Methods, systems, and devices for wireless communication are described. A wireless device, such as a device in a wireless local area network, may use a radio frame structure that includes a high efficiency (HE) signal field and an HE data field for communications, for example, over shared radio frequency spectrum. One or more bits or symbols within the HE signal field may be adjusted to avoid a high peak-to-average power ratio (PAPR). In some cases, the adjustment may be to a signal A (SIG-A) or signal B (SIG-B) field. In some examples, a random bit sequence may be used for padding in a signal field. In other examples, bits may be reversed or scrambled. In yet other examples, bits may be modulated and a phase rotation may be applied to the corresponding signal.

Proposed are a method and a device 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. In a case in which the broadband is a 320 MHz band, the first phase rotation value is [1 1 1 −j j j j 1 j j j 1 −1 −1 −1 j].

Disclosed is a sequence generation method for: generating a basic sequence structure comprising C.sub.52, which is composed of 52 tones, and D.sub.12, which is composed of 12 tones; selecting any one among a plurality of phase rotation factors, which are determined in advance for a bandwidth and applied to the basic sequence structure by unit of C.sub.52 or C.sub.52D.sub.12; and generating a sequence inserted into a preamble to be transmitted to a terminal.

Certain aspects of the present disclosure generally relate to wireless communications. In some aspects, a wireless device reduces a peak-to-average power ratio (PAPR) of a discrete-time orthogonal frequency division multiplexing (OFDM) transmission by selecting a signal with low PAPR from a set of candidate discrete-time OFDM signals. The wireless device may generate a partial-update discrete-time OFDM signal by performing a sparse transform operation on a base data symbol sequence, and then linearly combine the partial-update discrete-time OFDM signal with a base discrete-time OFDM signal to produce an updated discrete-time OFDM signal, which is added to the set of candidate discrete-time OFDM signals. Numerous other aspects are provided.

A communication device maps a plurality of bits to a first set of transmission symbols corresponding to a first set of subcarriers within a component communication channel. Transmission symbols among the first set of transmission symbols correspond to respective subsets of one or more bits, and transmission symbols among the first set of transmission symbols are single carrier transmission symbols. The communication device maps the plurality of bits to a second set of transmission symbols corresponding to a second set of subcarriers within the component communication channel. At least a subset of multiple transmission symbols in the second set of transmission symbols correspond to phase adjusted versions of transmission symbols in a corresponding at least a subset of multiple transmission symbols in the first set of transmission symbols. The communication device generates a transmission signal using the first set of transmission symbols and the second set of transmission symbols.

An apparatus for receiving signals includes a receiver for receiving a time domain signal from a transmitter, wherein at least one first information bit is mapped, resulting in at least one first mapped symbol; at least one second information bit is mapped, resulting in at least one second mapped symbol; the at least one second mapped symbol is multiplied by at least one third information bit; and the time domain signal is generated from the at least one first mapped symbol and the at least one second mapped symbol.

Selective processing of one or more packets to be transmitted from a wireless communication device to another wireless communication device is effective to reduce the peak to average power ratio (PAPR) of the transmission. The one or more packets are transmitted via two or more sub-bands of an available transmission medium. The number of coefficients or factors within that sequence corresponds to the number of sub-bands via which the one or more packets are to be transmitted. Also, a phase ramp or time-domain cyclic shift may be added to one or more of the packets after having undergone multiplication by one of the coefficients or factors within the sequence.

Embodiments of this application provide a side information transmission method and apparatus. Data to be transmitted by a transmit end includes at least one first data sub-block and at least one second data sub-block. A first modulated signal is obtained based on a first phase rotation factor. A second modulated signal is obtained based on a second phase rotation factor. Side information is generated based on the first phase rotation factor and the second phase rotation factor. The first data sub-block is carried on a first subcarrier, and the side information is also mapped to the first carrier. The first modulated signal corresponding to the at least one first data sub-block, the second modulated signal corresponding to the at least one second data sub-block, and a modulated signal corresponding to the side information are superposed to obtain a to-be-transmitted signal.

A method and apparatus for transmitting an EHT PPDU in a wireless LAN system is proposed. Specifically, a transmitting STA generates an EHT PPDU including a STF signal. The transmitting STA transmits the EHT PPDU to a receiving STA. The STF signal is generated on the basis of an EHT STF sequence for a 320 MHz band or a 160+160 MHz band. The EHT STF sequence for the 320 MHz band is a first sequence in which a predetermined M sequence is repeated, which is defined as {M 1 M 1 M 1 −M 0 M 1 −M 1 −M 1 M 0 M 1 M 1 M 1 −M 0 −M −1 M −1 M −1 −M}*(1+j)/sqrt(2). The sqrt( ) represents the square root. The predetermined M sequence is defined as M={−1, −1, −1, 1, 1, 1, −1, 1, 1, 1, −1, 1, 1, −1, 1}.

Techniques are provided for constructing or determining a training sequence as a part of transmission preamble to minimize (or at least reduce) a peak-to-average power ratio (PAPR) at a transmitting node. In one example, a long training field (LTF) sequence of a preamble is determined that combines a set of interpolating sequences with LTF tone values. The LTF tone values may cover at least a portion of bandwidth of a first size, with each of the LTF tone values repeated for different subcarriers. The phases of tones of the LTF sequence may be rotated per bandwidth of the first size and certain tones of the LTF sequence may have a stream of values at pilot locations. For example, the phases of tones of the LTF sequence may be rotated in an effort to reduce PAPR during a transmission of the LTF sequence.