Follow up on Preamble Design for WUR Month Year doc.: IEEE 802.11-yy/xxxxr0 July 2017 Follow up on Preamble Design for WUR Date: 2017-07-10 Authors: Name Affiliation Address Phone Email Jianhan Liu Mediatek USA 2840 Junction Ave, San Jose, CA 95134, USA +1-408-526-1899 jianhan.Liu@mediatek.com Tianyu Wu Thomas Pare Frank Hsu Mediatek Jianhan Liu, Mediatek, et. al. Hongyuan Zhang, Marvell; etc.

Recap of the Preamble Design July 2017 Recap of the Preamble Design Proposed WUR packet structure: AGC/Sync sequence: Propose OOK modulated ‘1 0 1 0 1 0’ sequence. Power measurement is stable in any measuring window of 2 bit width. AGC adjustment will be accurate and quick. The sequence also accelerates synchronization by measuring the power within each symbol. The symbol boundary can be easily detected by choosing the 4us window with maximum power. AGC/Sync Sequence WUR Signature Sequence Control Information WUR preamble part

Recap of the Preamble Design – cont’d July 2017 Recap of the Preamble Design – cont’d WUR Signature Sequence Specific OOK modulated sequence. Can be m sequence, Golay sequence or a pseudo-random sequence. The WUR receiver relies on the detection of WUR signature sequence to claim the WUR packet detection and to find the boundary between preamble and control information. Propose to use WUR signature sequence to indicate different data rate for WUR packet payload part. Our design is to introduce multiple signature sequences and each signature sequence indicates one specific data rate. For example, the data rate of the control information can be 125kbps, 250Kbps or 500kbps. Then 3 different signature sequences with large hamming distance are used. The first signature sequence indicates data rate 125kbps, the second signature sequence indicates 250kbps and the third signature sequence indicates 500kbps.

Example AGC/Sync sequence: a number of repetitions of ‘1 0’. Signature sequence: M sequence M sequence has following nice properties: Occurrence of 0 and 1 in the sequence is approximately the same Autocorrelation function is close to delta function Large and stable Hamming distance between M sequences. For m sequences of length 15, the Hamming distance is always 8 between any pair of them. Use three 15bits M sequences to signal 3 different rates, for example: 125k: ‘1 0 1 1 1 1 0 0 0 1 0 0 1 1 0’ 256k: ‘1 1 0 0 0 1 0 0 1 1 0 1 0 1 1’ 512k: ‘1 0 0 0 1 0 0 1 1 0 1 0 1 1 1’

Simulation settings Channel model D-NLOS Phase noise model follow reference [1]. 5th order Butterworth filter 250kbps rate 4Mhz WUR BW Null GI inserted to avoid ISI

July 2017 Simulation results (1) Longer AGC/SYNC sequence will bring some gain by finding more accurate boundary and better threshold. 8 or 12 bits for AGC/SYNC sequence seems to be a reasonable length for AGC/SYNC sequence.

Simulation results (2) False alarm rate: The probability of detect interference (random OFDM symbols) as target signature sequence. FA rate is slightly above 10-4.

Simulation results (3) Signature sequence error rate: The probability of detecting target signature sequence as a wrong signature sequence. This probability is very low for the SNR range of interest.

Conclusion Suggest 8 or 12 bits AGC/SYNC sequence of OOK modulated ‘1 0’ repetitions M sequence is a good candidate for signature sequence. Using different signature sequence to indicate different WUR packet rate is very reliable.

July 2017 Straw poll #1 Do you agree to use different signature sequences to indicate different data rates? Jianhan Liu, Mediatek, et. al.

References [1] 11-17/0326r0 WUR phase noise model - follow-up