domain; mapping the pre-processed data symbols to the resources in the second 2D domain; and performing multi-carrier modulation on the data symbols mapped to the resources in the second 2D domain for each of the resources in the second 2D domain.

A method and device to modulate an FBMC/OQAM signal, the device comprising at least one QAM mapper mapping a binary stream into complex symbols, a first and a second transmission chain. Each chain comprises: a precoder transposing respective sets of symbols into frequency domain real/imaginary samples, a phase rotator applying a phase quadrature keying to said samples, an FBMC modulator to modulate the output of the phase rotator into an FBMC symbol. The device further comprises an adder of the output of the first transmission chain with a delayed output of the second transmission chain, and is configured to insert guard interval sequences into the binary stream or into the symbols processed by the precoders. A corresponding radio communication equipment, computer program and readable medium is provided.

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.

Methods, systems and device for achieving synchronization in an orthogonal time frequency space (OTFS) signal receiver are described. An exemplary signal reception technique includes receiving an OTFS modulated wireless signal comprising pilot signal transmissions interspersed with data transmissions, calculating autocorrelation of the wireless signal using the wireless signal and a delayed version of the wireless signal that is delayed by a pre-determined delay, thereby generating an autocorrelation output, processing the autocorrelation filter through a moving average filter to produce a fine timing signal. Another exemplary signal reception technique includes receiving an OTFS modulated wireless signal comprising pilot signal transmissions interspersed with data transmissions, performing an initial automatic gain correction of the received OTFS wireless signal by peak detection and using clipping information, performing coarse automatic gain correction on results of a received and initial automatic gain control (AGC)-corrected signal.

Embodiments of the present disclosure relate to wireless communication devices, systems comprising wireless communication devices, and to an apparatus, a method and a computer program for a wireless communication device. The apparatus comprises a transceiver module for transmitting and receiving wireless transmissions. The apparatus comprises a processing module that is configured to control the transceiver module. The processing module is configured to communicate with a further wireless communication device via the transceiver module. The communication with the further wireless communication device is based on a transmission of data frames between the wireless communication device and the further wireless communication device. Each data frame is based on a two-dimensional grid in a time-frequency plane having a time dimension resolution and a frequency dimension resolution. The processing module is configured to select a communication mode from a plurality of communication modes for the communication between the wireless communication device and the wireless communication device. The communication mode defines a combination of a frequency dimension resolution and a time dimension resolution of the two-dimensional grid in the time-frequency plane. The communication mode is selected from the plurality of communication modes based on an estimated self-interference of the plurality of communication modes.

A method and apparatus for underwater acoustic communication are disclosed. A data packet frame structure in the communication transmission includes a preamble, a synchronization code, and a data code. A guard interval is disposed between the preamble and the synchronization code. This method utilizes the different impact response environments of linear frequency modulation signals in different frequency bands to obtain the mapping relationships corresponding to the characteristics of the impulse responses in the frequency band, and adopts the quadrature phase shift keying (QPSK) modulation method to convert four groups of LMF signals with different center frequencies and the same modulation frequency, representing different symbols for signal transmission, where the LFM carrier signal of each center frequency can represent two bits of binary information to improve transmission efficiency. The apparatus for underwater acoustic communication also has the above-mentioned technical effects.

Systems, devices, and methods of the present invention enhance data transmission through the use of polynomial symbol waveforms (PSW) and sets of PSWs corresponding to a symbol alphabet is here termed a PSW alphabet. Methods introduced here are based on modifying polynomial alphabet by changing the polynomial coefficients or roots of PSWs and/or shaping of the polynomial alphabet, such as by polynomial convolution, to produce a designed PSW alphabet including waveforms with improved characteristics for data transmission.