1. 9-July-2007
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [DecaWave Proposal for TG3c Alternative PHY]
Date Submitted: [2007-July-9th]
Source: [Michael Mc Laughlin, Brian Gaffney] Company [DecaWave]
Address [25 Meadowfield, Sandyford, Dublin 18, Ireland]
Voice:[ ], FAX: [none],
Re: [Response to Call for Proposals]
Abstract: [Alternative PHY Proposal for TG3c]
Purpose: [To assist TG3c in selecting a mm Wave PHY]
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
Gaffney, Mc Laughlin, DecaWave

2. Outline Coding and modulation scheme Low complexity.
9-July-2007
Outline
Coding and modulation scheme
Low complexity.
Allows for Non coherent receivers so that simple devices can receive the same signal as more robust coherent receivers.
All modes all derived from a single base mode.
Gaffney, Mc Laughlin, DecaWave

3. System Design 8-QAM constellation for all modes.
9-July-2007
System Design
8-QAM constellation for all modes.
Convolutional code concatenated with a GF(26) Reed Solomon code for additional error correcting capabilities.
Different data rate modes are achieved by using a unpunctured convolutional code, punctured convolutional code and ignoring the code altogether.
The base mode can be received by non-coherent receivers.
Gaffney, Mc Laughlin, DecaWave

4. 8-QAM 8-QAM Allows for Non-Coherent reception Only two levels
9-July-2007
8-QAM
8-QAM
Used in the V.29 modem standard due to resilience to phase noise.
Higher bandwidth efficiency than QPSK.
More resilient to phase noise problems than higher order constellations (16-QAM or 8-PSK).
Allows for Non-Coherent reception
Only two levels
R1=√2, R0=1+√3 Q
001
100
101
000
010 I R1
111
110 R0
011
Gaffney, Mc Laughlin, DecaWave

5. 9-July-2007
8-QAM
001
100
101
000
010
111
110
011
Gaffney, Mc Laughlin, DecaWave

6. 9-July-2007
Inner Coding
The systematic Reed Solomon code is over the Galois field GF(26) and is given as RS(63,55)
Input of 55 symbols creates 8 parity symbols for a rate 0.87 code
Systematic gives the option of ignoring the parity symbols in low complexity receivers
Currently used in IEEE a standard
Gaffney, Mc Laughlin, DecaWave

7. Interleaver An interleaver is placed between the Inner and Outer Code.
9-July-2007
Interleaver
An interleaver is placed between the Inner and Outer Code.
The errors from the Viterbi decoder are impulsive in nature and the interleaver separates these errors such that they occur in different RS code blocks.
This improves the performance significantly.
Gaffney, Mc Laughlin, DecaWave

8. Outer code Outer code is a rate 1/3 systematic convolutional code.
9-July-2007
Outer code
Outer code is a rate 1/3 systematic convolutional code.
Four parallel encoders/decoders used to reduce decoding speed.
Low constraint length keeps the complexity very low.
Gaffney, Mc Laughlin, DecaWave

9. Base Mode – 1.4Gbps Base mode Inner and Outer coding 8 QAM modulation
9-July-2007
Base Mode – 1.4Gbps
Base mode
One bit per symbol.
Data rate = 0.87*B Gbs
Inner and Outer coding
Interleaver in between
8 QAM modulation
Gaffney, Mc Laughlin, DecaWave

10. Base Mode Transmitter Block Diagram
9-July-2007
Base Mode Transmitter Block Diagram CC
Mapping CC
Mapping RS
S/P
P/S CC
Mapping CC
Mapping
Gaffney, Mc Laughlin, DecaWave

11. Base Mode Receiver Block Diagram
9-July-2007
Base Mode Receiver Block Diagram
Viterbi
Viterbi
S/P
P/S
RS Decode
Mapping
Viterbi
Viterbi
Gaffney, Mc Laughlin, DecaWave

12. 9-July-2007
Base Mode
Gaffney, Mc Laughlin, DecaWave

13. High Data Rate Mode – 2.8Gbps
9-July-2007
High Data Rate Mode – 2.8Gbps
High Data Rate mode
Two bits per symbol
Punctured Base mode
Interleave RS output
Data rate = 2*0.87*B Gbs
Same Tx as Base mode, put with symbol puncturing.
Gaffney, Mc Laughlin, DecaWave

