334r1

1
Project IEEE P802.15 Working Group for Wireless
Personal Area Networks (WPANs) Submission Title
Hitachi Direct Sequence UWB Impulse Radio System
Date Submitted January 2005 Source
(1)Akira Maeki, Ryosuke Fujiwara, Kenichi
Mizugaki, Masayuki Miyazaki, Masaru Kokubo,
(2)Yasuyuki Okuma, Miki Hayakawa,
Shinsuke Kobayashi, Noboru Koshizuka, Ken
Sakamura Company (1) Hitachi, Ltd., Central
Research Laboratory and Advanced Research
Laboratory, (2) YRP
Ubiquitous Networking Laboratory Address (1)
1-280 Higashi Koigakubo Kokubunji-shi, Tokyo
185-8601 JAPAN (2)28th KOWA
Bldg., 2-20-1, Nishi-Gotanda Shinagawa-ku, Tokyo
141-0031 JAPAN Voice81 42.323.1111, FAX
81 42.327.7849, E-Maila-maeki_at_crl.hitachi.co.
jp Re Response to Call for Proposals Abstrac
t This document proposes Hitachi, Ltd.s PHY
proposal for the IEEE 802.15.4 alternate PHY
standard Purpose Proposal for the
IEEE802.15.4a standard. Notice This document
has been prepared to assist the IEEE P802.15. 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 P802.15.
2
Hitachi, Ltd. Proposal for IEEE 802.15.4a
DS- UWB Impulse Radio

• Akira Maeki
• Hitachi, Ltd.

3
Contents

• DS-UWB IR Proposal
• Details of the System Evaluation
• Location Awareness
• Summary

4
Direct Sequence UWB Impulse Radio System (DS-UWB
IR)
Impulse Radio
DBPSK
Transmitter
t
PRFTens of MHz
PRF Pulse Repetition Frequency
Receiver
RF
BB
5
UWB Pulse and Spectrum
Initial Target Arbitrary Pulse in Low Band
(3.1-5.1GHz)
-40
-50
-60
EIRP (dBm/MHz)

• Example
• 2.5ns Gaussian Pulse
• Center Frequency4.1GHz
• 10dB BW1.4GHz
• TxPower (ave.) -13.3dBm

-70
Low Band (3.1-5.1GHz)
High Band (6-10GHz)
-80
-90
0
1
2
3
4
5
6
7
8
9
10
11
Frequency (GHz)
6
Why DS-UWB IR?

• Low Power Consumption
• -Very Simple Architecture
• -Low Rate Sampling ADC Tens of Msps,
  2-4bits
• Low Cost
• -CMOS Implementation is Feasible (Peak Power
  lt10dBm)
• -Low Band (3.1-5.1GHz)
• High Location Accuracy
• -Narrow Pulse (2.5ns) ? 30cm in 30m region
  (AWGN)
• Scalability by Spread Factor
• 258kbps _at_30m (cf. ZigBee 250kbps
  _at_30-70m)
• 10.7Mbps _at_10m (cf. Bluetooth 1Mbps _at_10m)

7
Evaluation Results

• Scalability
• 258kbps at 30m, 10.7Mbps at 10m
• Low Power Consumption
• Tx30mW, Rx120mW
• Low Cost
• CMOS implementation
• High Location Accuracy
• 30cm at 30m (AWGN)
• lt40cm at 40m (CM1)

8
Benchmark
Hitachi Proposal DS-UWB
IEEE802.15.4
Data Rate Range
10.7Mbps _at_10m 258kbps _at_30m
250kbps _at_30-70m
Tx 30mW Rx 120mW
Tx 50-60mW 1 Rx 50-60mW
Power Consumption
Location Accuracy (30m range in AWGN)
30cm
2-3m 2
1 commercial chip example 2 Sampling
Rate64Msps
9
Details of the System Evaluation
1. General Definitions 2. Signal Robustness 3.
Technical Feasibility
10
1. General Definitions
-Overview -Parameters for the Simulations -Scalabi
lity -Link Budget
11
Overview
SOP evaluation Not finished yet

• System Parameters (Slide 12-13)
• Frame Format (Slide 19)
• System Performance (Slide 22-24)

