July 2010 doc IEEE 802 11 100811 r

July 2010 doc. : IEEE 802. 11 -10/0811 r 1 Pilot Sequence for VHT-DATA Date: 2010 -07 -12 Authors: Submission 1 Allert van Zelst, Qualcomm

July 2010 doc. : IEEE 802. 11 -10/0811 r 1 Abstract A pilot sequence is proposed for VHT-DATA that can be used in combination with the phase tracking during VHTLTF ([1]). Submission 2 Allert van Zelst, Qualcomm

July 2010 doc. : IEEE 802. 11 -10/0811 r 1 Introduction • As indicated in [1], single stream pilot tones during the VHT-LTFs can be used to improve MIMO channel estimation considerably, especially in case of phase noise and/or residual carrier frequency offset on the VHT-LTFs • The pilot tones in VHT-LTF only provide a SIMO channel estimate • Since VHT-LTF pilots are single-stream, it makes sense to also use a single stream pilot mapping for VHTDATA Submission 3 Allert van Zelst, Qualcomm

July 2010 doc. : IEEE 802. 11 -10/0811 r 1 Pilot Sequence • • For 20 and 40 MHz, the pilot sequence shall be the single spatial stream pilot sequence of 11 n copied to the NSTS streams before the per-stream CSDs are applied. For 80 MHz, the pilot sequence shall be the following sequence (which is the 40 MHz pilot sequence for NSTS = 1 extended with a [1, 1] on the right, resulting in the lowest PAPR on the pilot tones after applying [1 -1 -1 -1] rotation on the 20 MHz subbands), copied to the NSTS streams before the per-stream CSDs are applied: 0 1 2 3 4 5 6 7 1 1 1 -1 -1 1 20 MHz 1 ss pilot sequence 40 MHz 1 ss pilot sequence Submission 4 Allert van Zelst, Qualcomm

July 2010 doc. : IEEE 802. 11 -10/0811 r 1 Application of Pilot Sequence in 20 MHz • The pilot tone mapping in 20 MHz shall be: • where is given by the NSTS = 1 row of Table 20 -18 of the 11 n standard, and where n is the VHT-DATA symbol index starting at 0. • Including the pseudo random scrambling sequence, the pilot value for the kth tone, with k = {-21, -7, 7, 21}, is pn+z. Pnk, where z = 4 for VHT, and where pn is defined in Section 17. 3. 5. 9 of IEEE 802. 11. Submission 5 Allert van Zelst, Qualcomm

July 2010 doc. : IEEE 802. 11 -10/0811 r 1 Application of Pilot Sequence in 40 MHz • The pilot tone mapping in 40 MHz shall be: • where is given by the NSTS = 1 row of Table 20 -19 of the 11 n standard , and where n is the VHT-DATA symbol index starting at 0. • Including the pseudo random scrambling sequence, the pilot value for the kth tone, with k = {-53, -25, -11, 25, 53}, is pn+z. Pnk, where z = 4 for VHT, and where pn is defined in Section 17. 3. 5. 9 of IEEE 802. 11. • This does not include the rotation per 20 MHz subband yet. Submission 6 Allert van Zelst, Qualcomm

July 2010 doc. : IEEE 802. 11 -10/0811 r 1 Application of Pilot Sequence in 80 MHz • The pilot tone mapping in 80 MHz shall be: • where is given in the table on slide 3, and where n is the VHTDATA symbol index starting at 0. • Including the pseudo random scrambling sequence, the pilot value for the kth tone, with k = {-103, -75, -39, -11, 39, 75, 103}, is pn+z. Pnk, where z = 4 for VHT, and where pn is defined in Section 17. 3. 5. 9 of IEEE 802. 11. • This does not include the rotation per 20 MHz subband yet. Submission 7 Allert van Zelst, Qualcomm

July 2010 doc. : IEEE 802. 11 -10/0811 r 1 Application of Pilot Sequence in 160 MHz • For 160 MHz transmissions, the pilot mapping shall be the replication of the 80 MHz pilot mapping (as given on slide 7) in the two 80 MHz subbands for 160 MHz VHT-DATA symbols. Submission 8 Allert van Zelst, Qualcomm

July 2010 doc. : IEEE 802. 11 -10/0811 r 1 Straw Poll • Do you support adding the following paragraph in the specification framework document, 11 -09/0992? – Pilot Subcarriers • [Copy the text of slides 4 – 8] Submission 9 Allert van Zelst, Qualcomm

July 2010 doc. : IEEE 802. 11 -10/0811 r 1 References [1] Submission Kai Shi et al, “Phase Tracking During VHT-LTF”, IEEE 802. 11 -10/0771 r 0, July 2010 10 Allert van Zelst, Qualcomm