14. High Data Rate Mode Puncturing
9-July-2007
High Data Rate Mode Puncturing s1 s2 s3 s4 s5 s6 s7 s8
Every second symbol is punctured in each of the parallel encoders/decoders.
Receiver the same as base mode.
Gaffney, Mc Laughlin, DecaWave

15. 9-July-2007
High Data Rate Mode
Gaffney, Mc Laughlin, DecaWave

16. Very High Data Rate Mode – 4.2Gbps
9-July-2007
Very High Data Rate Mode – 4.2Gbps
Very High Data Rate mode
No convolutional code
Reed Solomon RS(63,55)
Interleave RS output
Data rate = 3*0.87*B Gbs
Gaffney, Mc Laughlin, DecaWave

17. Very High data Rate Mode
9-July-2007
Very High data Rate Mode RS
Mapping
Gaffney, Mc Laughlin, DecaWave

18. Very High Data Rate Mode
9-July-2007
Very High Data Rate Mode
Gaffney, Mc Laughlin, DecaWave

19. Non Coherent Mode – 1.4Gbps
9-July-2007
Non Coherent Mode – 1.4Gbps
The Non Coherent receiver is ideal for File Transfer or Kiosk modes
The systematic bit decides which “ring” the transmitted symbol is on. Therefore, by using a simple energy detector receiver we can decode the systematic bit from any base mode signal.
The Outer Reed Solomon code then gives some optional error correcting capabilities
Gaffney, Mc Laughlin, DecaWave

20. Non Coherent Mode Compatible with ASK and OOK receivers.
9-July-2007
Non Coherent Mode
Compatible with ASK and OOK receivers.
Enables a very low cost, very low power, implementation
Ideal for integration into media players, phones, cameras etc.
Gaffney, Mc Laughlin, DecaWave

21. 9-July-2007
Non Coherent Mode
Gaffney, Mc Laughlin, DecaWave

22. 9-July-2007
Modes
Gaffney, Mc Laughlin, DecaWave

23. Link Budget (LOS) Parameter Low Base High Rate Very High Rate
9-July-2007
Parameter
Low
Base
High Rate
Very High Rate
Non Coherent
PHY-SAP Payload Bit Rate (Rb)
67Mb/s
1.4Gb/s
2.8Gb/s
4.2Gb/s
Average Transmit Power
10dBm
Transmit Antenna Gain
10dBi
Center frequency (fc)
60GHz
Path loss at 1 meter
68dB
Receive Antenna Gain
0dBi
Average noise power per bit
-69.3dBm
-82.5dBm
-79.5dBm
-77.7dBm
Noise Figure
8dB
-74.5dBm
-71.5dBm
-69.7dBm
Minimum Eb/N0 for AWGN channel
2.5dB
4.6dB
6.5dB
9.1dB
22.6dB
Shadowing link margin
1dB
Implementation Loss
2dB
Tolerable path loss
34.25dB
28.6dB
24dB
19.6dB
10.9dB
Maximum operating range (d = 10 PL/10n,n=2)
51.6m
27m
15.9m
10.2m
3.5m
Gaffney, Mc Laughlin, DecaWave

24. Link Budget (NLOS) Parameter Base High Rate 9-July-2007
PHY-SAP Payload Bit Rate (Rb)
1.4Gb/s
2.8Gb/s
Average Transmit Power
10dBm
Transmit Antenna Gain
13dBi
Center frequency (fc)
60GHz
Path loss at 1 meter
68dB
Receive Antenna Gain
Average noise power per bit
-82.5dBm
-79.5dBm
Noise Figure
8dB
-74.5dBm
-71.5dBm
Minimum Eb/N0 for AWGN channel
4.6dB
6.5dB
Shadowing link margin
5dB
Implementation Loss
2dB
Tolerable path loss
30.6dB
24dB
Maximum operating range (d = 10 PL/10n,n=2.5)
16.7m
9.1m
Gaffney, Mc Laughlin, DecaWave

25. Summary of our proposal
9-July-2007
Summary of our proposal
8-QAM modulation scheme
4 Data rates
Base mode of 1.4Gps obtained with outer RS (rate 0.87) and inner convolutional (rate 1/3) coding
High data rate mode of 2.8Gps obtained by puncturing base mode signal
Very high data rate mode of 4.2Gps obtained by using only RS code
Lower rate for back channel using Direct Sequence code
Systematic code developed specifically for the 8-QAM constellation which enables a Non-coherent receiver architecture
Gaffney, Mc Laughlin, DecaWave