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Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [ Sync Field Delimiter Design ] Date Submitted: [ 18 July 2006 ] Source: [ Francois Chin ] Company : [Institute for Infocomm Research, Singapore]
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Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Sync Field Delimiter Design] Date Submitted: [18 July 2006] Source: [Francois Chin] Company: [Institute for Infocomm Research, Singapore] Address: [21 Heng Mui Keng Terrace, Singapore 119613] Voice: [65-68745687] E-Mail: [chinfrancois@i2r.a-star.edu.sg] Abstract: [propose a couple of SFDs with better detectability] Purpose: [Assist the group in the selection of a SFD] Notice: This document has been prepared to assist the IEEE P802.15. 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 P802.15. Francois Chin (I2R)
Recap – Requirements for Long SFD • Balanced 64-chip: 32 ‘0’; 16 ’+’ and 16 ’-’ • Gives zero detector outputs in both coherent and non-coherent receiver during preamble period for low rate mode • Non-zero detector outputs is the main contributor to detection errors • Balanced short SFD (first 8-chip): 4 ‘0’; 2 ’+’ and 2 ’-’ • Gives zero detector outputs in both coherent and non-coherent receiver during preamble period for high rate mode • This is even more critical due to short SFD length • First set of 8-chip identical to second set of 8-chip • So that non-low rate device can detect the long SFD using the same 8-chip SFD correlation sequence Long SFD V #1 V #1 V #2 16 Symbols 48 Symbols Francois Chin (I2R)
Proudly presents 4 beauties …. SFD #1 -0+-00+0 -0+-00+0 ++0000++0-0-0+-0+0+00-00-+00-0-000--+--0-+0000++ SFD #2 -0+-00+0 -0+-00+0 0++0-0-0+-0+0+00-++0000-0-000--+--0-+0000++00-+0 SFD #3 0+0-+00- 0+0-+00- -00+0-0+0+000-0-0-00+0--0-+0000++00---+-++0000++ SFD #4 -00+0+0- -00+0+0- +0+0000++00+00---+-0++-0000000++-00+-0--+--0-000 Francois Chin (I2R)
Low Rate Mode Francois Chin (I2R)
SFD #1 (Low Rate Mode) Coherent Side-lobe: 6 Non-Coherent side-lobe: 7 Francois Chin (I2R)
SFD #2 (Low Rate Mode) Coherent Side-lobe: 6 Non-Coherent side-lobe: 6 Francois Chin (I2R)
SFD #3 (Low Rate Mode) Coherent Side-lobe: 6 Non-Coherent side-lobe: 8 Francois Chin (I2R)
SFD #4 (Low Rate Mode) Coherent Side-lobe: 7 Non-Coherent side-lobe: 8 Francois Chin (I2R)
Long SFD PDetect Comparison (Th=24) Identical performance for All SFDs Francois Chin (I2R)
Long SFD PDetect Comparison (Th=24) Identical performance for All SFDs Francois Chin (I2R)
High Rate Mode Francois Chin (I2R)
SFD #1 (High Rate Mode) 3 sidelobes with abs(.)=2 before peak 2 sidelobes with abs(.)=2 before peak Francois Chin (I2R)
SFD #2 (High Rate Mode) 3 sidelobes with abs(.)=2 before peak 2 sidelobes with abs(.)=2 before peak Francois Chin (I2R)
SFD #3 (High Rate Mode) 0 sidelobes with abs(.)=2 before peak 1 sidelobes with abs(.)=2 before peak Francois Chin (I2R)
SFD #4 (High Rate Mode) 0 sidelobes with abs(.)=2 before peak 1 sidelobes with abs(.)=2 before peak Francois Chin (I2R)
Short SFD PDetect Comparison (Th=3) Taking first 8 bits of the long SFD SFD #1 And SFD #2 SFD #3 And SFD #4 Francois Chin (I2R)
Short SFD PDetect Comparison (Th=3) Taking first 8 bits of the long SFD SFD #1 And SFD #2 SFD #3 And SFD #4 Francois Chin (I2R)
Summary of Comparison So far, SFD #3 and SFD #4 are better choices ….And they get into the final round …. SFD #3 0+0-+00- 0+0-+00- -00+0-0+0+000-0-0-00+0--0-+0000++00---+-++0000++ SFD #4 -00+0+0- -00+0+0- +0+0000++00+00---+-0++-0000000++-00+-0--+--0-000 Francois Chin (I2R)
Final Round….leading bit test Let’s look at the leading bit….SFD #3 has a leading ‘0’…. SFD #3 0+0-+00- 0+0-+00- -00+0-0+0+000-0-0-00+0--0-+0000++00---+-++0000++ while SFD #4 has a leading ‘-’ SFD #4 -00+0+0- -00+0+0- +0+0000++00+00---+-0++-0000000++-00+-0--+--0-000 And a ‘-’ is desirable to indicate the end of preamble section Francois Chin (I2R)
Recommendation • Adopt SFD #4 as the long SFD in IEEE 802.15.4a packets for low data rate option • Adopt the first 8 bits of the SFD #4 as the short SFD in IEEE 802.15.4a packets for the mandatory data rate and high data rate option SFD #4 -00+0+0- -00+0+0- +0+0000++00+00---+-0++-0000000++-00+-0--+--0-000 Francois Chin (I2R)