1. 7-May-2007
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [DecaWave Proposal for TG3c Alternative PHY]
Date Submitted: [2007-May-7th]
Source: [Brian Gaffney, Michael Mc Laughlin] Company [DecaWave]
Address [25 Meadowfield, Sandyford, Dublin 18, Ireland]
Voice:[ ], FAX: [none],
Re: [Response to Call for Proposals c-tg3c-call-proposals.doc]
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. 7-May-2007
DecaWave 3c Proposal
Gaffney, Mc Laughlin, DecaWave

3. Proposal Outline Single Carrier system. Low Complexity Low Power
7-May-2007
Proposal Outline
Single Carrier system.
Low Complexity
Low Power
Adaptive Phased Antenna Array to boost SNR at receiver and provide spatial multiple access
Gaffney, Mc Laughlin, DecaWave

4. Proposed Band Plan U.S. Japan 57 59 64 66 f(Ghz) 3dB BW 1.6 Ghz
7-May-2007
Proposed Band Plan
U.S.
Japan
3dB BW 1.6 Ghz
400
MHz
400
MHz 1 2 3 4 57 59 64 66
f(Ghz)
~2.2Ghz
Separation
Gaffney, Mc Laughlin, DecaWave

5. Base Mode Modulation: 1.4Gbps
7-May-2007
Base Mode Modulation: 1.4Gbps RS
Encoder
(63,55)
Symbol
Interleaver
Systematic
Convolutional
Code R 1/3
8-QAM
Constellation
Mapping
Gaffney, Mc Laughlin, DecaWave

6. Modulation Scheme 8-QAM Allows for Non-Coherent reception
7-May-2007
Modulation Scheme
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 and power amplifier problems than higher order constellations (16-QAM).
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

7. Error Correction Coding
7-May-2007
Error Correction Coding
Outer systematic Reed Solomon block code.
Inner systematic Convolutional code.
Constraint length K = 5 and rate 1/3.
One information bit in produces 3 bits out (the information bit and two parity bits) which are mapped to a symbol in the 8-QAM constellation.
Systematic to allow for Non-Coherent Reception for low complexity receivers
File Transfer and Kiosk usage scenarios
Both low complexity codes
Overall coding gain of 8dB
Gaffney, Mc Laughlin, DecaWave

8. 7-May-2007
Outer Reed Solomon
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
Interleaved output before input to inner code improves performance by separating burst errors at the receiver
Gaffney, Mc Laughlin, DecaWave

9. Convolutional Code: Rate 1/3, K=5
7-May-2007
Convolutional Code: Rate 1/3, K=5 + +
Generator Polynomial: g1=208, g2 = 278, g3 =328.
Gaffney, Mc Laughlin, DecaWave

10. Convolutional Code Rate 1/3 Low complexity
7-May-2007
Convolutional Code
Rate 1/3
Low complexity
With K=5, there are only 16 possible states.
8 branch metrics need to be calculated per symbol
Gaffney, Mc Laughlin, DecaWave

11. 7-May-2007
Convolutional Code
Systematic code gives the option of ignoring the parity bits
Important for Non-Coherent receiver. To be covered later.
However, systematic codes are known to perform worse than non-systematic.
The combination of this systematic code with this constellation mapping approaches the performance optimal non-systematic code with a Gray coded constellation
Gaffney, Mc Laughlin, DecaWave

12. 8-QAM Constellation 001 100 101 000 010 111 110 011 7-May-2007
Gaffney, Mc Laughlin, DecaWave

13. Our 8-QAM versus Gray Coded
7-May-2007
Our 8-QAM versus Gray Coded
Gaffney, Mc Laughlin, DecaWave

14. Data Modes Four Data Modes: Base mode 1.4Gbps
7-May-2007
Data Modes
Four Data Modes:
Base mode 1.4Gbps
High data rate mode 2.8Gbps
Very High data rate mode 4.2Gbps
Low rate (67Mbps) back channel mode obtained by sending a direct sequence code
Gaffney, Mc Laughlin, DecaWave

15. Base Mode – 1.4Gbps Base mode Inner and Outer coding 8 QAM modulation
7-May-2007
Base Mode – 1.4Gbps
Base mode
One bit per symbol.
Pulse Repetition Frequency (PRF) = Bandwidth (B)
Data rate = 0.87*B Gbs
Inner and Outer coding
Interleaver in between
8 QAM modulation
Gaffney, Mc Laughlin, DecaWave

