Apparatuses, methods, and systems are disclosed for multiple discrete Fourier transforms for transmission and reception. An apparatus includes a transceiver that receives a first configuration from a network to apply multiple discrete Fourier transform (DFT)-based waveforms at one or more of a transmitter and a receiver, receives a second configuration from the network for a physical channel, the second configuration comprising DFT configuration information, and receives a third configuration from the network for determining, based on the second configuration, an inverse-DFT (IDFT) configuration. An apparatus includes a processor that performs multiple DFT-based transmissions on a time-domain symbol transmitted to the network based on the first and second configurations and performs multiple IDFT-based receptions of a time-domain symbol received from the network, based on the IDFT configuration.

Techniques and apparatus for transmission and reception with partial allocation in orthogonal frequency division multiple access (OFDMA)/single-carrier frequency division multiple access (SC-FDMA) systems are provided. One technique includes determining first parameter(s) to apply to transmission/receive processing of a signal, based in part on a resource allocation for the signal. The resource allocation is partitioned out of a larger system bandwidth. Second parameter(s) to apply to the transmission/receive processing are determined based at least in part on the first parameter(s). Transmission/receive processing of the signal is performed in accordance with the first and second parameters.

A method for transmitting a demodulation reference signal (DMRS) for a physical uplink shared channel (PUSCH), by a user equipment (UE), in a wireless communication system. The UE generates first, second, and third DMRS sequences, which are associated with first, second, and third layers respectively, by applying first, second, and third cyclic shifts to the first, second, and third DMRS sequences respectively. The UE transmits the first, second, and third DMRS sequences to a base station, wherein the first, second, and third cyclic shifts are determined based on first, second, and third cyclic shift values respectively. The first and second cyclic shift values are separated from each other by a maximum separation value, which is determined based on a total number of cyclic shifts. The third cyclic shift value is determined by increasing cyclically by a median separation value between the first and second cyclic shift values.

A method for transmitting a demodulation reference signal (DM-RS), by a user equipment (UE), in a wireless communication system is discussed. The method includes receiving, by the UE from a base station, a cyclic shift field in downlink control information (DCI), wherein the cyclic shift field indicates first, second, and third cyclic shift values for first, second, and third layers respectively, generating, by the UE, first, second, and third DMRSs for the first, second, and third layers respectively, based on first, second, and third cyclic shifts respectively, wherein the first, second, and third cyclic shifts are determined based on the first, second, and third cyclic shift values respectively, and transmitting, by the UE to the base station, the first, second, and third DMRSs.

A method, system, and computer program product is provided for transmitting output symbols in sub-slots that each have a pre-determined length. A UE (102) generates (1402) a first output symbol having a first symbol length, and transmits (1404) the first output symbol with a guard period having a guard period length. During the guard period, no transmission is made by the UE (102). The sum of the first symbol length and the guard period length is less than or equal to the predetermined length. Further, the UE (102) generates (1406) a plurality of other output symbols that each have the predetermined length. Then, immediately following the transmission of the first output symbol, the UE transmits (1408) the plurality of other output symbols. Such a resulting fractional guard period located either at the beginning or the end of a subframe prevents collision or overlapping of D2D communication and normal UE to eNB transmissions.

In 60 GHz WiGig/IEEE 802.11ad, Orthogonal Frequency Division Multiplexing (OFDM) is used to achieve higher throughput. However, OFDM has one problem of high Peak-to-Average Power Ratio (PAPR) caused by the summing up of the large number of subcarriers. A high PAPR signal degrades the efficiency of power amplifier (PA) and may cause spurious emissions because of the PA non linearity. In order to reduce PAPR, Generalized Frequency Division Multiplexing (GFDM) which has the characteristics of both single carrier and multi carrier transmission has been studied. By introducing GFDM, the number of subcarriers can be decreased while still maintaining a high throughput.

A method and a device for transmitting a data unit are disclosed. A method for transmitting a PPDU can comprise the steps of: generating, by an STA, the PPDU including a first portion and a second portion; and transmitting, by the STA, the PPDU, wherein the first portion is generated by performing IFFT according to a first FFT size, the second portion is generated by performing IFFT according to a second FFT size, and the first FFT size can differ from the second FFT size.

A method and an apparatus for transmitting broadcast signals thereof are disclosed. The apparatus for transmitting broadcast signals comprises an encoder for encoding service data, a mapper for mapping the encoded service data into a plurality of OFDM (Orthogonal Frequency Division Multiplex) symbols to build at least one signal frame, a frequency interleaver for frequency interleaving data in the at least one signal frame by using a different interleaving-seed which is used for every OFDM symbol pair comprised of two sequential OFDM symbols, a modulator for modulating the frequency interleaved data by an OFDM scheme and a transmitter for transmitting the broadcast signals having the modulated data.

An FBMC transmission/reception system wherein a phase pre-compensation and an amplitude pre-compensation are done on a block of modulation symbols. The symbol block thus compensated is segmented into a number M of sub-blocks equal to the number of carriers of an FBMC modulator. The sub-blocks are divided into vectors with size N/2 and padded with isolation zeroes to form padded vectors with size N. Each of these padded M is processed by an IFFT to give time sequences to which cyclic prefixes and suffixes are added. The resulting cyclic sequences are then input to the M input channels of the FBMC modulator. The reception symbols can be recovered at the receiver by a simple FFT with size NM/2.

A method and a device for transmitting a data unit are disclosed. A method for transmitting a PPDU can comprise the steps of: generating, by an STA, the PPDU including a first portion and a second portion; and transmitting, by the STA, the PPDU, wherein the first portion is generated by performing IFFT according to a first FFT size, the second portion is generated by performing IFFT according to a second FFT size, and the first FFT size can differ from the second FFT size.