1. Submission Title: [SFD comparison] Date Submitted: [18−July−2006]
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [SFD comparison]
Date Submitted: [18−July−2006]
Source: [Michael Mc Laughlin] Company [Decawave Ltd.]
Address [25 Meadowfield, Sandyford, Dublin 18, Ireland]
Voice:[+353−1− ], FAX: [What’s a FAX?], E−Mail:
Re: [ a.]
Abstract: [Compares properties of three SFDs which have been proposed]
Purpose: [To promote discussion in a.]
Notice: This document has been prepared to assist the IEEE P 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
Mc Laughlin, Decawave

2. The four sequences are:
July 2006
Four SFDs which have been proposed are compared by looking at the correlator outputs.
The four sequences are:
V = −0−+0−00 −0−+0− − − − −−−0−
Y = +−000−0+ 0−− −+00−00 +−−−−0− − −++0 −+−−−000
Z = −+00− 0+0−+00− −00+0− −0− 0−00+0−− 0− −−−+−
F = +00−0−0+ +00−0−0+ −0−0000− −00−00++ +−+0−− −− +00−+0++ −
where a + sign indicates a positive preamble sequence, a − sign indicates a negative preamble sequence and a 0 indicates 31 (or 127) zeros.
Mc Laughlin, Decawave

3. Sequence V correlator output using Length 31 code 3 as inner code
July 2006
Sequence V correlator output using Length 31 code 3 as inner code
Mc Laughlin, Decawave

4. Sequence Y correlator output using Length 31 code 3 as inner code
July 2006
Sequence Y correlator output using Length 31 code 3 as inner code
Mc Laughlin, Decawave

5. Sequence V correlator output using Length 31 code 2 as inner code
July 2006
Sequence V correlator output using Length 31 code 2 as inner code
Mc Laughlin, Decawave

6. Sequence Y correlator output using Length 31 code 2 as inner code
July 2006
Sequence Y correlator output using Length 31 code 2 as inner code
Mc Laughlin, Decawave

7. Lots of −2 outputs before the main output
July 2006
Sequence V correlator output using Length 31 code 2 as inner code
Lots of −2 outputs before the main output
Mc Laughlin, Decawave

8. This is the only one −2 before the main output
July 2006
Sequence Y correlator output using Length 31 code 2 as inner code
This is the only one −2 before the main output
Mc Laughlin, Decawave

9. Sequence Z correlator output using Length 31 code 2 as inner code
July 2006
Sequence Z correlator output using Length 31 code 2 as inner code
Mc Laughlin, Decawave

10. +1/−1 is worst peak before the main output
July 2006
Sequence Z correlator output using Length 31 code 2 as inner code
+1/−1 is worst peak before the main output
Mc Laughlin, Decawave

11. Sequence Z correlator output using Length 31 code 2 as inner code
July 2006
Sequence Z correlator output using Length 31 code 2 as inner code
Mc Laughlin, Decawave

12. Sequence Z correlator output using Length 31 code 2 as inner code
July 2006
Sequence Z correlator output using Length 31 code 2 as inner code
Mc Laughlin, Decawave

13. Sequence F shows exactly the same properties as Z except for this one
July 2006
Sequence F shows exactly the same properties as Z except for this one
Length 31 code 2 as inner code
Mc Laughlin, Decawave

14. Summary All four will work well for the long detector
July 2006
Summary
All four will work well for the long detector
Sequences V & Z & F have the advantage of two outputs for the short detector
Sequences Y & Z & F have zero output during preamble for coherent cases
Sequences Z & F has worst case +/−1 before the +4 for the short detector
Mc Laughlin, Decawave

15. July 2006
Conclusions
Sequences Z & F have all the best qualities and none of the downsides and would make the best SFDs.
Sequence Z is slightly better for long coherent detector (slides 13 & 9)
F starts with -1, Z starts with 0.
Mc Laughlin, Decawave