A method for transmitting by a first station, STA, a physical protocol data unit, PPDU, to a second STA in a wireless local area network, WLAN, system, the method comprising: obtaining a first parameter including information for a tentative number of single carrier, SC, blocks of the PPDU, wherein the PPDU includes a first portion and a second portion; setting a value of a second parameter and a value of a third parameter based on a value of the first parameter and an applied modulation and coding scheme, MCS, wherein the second parameter includes information for a number of the SC blocks of the PPDU, wherein the third parameter includes information for a length of a training field included in the PPDU; configuring a header field of the PPDU, wherein the header field includes the second parameter and the third parameter; and transmitting the PPDU based on the header field, wherein the tentative number of the SC blocks of the PPDU is N BLKS ' which is determined by a following equation, N BLKS ′ = ⌈ TXTIME EDMG − T STF + T CE + T Header − 64 × T c 512 × T c ⌉ wherein TXTIME EDMG is a time duration required to transmit the PPDU, wherein T STF is a time duration of a legacy short training field, L-STF, wherein T CE is a time duration of a legacy channel estimation, L-CE, wherein T Header is a time duration of the header field, wherein Tc is a time duration of an SC chip, wherein ┌A┐ is a smallest value among integers equal to or greater than A, wherein the PPDU is an enhanced directional multi gigabit, EDMG, PPDU, wherein the first portion is a non-EDMG portion of the EDMG PPDU, wherein the second portion is an EDMG portion of the EDMG PPDU, and wherein the header field is a legacy header, L-header, field included in the non-EDMG portion of the EDMG PPDU. obtaining a first parameter including information for a tentative number of single carrier, SC, blocks of the PPDU, wherein the PPDU includes a first portion and a second portion; setting a value of a second parameter and a value of a third parameter based on a value of the first parameter and an applied modulation and coding scheme, MCS, wherein the second parameter includes information for a number of the SC blocks of the PPDU, wherein the third parameter includes information for a length of a training field included in the PPDU; configuring a header field of the PPDU, wherein the header field includes the second parameter and the third parameter; and transmitting the PPDU based on the header field, wherein the tentative number of the SC blocks of the PPDU is N BLKS ' which is determined by a following equation, N BLKS ′ = ⌈ TXTIME EDMG − T STF + T CE + T Header − 64 × T c 512 × T c ⌉ wherein TXTIME EDMG is a time duration required to transmit the PPDU, wherein T STF is a time duration of a legacy short training field, L-STF, wherein T CE is a time duration of a legacy channel estimation, L-CE, wherein T Header is a time duration of the header field, wherein Tc is a time duration of an SC chip, wherein ┌A┐ is a smallest value among integers equal to or greater than A, wherein the PPDU is an enhanced directional multi gigabit, EDMG, PPDU, wherein the first portion is a non-EDMG portion of the EDMG PPDU, wherein the second portion is an EDMG portion of the EDMG PPDU, and wherein the header field is a legacy header, L-header, field included in the non-EDMG portion of the EDMG PPDU. wherein TXTIME EDMG is a time duration required to transmit the PPDU, wherein T STF is a time duration of a legacy short training field, L-STF, wherein T CE is a time duration of a legacy channel estimation, L-CE, wherein T Header is a time duration of the header field, wherein Tc is a time duration of an SC chip, wherein ┌A┐ is a smallest value among integers equal to or greater than A, wherein the PPDU is an enhanced directional multi gigabit, EDMG, PPDU, wherein the first portion is a non-EDMG portion of the EDMG PPDU, wherein the second portion is an EDMG portion of the EDMG PPDU, and wherein the header field is a legacy header, L-header, field included in the non-EDMG portion of the EDMG PPDU.