1. November 18
March 2009
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: Multi-Rate PHY Proposal for the TG4g PHY Amendment
Date Submitted: March 2009
Source: Michael Schmidt, Dietmar Eggert, Frank Poegel, Torsten Bacher, Sascha Beyer, Atmel
Contact: Michael Schmidt, Atmel
Voice: ,
Re: TG4g Call for proposals
Abstract: PHY enhancements towards TG4g supporting multiple data rates
Purpose: PHY proposal for the TG4g PHY amendment
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
Slide 1
Michael Schmidt
Page 1

2. Overview Flexible but simple binary block coding GMSK modulation
November 18
March 2009
Overview
Flexible but simple binary block coding
GMSK modulation
Chip Rate
SHR/PHR structure
Frequency Hopping
Extension of the European Frequency Band
Slide 2
Michael Schmidt
Page 2

3. March 2009
Coding and Modulation
Slide 3
Michael Schmidt

4. Binary Block Coding Simple C(K=4,N) binary block coding
March 2009
Binary Block Coding
Simple C(K=4,N) binary block coding
Binary coefficients (chips)
Considerably simplifies TX and RX architecture
Small number of code words (2K = 16)
Allows simple ML-soft decision decoding
Flexible code length N to adjust the data rate
Slide 4
Michael Schmidt

5. March 2009
Binary Block Coding
Adjust data rate by code length N out of {4,8,16,32,64,128}
High Data Rate:
N = 4,8
short range
Medium Data Rate:
N = 16,32 (like DSSS for IEEE O-QPSK PHYs)
medium range
Low Data Rate:
N = 64,128
long range, higher multipath robustness
Improved SHR and PHR detection
Slide 5
Michael Schmidt

6. March 2009
Binary Block Coding
Within PSDU, more advanced but more complex coding is conceivable, since large PSDU lengths are desired.
C(k,N) block coding with K > 4 obtaining a relevant coding gain
Low rate coding within SHR and PHR
Slide 6
Michael Schmidt

7. Binary GMSK Modulation
March 2009
Binary GMSK Modulation
Improved spectral efficiency versus O-QPSK (with half-sine shaping)
Constant envelope modulation
Similar performance as O-QPSK
Simple differential demodulation for BT approx. 0.5 (no Trellis-based detection required)
GMSK is detectable for IEEE legacy devices using O-QPSK with appropriate coding
Slide 7
Michael Schmidt

8. Chip Rate March 2009 2 MHz IEEE 802.15.4-2006 @ 2.4 GHz ISM
No need for frequency hopping for 1 W TX power (FCC CFR 47)
1 MHz
IEEE MHz
< 0.5 MHz
Need for frequency hopping for 1 W TX power (FCC CFR 47)
>= 75 hopping 2.4 GHz ISM
>= 50 hopping MHz
Slide 8
Michael Schmidt

9. SHR + PHR Problem with IEEE 802.15.4-2006 O-QPSK PHYs:
March 2009
SHR + PHR
Problem with IEEE O-QPSK PHYs:
Relative short duration of SHR and PHR, hard for:
antenna diversity,
channel estimation
PHR is not sufficiently protected
More preamble bytes or low rate transmission, e.g. C(4,128)- coding
Slide 9
Michael Schmidt

10. Frequency Hopping (FH)
March 2009
Frequency Hopping (FH)
Increased robustness against interferer
GMSK modulation applied in the 2.4 GHz ISM band allows tighter channel spacing than 5 MHz
However, FH addresses many issues to be solved:
FH Synchronisation (e.g. FHS packet information)
Clock frequency accuracy
Hopping sequences
Power efficiency
Slide 10
Michael Schmidt

11. Extension of European Frequency Band (863 – 870 MHz)
March 2009
Extension of European Frequency Band (863 – 870 MHz)
Harmonized standard ETSI EN defines frequency band of 863 – 870 MHz with different power limits for digital modulation systems using DSSS
Duty cycle limitations do not apply to systems using Listen Before Talk techniques combined with Adaptive Frequency Agility (AFA)
Slide 11
Michael Schmidt

12. DSSS Proposal March 2009 channels with RF bandwidth of 0.6 MHz
863.5 MHz, MHz, MHz with reduced power of -4.5 dBm/100 kHz
865.3 MHz, MHz, MHz, MHz with increased output power of 6.2 dBm/100 kHz
868.3 MHz IEEE legacy channel
868.9MHz and MHz using -0.8 dBm/100 kHz output power
channels with RF bandwidth up to 1.4 MHz
864.1 MHz with reduced power of -4.5 dBm/100 kHz
865.8 MHz and MHz with increased output power of 6.2 dBm/100 kHz
868.3 MHz IEEE legacy channel
869.3MHz using -0.8 dBm/100 kHz output power
Michael Schmidt

13. March 2009
FHSS
Listen Before Talk (LBT) has to be applied at each hopping channel.
Carrier power is limited to 25 mWerp
Michael Schmidt

14. Other European Frequency Bands (To Do)
March 2009
Other European Frequency Bands (To Do)
Consider improved usage of the 2.4 GHz band
(ETSI EN )
Consider usage of the 433 MHz band
Michael Schmidt