Physical layer preamble design for special packet types
This disclosure provides methods, devices and systems for generating packet preambles. Some implementations more specifically relate to preamble designs for special cases such as, for example, full-bandwidth multi-user multiple-input multiple-output (MU-MIMO), single-user (SU) preamble puncturing, hybrid automatic repeat request (HARQ), and multi-AP coordination. Multi-AP coordination may refer to coordinated beamforming (CoBF), joint transmission (JT), or coordinated orthogonal frequency division multiple access (C-OFDMA). Additionally, or alternatively, some implementations more specifically relate to preamble designs that accommodate signal fields of different cases.
1 . A method of wireless communication by a first wireless access point (AP), comprising:
generating a first portion of a first physical layer protocol data unit (PPDU) in accordance with a second PPDU to be transmitted by a second wireless AP, the first portion including at least a legacy signal field (L-SIG), a repeat of the L-SIG (RL-SIG) that immediately follows the L-SIG and a universal signal field (U-SIG) that immediately follows the RL-SIG and carries information for interpreting one or more subsequent fields of a second portion, the U-SIG including BSS color information to identify a multi-AP group, the second portion of the first PPDU including at least a short training field, a long training field, and a data field; and
transmitting the first PPDU to a first receiving device, concurrently with transmission of the second PPDU by the second wireless AP, wherein the first and second PPDUs are transmitted as multi-AP transmissions coordinated between at least the first and the second APs, and wherein a beamformed portion of the first PPDU does not include the first portion of the first PPDU.
2 . The method of claim 1 , wherein the first and second PPDUs are transmitted by the first and second wireless APs, the first and second wireless APs belonging to first and second basic service sets (BSSs), respectively.
3 . The method of claim 2 , wherein the first and second PPDUs are transmitted as coordinated beamforming (CoBF) transmissions and wherein the first receiving device belongs to the first BSS and the second PPDU is transmitted to a second receiving device belonging to the second BSS, wherein at least a portion of each of the first and second PPDUs is transmitted using beamforming, a beamformed portion of the first PPDU being protected from overlapping BSS (OBSS) interference through nulling of the interference by a beamformed portion of the second PPDU.
4 . The method of claim 2 , wherein the information in the U-SIG is common to the first and second BSSs, and wherein the information common to all BSSs includes the BSS color information.
5 . The method of claim 4 , further comprising:
transmitting a setup PPDU to the first receiving device prior to the transmission of the first PPDU, the setup PPDU carrying user specific information for the first receiving device.
6 . The method of claim 3 , wherein the first PPDU functions as a single BSS PPDU without OBSS interference in the beamformed portion of the first PPDU.
7 . The method of claim 3 , wherein beamforming is only performed on the second portion of the first PPDU, and wherein the first portion of the first PPDU is transmitted omnidirectionally.
8 . The method of claim 1 , wherein the transmission of the first PPDU is synchronized in time and frequency with the transmission of the second PPDU.
9 . The method of claim 1 , wherein the first PPDU and the second PPDU have a same LTF symbol duration, and a same guard interval duration.
10 . The method of claim 1 , further comprising:
transmitting a trigger frame, prior to the transmission of the first PPDU, to indicate to other wireless communication devices not to interfere with the transmission of the first PPDU, wherein the trigger frame comprises a request to send (RTS) frame or a clear to send (CTS)-to-self frame.
11 . The method of claim 1 , wherein the first portion of the first PPDU is identical to a first portion of the second PPDU.
12 . The method of claim 1 , wherein the first and second PPDUs are transmitted as joint transmissions by the first and second wireless communication devices, and wherein the second PPDU is also transmitted to the first receiving device.
13 . The method of claim 12 , further comprising:
transmitting synchronization information to the second wireless communication device during one or more gaps in the transmission of the first PPDU, wherein the one or more gaps are periodically repeated over a duration of the transmission of the first PPDU.
14 . The method of claim 1 , wherein the first wireless AP comprises a primary AP and the second wireless AP comprises a secondary AP.
15 . The method of claim 1 , wherein at least a portion of each of the first and second PPDUs is transmitted using beamforming and wherein the beamformed portion of the first PPDU includes the first portion of the first PPDU.
16 . The method of claim 1 , wherein the first and second PPDUs are transmitted as coordinated spatial reuse (CoSR) transmissions.
17 . An apparatus for wireless communication by a first wireless access point (AP), comprising:
a processing system that includes one or more processors and one or more memories coupled with the one or more processors, the processing system configured to cause the apparatus to:
generate a first portion of a first physical layer protocol data unit (PPDU) in accordance with a second PPDU to be transmitted by a second wireless AP, the first portion including at least a legacy signal field (L-SIG), a repeat of the L-SIG (RL-SIG) that immediately follows the L-SIG and a universal signal field (U-SIG) that immediately follows the RL-SIG and carries information for interpreting one or more subsequent fields of a second portion, the U-SIG including BSS color information to identify a multi-AP group, the second portion of the first PPDU including at least a short training field, a long training field, and a data field; and
transmit the first PPDU, to a first receiving device, concurrently with transmission of the second PPDU by the second wireless AP, wherein the first and second PPDUs are transmitted as multi-AP transmissions coordinated between at least the first and the second APs, and wherein a beamformed portion of the first PPDU does not include the first portion of the first PPDU.
18 . The apparatus of claim 17 , wherein the first and second PPDUs are transmitted as coordinated beamforming (CoBF) transmissions and wherein the first receiving device belongs to the first BSS and the second PPDU is transmitted to a second receiving device belonging to the second BSS, wherein at least a portion of each of the first and second PPDUs is transmitted using beamforming, a beamformed portion of the first PPDU being protected from overlapping BSS (OBSS) interference through nulling of the interference by a beamformed portion of the second PPDU.
19 . The apparatus of claim 17 , wherein the first and second PPDUs are transmitted as joint transmissions by the first and second wireless APs, and wherein the second PPDU is also transmitted to the first receiving device.