Frame transmitting method and frame receiving method
View Patent ↗A method of transmitting a frame is provided by a device in a WLAN. The device sets as additional data subcarriers some of subcarriers which are not set as data subcarriers in at least part of fields included in a frame of a legacy frame format, and allocates information to the additional data subcarriers.
1. An apparatus for facilitating wireless communication, the apparatus comprising:
a Radio Frequency (RF) transmitter;
an antenna coupled to the RF transmitter, and
a processor configured to transmit, using the RF transmitter and the antenna, a frame, the frame including:
a first set of symbols used for carrying training information, each symbol of the first set of symbols having a direct current (DC) subcarrier and guard tones, wherein an index of the DC subcarrier is 0 and indices of the guard tones are −27 to −32 and 27 to 31 on a 20 MHz bandwidth basis, and
a second set of symbols, each symbol of the second set of symbols having a DC subcarrier, guard tones, and additional data subcarriers, wherein an index of the DC subcarrier is 0, indices of the guard tones are −29 to −32 and 29 to 31, and indices of the additional data subcarriers are −27, −28, 27 and 28 on a 20 MHz bandwidth basis, and wherein the additional data subcarriers include training information,
wherein a number of symbols included in the first set of symbols is identical to a number of symbols included in the second set of symbols.
2. The apparatus of claim 1 , wherein the frame further including:
a third set of symbols, each symbol of the third set of symbols having a direct current (DC) subcarrier and guard tones, wherein an index of the DC subcarrier is 0 and indices of the guard tones are −29 to −32 and 29 to 31 on a 20 MHz bandwidth basis.
3. The apparatus of claim 1 , wherein the second set of symbols are located immediately after the first set of symbols.
4. The apparatus of claim 2 , wherein the second set of symbols are located immediately after the first set of symbols and the third set of symbols are located immediately after the second set of symbols.
5. The apparatus of claim 1 , wherein the additional data subcarriers include a predetermined pattern using a value 1 or −1.
6. The apparatus of claim 1 , wherein the first set of symbols are included in a legacy long training field (L-LTF), and the second set of symbols are included in a legacy signal field (L-SIG) and one field immediately following the L-SIG.
7. The apparatus of claim 1 , wherein the number of symbols included in the first and second set of symbols is two.
8. The apparatus of claim 1 , wherein each symbol of the first set of symbols include the DC subcarrier, 4 pilot symbols, 11 guard tones, and 48 data subcarriers.
9. The apparatus of claim 1 , wherein each symbol of the second set of symbols include the DC subcarrier, 4 pilot symbols, 7 guard tones and 52 data subcarriers.
10. The apparatus of claim 9 , wherein the additional data subcarriers are part of the 52 data subcarriers.
11. The apparatus of claim 2 , wherein each symbol of the third set of symbols include the DC subcarrier, 4 pilot symbols, 7 guard tones and 52 data subcarriers.
12. An apparatus for facilitating wireless communication, the apparatus comprising:
an antenna;
a Radio Frequency (RF) receiver coupled to the antenna, and
a processor configured to:
receive, using the antenna and the RF receiver, a frame including a first set of symbols used for carrying training information and a second set of symbols; and
process the frame to obtain training information,
wherein each symbol of the first set of symbols having a direct current (DC) subcarrier and guard tones, wherein an index of the DC subcarrier is 0 and indices of the guard tones are −27 to −32 and 27 to 31 on a 20 MHz bandwidth basis,
wherein each symbol of the second set of symbols having a DC subcarrier, guard tones, and additional data subcarriers, wherein an index of the DC subcarrier is 0, indices of the guard tones are −29 to −32 and 29 to 31, and indices of the additional data subcarriers are −27, −28, 27 and 28 on a 20 MHz bandwidth basis, and wherein the additional data subcarriers include training information, and
wherein a number of symbols included in the first set of symbols is identical to a number of symbols included in the second set of symbols.
13. The apparatus of claim 12 , wherein the frame further including:
a third set of symbols, each symbol of the third set of symbols having a direct current (DC) subcarrier and guard tones, wherein an index of the DC subcarrier is 0 and indices of the guard tones are −29 to −32 and 29 to 31 on a 20 MHz bandwidth basis.
14. The apparatus of claim 13 , wherein the second set of symbols are located immediately after the first set of symbols and the third set of symbols are located immediately after the second set of symbols.
15. The apparatus of claim 12 , wherein the additional data subcarriers include a predetermined pattern using a value 1 or −1.
16. The apparatus of claim 12 , wherein the first set of symbols are included in a legacy long training field (L-LTF), and the second set of symbols are included in a legacy signal field (L-SIG) and one field immediately following the L-SIG.
17. The apparatus of claim 12 , wherein the number of symbols included in the first and second set of symbols is two.
18. The apparatus of claim 12 , wherein each symbol of the first set of symbols include the DC subcarrier, 4 pilot symbols, 11 guard tones, and 48 data subcarriers.
19. The apparatus of claim 12 , wherein each symbol of the second set of symbols include the DC subcarrier, 4 pilot symbols, 7 guard tones and 52 data subcarriers.
20. The apparatus of claim 19 , wherein the additional data subcarriers are part of the 52 data subcarriers.