A method and an apparatus for transmitting an EHT PPDU in a WLAN system are proposed. Specifically, a transmitter generates an EHT PPDU and transmits, on the basis of an RF, the EHT PPDU to a receiver through a 320 MHz band in which an 80 MHz band is punctured. A legacy preamble includes an L-STF and an L-LTF. The legacy preamble is generated by applying a first phase rotation value. The first phase rotation value is determined on the basis of a first scheme and a second scheme. The first scheme is a scheme of obtaining an optimal PAPR in the L-STF and the L-LTF. The second scheme is a scheme of obtaining an optimal PAPR on the basis of the maximum transmission bandwidth supported by the RF. The first phase rotation value is obtained on the basis of a second phase rotation value and a third phase rotation value. The second phase rotation value is a phase rotation value that repeats a phase rotation value defined for the 80 MHz band in an 802.11ax system. The third phase rotation value is a phase rotation value defined in units of the 80 MHz band in the 320 MHz band.

Proposed are a method and an apparatus for receiving a PPDU in a wireless LAN system. Specifically, a reception STA receives a PPDU from a transmission STA through a broadband and decodes the PPDU. The PPDU includes a legacy preamble, and a first and a second signal field. The legacy preamble and the first and the second signal field are generated on the basis of a first phase rotation value. When a first band is a 40 MHz band, the first phase rotation value is [1, −1, −1, −1]. Each element of the first phase rotation value is applied for each 10 MHz band in the first band.

Disclosed is a sequence generation method comprising: generating a basic sequence structure including C.sub.48 having 48 tones, X.sub.6 having six tones, and X.sub.5 having five tones; selecting any one of a plurality of phase rotation factors predetermined for a bandwidth; and generating a sequence to be inputted into a preamble to be transmitted to a terminal, by using the phase rotation factor, applied in basic sequence structural units, and the basic sequence structure.

The present disclosure is related to a Long Training Field (LTF) signal used in a wireless local area network (WLAN) system. The LTF signal may be generated by a transmitting station (STA) and received by a receiving STA. The LTF signal may be included in a physical protocol data unit (PPDU), and the PPDU may be transmitted an 80 MHz band. The LTF sequence may include at least two parts, i.e., a first LTF sequence and a second LTF sequence.

A method for reducing a peak to average power ratio (PAPR) of an orthogonal frequency division multiplexing (OFDM) signal. A first signal in the frequency domain is processed to generate a second signal by performing a modular permutation on the first signal according to a modular permutation index, and/or by performing a cyclic shift on the first signal according to a cyclic shift parameter. The second signal is then mapped to a number of tones, and transformed into a time-domain signal for transmission. The modular permutation index and/or the cyclic shift parameter are selected so that the signal for transmission has a PAPR that satisfies a predefined PAPR criteria.

This disclosure provides data sending and receiving methods and apparatuses. In an implementation, a device performs a non-replication operation on a frequency domain sequence on subcarriers of a first bandwidth, to obtain a frequency domain sequence on subcarriers of a second bandwidth in a transmission bandwidth, transforms the frequency domain sequence on the subcarriers of the first bandwidth and the frequency domain sequence on the subcarriers of the second bandwidth into a time domain, and performs radio frequency processing on time domain data and then sends the processed time domain data.

A method and an apparatus for transmitting an EHT PPDU to a WLAN system are proposed. Specifically, a transmitter generates and transmits an EHT PPDU to a receiver through a 320 MHz band from which an 80 MHz band is punctured. The EHT PPDU includes a legacy preamble and an EHT field. The legacy preamble includes an L-STF and an L-LTF. The legacy preamble is generated by applying a first phase rotation value. The first phase rotation value is obtained on the basis of a second phase rotation value and a third phase rotation value. The second phase rotation value is a phase rotation value that repeats a phase rotation value defined for the 80 MHz band in an 802.11ax system. The third phase rotation value is a phase rotation value defined in unit of the 80 MHz band in the 320 MHz band on the basis of an optimal PAPR of the L-STF and L-LTF. The first phase rotation value is [1 1 −1 −1 −j −j j j 1 1 −1 −1 −j −j j j].

A transmitter for transmitting data to communications devices via a wireless access. The transmitter including modulator circuitry configured to receive modulation symbols of a segment and to rotate each modulation symbol by an angle dependent on a choice of modulation scheme, and receive each of the segments of rotated modulation symbols and for each segment to separate real and imaginary components of the rotated modulation symbols for the segment and to interleave the real components of the rotated modulation symbols of the segment differently to the imaginary components of the rotated modulation symbols of the segment. The circuitry also is configured to recombine the real and imaginary interleaved components of the rotated modulation symbols of each segment and to form from the real and imaginary components modulation cells.

Methods, apparatus, and systems for reducing Peak Average Power Ratio (PAPR) in signal transmissions are described. In one example aspect, a wireless communication method includes determining, for an input sequence, an output sequence corresponding to an output of a convolutional modulation between a plurality of values and an intermediate sequence. The intermediate sequence is generated by inserting a set of coefficients between coefficients of the input sequence. Each non-zero coefficient of the set of coefficients is inserted between a first adjacent coefficient and a second adjacent coefficient. Each non-zero coefficient has a power that is between a first power of the first adjacent coefficient and a second power of the second adjacent coefficient and a phase value between a first phase value of the first adjacent coefficient and a second phase value of the second adjacent coefficient. The method also includes generating a waveform using the output sequence.

A peak-to-average ratio reduction method, including dividing subcarriers of an orthogonal frequency division multiplexing (OFDM) symbol that carries to-be-transmitted data to obtain multiple blocks, determining multiple phase factors corresponding to the multiple blocks, where the multiple phase factors reduce a peak-to-average ratio of the OFDM symbol, transmitting the multiple phase factors using a particular subcarrier of the OFDM symbol, multiplying data transmitted on each block in the multiple blocks by a corresponding phase factor, and transmitting data obtained by means of multiplication. Phase factor information of each block is transmitted using the particular subcarrier such that application of a partial transmit sequence (PTS) method in a WI-FI system becomes possible, thereby effectively reducing a peak-to-average power ratio (PAPR) of data.