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.

Embodiments of the present disclosure relate to a communication system to generate a waveform by multiplexing multiple user data. The system comprises at least one transceiver, a multiplexer and a processor. The at least one transceiver configured to perform at least one of receiving a plurality of data from a transmitter, and transmitting a generated waveform to a destination. The multiplexer configured to multiplex a plurality of data associated with a plurality of users, to generate multiplexed data. The processor is configured to perform a rotation operation on the multiplexed data to produce a rotated data. Also, the processor is configured to transform the rotated data using Fourier transform to produce transformed data. Further, the processor is configured to map the transformed data using a predefined number of subcarriers to produce a mapped data sequence and thereafter, process the mapped data sequence to generate the waveform.

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 method for wireless communication by a user equipment (UE) includes modulating a symbol stream onto at least one subcarrier to generate an uplink signal in a frequency domain for transmitting to a receiver in a non-terrestrial network. The method also includes applying an amount of phase rotation to the at least one subcarrier in the frequency domain. The method further includes transforming the uplink signal from the frequency domain into a time domain uplink signal. The method includes transmitting the time domain uplink signal to the receiver, after applying the phase rotation to the at least one subcarrier.

This application provides a signal transmission method and an apparatus, to reduce an envelope ripple of a transmission signal. The method includes: A base station obtains a first bit sequence and maps the first bit sequence to a first modulation symbol sequence, where a value of each modulation symbol in the first modulation symbol sequence belongs to a first constellation point set, the first constellation point set includes K modulation symbols, and each of the K modulation symbols has a different amplitude. The base station sequentially performs a DFT, weighting, and an IFFT on each modulation symbol in the first modulation symbol sequence to obtain a first signal. Based on the foregoing solution, an envelope ripple of the signal generated by the base station in time domain is small. This facilitates demodulation of the transmission signal by a terminal.

Techniques for peak-to-average power ratio (PAPR) reduction are described. Wireless devices may provide signaling with respect to one or more PAPR shaping resources. For example, a wireless device may provide signaling of PAPR shaping capability information. PAPR shaping capability information may include information regarding one or more PAPR shaping resources the wireless device has a capability to implement. Additionally or alternatively, a wireless device may provide signaling of PAPR shaping information. PAPR shaping information may include information regarding shaping the signal by a wireless device prior to transmission in a communication link by implementing one or more PAPR shaping resources. Other aspects and features are also claimed and described.

Embodiments of the present disclosure relate to a communication system to generate a waveform by multiplexing multiple user data. The system comprises at least one transceiver, a multiplexer and a processor. The at least one transceiver configured to perform at least one of receiving a plurality of data from a transmitter, and transmitting a generated waveform to a destination. The multiplexer configured to multiplex a plurality of data associated with a plurality of users, to generate multiplexed data. The processor is configured to perform a rotation operation on the multiplexed data to produce a rotated data. Also, the processor is configured to transform the rotated data using Fourier transform to produce transformed data. Further, the processor is configured to map the transformed data using a predefined number of subcarriers to produce a mapped data sequence and thereafter, process the mapped data sequence to generate the waveform.

A method to provide robustness against noise and interference in wireless communications, a transmitter and computer program products, involving sending to a receiver (13), through a wireless channel (12), information using a constant-envelope waveform with complex baseband representation of the form s[n]=A.sub.c exp{j[n]}. The phase [n] following the expression

[00001]$\left(\left[n\right]-\left[n-1\right]\right)=2.Math..Math..Math.m.Math.\underset{k=k_0+1}{\overset{k_0+N_{a,F.Math..Math.M}^{+}-1}{.Math.}}.Math.x\left[k\right].Math.\exp \left(j.Math..Math.\frac{2.Math..Math..Math.\mathrm{kn}}{N}\right),$

and the wireless channel has an Additive White Gaussian Noise component and flat-fading conditions, wherein the transmitter (110) calculates a FFT length, N, and a number of active positive subcarriers, N.sub.a,FM.sup.+, needed in order to have a given improvement in the signal to noise ratio at the active positive subcarriers of the instantaneous frequency spectrum containing the information; calculates a cutoff subcarrier k.sub.0 needed to overcome Doppler, phase noise and carrier frequency offset impairments at the receiver side, and generates a complex baseband signal waveform of the form s[n]=A.sub.c exp{j[n]} carrying information with the FFT length, number of active positive subcarriers and cutoff subcarrier.

A test device for simulating analog beams applied to a DUT includes a memory that stores instructions and a processor that executes the instructions. When executed by the processor, the instructions cause the test device to perform a process that includes obtaining, from the memory and based on instructions received for testing the DUT, a predetermined power level for a beam to be simulated for the DUT and a predetermined time delay for the beam to be simulated for the DUT. The process also includes applying the predetermined power level for the beam and the predetermined time delay for the beam to a set of subcarriers and cyclic prefix orthogonal frequency-division multiplexing (CP-OFDM) symbol to obtain simulated characteristics of the beam from the perspective of the DUT. The process also includes sending, over a wired connection, the simulated characteristics of the beam from the processor to the DUT.

Provided are a method for a user equipment to select a codebook index in a wireless communication system and an apparatus supporting the method. The method performed by the user equipment comprises performing zero padding for a first vector, wherein the first vector represents a channel state measured by a receive antenna for a first transmit antenna; performing IFFT for a second vector, wherein the second vector is obtained by performing the zero padding for the first vector; performing receive antenna combining for a third vector, wherein the third vector is obtained by performing IFFT for the second vector; and detecting a maximum element from a fourth vector, wherein the fourth vector is obtained by performing the receive antenna combining for the third vector.