16. 7-May-2007
Base Mode – 1.4Gbps
Gaffney, Mc Laughlin, DecaWave

17. High Rate Mode : 2.8Gbps RS Encoder (63,55) Symbol Interleaver
7-May-2007
High Rate Mode : 2.8Gbps RS
Encoder
(63,55)
Symbol
Interleaver
Systematic
Convolutional
Code R 1/3
Puncture
8-QAM
Constellation
Mapping
Gaffney, Mc Laughlin, DecaWave

18. High Data Rate Mode – 2.8Gbps
7-May-2007
High Data Rate Mode – 2.8Gbps
High Data Rate mode
Two bits per symbol
Punctured Base mode
PRF = B
Interleave RS output
Data rate = 2*0.87*B Gbs
Not transmitted
From convolutional coder s1 s2 s3 s4 s5 s6
Gaffney, Mc Laughlin, DecaWave

19. High Data Rate Mode – 2.8Gbps
7-May-2007
High Data Rate Mode – 2.8Gbps
Gaffney, Mc Laughlin, DecaWave

20. Very High Rate Mode : 4.2Gbps
7-May-2007
Very High Rate Mode : 4.2Gbps RS
Encoder
(63,55)
8-QAM
Constellation
Mapping
Gaffney, Mc Laughlin, DecaWave

21. Very High Data Rate Mode – 4.2Gbps
7-May-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

22. Very High Data Rate Mode – 4.2Gbps

23. Low Data Rate Mode – 67Mbps
7-May-2007
Low Data Rate Mode – 67Mbps
Low data rate back channel mode.
Length 21 Ipatov ternary sequence.
+00−++−0+0+−+++++−−0−
Golay Merit Factor of 5.3
Gives the option of 67Mbs (base mode) or 133Mbs (high data mode) which is more resistant to errors
Gaffney, Mc Laughlin, DecaWave

24. Non Coherent Reception
7-May-2007
Non Coherent Reception
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

25. Non Coherent Reception
7-May-2007
Non Coherent Reception
to RS decoder
from antenna
BPF
Gaffney, Mc Laughlin, DecaWave

26. Non Coherent Reception
7-May-2007
Non Coherent Reception
Used with a directional antenna, we can achieve a data rate of 1.4Gbs at short range
Enables a very low cost, very low power, implementation
Ideal for integration into media players, phones, cameras etc.
Gaffney, Mc Laughlin, DecaWave

27. Non Coherent Reception – 1.4Gbps
7-May-2007
Non Coherent Reception – 1.4Gbps
Gaffney, Mc Laughlin, DecaWave

28. 7-May-2007
Phased Antenna Array
We propose using a phased antenna array to boost the signal to noise ratio at the receiver input and provide spatial multiple access.
The phased antenna array can adapt to any direction of arrival (assuming omni directional elements)
The phased antenna array offers a low complexity solution
Gaffney, Mc Laughlin, DecaWave

29. 7-May-2007
Phased Antenna Array +
Gaffney, Mc Laughlin, DecaWave

30. 7-May-2007
Phased Antenna Array
For omni directional antenna elements, the phased antenna array can achieve a high gain in any given direction. For example, ten elements (uniform linear array) can give a gain of 10dBi
To achieve higher gains, directive elements need to be applied which require some physical alignment of Tx and Rx
The non-coherent mode could have a single highly directive element and assume the user will align the Tx and Rx
Gaffney, Mc Laughlin, DecaWave

31. 7-May-2007
Hidden Node Problems
Major problem with directive antenna systems is finding Nodes.
To combat this problem, we propose using a single element mode.
For omni-directional antenna elements, we can now “see” in every direction.
For directive antenna elements, we can only “see” in the direction we can adapt in.
Gaffney, Mc Laughlin, DecaWave

32. 7-May-2007
Hidden Node Problems
However, the path loss is so high at 60Ghz, a very weak signal is received when we are not using the antenna array gain
The Solution:
Compensate for the lack of antenna array gain at Tx and Rx by spreading the signal to obtain an equal or higher processing gain
Gaffney, Mc Laughlin, DecaWave

