March 2006 Dec IEEE 15 06 0110 01

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a Project: IEEE P 802. 15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Better SFD and CCA] Date Submitted: [3 March 2006] Source: [Francois Chin and Yuen-Sam Kwok] Company: [Institute for Infocomm Research, Singapore] Address: [21 Heng Mui Keng Terrace, Singapore 119613] Voice: [65 -68745687] E-Mail: [chinfrancois@i 2 r. a-star. edu. sg] Source: [Vern Brethour] Company: [Time Domain Corp. ] Address: [7057 Old Madison Pike; Suite 250; Huntsville, Alabama 35806] Voice: [Vern: (256) 428 -6331], E-Mail: [vern. brethour@timedomain. com] Abstract: [propose a couple of SFDs with better detectability and coresponding CCA] Purpose: [Assist the group in the selection of a SFD] Notice: This document has been prepared to assist the IEEE P 802. 15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P 802. 15. TG 4 a 1 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a Objectives • To propose SFDs with better detectability than the baseline SFD [-S 0 -S 0] • To review CCA signaling structure TG 4 a 2 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a SFD Selection Criteria • Through Exhaustive search • Select SFD sequences that gives – min correlation values during the transition from the repeated preamble symbols to the SFD – Min correlation values right after peak, during the transition from SFD to Data • … For both coherent and energy detector • Proposed SFDs for ~0. 8 Mbps Mode – 6 length-8 SFD – 5 length-16 SFD • SFD detection error probability evaluation based on coherent receiver only TG 4 a 3 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a On Simulation … • Sampling rate = 499. 2 MHz • Preamble - 64 symbols (code length 31) – Ave PRF = 15. 6 MHz – Premable sequence (index #1) [− 0000+0− 0+++0+− 000+−+++00−+0− 00] • Coherent receiver only • Floating point simulation TG 4 a 4 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a Baseline SFD Preamble S … S SFD -S 0 Data For Coherent Rxr TG 4 a 5 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a Length 8 SFD (1 st Sequence) Preamble S … S SFD -S 0 0 0 -S -S Data For Coherent Rxr TG 4 a 6 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a Length 8 SFD (2 nd Sequence) Preamble S … S SFD -S 0 0 0 -S +S Data For Coherent Rxr TG 4 a 7 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a Length 8 SFD (3 rd Sequence) For Coherent Rxr TG 4 a 8 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a Length 8 SFD (4 th Sequence) For Coherent Rxr TG 4 a 9 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a Length 8 SFD (5 th Sequence) For Coherent Rxr TG 4 a 10 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a Length 8 SFD (6 th Sequence) For Coherent Rxr TG 4 a 11 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a Length 16 SFD (1 st Sequence) For Coherent Rxr TG 4 a 12 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a Length 16 SFD (2 nd Sequence) For Coherent Rxr TG 4 a 13 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a Length 16 SFD (3 rd Sequence) For Coherent Rxr TG 4 a 14 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a Length 16 SFD (4 th Sequence) For Coherent Rxr TG 4 a 15 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a Length 16 SFD (5 th Sequence) For Coherent Rxr TG 4 a 16 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a Extended SFD for 0. 1 Mbps • Via symbol repetition • 8 x data rate reduction -> 8 x symbol repetition to achieve similar SFD detection error probability • Trade-off between SFD detection and packet efficiency, though the former is more important S … S -S 0 0 0 -S +S … S -S … -S 8 x symbol repetition TG 4 a 0 … 0 8 x symbol repetition 17 … … … +S 8 x symbol repetition Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a Summary • Length-16 SFD gives 1% PER @ ~ 5 d. B Eb/N 0 • Length-8 SFD gives 1% PER @ ~ 6 d. B Eb/N 0 • Potential candidates for SFD for 0. 8 Mbps Mode and above – length-8 SFD (sequence #1, 2 or 4) – Or any of the proposed Length-16 SFD? – Depending on the data PER for coherent receiver • Extended SFD for 0. 1 Mbps Mode – 8 x symbol repetition TG 4 a 18 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a SFD Recommendations • Use Length-8 SFD (sequence #1) • Extended SFD for 0. 1 Mbps Mode via 8 x symbol repetition SFD for 0. 8 Mbps & higher Mode Preamble S … S -S 0 … S -S … -S 8 x symbol repetition TG 4 a 0 -S -S … SFD for 0. 1 Mbps Mode Preamble S 0 0 … 0 8 x symbol repetition 19 … … … -S 8 x symbol repetition Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a CCA baseline • Baseline CCA Mode – 0. 8 Mbps Mode - ONE inserted preamble symbol for every 4 data symbols • Baseline CCA window size – 8 inserted preamble symbols in CCA window ~40 symbol duration ~ 41 us TG 4 a 20 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a CCA Concerns • CCA Mode for 0. 1 Mbps mode – ONE inserted preamble symbol for every data symbol • CCA window size according to 0. 1 Mbps mode – 8 inserted preamble symbols in CCA window means ~72 symbol duration ~ 74 us • If max CCA window size is limited by freq offset (within 50 us), – then there shall be one inserted preamble symbol for each data symbol (corresponding to ~0. 2 Mbps mode) – Then lowest data rate mode is ~0. 2 Mbps TG 4 a 21 Francois Chin (I 2 R)

March 2006 Dec: IEEE 15 -06 -0110 -01 -004 a CCA Recommendation • Given 8 inserted preamble symbols within CCA window (false alarm ratio < 2%, the correction CCA probability is 96% @ SNR=10 d. B), either 1) Adopt current baseline CCA window size (< 50 ns) and take ~0. 2 Mbps as the lowest rate mode OR 2) Adopt longer CCA window size (~ 74 ns) and keep ~0. 1 Mbps as the lowest rate mode TG 4 a 22 Francois Chin (I 2 R)