One example discloses an IEEE 802.11 compliant wireless communications device, including: a processor configured to generate a hybrid-physical protocol data unit (hybrid-PPDU) that includes a set of sub-PPDUs; a first sub-PPDU in the set of sub-PPDUs includes a first preamble portion and a first data payload portion; a second sub-PPDU in the set of sub-PPDUs includes a second preamble portion and a second data payload portion; wherein an OFDMA communications signal includes a set of symbol tones divided into a set of resource units (RUs); wherein the processor is configured to map the first sub-PPDU to a first RU within the set of RUs, and map the second sub-PPDU to a second RU within the set of RUs; and wherein the first preamble portion corresponds to a first 802.11 packet format, and the second preamble portion corresponds to a second 802.11 packet format.

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 a time-domain sequence x(i), an output sequence s(k). The output sequence s(k) is an inverse Fourier transform of a frequency-domain sequence S(j), and S(j) represents a dot-multiplication of a frequency-domain sequence Y(j) corresponding to the time-domain sequence x(i) and a frequency-domain sequence Z(j) corresponding to a three-coefficient function associated with

[00001]$\frac{\sqrt{2}}{2},$

1, and

[00002]$\frac{\sqrt{2}}{2}.$

The method also includes generating a waveform using the output sequence s(k), where i is from 0 to I−1, j is from 0 to J−1, k is from 0 to K−1, and I<J<=K.

A signal transmission method and apparatus are provided, to resolve a problem that because a PAPR of a signal is comparatively high, a waveform distortion of the signal is comparatively serious after power amplification is performed on the signal by using a PA. The method includes: separately performing phase rotation on M pieces of modulated data to obtain M pieces of phase-rotated data, where a phase factor for performing phase rotation on the M pieces of modulated data is determined based on M. The method further includes: determining time domain data based on the M pieces of phase-rotated data, and sending the time domain data to a receive end.

A system includes a modulator, a repetition module, and a phase rotation module. The modulator is configured to (i) modulate data using a first modulation scheme and dual sub-carrier modulation, and (ii) generate modulated symbols for transmission on a plurality of subcarriers. The dual sub-carrier modulation modulates the same information on a pair of subcarriers. The repetition module is configured to repeat the modulated symbols from a first half of the plurality of subcarriers to a second half of the plurality of subcarriers. The phase rotation module is configured to rotate phase of the modulated symbols on selected subcarriers of the second half of the plurality of subcarriers. The selected subcarriers of the second half of the plurality of subcarriers include at least one half of the second half of the plurality of subcarriers.

Proposed are a method and apparatus for receiving a PPDU in a wireless LAN system. In detail, a reception STA receives a PPDU from a transmission STA through a first band and decodes the PPDU. The PPDU includes a preamble and a data field. The first band includes first and second subblocks. The data field includes first data for the first subblock and second data for the second subblock. The first data is generated on the basis of data in which constellation mapping is performed on encoded data bits. The second data is generated on the basis of data obtaining by duplicating the first data and applying phase rotation thereto.

A device is provided, which includes radio-frequency circuitry and an encoder. The encoder is configured to modulate input data to generate a long-range packet, and to transmit the long-range packet to a receiver through the radio-frequency circuitry. The long-range packet includes a long-range signal field (LR-SIG) and a long-range data field (LR-DATA). Each modulated bit in the long-range signal field and the long-range data field is spread into a plurality of spread modulated bits that are distributed into a plurality of symbols in a frequency domain.

A method and an apparatus for receiving a PPDU in a wireless LAN system are proposed. Specifically, a receiving STA receives the PPDU from a transmitting STA through an 80 MHz band, and decodes the PPDU. The PPDU includes a preamble and a data field. The 80 MHz band includes first and second 484 tones RUs. The data field includes first data for the first 484 tone RU and second data for the second 484 tone RU. The second data is data obtained by duplicating the first data. The first and second 484 tone RUs are resource units including 484 tones.

A transmitter includes: a phase rotation sequence generation unit that generates, on the basis of transmit bits being input, a phase rotation sequence in which a frequency response has a bandwidth; an up-sampling unit that changes a sample rate of the phase rotation sequence and further replicates the phase rotation sequence; and a frequency shift unit that shifts, by a specified amount of shift on a frequency axis, a frequency component of the phase rotation sequence acquired from the up-sampling unit.

A signal transmission method and an apparatus are provided, to resolve a problem, in a conventional technology, that transmission performance is poor when a signal is transmitted in a DFT-s-OFDM waveform. A transmitting end maps a plurality of modulation symbols to a plurality of layers, performs discrete Fourier transform (DFT) on a modulation symbol at a part of the layers to obtain a first symbol, and performs discrete Fourier transform DFT and phase offset on a modulation symbol at a remaining part of the layers to obtain a second symbol. Phase offset is performed on a symbol at a part of layers, so that a PAPR can be reduced.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may receive a resource allocation indicating a plurality of transmission tones comprising a subset of data tones of a plurality of data tones and a subset of peak reduction tones (PRTs) of a plurality of PRTs, wherein the resource allocation indicates locations for the plurality of data tones and locations for the plurality of PRTs within a particular bandwidth, wherein the locations for the plurality of PRTs are arranged relative to the locations for the plurality of data tones according to a PRT subsequence of a universal PRT sequence, and wherein the PRT subsequence corresponds to a sub-band of the particular bandwidth; and transmit a data transmission using a waveform based at least in part on the resource allocation. Numerous other aspects are provided.