Provided is a communication system that can sustain a reduction in delay in FFT/IFFT processing by code blocking user data, even in a case where the functions of upper layers such as a MAC scheduler and the function of the radio physical layer are implemented separately. In a radio base station (communication system) including a central aggregation device 210 and a remote device 220, the central aggregation device 210 transmits code blocks in a number necessary for generating an OFDM symbol as a piece of data to the remote device 220, the code blocks being produced by dividing user data into units of encoding processing.

A method and apparatus for generating a preamble symbol in an Orthogonal Frequency Division Multiplexing (OFDM) system by generating a first main body sequence in a time domain by performing an inverse fast Fourier transform (IFFT) on a preset sequence in a frequency domain, generating a first postfix by copying samples in a preset section in the first main body sequence, generating a first prefix by copying samples in at least a portion of a section remaining by excluding the preset section from the first main body sequence, and generating a plurality of symbols, based on a combination of the first main body sequence, the first prefix, and the first postfix.

In an operation in a license-exempt band (unlicensed band), the present invention contributes to the provision of a mobile station, a base station, a transmission method and a receiving method which suitably transmit and receive a signal. The mobile station 200 includes: a transmission unit 205 which transmits an uplink signal; and a control unit 201 which, when a first number indicating a first resource amount that can be used in the transmission of the uplink signal includes a third number, which is different from a specific second number, as a prime factor, controls the transmission of a signal of a fourth number that does not include the third number as the prime factor by using a second resource.

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.

Disclosed are a method and a device for transmitting data unit in a WLAN. A method for transmitting data unit in a WLAN comprises: a step of an STA generating a PPDU; and a step of the STA transmitting the PPDU to an access point (AP), wherein the PPDU comprises a first field and a second field, wherein the first field is transmitted on the basis of a first IFFT and the second field is transmitted on the basis of a second IFFT.

An apparatus and a method for estimation a wireless channel are disclosed. For example, the method correlates, by a correlator, a plurality of signals of a combined signal received by a receive antenna over the wireless channel from a plurality of transmit antennas, with respective DMRSs of the plurality of transmit antennas, converts, by a converter, the correlated plurality of signals from frequency to time domain, iteratively peak cancels, by a peak canceller, a largest peak of the combined impulse response and stores a scaling factor and location pair of the cancelled peak until a magnitude of a next largest peak is below a predetermined threshold, assigns, by an assigner, each of the scaling factor and location pairs to a transmit antenna, and estimates, by an estimator, for each of the plurality of transmit antennas, the wireless channel based on the assigned scaling factor and location pairs.

A communication device for handling a Peak-to-Average Power Ratio (PAPR), includes a transforming module, configured to perform a first plurality of inverse fast Fourier transforms (IFFTs) on a plurality of coefficients in a scene according to a first inverse fast Fourier transform (IFFT) size and the scene, to obtain a plurality of results; a processing module, coupled to the transforming module, configured to obtain a plurality of norms of the plurality of results, and to obtain a plurality of values of the plurality of coefficients; and a transmitting module, coupled to the processing module, configured to perform a second plurality of IFFTs on a plurality of frequency-domain signals according to a second IFFT size, the plurality of coefficients with the plurality of values and the scene, to obtain a plurality of time-domain signals, wherein the second IFFT size is greater than the first IFFT size.

A transmitter includes: a frame generator configured to generate a frame including a frame starting symbol, at least one data symbol and a frame closing symbol; a pilot and reserved tone inserter configured to insert pilots and reserved tones in at least one of the frame starting symbol, the data symbol and the frame closing symbol such that positions of the reserved tones do not overlap positions of the pilots in the at least one of the frame starting symbol, the data symbol and the frame closing symbol; and a transmitter configured to transmit the frame in which the pilots and the reserved tones are inserted, wherein the reserved tones are not used to transmit data in the frame.

An apparatus and a method for estimation a wireless channel are disclosed. For example, the method correlates, by a correlator, a plurality of signals of a combined signal received by a receive antenna over the wireless channel from a plurality of transmit antennas, with respective DMRSs of the plurality of transmit antennas, converts, by a converter, the correlated plurality of signals from frequency to time domain, iteratively peak cancels, by a peak canceller, a largest peak of the combined impulse response and stores a scaling factor and location pair of the cancelled peak until a magnitude of a next largest peak is below a predetermined threshold, assigns, by an assigner, each of the scaling factor and location pairs to a transmit antenna, and estimates, by an estimator, for each of the plurality of transmit antennas, the wireless channel based on the assigned scaling factor and location pairs.

In an operation in a license-exempt band (unlicensed band), the present invention contributes to the provision of a mobile station, a base station, a transmission method and a receiving method which suitably transmit and receive a signal. The mobile station 200 includes: a transmission unit 205 which transmits an uplink signal; and a control unit 201 which, when a first number indicating a first resource amount that can be used in the transmission of the uplink signal includes a third number, which is different from a specific second number, as a prime factor, controls the transmission of a signal of a fourth number that does not include the third number as the prime factor by using a second resource.