A terminal (transmission apparatus) is disclosed, which is capable of appropriately configuring processing of a Post-IFFT section in accordance with a communication environment in signal waveform generation. In the terminal, an IFFT section performs IFFT processing on a transmission signal; a control section determines a signal waveform configuration for the transmission signal after the IFFT processing in accordance with a communication environment of the terminal; and the Post-IFFT section performs Post-IFFT processing on the transmission signal after the IFFT processing based on the determined signal waveform configuration.

Certain aspects of the present disclosure generally relate to wireless communications. In some aspects, a wireless device reduces a peak-to-average power ratio (PAPR) of a discrete-time orthogonal frequency division multiplexing (OFDM) transmission by selecting a signal with low PAPR from a set of candidate discrete-time OFDM signals. The wireless device may generate a partial-update discrete-time OFDM signal by performing a sparse transform operation on a base data symbol sequence, and then linearly combine the partial-update discrete-time OFDM signal with a base discrete-time OFDM signal to produce an updated discrete-time OFDM signal, which is added to the set of candidate discrete-time OFDM signals. Numerous other aspects are provided.

Examples described herein include Weighted Overlap Beamform and Add techniques for calculating frequency-localized weights for adaptive beamformers. Intermediate weights are calculated for overlapping subbands (e.g., using a least-squares solution or a windowed least-squares solution). Each set of intermediate weights may be multiplied by an overlap factor, and combined to provide final weights for a subcarrier.

A system and method are provided for processing symbols for transmission. A set of 2K outputs is produced that includes K real components and K imaginary components from K complex symbols. A Fourier transform operation on the 2K outputs produces 2K Fourier transform outputs. Transmit pulse shaping is applied to the 2K Fourier transform outputs. The transmit pulse shape may be Nyquist or non-Nyquist. An inverse Fourier transform operation on the J pulse shaped outputs produces an inverse Fourier transform output. In the receiver, equalization is performed to remove the effect of both the channel and the transmit pulse shape. Nyquist pulse shaping is performed by applying a Nyquist pulse shape prior to converting back to time domain. The approach avoids self-interference, even in situations where the transmit pulse shape is non-Nyquist. The transmitter is free to select a pulse shape to optimize PAPR without being concerned with interference.

A terminal (transmission apparatus) is disclosed, which is capable of appropriately configuring processing of a Post-IFFT section in accordance with a communication environment in signal waveform generation. In the terminal, an IFFT section performs IFFT processing on a transmission signal; a control section determines a signal waveform configuration for the transmission signal after the IFFT processing in accordance with a communication environment of the terminal; and the Post-IFFT section performs Post-IFFT processing on the transmission signal after the IFFT processing based on the determined signal waveform configuration.

A UE determines a respective set of subcarriers from N subcarriers in each OFDM symbol of M1 consecutive OFDM symbols within a slot. The respective set of subcarriers carries a respective set of SRSs that form transmission combs of a transmission comb size. The respective set of subcarriers in one of the M1 consecutive OFDM symbols do not overlap in frequency domain with the respective set of subcarriers in any other one of the M1 consecutive OFDM symbols. The UE applies the respective set of phase rotations to the respective set of SRSs in each OFDM symbol to obtain a cyclic shift. The UE maps the respective set of SRSs applied with phase rotations to the respective set of subcarriers in each OFDM symbol. The UE transmits the respective sets of SRSs in the M OFDM symbols.

A system and method are provided for processing symbols for transmission. A set of 2K outputs is produced that includes K real components and K imaginary components from K complex symbols. A Fourier transform operation on the 2K outputs produces 2K Fourier transform outputs. Transmit pulse shaping is applied to the 2K Fourier transform outputs. The transmit pulse shape may be Nyquist or non-Nyquist. An inverse Fourier transform operation on the J pulse shaped outputs produces an inverse Fourier transform output. In the receiver, equalization is performed to remove the effect of both the channel and the transmit pulse shape. Nyquist pulse shaping is performed by applying a Nyquist pulse shape prior to converting back to time domain. The approach avoids self-interference, even in situations where the transmit pulse shape is non-Nyquist. The transmitter is free to select a pulse shape to optimize PAPR without being concerned with interference.

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for transmitting signals with a high data rate. In some implementations, an apparatus includes a first digital signal processor outputting first data at a first data rate. A second digital signal processor outputting second data at a second data rate. A filter circuitry receiving and up-sampling the first and second data. Additionally, the apparatus includes a combiner circuit that receives the first up-sampled data and the second up-sampled data, the combiner circuit combining the first and second up-sampled data to provide a multiplexed output, the multiplexed output having a third data rate that is greater than the first data rate or the second data rate.

A transmission device that improves data reception quality includes: a weighting synthesizer that generates a first precoded signal and a second precoded signal from a first baseband signal and a second baseband signal, respectively; a phase changer that applies a phase change of i to the second precoded signal; an inserter that inserts a pilot signal into the second precoded signal applied with the phase change; and a phase changer that applies a phase change to the second precoded signal applied with the phase change and inserted with the pilot signal. satisfies /2 radians<< radians or radians<<3/2 radians. Each of the first baseband signal and the second baseband signal is modulated via a modulation scheme of quadrature amplitude modulation (QAM) using non-uniform mapping.

A securely pre-coded orthogonal frequency division multiplexing (SP-OFDM) system includes a transmitter configured to transmit a secure transmit signal through a dynamic constellation and a receiver configured to recover the original signal from the received secure transmit signal. It is aimed to reinforce the physical layer security of wireless communications under hostile interference. Potential applications include 4G and 5G communication systems, ASTC3.0 HDTV systems, WiFi systems, and any future wireless systems that utilize OFDM.