33. Ternary Spreading Sequence
7-May-2007
Ternary Spreading Sequence
Ipatov Sequence
Perfect Periodic Autocorrelation properties.
Allows for accurate channel estimation for Channel Matched Filtering (CMF) and Antenna Array adaptation.
Used in a
For example, a length 183 sequence is equivalent to an antenna array gain of approximately 22.2 dBi
Many such sequences allows separate piconets to co-exist
Example length 183 Ipatov Sequence:
+−−−+0+−−−−−++−− −−++0+−+−+−+−−00−−+−+−++−−++−−+−0−−−++−−0−++−0−−+++−+++−−+−+−−+−+++++0−−++−−++−+−−− −0−−−−−+−++−−0++++−+−−−−+++−+−+−−++−++−+0−++++−+−++++−++− −+−−+
Gaffney, Mc Laughlin, DecaWave

34. Ternary Spreading Sequence
7-May-2007
Ternary Spreading Sequence
Periodic Auto Correlation of Length 183 Ipatov Sequence
Gaffney, Mc Laughlin, DecaWave

35. Ternary Spreading Sequence
7-May-2007
Ternary Spreading Sequence
With the perfect autocorrelation we can obtain an excellent estimate of the channel for the Channel Matched Filter (CMF)
Send 16 times before each packet
Gaffney, Mc Laughlin, DecaWave

36. Interference & susceptibility
7-May-2007
Interference & susceptibility
All out of band interference filtered out.
Adjacent channel interference is filtered out.
However, power amplifier backoff will affect this and will be addressed fully at future meetings.
Co-channel interference is avoided by spatial multiple access.
Narrowband interference rejection with digital notch filter
Tones can be detected at the A/D output.
A simple notch filter either at the input or output of the matched filter can then remove this completely with no loss in performance (if notch is narrow enough).
Gaffney, Mc Laughlin, DecaWave

37. Link Budget (LOS) Parameter Low Base High Rate Very High Rate
7-May-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
8.4dB
8.5dB
22.6dB
Shadowing link margin
1dB
Implementation Loss
2dB
Tolerable path loss
34.25dB
28.6dB
22dB
20.2dB
10.9dB
Maximum operating range (d = 10 PL/10n,n=2)
51.6m
27m
12.6m
10.2m
3.5m
Gaffney, Mc Laughlin, DecaWave

38. Link Budget (NLOS) Parameter Base High Rate 7-May-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
8.4dB
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

39. Link Budget Summary 51.6m 27m 12.6m 10.2m 4.7m
7-May-2007
Link Budget Summary 51.6m 27m 12.6m 10.2m 4.7m
Bit Rate
Channel Model
Range for 10-2 PER
67Mbps
LOS
51.6m
1.4Gbps
27m
2.8Gbps
12.6m
4.2Gbps
10.2m
NLOS
15.5m
8.4m
Gaffney, Mc Laughlin, DecaWave

40. Base Mode: 1.4Gbps CM 1.3 (LOS)
7-May-2007
Base Mode: 1.4Gbps CM 1.3 (LOS)
Gaffney, Mc Laughlin, DecaWave

41. Base Mode: 1.4Gbps CM 2.3 (NLOS)
7-May-2007
Base Mode: 1.4Gbps CM 2.3 (NLOS)
Gaffney, Mc Laughlin, DecaWave

42. Base Mode: 1.4 Gbps CM 3.1 (LOS)
7-May-2007
Base Mode: 1.4 Gbps CM 3.1 (LOS)
Gaffney, Mc Laughlin, DecaWave

43. 7-May-2007
High Data Rate CM 1.3
Gaffney, Mc Laughlin, DecaWave

44. Performance Summary Bit Rate Channel Model Range for 10-2 PER
7-May-2007
Performance Summary
Bit Rate
Channel Model
Range for 10-2 PER
1.4Gbps
CM 1.3
33m
CM 2.3
10.5m
CM 3.1
23.5m
2.8Gbps
14.8m
Gaffney, Mc Laughlin, DecaWave

45. Summary of our proposal
7-May-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
Node discovery and channel adaptation with omni directional antenna mode with spreading gain from long ternary sequence
Gaffney, Mc Laughlin, DecaWave

46. Advantages Low Power, Low Complexity solution
7-May-2007
Advantages
Low Power, Low Complexity solution
Constellation resilient to RF impairments
Simple Non-coherent mode
Ideal for low cost receiver e.g. for media player
Single carrier
potential common signalling mode operation
More resistant to multipath
Ternary sequences and omni-directional antenna mode allows easy node discovery and channel estimation
Gaffney, Mc Laughlin, DecaWave