1. doc.: IEEE 802.15-<doc#>
<month year>
doc.: IEEE <doc#>
January 2009
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: Combined Preliminary Proposal
Date Submitted: 9 March 2009
Source: Frederick Martin, Paul Gorday, Ed Callaway, Monique Brown, Motorola, Inc.
Address: 8000 W. Sunrise Blvd., Plantation, FL, 33322, USA
Voice: , FAX: ,
Re: TG6 Call For Proposals, IEEE P , 3 December 2008.
Abstract: Key requirements of the BAN standards effort, including power, cost and throughput scalability, can be addressed using a scalable direct sequence waveform. In addition, this approach facilitates receiver novel ultra-low cost receiver implementations.
Purpose: This document is intended as a preliminary proposal for addressing the requirements of the TG6 standard.
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
Martin, Motorola
<author>, <company>

2. doc.: IEEE 802.15-<doc#>
<month year>
doc.: IEEE <doc#>
March 2009
Contributors
Frederick Martin
Motorola, Inc.
Paul Gorday
Ed Callaway
Monique Brown
James Spoto
Kairos Microsystems
John V. Lampe
consultant
Martin et al
<author>, <company>

3. Proposal outline only – details to be presented at future meetings
January 2009
Presentation Summary
Proposal outline only – details to be presented at future meetings
Partial Proposal – PHY Only – compatible with many MAC proposals
Focus – cost, power, form factor
Martin, Motorola

4. The BAN Challenge: Scalability
January 2009
The BAN Challenge: Scalability
Standard must meet many applications with a single solution
Must span 10 kbit/s to 10 Mbit/s
Must scale power with throughput
(Low bit rate solutions must be competitive with low throughput point solutions)
Must be size and cost competitive with non-scalable solutions
Must promote BAN size power and form factor constraints
Martin, Motorola

5. direct sequence (chip) waveform
January 2009
Proposal
direct sequence (chip) waveform
-- similar in structure to
Moderate sequence length (length 16, 32, 64 ??)
Ortogonal cyclical shift coding for increased throughput
-- chip rate scaled with throughput
Low chip rate, narrow transmission band for low throughput
Higher chip rate, wider transmission bandwidth for higher throughput
Martin, Motorola

6. Simplicity: lends itself to low-power, low cost
January 2009
Why DSSS?
Simplicity: lends itself to low-power, low cost
Scalability: Same structure can be used for low or high throughput
Compatibility: Can be made compatible with existing hardware
Extendibility: Creates opportunities for ultra-low cost receiver implementations
Martin, Motorola

7. January 2009
PHY Scalability
IEEE uses a fixed DSSS approach at 2.4 GHz
… add scalability using chip rate and coding options:
Chip Rate
(Mchip/s)
20-dB Signal Bandwidth
(MHz)
Data Rate
OC(32,4)*
(Mbit/s)
Uncoded 16
20.8 2 8
10.4 1 4
5.2
0.5
2.6
0.25
1.3
0.125
0.65
0.065
* OC = Orthogonal Coding.
Martin, Motorola

8. 802.15.4 PHY Review Modulation 4 bits per symbol
January 2009
PHY Review Modulation
4 bits per symbol
16-ary symbol alphabet (nearly-orthogonal PN sequences)
32 chips per symbol
Chip modulation is O-QPSK with half-sine pulse shape (similar to MSK)
Serial To
Parallel s0 s1
s15 .
z-1 I Q
O-QPSK
Modulation
PN Sequence
Selection
Bits
4-Bit
Index
32-Chip
Sequence
Martin, Motorola

9. 802.15.4 PHY Review Matched Filter Detection
January 2009
PHY Review Matched Filter Detection
Textbook detection: Sequence matched filters (non-coherent)
Advantage: Low Eb/No, low C/I
Disadvantage: Requires good frequency control s0 .
PN Sequence
Matched Filters
Bits
Parallel to
Serial
4-bit
Symbol
Value I Q 
Magnitude
Choose
Largest
Chip Matched Filters s1
s15
Martin, Motorola

10. High Efficiency BAN Option Uncoded
January 2009
High Efficiency BAN Option Uncoded
No coding → Modulate bits directly using O-QPSK (or MSK)
Recover bits with FM detection or differential phase detection
Advantage: Higher spectral efficiency
Disadvantage: No coding/processing gain
z-1 I Q
O-QPSK
Modulation
Bits
Bits I Q
Baseband
Chip
Filtering
FM or Differential
Phase Detection
Detection
Martin, Motorola

