Transmitting/receiving device and method in wireless communication system
Disclosed herein is a station (STA) device of a wireless LAN (WLAN) system. The STA device includes a radio frequency (RF) unit sending and receiving a radio signal and a processor controlling the RF unit. The processor may generate a physical protocol data unit (PPDU) including a physical preamble and a data field and send the PPDU using the RF unit.
1. An access point (AP) device in a wireless local area network (WLAN) system, the AP device comprising:
a transceiver; and
a processor,
wherein the processor is configured to:
generate a physical protocol data unit (PPDU) including a physical preamble and a data field, and
control the transceiver to send the PPDU to one or more stations (STAs) by spatial multiplexing a plurality of streams,
wherein the physical preamble includes a legacy preamble and a high efficiency (HE) preamble,
wherein the HE preamble includes an HE signal A (HE-SIG-A) field, an HE signal B (HE-SIG-B) field, an HE-short training field (STF), and an HE-long training field (LTF), the HE-SIG-B field being located in front of the HE-STF and the HE-LTF,
wherein an HE-LTF sequence for each of the plurality of streams is mapped to frequency resources in a single symbol, and
wherein HE-LTF sequences for one or more streams mapped to a same subcarrier among the plurality of streams are code division multiplexed by a P matrix to generate a multiplexed HE-LTF.
2. The AP device of claim 1 , wherein the HE-SIG-B field is encoded in a bandwidth unit forming a channel and transmitted.
3. The AP device of claim 1 , wherein the multiplexed HE-LTF is repeated at tone intervals of a specific number in a frequency domain.
4. The AP device of claim 3 , wherein the specific number is 2 or 4.
5. A method for transmitting, by an access point (AP) device, data in a wireless local area network (WLAN) system, the method comprising:
generating a physical protocol data unit (PPDU) including a physical preamble and a data field; and sending the PPDU to one or more stations (STAs) by spatial multiplexing a plurality of streams,
wherein the physical preamble includes a legacy preamble and a high efficiency (HE) preamble,
wherein the HE preamble includes an HE signal A (HE-SIG-A) field, an HE signal B (HE-SIG-B) field, an HE-short training field (STF), and an HE-long training field (LTF), the HE-SIG-B field being located in front of the HE-STF and the HE-LTF,
wherein an HE-LTF sequence for each of the plurality of streams is mapped to frequency resources in a single symbol, and
wherein HE-LTF sequences for one or more streams mapped to a same subcarrier among the plurality of streams are code division multiplexed by a P matrix to generate a multiplexed HE-LTF.
6. The method of claim 5 , wherein the HE-SIG-B field is encoded in a bandwidth unit forming a channel and transmitted.
7. The method of claim 5 , wherein the multiplexed HE-LTF is repeated at tone intervals of a specific number in a frequency domain.
8. The method of claim 7 , wherein the specific number is 2 or 4.