Fare clic per modificare
Memoslo stile del titolo
 Filename may not ends with a numeric, as it may cause some
problem with some mail readers which put numbers
automatically to attached files. So the file is named as
R2nd R3rd, R4th etc.
 Omit to use bright red on white background, as it is too
strong. In addition, there are many people who can not see
pure-red (red-blindness is the most popular color-blindness)
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
1
Università degli Studi di Udine
Nagoya University
Wireless and Power Line Communications Lab
EcoTopia Science Institute
Tutorial at IEEEE SmartGridComm 2011
October 17, 2011
Power Line Communications for the Smart Grid
Andrea M. Tonello and Masaaki Katayama
Wireless and Power Line Communications Lab
University of Udine, Italy
EcoTopia Science Institute
Nagoya University, Japan
[email protected]
www.diegm.uniud.it/tonello
[email protected]
www.katayama.nuee.nagoya-u.ac.jp
2
Self-introductions of the Speakers
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
3
Fare clic perMasaaki
modificare
lo stile del titolo
Katayama

Short Bio

– Born in Kyoto Japan, in 1959.
– B.S., M.S., and Ph.D. from Osaka Univ. Japan
in 1981, 1983, 1986.
– Assistant Professor at
Toyohashi University of Technology from 1986 to 1989
– Lecturer at Osaka University from 1989 to 1992
– Associate Professor at Nagoya University from 1992
– Professor at Nagoya University from 2001
Member Ship
– Fellow of IEICE and Senior Member of IEEE
PLC Activity
– Presentations in ISPLC since 1998 (the 2nd ISPLC)
– Organizer of ISPLC2003
– Steering Committee Member for multiple ISPLCs
– GC’09 Selected Areas in Communications co-chair
– TPC Chair of ISPLC2012, Beijing China

PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
4
Fare clic per Nagoya
modificare
lo stile del titolo
Univ.


