Method for transmitting signals in DCM mode in wireless LAN system, and device for same
Disclosed according to one embodiment of the present invention is a method whereby a first station (STA) transmits signals using dual carrier modulation (DCM) in a wireless LAN system, comprising: modulating HE-SIG B field information and/or data field information on a wireless frame transmitted by the first STA and transmitting same to a second STA, wherein in the case of modulating the HE-SIG B field information and/or the data field information in a BPSK mode, if a random symbol C1 among symbols modulated in the BPSK mode is mapped to a subcarrier K, a symbol formed by rotating the phase of the symbol C1 is mapped to a subcarrier K+N/2 in a repeating manner, wherein N corresponds to the number of subcarriers of a resource unit for transmitting the HE-SIG B field information and the data field information and K is a random integer equal to or less than N/2.
1. A method for a first station (STA) to transmit signals based on a Dual Carrier Modulation (DCM) in a wireless local area network (WLAN), the method comprising:
modulating the signals for at least one of a High Efficiency-Signaling (HE-SIG) B field or a data field of a radio frame to be transmitted by the first STA based on a Binary Phase Shift Keying (BPSK) scheme;
mapping a symbol (C1) of BPSK modulated symbols to a subcarrier K and repeatedly mapping a phase shifted symbol of the symbol (C1) to a subcarrier K+N/2,
wherein N corresponds to a number of resource units for transmitting the signals for the at least one of the HE-SIG B field or the data field, and wherein K is an integer equal to or less than N/2; and
transmitting the modulated symbols mapped to the subcarriers to a second STA.
2. The method according to claim 1 , wherein the phase shifted symbol of the symbol (C1) is generated by multiplying a phase rotator to the symbol (C1).
3. The method according to claim 2 , wherein the phase rotator corresponds to exp j(K+N/2)π.
4. The method according to claim 1 , wherein a HE-SIG A field of the radio frame includes an indicator indicating whether the DCM is applied to the signals for the at least one of the HE-SIG B field or the data field.
5. The method according to claim 4 , wherein the indicator has 1 bit length, and wherein the first STA determines the BPSK scheme for the signals based on information on a Modulation and Coding Scheme (MCS) field and the indicator of the HE-SIG Afield.
6. The method according to claim 1 , further comprising:
mapping each bit of the signals to each of the BPSK modulated symbols, and wherein the BPSK modulated symbols are mapped to subcarriers at a lower half of the resource units.
7. A station (STA) transmitting signals based on a Dual Carrier Modulation (DCM) in a wireless local area network (WLAN), the STA comprising:
a processor configured to modulate the signals for at least one of a High Efficien cy-Signaling (HE-SIG) B field or a data field of a radio frame to be transmitted by the STA based on a Binary Phase Shift Keying (BPSK) scheme; and
a transceiver configured to transmit symbols modulated by the processor to a different STA,
wherein the processor is further configured to:
map a symbol (C1) of BPSK modulated symbols to a subcarrier K and repeatedly map a phase shifted symbol of the symbol (C1) to a subcarrier K+N/2,
wherein N corresponds to a number of resource units for transmitting the signals for the at least one of the HE-SIG B field or the data field, and wherein K is an integer equal to or less than N/2.
8. The STA according to claim 7 , wherein the processor is configured to generate the phase shifted symbol of the symbol (C1) by multiplying a phase rotator to the symbol (C1).
9. The STA according to claim 8 , wherein the phase rotator corresponds to exp j(K+N/2) π.
10. The STA according to claim 7 , wherein the processor is configured to make a HE-SIG Afield of the radio frame have an indicator indicating whether the DCM is applied to the signals for the at least one of the HE-SIG B field or the data field.
11. The STA according to claim 10 , wherein the indicator has 1 bit length, and wherein the processor is configured to determine the BPSK scheme for the signals based on information on a Modulation and Coding Scheme (MCS) field and the indicator of the HE-SIG A field.
12. The STA according to claim 7 , wherein the processor is further configured to:
map each bit of the signals to each of the BPSK modulated symbols, and wherein the BPSK modulated symbols are mapped to subcarriers at a lower half of the resource unit.