Method and apparatus for receiving PPDU through broadband in wireless LAN system

1. A method in a wireless LAN system, the method comprising:

receiving a Physical Protocol Data Unit (PPDU) by a receiving station (STA) from a transmitting STA through a broadband; and

decoding the PPDU by the receiving STA,

wherein the broadband is a 320 MHz band or a 160+160 MHz band,

the PPDU includes a first field and a second field,

the first field includes a Legacy-Short Training Field (L-STF) and a Legacy-Long Training Field (L-LTF),

the first field is generated based on a first phase rotation value,

the first phase rotation value is generated based on a second phase rotation value and a third phase rotation value,

the second phase rotation value is obtained by repeating a phase rotation value for a 160 MHz band defined in the 802.11ax wireless LAN system,

the third phase rotation value is a phase rotation value defined in units of 80 MHz bands based on optimal Peak-to-Average Power Ratio (PAPR) of the L-STF and the L-LTF,

the optimal PAPR of the L-STF and the L-LTF is obtained based on a combination of Radio Frequencies (RFs) used when the PPDU is transmitted, and

the combination of RFs combines RF with 80 MHz capability, RF with 160 MHz capability, or RF with 320 MHz capability.

2. The method of claim 1 , wherein the first phase rotation value is [1−1 −1−1 1−1 −1−1 −1 1 1 1−1 1 1 1],

one element of the first phase rotation value is a phase rotation value applied to each 20 MHz band of the 320 MHz band or the 160+160 MHz band, and

the first phase rotation value is obtained based on a product of the second phase rotation value and the third phase rotation value.

3. The method of claim 2 , wherein the 320 MHz band or the 160+160 MHz band consists of subcarriers of which the subcarrier index ranges from −512 to 511,

the second phase rotation value is [1−1 −1−1 1−1 −1−1 1−1 −1−1 1−1 −1−1],

the first element 1 of the second phase rotation value is applied to subcarriers having a subcarrier index ranging from −512 to −449,

the second element −1 of the second phase rotation value is applied to subcarriers having a subcarrier index ranging from −448 to −385,

the third element −1 of the second phase rotation value is applied to subcarriers having a subcarrier index ranging from −384 to −321,

the fourth element −1 of the second phase rotation value is applied to subcarriers having a subcarrier index ranging from −320 to −257,

the fifth element 1 of the second phase rotation value is applied to subcarriers having a subcarrier index ranging from −256 to −193,

the sixth element −1 of the second phase rotation value is applied to subcarriers having a subcarrier index ranging from −192 to −129,

the seventh element −1 of the second phase rotation value is applied to subcarriers having a subcarrier index ranging from −128 to −65,

the eighth element −1 of the second phase rotation value is applied to subcarriers having a subcarrier index ranging from −64 to −1,

the ninth element 1 of the second phase rotation value is applied to subcarriers having a subcarrier index ranging from 0 to 63,

the tenth element −1 of the second phase rotation value is applied to subcarriers having a subcarrier index ranging from 64 to 127,

the eleventh element −1 of the second phase rotation value is applied to subcarriers having a subcarrier index ranging from 128 to 191,

the twelfth element −1 of the second phase rotation value is applied to subcarriers having a subcarrier index ranging from 192 to 255,

the thirteenth element 1 of the second phase rotation value is applied to subcarriers having a subcarrier index ranging from 256 to 319,

the fourteenth element −1 of the second phase rotation value is applied to subcarriers having a subcarrier index ranging from 320 to 383,

the fifteenth element −1 of the second phase rotation value is applied to subcarriers having a subcarrier index ranging from 384 to 447, and

the sixteenth element −1 of the second phase rotation value is applied to subcarriers having a subcarrier index ranging from 448 to 511.

4. The method of claim 3 , wherein the third phase rotation value is [1 1 −1−1],

the first element 1 of the third phase rotation values is applied to the first 80 MHz band of the 320 MHz band or the 160+160 MHz band,

the second element 1 of the third phase rotation values is applied to the second 80 MHz band of the 320 MHz band or the 160+160 MHz band,

the third element −1 of the third phase rotation values is applied to the third 80 MHz band of the 320 MHz band or the 160+160 MHz band, and

the fourth element −1 of the third phase rotation values is applied to the fourth 80 MHz band of the 320 MHz band or the 160+160 MHz band.

