Method and device for applying optimized phase rotation in wlan environment including wireless devices having mutually different maximum transmittable rf bandwidths

A transmitting device for transmitting an extreme high throughput (EHT) physical protocol data unit (PPDU) in a WLAN system, the transmitting device comprising:

• a memory;
• a transceiver;
• and
• a processor operably connected to the memory and the transceiver,
• wherein the processor is configured:
• to generate the EHT PPDU, the EHT PPDU including a legacy preamble and an EHT field;
• and
• to transmit the EHT PPDU to a receiving device through a 320 MHz band based on a radio frequency (RF),
• wherein the legacy preamble includes a legacy-short training field (L-STF) and a legacy-long training field (L-LTF),
• the legacy preamble is generated by applying first phase rotation values,
• the first phase rotation values are determined based on a first method and a second method,
• the first method is a method of obtaining an optimum PAPR in the L-STF and the L-LTF,
• the second method is a method of obtaining an optimum PAPR based on a maximum transmission bandwidth supported by the RF,
• the first phase rotation values are obtained based on second phase rotation values and third phase rotation values,
• the second phase rotation values are obtained by repeating phase rotation values defined for an 80 MHz band in an 802.11ax system, and
• the third phase rotation values are defined in units of 80 MHz in the 320 MHz band.

A method for receiving an extreme high throughput (EHT) physical protocol data unit (PPDU) in a WLAN system, the method comprising:

• receiving, by a receiving device, the EHT PPDU from a transmitting device through a 320 MHz band based on a radio frequency (RF), the EHT PPDU including a legacy preamble and an EHT field;
• and
• decoding, by the receiving device, the EHT PPDU,
• wherein the legacy preamble includes a legacy-short training field (L-STF) and a legacy-long training field (L-LTF),
• the legacy preamble is generated by applying first phase rotation values,
• the first phase rotation values are determined based on a first method and a second method,
• the first method is a method of obtaining an optimum PAPR in the L-STF and the L-LTF,
• the second method is a method of obtaining an optimum PAPR based on a maximum transmission bandwidth supported by the RF,
• the first phase rotation values are obtained based on second phase rotation values and third phase rotation values,
• the second phase rotation values are obtained by repeating phase rotation values defined for an 80 MHz band in an 802.11ax system, and
• the third phase rotation values are defined in units of 80 MHz in the 320 MHz band.