The present disclosure relates to a method performed in a radio device for transmitting a multi-carrier waveform comprising multi-carrier symbols. The method comprises precoding S2 the time domain waveform of the multi-carrier symbols to a plurality of transmitter antenna elements of the radio device. The precoding S2 comprises switching S2b from using S2a first set of precoder weights to using S2c a second set of precoder weights, different from the first set of weights. The switching S2b is done by use of at least one intermediate set of precoder weights during an interlude between two of the symbols in time domain. The method also comprises transmitting S3 the precoded signal from the transmitter antenna elements.

The present disclosure relates to a communication method and system for converging a 5G communication system for supporting higher data rates beyond a 4G system with an IoT technology. The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The present disclosure can reduces a peak-to-average power ration (PAPR) by performing time domain cyclic filtering. Further, a data rate or coverage can be improved by selectively transmitting transmission waveforms through cyclic prefix (CP)-orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform-spread-OFDM (DFT-s-OFDM).

System and methods for shaped single carrier orthogonal frequency division multiplexing with low peak to average power ratio are provided. The system receives an input signal and modulates the input signal to form Dirichlet kernels in a time domain to generate an offset Dirichlet kernel output time array where each Dirichlet kernel has a main lobe and a plurality of side lobes. Modulating the input signal suppresses a peak to average power ratio of the offset Dirichlet kernel output time array by reducing the plurality of side lobes of each Dirichlet kernel and respective amplitudes of the side lobes.

Waveforms may be shaped in a wireless communications device by processing head tones of a multi-tone carrier using a head tone waveform shaping characteristic to provide a first sub-symbol, processing tail tones of the multi-tone carrier using a tail tone waveform shaping characteristic to provide a second sub-symbol, and processing center tones of the multi-tone carrier using a center tone waveform shaping characteristic to provide a third sub-symbol. The first, second, and third waveform shaping characteristics may be different from each other, i.e., the waveform shaping may be asymmetric. The first, second, and third sub-symbols may be combined to provide an output symbol.

A system combining OFDM standard modulation with a superimposition of Orbital Angular Momentum modes, each OAM modes consisting in an overlapping decimated IFFTs with the main mode standard OFDM signal. Orthogonality of the OAM modes is assessed. A frame structure embodying both main mode OFDM samples and overlapping OAM modes is proposed.

Waveforms may be shaped in a wireless communications device by processing head tones of a multi-tone carrier using a head tone waveform shaping characteristic to provide a first sub-symbol, processing tail tones of the multi-tone carrier using a tail tone waveform shaping characteristic to provide a second sub-symbol, and processing center tones of the multi-tone carrier using a center tone waveform shaping characteristic to provide a third sub-symbol. The first, second, and third waveform shaping characteristics may be different from each other, i.e., the waveform shaping may be asymmetric. The first, second, and third sub-symbols may be combined to provide an output symbol.

A method to generate a wireless waveform for use in a wireless communication system, a wireless communication system and computer program product thereof The method comprises the generation of a waveform for application in the wireless communication system characterized by significant phase noise, Doppler spread, multipath, frequency instability, and/or low power efficiency by at the transmitter side: creating a discrete-time instantaneous frequency signal {tilde over (f)}[n]; appending a cyclic prefix with length L.sub.CP to the beginning of the discrete-time instantaneous frequency signal {tilde over (f)}[n]; constructing a discrete-time unwrapped instantaneous phase [n]; constructing a discrete-time complex baseband signal, and appending at the beginning a Constant Amplitude Zero Autocorrelation, CAZAC, signal of length L.sub.CP for multipath detection; and passing the constructed discrete-time complex baseband signal through a digital-to-analog, DAC, converter to yield the continuous-time radio frequency signal s(t) after conversion to the carrier frequency.

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.

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.

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.