The present invention relates to a method for transmitting, by a base station, a downlink signal using a plurality of transmission antennas comprises the steps of: applying a precoding matrix indicated by the PMI, received from a terminal, in a codebook to a plurality of layers, and transmitting the precoded signal to the terminal through a plurality of transmission antennas. Among precoding matrices included in the codebook, a precoding matrix for even number transmission layers can be a 22 matrix containing four matrices (W1s), the matrix (W1) having rows of a number of transmission antennas and columns of half the number of transmission layers, the first and second columns of the first row in the 22 matrix being multiplied by 1, the first column of the second row being multiplied by coefficient a of a phase, and the first column of the second row being multiplied by a.

Disclosed is a method for a station (STA) device transmitting data in a Wireless Local Area Network (WLAN) system. The method for transmitting data, according to one embodiment of the present invention, comprises the steps of: FEC encoding transmission data; interleaving the transmission data; constellation mapping the transmission data; performing IDFT on the transmission data; and upconverting the transmission data and transmitting a transmission signal, wherein the transmission signal comprises a first part and a second part, and IDFT is performed using different FFT sizes for the first part and the second part.

Various embodiments of carrier aggregation are provided that increase communications capacity and throughput. According to some embodiments, a receiver may be configured with a plurality of receiver chains and, responsive to an aggregate bandwidth of an overall signal that is to be received by the receiver, a plurality of components of the overall signal, each comprising a bandwidth that is less than a frequency span of the overall signal, are received by a respective plurality of receiver chains. Accordingly, each component of the plurality of components of the overall signal may be received by a respective receiver chain of the plurality of receiver chains of the receiver thus avoiding bandwidth limitations associated with receiver elements.

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.

Various embodiments of carrier aggregation are provided that increase communications capacity and throughput. According to some embodiments, a transmitter is configured with a plurality of transmitter chains and, responsive to an aggregate bandwidth and/or frequency content of an overall signal that is to be transmitted by the transmitter, the overall signal is segmented into a plurality of components, each one of which comprises a bandwidth that is smaller than the bandwidth of the overall signal, and is thus transmitted by the plurality of transmitter chains of the transmitter. Accordingly, each component of the plurality of components of the overall signal is processed by a respective transmitter chain of the plurality of transmitter chains. Systems/methods of spatial multiplexing are also provided further increasing network capacity and throughput.

A mobile terminal device may include a radio processing circuit and a baseband processing circuit adapted to interact with the baseband processing circuit. The mobile terminal device may be configured to calculate a plurality of inverse frequency transforms with inputs of a plurality of samples of a frequency-domain signal sequence to generate a plurality of intermediate transforms, wherein each of the plurality of intermediate transforms are composed of a respective plurality of samples, combine the respective plurality of samples of each of the plurality of intermediate transforms to generate a time-domain representation of the frequency-domain signal sequence, generate a random access preamble with the time-domain representation of the frequency-domain signal sequence, and transmit the random access preamble.

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.

A method is provided for transmitting, by a user equipment (UE), a demodulation reference signal (DMRS) for a physical uplink shared channel (PUSCH) in a wireless communication system. First, second, and third DMRS sequences associated with first, second, and third layers respectively are generated. First, second, and third cyclic shifts are allocated to the first, second, and third DMRS sequences respectively, The first, second, and third DMRS sequences are transmitted to a base station. The first, second, and third cyclic shifts are respectively determined based on first, second and third cyclic shift values, which are indicated by a cyclic shift field in downlink control information (DCI) received through a physical downlink control channel (PDCCH). The first and second cyclic shift values are separated by a maximum separation value corresponding to a total number of cyclic shifts and being determined for transmission of DMRS signal in the system using four layers.

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.

The present invention provides a method and apparatus for transmitting uplink control information (UCI) with user equipment in a wireless communication system. The user equipment performs channel coding on information bits of UCI to generate encoded information bits; modulates the generated encoded information bits to generate complex modulation symbols; spreads the complex modulation symbols blockwise into a plurality of single carrier frequency division multiple access (SC-FDMA) symbols on the basis of an orthogonal sequence; and transmits the spread complex modulation symbols to a base station.