Method and device for transmitting data based on different pilot tone patterns in wireless LAN
Disclosed are a method and a device for transmitting data based on different pilot tone patterns in a wireless LAN. The method for transmitting data based on the different pilot tone patterns in a wireless LAN may comprise the steps of: an AP transmitting, to a first STA, a first data field generated based on a first pilot tone pattern, from a first frequency bandwidth; and the AP transmitting, to a second STA, a second data field generated based on a second pilot tone pattern, from a second frequency bandwidth, wherein the size of the first frequency bandwidth is n times larger than the size of the second frequency bandwidth, the size of IFFT applied to the first data field and the size of IFFT applied to the second data field are identical, the first pilot tone pattern includes a plurality of first pilot tones, wherein the plurality of first pilot tones are respectively allocated to each of a plurality of first pilot tone indexes, the second pilot tone pattern includes a plurality of second pilot tones, wherein the plurality of second pilot tones are respectively allocated to each of a plurality of second pilot tone indexes, and wherein a portion of the first pilot tone indexes may be identical to the plurality of second pilot tone indexes.
1. A method for transmitting data based on different pilot tone patterns in a wireless LAN, comprising:
transmitting, by an access point (AP), a first data field being generated based on a first pilot tone pattern within a first frequency bandwidth to a first station (STA); and
transmitting, by the AP, a second data field being generated based on a second pilot tone pattern within a second frequency bandwidth to a second STA,
wherein a size of the first frequency bandwidth is n times (wherein n is an integer equal to or greater than 2) larger than a size of the second frequency bandwidth,
wherein an inverse fast fourier transform (IFFT) size being applied to the first data field is equal to an IFFT size being applied to the second data field,
wherein the first pilot tone pattern includes a plurality of first pilot tones,
wherein each of the plurality of first pilot tones is allocated to each of a plurality of first pilot tone indexes,
wherein the second pilot tone pattern includes a plurality of second pilot tones,
wherein each of the plurality of second pilot tones is allocated to each of a plurality of second pilot tone indexes,
wherein a part of the plurality of first pilot tone indexes is identical to the plurality of second pilot tone indexes, and
wherein a pilot tone index has a positive value that increases in a direction along which the frequency increases based on a direct current (DC) tone and is mapped to each of a plurality of tones, and a pilot tone index has a negative value that decreases in a direction along which the frequency decreases based on the DC tone and is mapped to each of a plurality of tones.
2. The method of claim 1 , wherein a plurality of the second pilot tone indexes are identical to odd-number indexed pilot tone indexes of odd-numbered pilot tones being located at odd-number indexed positions based on a DC tone, among the plurality of first pilot tones, or a plurality of the second pilot tone indexes are identical to even-number indexed pilot tone indexes of even-numbered pilot tones being located at even-number indexed positions based on the DC tone, among the plurality of first pilot tones.
3. The method of claim 2 , wherein, in case a size of the first frequency bandwidth is equal to 80 MHz, the plurality of first pilot tone indexes correspond to {±11, ±39, ±75, ±103},
wherein, in case a size of the second frequency bandwidth is equal to 20 MHz, and in case the plurality of second pilot tone indexes are identical to the odd-number indexed pilot tone indexes among the plurality of first pilot tones, the pilot tone indexes of the second pilot tones correspond to {±11, ±75}, and
wherein, in case the size of the second frequency bandwidth is equal to 20 MHz, and in case the plurality of second pilot tone indexes are identical to the even-number indexed pilot tone indexes among the plurality of first pilot tones, the pilot tone indexes of the second pilot tones correspond to {±39, ±103}.