Code 3
Code 1
Multiple Access CDMA (Slide 18) 31chip
M-Sequence

• Transceiver
• (Slide 15)

Tx
Anchor Nodes (Known position)
PAN coordinator
Rx

• Tx (Slide 17)
• Rx (Slide 28-29)

Code 2
Interference
Interferer
Sync. Node

• Coexistence (Slide 25)

FFD (Full Function Device)
Location Awareness (Slide 33-40)
RFD (Reduced Function Device)
12
System Parameters
Data Rate
Data Rate
Range
32MHz (31ns)
2.5ns
Nominal
258kbps
30m
Optional
10.7Mbps
10m
1 symbol for 10.7Mbps mode (optional)
2.5ns Gaussian Pulse with PRF32MHz (Data
Rate depends on Spread Factor124 for 258kbps, 3
for 10.7Mbps)

• Hardware specifications
• Crystal 20ppm
• ADC32Msps, 4bits (Including Location Awareness)

13
Scalability with spread factor
Data Rate Modulation Spread Factor Number of Pulses / Bit
32.0 Mbps DBPSK 1 1
10.7 Mbps DBPSK 3 3
4.57 Mbps DBPSK 7 7
2.13 Mbps DBPSK 15 15
1.03 Mbps DBPSK 31 31
258 kbps DBPSK 124 124
129 kbps DBPSK 248 248
PRF32MHz
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Link Budget
Parameters Value 258kbps 30m Value 10.7Mbps 10m Units
Center Frequency 4096 4096 MHz
Average Transmit Power (2.5ns Gaussian Pulse) -13.3 -13.3 dBm
PRF 32 32 MHz
Spread Factor 124 3
Data Rate 258 10666 kbps
Path Loss at 1m 44.7 44.7 dB
Distance 30 10 m
Decay coefficient 2.0 2.0 -
Additional Path Loss at 30m,10m 29.5 20.0 dB
Implementation Loss 3.0 3.0 dB
Antenna gain -3.0 -3.0 dBi
Required Eb/N0 _at_PER1, 32B 14.0 9.8 dB
Noise Power Density -174 -174 dBm
Receiver Total NF 7.0 7.0 dB
Margin 5.4 2.9 dB
15
Transceiver Architecture
Transmitter
Modulation Spreading
PA
Data
Pulse Generator
Antenna
Digital PHY
ANT. Switch
Analog RF
MAC
BPF
I
LPF
ADC
Digital Block
LNA
Xtal
Data

• Matched Filter
• Signal Acquisition
• Tracking
• Ranging
• etc.

0/90
PLL
20ppm
4.1GHz
Receiver
ADC
LPF
lt100kgates
32MHz, 2-4bits
Q
16
Modulation and Spreading
Items Specifications
Pulse Shape 2.5ns Gaussian Pulse
RF Frequency 4096700MHz (10dB BW)
PRF 32MHz
Modulation DBPSK
Spreading Direct Sequence
Despreading Matched Filter
Sequence M-Sequence
17
Modulation and Spreading
Differential Coding
Spreading
Spreading
DATA
PG
D
Spread Sequence 1
Spread Sequence 2
Spread Sequence 1
Spread Sequence 2
Length value
1 1
4 1,1,0,1
8 1,1,1,0,0,1,0,1
Length Value
1 1
3 1,1,0
7 1,1,1,0,0,1,0
15 1,1,1,1,0,0,0,1,0,0,1,1,0,1,0
31 1,1,1,1,1,0,0,0,1,1,0,1,1,1,0,1,0,1,0,0,0,0,1,0,0,1,0,1,1,0,0
Nominal Data Rate 258kbps Spread Factor 124
Spread Sequence (4, 31) Optional Data Rate
10.7Mbps Spread Factor 3 Spread Sequence
(1, 3 )
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Multiple Access

• Multiple access CDMA
• Each Piconet has its own sequence (One sequence /
  Piconet)
• 31 chip M-sequence has 6 nearly orthogonal
  sequences.