5. The method of claim 1 , wherein the PPDU is not transmitted in a combination in which the RF with 160 MHz capability is used in the middle 160 MHz band in the 320 MHz band or the 160+160 MHz band, and the RF with 80 MHz capability is used in both of the remaining 80 MHz bands in the 320 MHz band or the 160+160 MHz band.

6. The method of claim 1 , wherein the first phase rotation value is obtained based on a preamble puncturing pattern, and

the preamble puncturing pattern includes all patterns of a band in which an 80 MHz band is punctured in the 320 MHz band or 160+160 MHz band.

7. The method of claim 1 , wherein the first field further includes control information on the L-STF sequence and the L-LTF sequence, and

the first phase rotation value is applied to the L-STF sequence and the L-LTF sequence, and

the second field includes a control field and a data field supporting the 802.11be wireless LAN system.

8. A receiving station (STA) in a wireless LAN system, the receiving STA comprising:

a memory;

a transceiver; and

a processor combined operatively with the memory and the transceiver, wherein the processor is configured to:

receive a Physical Protocol Data Unit (PPDU) from a transmitting STA through a broadband; and

decode the PPDU,

wherein the broadband is a 320 MHz band or a 160+160 MHz band,

the PPDU includes a first field and a second field,

the first field includes a Legacy-Short Training Field (L-STF) and a Legacy-Long Training Field (L-LTF),

the first field is generated based on a first phase rotation value,

the first phase rotation value is generated based on a second phase rotation value and a third phase rotation value,

the second phase rotation value is obtained by repeating a phase rotation value for a 160 MHz band defined in the 802.11ax wireless LAN system,

the third phase rotation value is a phase rotation value defined in units of 80 MHz bands based on optimal Peak-to-Average Power Ratio (PAPR) of the L-STF and the L-LTF,

the optimal PAPR of the L-STF and the L-LTF is obtained based on a combination of Radio Frequencies (RFs) used when the PPDU is transmitted, and

the combination of RFs combines RF with 80 MHz capability, RF with 160 MHz capability, or RF with 320 MHz capability.

9. A method in a wireless LAN system, the method comprising:

generating a Physical Protocol Data Unit (PPDU) by a transmitting station (STA); and

transmitting the PPDU to a receiving STA by the transmitting STA through a broadband,

wherein the broadband is a 320 MHz band or a 160+160 MHz band,

the PPDU includes a first field and a second field,

the first field includes a Legacy-Short Training Field (L-STF) and a Legacy-Long Training Field (L-LTF),

the first field is generated based on a first phase rotation value,

the first phase rotation value is generated based on a second phase rotation value and a third phase rotation value,

the second phase rotation value is obtained by repeating a phase rotation value for a 160 MHz band defined in the 802.11ax wireless LAN system,

the third phase rotation value is a phase rotation value defined in units of 80 MHz bands based on optimal Peak-to-Average Power Ratio (PAPR) of the L-STF and the L-LTF,

the optimal PAPR of the L-STF and the L-LTF is obtained based on a combination of Radio Frequencies (RFs) used when the PPDU is transmitted, and

the combination of RFs combines RF with 80 MHz capability, RF with 160 MHz capability, or RF with 320 MHz capability.

10. The method of claim 9 , wherein the first phase rotation value is [1−1 −1−1 1−1 −1−1 −1 1 1 1−1 1 1 1],

one element of the first phase rotation value is a phase rotation value applied to each 20 MHz band of the 320 MHz band or the 160+160 MHz band, and

the first phase rotation value is obtained based on a product of the second phase rotation value and the third phase rotation value.

11. The method of claim 9 , wherein the PPDU is not transmitted in a combination in which the RF with 160 MHz capability is used in the middle 160 MHz band in the 320 MHz band or the 160+160 MHz band, and the RF with 80 MHz capability is used in both of the remaining 80 MHz bands in the 320 MHz band or the 160+160 MHz band.

12. The method of claim 9 , wherein the first phase rotation value is obtained based on a preamble puncturing pattern, and

the preamble puncturing pattern includes all patterns of a band in which an 80 MHz band is punctured in the 320 MHz band or 160+160 MHz band.