4. The method of claim 2 , wherein, in case the size of the first frequency bandwidth is equal to 160 MHz, the plurality of first pilot tone indexes correspond to {±25, ±53, ±89, ±117, ±139, ±167, ±203, ±231},
wherein, in case the size of the second frequency bandwidth is equal to 40 MHz, and in case the plurality of second pilot tone indexes are identical to the odd-number indexed pilot tone indexes among the plurality of first pilot tones, the pilot tone indexes of the second pilot tones correspond to {±25, ±89, ±139, ±203}, and
wherein, in case the size of the second frequency bandwidth is equal to 20 MHz, and in case the plurality of second pilot tone indexes are identical to the even-number indexed pilot tone indexes among the plurality of first pilot tones, the pilot tone indexes of the second pilot tones correspond to {±53, ±117, ±167, ±231}.
5. An access point (AP) for transmitting data based on different pilot tone patterns in a wireless LAN, comprising:
a radio frequency (RF) unit transmitting and receiving radio signals; and
a processor being operatively connected to the RF unit,
wherein the processor is configured:
to transmit a first data field being generated based on a first pilot tone pattern within a first frequency bandwidth to a first station (STA), and
to transmit a second data field being generated based on a second pilot tone pattern within a second frequency bandwidth to a second STA,
wherein a size of the first frequency bandwidth is n times (wherein n is an integer equal to or greater than 2) larger than a size of the second frequency bandwidth,
wherein an inverse fast fourier transform (IFFT) size being applied to the first data field is equal to an IFFT size being applied to the second data field,
wherein the first pilot tone pattern includes a plurality of first pilot tones,
wherein each of the plurality of first pilot tones is allocated to each of a plurality of first pilot tone indexes,
wherein the second pilot tone pattern includes a plurality of second pilot tones,
wherein each of the plurality of second pilot tones is allocated to each of a plurality of second pilot tone indexes,
wherein a part of the plurality of first pilot tone indexes is identical to the plurality of second pilot tone indexes, and
wherein a pilot tone index has a positive value that increases in a direction along which the frequency increases based on a direct current (DC) tone and is mapped to each of a plurality of tones, and a pilot tone index has a negative value that decreases in a direction along which the frequency decreases based on the DC tone and is mapped to each of a plurality of tones.
6. The AP of claim 5 , wherein a plurality of the second pilot tone indexes are identical to odd-number indexed pilot tone indexes of odd-numbered pilot tones being located at odd-number indexed positions based on a DC tone, among the plurality of first pilot tones, or a plurality of the second pilot tone indexes are identical to even-number indexed pilot tone indexes of even-numbered pilot tones being located at even-number indexed positions based on the DC tone, among the plurality of first pilot tones.
7. The AP of claim 6 , wherein, in case a size of the first frequency bandwidth is equal to 80 MHz, the plurality of first pilot tone indexes correspond to {±11, ±39, ±75, ±103},
wherein, in case a size of the second frequency bandwidth is equal to 20 MHz, and in case the plurality of second pilot tone indexes are identical to the odd-number indexed pilot tone indexes among the plurality of first pilot tones, the pilot tone indexes of the second pilot tones correspond to {±11, ±75}, and
wherein, in case the size of the second frequency bandwidth is equal to 20 MHz, and in case the plurality of second pilot tone indexes are identical to the even-number indexed pilot tone indexes among the plurality of first pilot tones, the pilot tone indexes of the second pilot tones correspond to {±39, ±103}.
8. The AP of claim 6 , wherein, in case the size of the first frequency bandwidth is equal to 160 MHz, the plurality of first pilot tone indexes correspond to {±25, ±53, ±89, ±117, ±139, ±167, ±203, ±231},
wherein, in case the size of the second frequency bandwidth is equal to 40 MHz, and in case the plurality of second pilot tone indexes are identical to the odd-number indexed pilot tone indexes among the plurality of first pilot tones, the pilot tone indexes of the second pilot tones correspond to {±25, ±89, ±139, ±203}, and
wherein, in case the size of the second frequency bandwidth is equal to 20 MHz, and in case the plurality of second pilot tone indexes are identical to the even-number indexed pilot tone indexes among the plurality of first pilot tones, the pilot tone indexes of the second pilot tones correspond to {±53, ±117, ±167, ±231}.