Sequence 1 1 1 1 1 1 0 0 0 1 1 0 1 1 1 0 1 0 1 0 0 0 0 1 0 0 1 0 1 1 0 0
Sequence 2 1 1 1 0 1 1 1 0 0 0 1 0 1 0 1 1 0 1 0 0 0 0 1 1 0 0 1 0 0 1 1
Sequence 3 0 0 1 1 0 1 1 1 1 1 0 1 0 0 0 1 0 0 1 0 1 0 1 1 0 0 0 0 1 1 1
Sequence 4 0 1 0 1 0 1 1 1 0 1 1 0 0 0 1 1 1 1 1 0 0 1 1 0 1 0 0 1 0 0 0
Sequence 5 0 1 1 1 1 1 0 0 1 0 0 1 1 0 0 0 0 1 0 1 1 0 1 0 1 0 0 0 1 1 1
Sequence 6 1 1 0 0 1 1 1 0 0 0 0 1 1 0 1 0 1 0 0 1 0 0 0 1 0 1 1 1 1 1 0
Auto Correlation
Cross Correlation
Cross Correlation
19
Frame Format
2
1
0/4/8
2
n
Octets
Data Payload
Frame Cont.
MAC Sublayer
Seq.
Address
CRC
MHR
MSDU
MFR
Data 32 (n23)
20
1
1
For ACK 5 (n0)
Octets
PHY Layer
Frame Length
Preamble
SFD
MPDU
SHR
PHR
PSDU
PPDU
20
System Throughput
Acknowledged transmission
5
22
32
22
32
22
HDR
PSDU
HDR
HDR
PSDU

tLIFS
ACK
DATA Frame 1
DATA Frame 2
tACK
Time for transmission
Nominal mode (X0 258 kbps)
? Throughput 100 kbps
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2. Signal Robustness

• Multipath Immunity
• Simultaneously Operating Piconets-Coexistence

22
System Performance in AWGN
-40ppm worst
0ppm ideal
40ppm worst
Error factors considered (IQ mismatch etc.)
PER
40ppm ideal
-40ppm ideal
PSDU 32Bytes
Eb/N0 (dB)
23
System Performance in Multipath Environment
Crystal Frequency Stability
0ppm ideal case
PER
PSDU 32Bytes
Eb/N0 (dB)
24
System Performance
Data Rate AWGN CM1 CM5
258 kbps 56m 27m 24m
10.7 Mbps 14m
Under evaluation
CM1 Indoor Residential (LOS), CM5 Outdoor
(LOS)
Results obtained using 4a channel model (doc
04/581r7).
Crystal0ppm, NF7dB, Implementation Loss3dB,
Zero Margin
25
Coexistence

• The band allocation of 3.1-5.1GHz allows
• the coexistence with Wireless LANs PANs
  (802.11a/b/g and 802.15.1/3/4)

UNII notch for desired criteria coexistence
-40
Meet the Desired Criteria in the
15.3a (Interferer at 0.3m)
-50
-60
EIRP (dBm/MHz)
-70
BPF Rejection30dB (_at_2.4GHz and 5GHz)
Low Band (3.1-5.1GHz)
High Band (6-10GHz)
-80
-90
0
1
2
3
4
5
6
7
8
9
10
11
Frequency (GHz)
26
3. Technical Feasibility

• Transceiver Architecture
• Synchronization
• -Complexity
• -Evaluation by a Test Bed

27
Transceiver Architecture
Example
Transmitter
Modulation Spreading
PA
Data
Pulse Generator
Antenna
Digital PHY
ANT. Switch
Analog RF
MAC
BPF
Rejection30dB _at_2.4GHz5GHz
I
LPF
ADC
Digital Block
LNA
Xtal
Data

• Matched Filter
• Signal Acquisition
• Tracking
• Ranging
• etc.