11. Simulated AWGN Performance
January 2009
Simulated AWGN Performance 2 4 6 8 10 12 14 16 -3 -2 -1
Eb/No (dB)
PER
Orthogonal Coding (MFD)
Orthogonal Coding (DD)
Uncoded (DD)
Basic AWGN results
Simulated in Matlab with 8 samples/chip
Symbol sync modeled
Otherwise ideal
256-byte payload
Measured at 10% PER:
Mode
Eb/No
(dB)
SNR*
OC-MFD
8.25
1.25
OC-DD
12.25
5.25
Uncoded-DD
13.0
12.0
*Assumes BW = 0.625Rc
Martin, Motorola

12. Channel Simulations (900 MHz, 2.4 GHz)
January 2009
Channel Simulations (900 MHz, 2.4 GHz)
BAN channel delay spread is relatively low (doc.# 780r4)
Body surface to body surface (CM3)
< 15 ns at 900 MHz
< 22 ns at 2.45 GHz
Body surface to external (CM4)
Delay spread not specified
Power delay profiles not specified for 900 MHz or 2.4 GHz
Use diffuse exponential model [1-4] to benchmark proposed PHY
Martin, Motorola

13. Channel Simulations (32-chip Orthogonal Code, MF Det.)
<month year>
doc.: IEEE <doc#>
January 2009
Channel Simulations (32-chip Orthogonal Code, MF Det.)
Simple receiver
synchronizes to the largest correlation peak.
Performs well for RMS delay spreads as high as the chip duration, Tc. >> More than sufficient for BAN applications. Rc
(Mchip/s) Tc
(ns) 1
1000 2
500 4
250 8
125 16
62.5
Rayleigh fading, all channels used in analysis
Martin, Motorola
<author>, <company>

14. Channel Simulations (Uncoded, Diff. Det.)
<month year>
doc.: IEEE <doc#>
January 2009
Channel Simulations (Uncoded, Diff. Det.)
Simple receiver with differential phase detection. No equalization.
Equalization or additional coding needed for delay spreads > 0.2Tb.
>> Issue for 8 Mbps and 16 Mbit/s modes. Rb
(Mbit/s)
0.2Tb
(ns) 1
200 2
100 4 50 8 25 16
12.5
Rayleigh fading, all channels used in analysis
Martin, Motorola
<author>, <company>

15. Power Spectrum (32-chip Orthogonal Code)
January 2009
Power Spectrum (32-chip Orthogonal Code)
IEEE
250 kbit/s
2 Mchip/s
5 MHz channels
Notes
Spectrum similar to MSK.
Effects of 32-chip code
are visible.
2.6 MHz
Martin, Motorola

16. Power Spectrum (32-chip Orthogonal Code)
January 2009
Power Spectrum (32-chip Orthogonal Code)
Wideband example:
2 Mbit/s
16 Mchip/s
22 MHz channels
Notes
Spectrum similar to MSK.
Effects of 32-chip code
more visible due to low
ratio of RBW to signal BW.
20.8 MHz
Martin, Motorola

17. Power Spectrum (Uncoded)
January 2009
Power Spectrum (Uncoded)
Narrowband example:
500 kbit/s
1 MHz channels
Notes
Spectrum of MSK.
0.65 MHz
Martin, Motorola

18. Link Budget – 500 kbit/s uncoded mode
January 2009
Link Budget – 500 kbit/s uncoded mode
Martin, Motorola

19. Multi-Piconet Coexistence
January 2009
MHz Band
16 non-overlapping channels (5 MHz spacing) with up to 2 Mbit/s uncoded, 250 kbit/s coded*
8 non-overlapping channels (10 MHz spacing) with up to 4 Mbit/s uncoded, 500 kbit/s coded*
2 non-overlapping channels (20 MHz spacing) with up to 16 Mbit/s uncoded, 2 Mbit/s coded*
* (30 dB adjacent channel)
Proposed MHz Band
19 non-overlapping channels (2 MHz spacing) with up to 500 kbit/s uncoded, 62.5 kbit/s coded
MHz Band
13 non-overlapping channels (2 MHz spacing) with up to 500 kbit/s uncoded, 62.5 kbit/s coded
Martin, Motorola

20. Crystal-less operation
January 2009
Optional addition to the proposal
By combining differential detection of coded a coded waveform with frequency-differentiated packet header, crystal-less transceiver operation can be achieved for chip rates 2 Mchips/s and greater.
See IEEE
Crystal-less operation facilitates low cost, small form factor for minimal on-body devices.
Martin, Motorola

21. Summary Preliminary proposal – scalable direct sequence waveform
January 2009
Summary
Preliminary proposal – scalable direct sequence waveform
-- meets requirements of BAN
-- low cost implementation features
PHY-layer partial proposal – we welcome collaboration with other proposers
Martin, Motorola