1. September 2006
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [PHY Layer Modulation for c - System Level Issues]
Date Submitted: [15 September 2006]
Source: [André Bourdoux, IMEC]
Address [Kapeldreef 75, 3001 Leuven, Belgium]
Voice:[ ], FAX: [ ],
Re: [TG3c technical requirements]
Abstract: []
Purpose: [Discussion of TG3c Modulation for System Requirements.]
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
André Bourdoux, IMEC

2. Introduction TG3c System Requirements (15-05-0353-07):
September 2006
Introduction
TG3c System Requirements ( ):
2 Gbps (mandatory) and 3 Gbps (optional)
4 channels in 7 GHz bandwidth
Impact on spectral efficiency, modulation ?
Link with front-end requirements ?
André Bourdoux, IMEC

3. PHY Layer Requirements
September 2006
PHY Layer Requirements
Data rate:
2 Gbps mandatory
3 Gbps optional
Physical bandwidth:
4 channels in 7 GHz: 7/4 = 1.75 GHz  ~1.5 GHz
? 3 channels in 7 GHz: 7/3 = 2.33 GHz  ~2.0 GHz ?
Spectral efficiency (uncoded):
2 Gbps
2 x (4/3) / 1.5 = 1.78 b/s/Hz
2 x (4/3) / 2.0 = 1.33 b/s/Hz
3 Gbps
3 x (4/3) / 1.5 = 2.66 b/s/Hz
3 x (4/3) / 2.0 = 2.00 b/s/Hz
3 channels option relaxes spectral efficiency requirements.
André Bourdoux, IMEC

4. Criteria for good Air Interface
September 2006
Criteria for good Air Interface
Low cost
Low power consumption
Modest FE requirements
Low channel equalization complexity
André Bourdoux, IMEC

5. Add CP for freq. domain equalizer
September 2006
System level approach
Battery-powered
PA is key consumer
Avoid OFDM
Simplify filtering
Low spectral regrowth
Avoid M-QAM
LOS Possible
Simplify equalization
Add CP for freq. domain equalizer
PSK-based: CP-OQPSK, CP-3/8-shifted 8PSK
CPM-based: CP-CPM (many flavours)
André Bourdoux, IMEC

6. Achieving required bit rates with CP-M-PSK
September 2006
Achieving required bit rates with CP-M-PSK Q Q I Q I I
QPSK
O-QPSK
3/8-8PSK
2 Gbps
3 Gbps
1.75 GHz
1.78 b/s/Hz
CP-OQPSK
2.66 b/s/Hz
CP-3/8-8PSK
2.33 GHz
1.33 b/s/Hz
2.00 b/s/Hz
André Bourdoux, IMEC

7. CPM parameters reminder
September 2006
CPM parameters reminder
log2M bits/symbol
Pulse shape and length (rect, raised cos, gaussian, …)
[Anderson, “Digital Phase Modulation”, 1986, Springer (Plenum Press)]
André Bourdoux, IMEC

8. Achieving spectral efficiency with CPM
September 2006
Achieving spectral efficiency with CPM
3COS,M=4,h=0.25
Good spectral performance
3COS,M=2,h=0.5 Low complexity
3COS,M=4,h=0.5 Good error performance
André Bourdoux, IMEC

9. Achieving required bit rates with CP-CPM
September 2006
Achieving required bit rates with CP-CPM I Q
QPSK I Q
CPM h=0.5 I Q
CPM h=0.25
1 Gbps
2 Gbps
3 Gbps
1.75 GHz
0.89 b/s/Hz
3COS, M=2, h=0.5
1.78 b/s/Hz
3COS, M=4, h=0.25
2.66 b/s/Hz ??
2.33 GHz
0.67 b/s/Hz
1.33 b/s/Hz
2.00 b/s/Hz
André Bourdoux, IMEC

10. September 2006
OFDM vs SC
André Bourdoux, IMEC

11. Conclusion for 60 GHz PHY layer
September 2006
Conclusion for 60 GHz PHY layer
For cost, power consumption and complexity:
O-QPSK or CPM are good, front-end friendly candidates
Cyclic prefix combined with single carrier modulation allows simple and optional frequency domain equalization
Channelization with 3 channels allows modulation with  2 bits/symbol
André Bourdoux, IMEC