0/90
PLL
20ppm
4.1GHz
Receiver
ADC
LPF
lt100kgates
Q
32MHz, 2-4bits
28
Synchronization

• Two Step Synchronization
• Pulse Correlation Sliding Correlation
• Code Correlation Digital Matched Filter

Example
Digital Domain
Pulse Correlator
Analog Domain
Code Correlator
CORR
Detector
MF
ADC

Threshold Detector
ABS
CORR

MF

ADC
ABS
90
Template Generator
LO
Timing Control

29
Two Step Synchronization
2.5ns
Rx Signal
Tw31.3ns
d0.5ns
Template
Sliding correlation for pulse synchronization
Symbol Ts
Received Signal
Template Wavelet
Pulse sync.
Tw
No pulse sync.
Sampled data
Sampling Timing
Output Of MF
Time
30
Unit Manufacturing Complexity
Preliminary Evaluation
External Components
Size

• Crystal 20ppm
• BPF
• (Rejection30dB_at_2.4GHz5GHz)
• Antenna
• -Ceramic Antenna
• -Pattern Antenna

Analog RF
12 mm2
Digital PHY
Base Band
100 kgates
1 kgates
Ranging
0.18mm Standard CMOS Process
Analog RF LNA, Mixer, PLL, ADC (Slide
27) Base Band Acquisition, Tracking etc.
(Slide 27) Ranging 1GHz Counter
(Slide 38).
31
Manufacturability Technical Feasibility
32
Feasibility Study by the Test Bed

• -Send 1000 Pseudo random packets through the
  variable attenuator
• (Variable attenuator represents
  Propagation Loss)
• -Measure the PER
• PERlt1 for 258kbps at 30m and 10.7Mbps at
  10m

1000 Pseudo Random Packets
HDR
PSDU
PER Measurement
32
22
Variable ATT.
Tx
Rx
Propagation Loss
33
Location Awareness
34
Location Awareness

• Trilateration for Location Awareness
• - 3 Known-position Nodes (1 sync. node)
• - Synchronization by a reference signal
• - TDOA (Time Difference Of Arrival) based
• High Location Accuracy
• AWGN 30cm in 30m
  Range
• Indoor Residential lt40cm in 40m Range

35
Active-TDOA
FFD (Anchor)

• One-way Ranging
• ? Can relax the RFD specifications
• ? Can save power consumption
• ? High Accuracy for mobile node location
• Synchronization
• Easier Sync. than TOA/OWR
• Accuracy
• Accuracy depends only on the clock at the
  FFD
• (Cf. TOA/TWR Error will be sum up in
  two nodes)

RFD
36
System Configuration
---Synchronization by a node--
-Expand the Range
Wireless/Wired Network
Monitor Terminal
Anchor Node 2
Server Data Base
Anchor Node 3
For Sync.
Node
System Configuration for 2D location measurements
Anchor Node 1
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TDOA Based Measuring
---Synchronization by a node--
Signal from a node whose position is known
Signal from a node for location
Anchor 1
Anchors are not synchronized
Anchor 2
time
Anchor 1
Temporary synchronization
Anchor 2
time
Reference time
Anchor 1
Measure the time difference of arrival
Anchor 2
time
The Location is calculated by the Time
Difference those
38
Receiver Architecture

• Count the time difference of arrival by the
  Counter
• The Counter and Memory are the additional
  circuits to the Rx
• (Gate size About 1kgates)

Receiver
Detection
Demod.
Sync.
Timing Counter
Counter
Memory
39
Parameters for Simulations
ADC 32Msps
Counter clock 1GHz
Packet Format same packet as data transmission
Crystal Accuracy 0ppm (ideal)
Number of trial 100 for each distance
Channel Model Indoor Residential LOS (CM1)
40
Simulation Results
Channel Model Indoor Residential LOS (CM1)
Frequency Stability 0ppm
41
Summary

• DS-UWB IR is Simple, Scalable and Reliable
• 258kbps at 30m (Nominal), 10.7Mbps at 10m
  (Optional)
• Location Awareness
• 40cm in 40m region (CM1)
• In a regular packet transmission, with one
  additional counter.
• Proposed DS-UWB IR
• - fc4.1GHz, BW1.4GHz at Low Band (3.1-5.1GHz)
• - 2.5ns Gaussian Pulse with PRF of 32MHz
• - DBPSK Modulation
• - TDOA for Location Awareness

42
Conclusion
Hitachi DS-UWB System
- Scalable data rate up to 10.7Mbps at 10m - High
Location Accuracy of 40cm in 40m range are the
main differentiation from the 15.4 system

• Still have evaluations to do
• Can show the feasibility in March
• by the Test Bed and TEG chip