Established in 1939
as the last (the 9th, after Seoul, Taipei, and Osaka)
Imperial University of Japan
Scale (as of May 1, 2009)
 Staffs :
3, 204
 Undergraduate Students: 9, 640
 Graduate Students:
6, 049
 Revenues :
94, 370, 000, 000 yen
 Expenditure :
92, 912, 000, 000 yen
 Ground Area:
3, 247, 424 m2
 Building Area
750, 344 m2
 Nobel Prize Laureates: 4
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
5
Fare clic perKatayama
modificare Lab.
lo stile del titolo
◆Staffs
Masaaki Katayama, Prof.
Takaya Yamazato, Prof.
Kentaro Kobayashi, Assist. Prof.
Yoshihiko Kito,
Technician
Aiko Ishikawa,
Secretary
Eriko Shiraishi
Secretary
◆Students
Ph.D. Candidates： 2
M.S. Course
: 13
Undergraduates
: 8
EcoTopia Science Institute
Research Institute Established in 2004.
Aim: Scientific studies for the realization of
an environmentally harmonized sustainable society
Faculties: about 60.
Katayama Lab. belongs to EcoTopia Science Institute
EECS( Dept. of Electrical and Electronic Engineering and
Computer Sciences)
Katayama Lab. also belongs to EECS.
Students of the lab. belong to EECS.
we are here
The Only One Lab.
for Wireless Communications
in Nagoya Univ.
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
6
Fare clicResearch
per modificare
stile Lab.
del titolo
Projects lo
of Katayama
Electric Energy EcoTopia Project
Large-Scale Real-Time Data Gathering and Control, Collaborations with other fields
Intelligent Transportation Systems [ITS]
Modulation/Coding, Access Methods, Position Estimation
Wireless Wire (Reliable Robust Radio)
Wireless Control of Industrial Machines, Drive by Wireless, Radio Control of Robots
Visible Light Communications
[LED-Traffic Light Communication, Information Light House for Visually Handicapped]
Modulation/Coding, Non-Gaussian Non-Stationary Noise
Sensor Networks
Cooperative Communications, Low-Power Consumptions,
Energy Harvesting, Wireless Energy Transmission
Power Line Communications
–
Adaptive Modulation/Coding/Demodulation, Smart Grid as an application of PLC
Reconfigurable Radio Systems
–
Cognitive Radio (Dynamic Spectrum Assignment, Piggy Back Modulation), System Architecture
New Generation Satellite Communications
–
High Speed Satellite Communications, Multi-Satellite Routing, Reconfigurable Satellite,
Satellite/Terrestrial Combined Network
Next Generation Mobile Communications
–
Advanced Modulation/Coding, Super-Speed Access, Heterogeneous Networks
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
7
Fare clic per modificare
lo stile del titolo
Andrea Tonello
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
8
Fare clic per modificare
Contents lo
1 stile del titolo
 Self-introductions of the Speakers
 Acitivities of TC-PLC of IEEE [A]
 Power line communications and Smart Grid communications [M]
 Application scenarios of PLC
 PLC Operating Frequecies
 Communications in Smart Grid and roles of PLC
 Channel characteristics and modeling [A]
 Main channel features in in-home and outdoor scenarios
 Results from measurements
 Top-down and bottom-up modeling
 Some results on MIMO channel modeling and open issues
 Noise characteristics and modeling [M]
 Main noise sources, In-home and outdoor noise sources
 Noise modeling
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
9
Fare clic per modificare
Contents lo
2 stile del titolo
 Physical layer techniques [A]
 CDMA, Single carrier (FSK) modulation and UWB
 Filter bank modulation (OFDM, Pulse shaped OFDM, FMT, Wavelet OFDM)
 Resource allocation and scalability
 UWB and narrow band OFDM
 Optimum Design of PLC Modem [M]
 Medium Access Control and Cooperation Teqniques [A]
 MAC in broadband systems
 MAC in narrowband systems
 Relay techniques for range extension
 Cooperation with flooding for large scale networks
 Protocols for sensing and control in the SG [M]
 Standardization [A]
 Coexistence and interoperability
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
10
Activities of TC-PLC of IEEE
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
11
Fare clic per modificare lo stile del titolo
 To be done...
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
12
Power line communications
and
Smart Grid communications
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
13
Fare clic per
PLCmodificare
Operatinglo
Bands
stile del titolo
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
14
Fare PLC:
clic per
notmodificare
a simple wireless
lo stile
system
del titolo
 Super "Ultra Wide Band (UWB)" Signal
– 2MHz～30MHz (λ＝10m～150m)
→ bandwidth／center frequency ≒175%!
– 10kHz～450kHz (λ＝700m ～ 30km)
→ bandwidth／center frequency ≒200%!
 Propagation
– Topology dependent propagation loss
(not a simple distance based model)
– Resonance and Absorbance
(multi-path is not a single cause of frequency selectivity)
– Time variant multi-path environment: often cyclostationary
(in mobile radio scenario,
this means construction/demolishment of buildings in 100-120 times a second)
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
15
Fare clic per
Application
modificare
Scenarios
lo stile del titolo
 Outdoor internet access
from: http://www.powerlinenetworking.co.uk
 In-Home
 Smart-grid
from advance 05
 In-Vehicle
Integrazione di ICE-PLiCOM nel
Dispositivo di Ricarica
from OMEGA 08
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
16
Fare
Outdoor
clic per
– Broad
modificare
Band Internet
lo stile del
Access
titolo
 It enables customer premises to
access the Internet through the
existing electrical infrastructure
from PLC book - Wiley
 Services
– High Speed Internet connection, video on demand, voice over IP, …
 Technology
– PHY layer: usually based on multicarrier modulation (OFDM)
– MAC: CSMA and/or TDMA depending on the vendor
 Deployments
– Italy, Austria, Germany, Spain,USA, …. under development countries
– Market suffers of highly penetrated xDSL services
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
17
Fare clic per
In-home
modificare
Networking
lo stile del titolo
 In-Home high speed services delivered
through the home gateway
– Home office networking, video conferences, …
– IPTV, 3D games, video streaming
 Integration of different technologies: PLC, Wireless (WiFi), UWB,
visible light communications, …
– This objective can be realized with the use of the Inter-MAC layer
developed in the FP7 Omega (home gigabit networks) project
– PLC can provide a high speed backbone
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
18
Fare clic per modificare
In-vehicle PLC
lo stile del titolo

