1. doc.: IEEE 802.15-<doc#>
<month year>
doc.: IEEE <doc#>
May 2005
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: How to realize the low data rate in CSS
Date Submitted: []
Source: Rainer Hach
Company: Nanotron Technologies
Address: Alt-Moabit 61, Berlin, Germany
Voice:
Re: []
Abstract: []
Purpose: material to be discussed
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
Hach, Nanotron
<author>, <company>

2. The actual 1Mb/s mode 2 x 3 information bits are
May 2005
The actual 1Mb/s mode
2 x 3 information bits are
mapped onto 2 x 4 code bits.
2 x 4 code bits are modulated onto
1 chirp symbol by using DQPSK
Modulator (1 Mb/s)
Data-rate: 1 Mb/s
S/P
Symbol
Mapper
P/S
Mapper
QPSK
Binary Data 1 3 3 4 1
S/P 1 1 2 2
S/P
Symbol
Mapper
P/S 1 3 3 4 1
DBO-QCSS
Signal
CSK
Gen.
2450 MHz PHY modulation 8-ary Differentially Bi-Orthogonal Quaternary-Chirp-Spread-Spectrum (DBO-QCSS) Modulator for 1 Mb/s Data-rate
Hach, Nanotron

3. Actual mapping scheme ham_dist = 0 2 2 2 4 2 2 2 2 0 2 2 2 4 2 2
May 2005
Actual mapping scheme
ham_dist =
avg_dist =
2.2857
8-ary Bi-Orthogonal
Symbol Mapping Table
Decimal
(m)
Binary
(b0,b1,b2)
Bi-Orthogonal Code
(01,02,03,04)
Hach, Nanotron

4. The actual proposal for lower data rate
May 2005
The actual proposal for lower data rate
1 x 3 information bits are
Mapped onto the 4 code bits.
4 code bits are modulated onto
1 chirp symbol by using DBPSK
Modulator (250 Kb/s)
Data-rate: 250 kb/s
Binary Data
FEC
Encoder
r=1/2
S/P
Symbol
Mapper
P/S 1 1 1 1 3 3 4 1 1
DBO-BCSS
Signal
CSK
Gen.
2450 MHz PHY modulation 8-ary Differentially Bi-Orthogonal Binary-Chirp-Spread-Spectrum (DBO-QCSS) Modulator for 250 Kb/s Data-rate
Hach, Nanotron

5. Lower data rate by modified mapping scheme (1)
May 2005
Lower data rate by modified mapping scheme (1)
4-ary
Symbol Mapping Table
ham_dist =
avg_dist =
2.6667
Decimal
(m)
Binary
(b0,b1)
Bi-Orthogonal Code
(01,02,03,04)
1, 1,-1,-1
1,-1, 1, 1
-1, 1,-1, 1
-1,-1, 1,-1
Effective Data rate:
2 bits /6us = 330 kBit/s
Hach, Nanotron

6. Lower data rate by modified mapping scheme (2)
May 2005
Lower data rate by modified mapping scheme (2)
4-ary
Symbol Mapping Table
Decimal
(m)
Binary
(b0,b1)
Bi-Orthogonal Code
(01,02,03,04)
ham_dist =
avg_dist = 4
1, 1, 1, 1
-1,-1,-1,-1
Effective Data rate:
1 bits /6us = 165 kBit/s
Pro
Original code words
We achieve lower rate by taking something away
Con
Doesn‘t meet the 250 kBit
Hach, Nanotron