Systems and methods for generating a microwave signal using two millimeter-wave frequencies. A first millimeter-wave up-conversion frequency, which is generated from a lower frequency source, is used to up-convert a baseband and/or intermediate signal into a first millimeter-wave signal, which is then down-converted into a microwave signal using a second millimeter-wave down-conversion frequency generated from the same lower frequency source. Each of the first and second millimeter-wave frequencies is associated with a phase noise that is higher than a phase noise associated with the lower frequency source, however, the frequency differential between the first millimeter-wave frequency and the second millimeter-wave frequency is free of the higher phase noise, as a result of the two millimeter-wave signal being generated from the single lower frequency source, thereby causing the resultant microwave signal to be free of the higher phase noise as well.

A signal processing apparatus (10) according to the present disclosure includes: an overlap-type FFT processing unit (11) that performs FFT processing overlapping input subcarrier signals each other for each of FFT blocks, and a generation unit (12) that generates a signal which is obtained by frequency shifting the subcarrier signals that have been subjected to the FFT processing by the overlap-type FFT processing unit (11) by a frequency shift amount of a subcarrier, a phase offset that occurs between the FFT blocks overlapping each other being compensated in the signal.

An OFDM (orthogonal frequency division multiplexing) transmitter includes an inverse fast Fourier transform circuit, which, in operation, generates, based on digital input data, a complex time-varying digital signal having real and imaginary components; and a multiplexer adapted to generate a time-multiplexed digital signal by time-multiplexing one or more of the real components with one or more of the imaginary components.

A device for transmitting a signal according to some embodiments of the present disclosure relates to a device for transmitting a signal using a hybrid waveform. The device may include a modulator configured to modulate an input signal and a signal transmitter configured to transmit the modulated final transmission signal through an LED light source, wherein the modulator is configured to modulate first information into a pulse signal based on frequency shift keying (FSK), and modulate second information into an orthogonal frequency division multiplexing (OFDM) signal, wherein the first information and the second information are different from each other and mix the pulse signal and the OFDM signal into one waveform to generate the final transmission signal.

A data transmission method is provided. The method includes: a transmitter generates a transmission signal on the basis of transmission information and modulates, by means of a carrier modulation, the transmission signal to a target time-frequency resource for transmission. The transmission information at least includes terminal identification information; or at least includes terminal identification information and signaling information; or at least includes terminal identification information and data information; or at least includes terminal identification information, data information and signaling information; or at least includes terminal identification information and cell identification information; or at least includes terminal identification information, cell identification information and signaling information; or at least includes terminal identification information, cell identification information and data information; or at least includes terminal identification information, cell identification information, data information and signaling information. A transmitter, a receiver and a storage medium are further provided.

Provided are an orbital angular momentum (OAM)-based transmitter, receiver, and communication method employing a radial concentric uniform circular array (UCA). The OAM-based communication method includes transmitting, by a transmitter, OAM multimode signals through a UCA-based transmitting antenna and receiving, by a receiver, the OAM multimode signals through a radial concentric UCA structure antenna including a plurality of UCA antennas. The plurality of UCA antennas each have the same number of antenna elements, and antenna elements having the same sequence number in the plurality of UCA antennas are on the same radial line in the radial concentric UCA structure antenna.

An apparatus and method for multiplexing signals using layered division multiplexing are disclosed. A signal multiplexing apparatus according to an embodiment of the present invention includes a combiner configured to combine a core layer signal and an enhanced layer signal at different power levels, and a time interleaver configured to perform interleaving applied to both the core layer signal and the enhanced layer signal.

An Orthogonal Time Frequency Space Modulation (OTFS) modulation scheme achieving multiple access by multiplexing multiple signals at the transmitter-side performs allocation of transmission resources to a first signal and a second signal, combining and converting to a transmission format via OTFS modulation and transmitting the signal over a communication channel. At the receiver, multiplexed signals are recovered using orthogonality property of the basis functions used for the multiplexing at the transmitter.

A method for transmitting a digital frame by an optical network unit in a digital communications network includes steps of arranging received data into a series of symbols, installing a primary cyclic prefix immediately preceding the series of symbols in time, and inserting individual ones of a plurality of secondary cyclic prefixes between each adjacent pair of symbols in the series of symbols. A length of each secondary cyclic prefix corresponds to a first duration shorter than an amount of time needed to turn on a laser of the optical network unit. The method further includes a step of providing to the optical network unit the digital frame. The digital frame includes the primary cyclic prefix, the plurality of secondary cyclic prefixes, and the series of symbols. The method further includes a step of modulating the provided digital frame by a laser of the optical network unit.

A method for a wireless transmitter is disclosed. The method comprises transmitting a wake-up signal over a frequency range during a time interval by transmitting a first signal part over a first frequency interval within the frequency range during the time interval and transmitting a second signal part over a second frequency interval within the frequency range during the time interval. The first and second frequency intervals are non-overlapping. The first signal part has a first auto-correlation value, and the second signal part is specifically constructed to provide a second autocorrelation value of the signal comprising the first and second signal parts which is lower than the first auto-correlation value. The invention to solve the problem of false detection of an MC-OOK modulated wake-up signal in an IEEE 802.11 system using OFDM.