Method and device for generating STF signals by means of binary sequence in wireless LAN system
Provided are method and device for generating STF signals which can be used in a wireless LAN system. STF signals are comprised in a field which is used for improving AGC estimation of MIMO transmission. Some of the STF signals are used for uplink transmission and can be used for an uplink MU PPDU transmitted from a plurality of STAs. The provided STF signals are, for example, used for an 80+80 MHz or 160 MHz band and can be generated on the basis of a sequence in which a preset M sequence is repeated. The preset M sequence can be a 15-bit length binary sequence.
1. A method in a wireless LAN system, the method comprising:
generating, by a transmitting apparatus, a short training field (STF) signal for a 80+80 MHz band; and
transmitting, by the transmitting apparatus, a PPDU (physical protocol data unit) including the STF signal to a receiving apparatus,
wherein the STF signal for the 80+80 MHz band is generated based on a 1x STF sequence,
wherein the first sequence 1x STF sequence is defined as first STF sequence second STF sequence,
wherein first STF sequence is a STF sequence for lower 80 MHz band and defined as {M, 1, −M, 0, −M, 1, −M}*(1+j)/sqrt(2)*sqrt(1/2),
wherein second STF sequence is a STF sequence for upper 80 MHz band and defined as {−M, −1, M, 0, −M, 1, −M} *(1+j)*sqrt(1/2),
wherein the sqrt( ) represents square root, and
wherein M is a sequence having 15 elements and is defined as {−1, −1, −1, 1, 1, 1, −1, 1, 1, 1, −1, 1, 1, −1, 1}.
2. The method of claim 1 ,
wherein the 1x STF sequence is arranged in a 16-tone interval from the lowest tone with tone index −1008 to the highest tone with tone index +1008.
3. The method of claim 1 ,
wherein the transmitting apparatus selects a first frequency tone interval or a second frequency tone interval and configures the STF signal based on the selected frequency tone interval.
4. The method of claim 3 ,
when the PPDU is an uplink multi-user (MU) PPDU for a trigger frame received from an AP, the first frequency tone interval is selected.
5. The method of claim 3 ,
wherein the first frequency tone interval is 8, and the second frequency tone interval is 16.
6. The method of claim 1 ,
wherein the STF signal is used to enhance automatic gain control (AGC) estimation in a multiple input multiple output (MIMO) transmission.
7. A transmitting apparatus in a wireless LAN system, the transmitting apparatus comprising:
a transceiver that transmits and receives a radio signal; and
a processor configured to control the transceiver, and
wherein the processor is further configured to:
generate a short training field (STF) signal for a 80+80 MHz band; and
transmit a PPDU (physical protocol data unit) including the STF signal to a receiving apparatus,
wherein the STF signal for the 80+80 MHz band is generated based on a 1x STF sequence,
wherein the first sequence 1x STF sequence is defined as first STF sequence second STF sequence,
wherein first STF sequence is a STF sequence for lower 80 MHz band and defined as {M, 1, −M, 0, −M, 1, −M}*(1+j)/sqrt(2)*sqrt(1/2),
wherein second STF sequence is a STF sequence for upper 80 MHz band and defined as {−M, −1, M, 0, −M, 1, −M} *(1+j)*sqrt(1/2),
wherein the sqrt( ) represents square root, and
wherein M is a preset sequence having 15 elements and is defined as {−1, −1, −1, 1, 1, 1, −1, 1, 1, 1, −1, 1, 1, −1, 1}.