A transmitter using a channel aggregation in which available channels existing in various frequency bands are bound and transmitted and using an Orthogonal Frequency Division Multiplexing (OFDM), an Orthogonal Frequency Division Multiple Access (OFDMA), or a system similar to them as a modulation system. One or a plurality of transmission units are provided in parallel, and one or a plurality of transmission processing units are provided in parallel. The transmission processing unit has an inverse fast Fourier transforming circuit or a discrete inverse Fourier transforming circuit, a GI and overlap margin (OM) insertion circuit, and a time-domain windowing processing unit. The time-domain windowing processing unit multiplies a universal time-domain window function in accordance with a spectrum mask and transport electric power which are required in each channel, thereby suppressing out-of-band radiation electric power every channel. A kind and a window transition duration of the time-domain window function can be arbitrarily set every channel.

According to an aspect, there is provided an apparatus comprising for performing the following. The apparatus receives a stream of orthogonal frequency division multiplexing symbols and associated cyclic prefixes produced by at least one orthogonal frequency-division multiplexing modulator of a radio transmitter or transceiver. The apparatus divides said stream into a plurality of overlapping processing blocks of a first length. At least one of the plurality of overlapping processing blocks comprises a non-overlapping section having values corresponding to a segment of said stream. The dividing comprises adjusting a length of the non-overlapping section at least based on whether a cyclic prefix is comprised in said segment and, if this is true, on a length of said cyclic prefix. The apparatus filters the plurality of overlapping processing blocks using fast convolution processing and concatenates filtered processing blocks to form an output signal for transmission using the radio transmitter or transceiver.

Circuit for wake-up receivers are provide. In some embodiments, the wake-up receivers include self-mixers that receive a gate bias voltage. Some of the self-mixers are single ended and some are differential. In some embodiments, the wake-up receivers include a matching network that is connected to the input of the self-mixer. In some embodiments, the wake-up receivers include a low frequency path connected to the output of the self-mixer. In some embodiments, the wake-up receivers include a high frequency path connected to the output of the self-mixer. In some embodiments, the wake-up receivers are configured to receive an encoded bit stream. In some embodiments, the wake-up receivers are configured to wake-up another receiver.

An orthogonal frequency division multiplexing (OFDM) transmitter maps a digital level into I and Q components. The transmitter uses every other digital level as an I or Q component or divides the MSBs and LSBs of a digital level into the I and Q components. An analog OFDM transmitter uses a pair of input analog levels as the I and Q components. An inverse FFT outputs a complex value and OFDM symbols are transmitted. An inverse FFT may also output a real value using complex conjugates. An optional encoder encodes digital or analog samples into L levels using N orthogonal codes before input into the OFDM transmitter. OFDM receivers receive the OFDM signal and output digital or analog samples. Video signals are input into a distributor that distributes analog or digital samples into vectors, each vector input into an OFDM transmitter that transmits to a corresponding receiver.

Embodiments of the present disclosure relate to systems and methods to generate a signal in a communication network. The method comprises filtering a discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) data signal, and one of a DFT-S-OFDM and orthogonal frequency division multiplexing (OFDM) reference signal (RS) using a data filter and a RS filter respectively, to produce filtered data signal and filtered RS. The RS filter has one to one relationship with the data filter. Thereafter, port mapping the filtered RS to a corresponding port assigned to the transmitter to obtain port mapped filtered RS, wherein the port mapped filtered RS comprises a first subset of non-zero locations comprising of the filtered RS values and a second subset of zero locations comprising of zero values.

A method comprising receiving a modulated radio signal transmitting coded information bits, performing demodulating on the modulated radio signal, wherein demodulating comprises performing orthogonal time frequency space demodulation, performing equalization on the demodulated radio signal to obtain equalized symbols, obtaining log-likelihood ratios for the coded information bits from the equalized symbols using a trained machine learning model, and reconstructing the coded information bits.

Embodiments of this application provide a signal transmission method and apparatus, and the method includes: filtering a first time domain orthogonal frequency division multiplexing (OFDM) signal at each of M spatial transmission layers, where M is an integer greater than or equal to 1; performing spatial precoding on the filtered first time domain OFDM signal at each of the M spatial transmission layers, and mapping the filtered first time domain OFDM signal at each of the M spatial transmission layers to each of N.sub.t transmit antenna ports, where N.sub.t is an integer greater than or equal to M; and superposing and transmitting the first time domain OFDM signals that are at the M spatial transmission layers and that are mapped to all the N.sub.t transmit antenna ports.

A receiver has an antenna to receive a pulse shaped transmit signal transmitted by a transmitter of a multi carrier (MC) pulse shaped transmission system. The pulse shaped transmit signal includes a predefined signal pattern. The predefined signal pattern is not subjected to pulse shaping. The receiver includes a filter to pulse shape filter the pulse shaped transmit signal to obtain data for the receiver. The predefined signal pattern is retrieved from the pulse shaped transmit signal prior to filtering the pulse shaped transmit signal.

Methods, systems, and devices for a rearrangement scheme for a Faster-than-Nyquist (FTN) waveform are described. An example method includes a user equipment (UE) receiving a phase rearrangement indication from a network entity, the phase rearrangement indication indicating one or more parameters associated with a phase rearrangement process for a FTN discrete Fourier transformation spread orthogonal frequency division multiplexing (DFT-s-OFDM) transmission scheme. The method may also include transmitting a signal based at least in part on the phase rearrangement indication and according to the DFT-s-OFDM transmission scheme. Another example method includes a network entity transmitting a phase rearrangement indication indicating one or more parameters associated with a phase rearrangement process for a DFT-s-OFDM transmission scheme and receiving a signal based at least in part on the phase rearrangement indication and according to the DFT-s-OFDM transmission scheme.

Aspects of the description provide a method and devices to allow frequency domain spectral shaping (FDSS) to be used on both a reference sequence and data to enable low PAPR. Being able to use FDSS on both the reference sequence and data allows the FDSS to be transparent to the receiver. The method comprises obtaining a first sequence, wherein the first sequence is a base sequence of a set of base sequences, the set of base sequences comprising sub group base sequences, the first sequence obtained by cyclically repeating the sub group sequences at least once; and transmitting, by the device, a reference signal based on the first sequence.