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.

The application provides a short training sequence design method and apparatus. The method includes: determining a short training sequence, where the short training sequence may be obtained based on an existing sequence, and the short training sequence with comparatively good performance may be obtained through simulation calculation, for example, by adjusting a parameter; and sending a short training field on a target channel, where the short training field is obtained by performing inverse fast Fourier transformation IFFT on the short training sequence, and a bandwidth of the target channel is greater than 160 MHz.

A sequence-based signal processing method and apparatus are provided. A sequence meeting a requirement for sending a signal by using a physical uplink control channel (PUCCH) is determined. The sequence is a sequence {f.sub.n} consisting of 12 elements, f.sub.n represents an element in the sequence {f.sub.n}, and the determined sequence {f.sub.n} is a sequence meeting a preset condition. Then, the 12 elements in the sequence {f.sub.n} are respectively mapped to 12 subcarriers, to generate a first signal, and the first signal is sent. By using the determined sequence, when the signal is sent by using the PUCCH, a low correlation between sequences can be maintained, and a relatively small peak-to-average power ratio (PAPR) value and a relatively small cubic metric (CM) value can be maintained. Therefore, a requirement of a communication application environment in which the signal is sent by using the PUCCH is met.

The application provides a short training sequence design method and apparatus. The method includes: determining a short training sequence, where the short training sequence may be obtained based on an existing sequence, and the short training sequence with comparatively good performance may be obtained through simulation calculation, for example, by adjusting a parameter, and sending a short training field on a target channel, where the short training field is obtained by performing inverse fast Fourier transformation IFFT on the short training sequence, and a bandwidth of the target channel is greater than 160 MHz.

Embodiments of the present invention provide several long training sequences that are in a wireless local area network and that comply with 802.11ax.

A sequence-based signal processing method and apparatus are provided. A sequence meeting a requirement for sending a signal by using a physical uplink control channel (PUCCH) is determined. The sequence is a sequence {f.sub.n} consisting of 12 elements, f.sub.n represents an element in the sequence {f.sub.n}, and the determined sequence {f.sub.n} is a sequence meeting a preset condition. Then, the 12 elements in the sequence {f.sub.n} are respectively mapped to 12 subcarriers, to generate a first signal, and the first signal is sent. By using the determined sequence, when the signal is sent by using the PUCCH, a low correlation between sequences can be maintained, and a relatively small peak-to-average power ratio (PAPR) value and a relatively small cubic metric (CM) value can be maintained. Therefore, a requirement of a communication application environment in which the signal is sent by using the PUCCH is met.

A method and an apparatus for transmitting a physical layer protocol data unit that can provide a short training field sequence for a larger channel bandwidth. The short training field sequence has a smaller peak-to-average power ratio PAPR and better performance. The method includes: generating a physical layer protocol data unit PPDU, where the PPDU includes a short training field, a length of a frequency domain sequence of the short training field is greater than a first length, and the first length is a length of a frequency domain sequence of a short training field of a PPDU transmitted on a channel with a bandwidth of 160 MHz; and sending the PPDU on a target channel, where a bandwidth of the target channel is greater than 160 MHz.

In a wireless local area network (WLAN) system, an LTF sequence for 320 MHz or 160+160 MHz band transmission can be defined.

A communication apparatus includes a receiver and a decoder. The receiver includes a plurality of antenna elements and, in operation, receives from a base station apparatus a modulated signal mapped to one of a plurality of subframes defined in a frame corresponding to a communicable range to which the communication apparatus belongs. The plurality of subframes are defined by time-division, frequency-division, or time-and-frequency division of the frame. A maximum number of modulated signals that can be simultaneously transmitted in a subframe from the base station apparatus varies depending on the communicable range. The decoder, in operation, decodes the received modulated signal.

A method of determining reserved tones to be used for reduction of a peak to average power ratio (PAPR) of a signal includes: randomly selecting carrier indices for the reserved tones and generating a kernel signal based on the randomly selected carrier indices for the reserved tones; calculating a comparison reference average value of the kernel signal, comparing the calculated comparison reference average value with a prestored comparison reference average value, and preliminarily determining carrier indices of the reserved tones based on the comparison; re-arranging an order of the preliminarily determined carrier indices of the reserved tones; calculating comparison reference average values of kernel signals generated by changing each of the re-arranged carrier indices of the reserved tones, and finally determining carrier indices of the reserved tones which generate a kerneal signal having the smallest comparison reference average value among the comparison reference average values as indices of the reserved tones.