In-vehicle communications via DC/AC power lines:
– Alternative or redundant communication channel (e.g., to CAN bus)
– Command and control of devices and sensors
– Multimedia services distribution (music, video, games, etc.)
 Benefits
– Weight reduction
– Lower the costs
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
19
Fare clic per modificare
Smart Grid
lo stile del titolo
distribution
generation
transmission
 A Smart Grid is composed by several domains
– Generation, Transmission, Distribution, Customer
 Intelligent and dynamic grid with
– Distributed generation and storage options
– Active participation by customers
 The Smart Grid elements of each domain are
interconnected through two-way communication
customer
From: http://smartgrid.ieee.org
Convergence of TLC and Electrical Networks
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
20
Fare clicSmart
per modificare
Grid Technologies
lo stile del titolo
 Supervisory control and data acquisition (SCADA)
 Smart meters
– Control and manage the flow of electricity to/from the customers
and provides information about energy usage and patterns
– Record actual consumption, update prices, etc.
 The smart grid has to provide access points for battery charging
– New opportunities will arise for delivering communication services
via the exploitation of the e-spots
 Technologies
– Convergence of PLC, wireless and wireline technologies
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
21
FareCommunications
clic per modificare
forloSmart
stile del
Grid
titolo
Basic Requirement
– Information Gathering: Sensor Network
– Equipment Control : Tele-Control
Special Features
– Scale
• Lager than conventional senor/control netowrks
– Security
• Information is highly private
• Robustness against natural desastesr is required
• Robustness against intentional atacks is requires
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
22
Channel Characterization and Modeling
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
23
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Couplinglo stile del titolo
 Coupling is necessary to remove the 50/60 Hz power signal
 Capacitive coupling is often used especially in LV
 Size is an issue of used in MV lines
 Inductive coupling simplifies installation which is good in
MV/HV lines. It has however, lower pass behavior
Inductive coupling in MV lines, courtesy of RSE
PLC for the Smart Grid – IEEE SmartGridComm 2011
Capacitive coupling in MV lines, courtesy of RSE
A. Tonello, M. Katayama
24
Fare clic Channel
per modificare
Characteristics
lo stile del titolo
 The channel exhibits
– Multipath propagation due to discontinuites and unmatched
loads
– Frequency Selective Fading
– Cyclic time variations due to periodic change of the loads with the
mains frequency
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
25
Fare
In-Home
clic perChannel
modificare
Characterization
lo stile del titolo
 Real – life residential sites
– Italian in-home scenario
 200 kHz – 100 MHz
 More than 660 links
– Channel frequency response
– Input impedance
 Static and time variant
channel acquisitions
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
26
Fare clic per
Path
modificare
Loss and lo
Phase
stile del titolo
Path Loss
Phase
20
50
0
0
Phase (rad)
Path Loss (dB)
-20
-40
-60
-50
-100
-80
-150
-100
-120
0

20
40
60
Frequency (MHz)
80
frequency-decreasing in average
PLC for the Smart Grid – IEEE SmartGridComm 2011
100
-200
0


20
40
60
Frequency (MHz)
80
100
The phase is not uniformly distributed
The average phase is not linear at low
frequencies
A. Tonello, M. Katayama
27
Fare clic
Relations
per modificare
between
lo Metrics
stile del titolo
 We study the relation between the coherence bandwidth, the
average channel gain, and the delay spread of the measured
channels
Measured
outliers
3000
Samples
Robust fit
2500
Coherence Bandwidth (kHz)
RMS-Delay Spread (s)
1
0.8
0.6
0.4
0.2
0
-60
2000
Samples
Best fit
1500
1000
500
-50
-40
-30
-20
-10
Average Channel Gain (dB)
PLC for the Smart Grid – IEEE SmartGridComm 2011
0
10
0
0
0.5
1
1.5
2
2.5
3
RMS Delay Spread (s)
3.5
4
4.5
A. Tonello, M. Katayama
28
Top-down channel modeling
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
29
Fare Top-Down
clic per modificare
Statistical
lo Modeling
stile del titolo
 The channel transfer function can be determinitically modeled
according to the Multipath Propagation Model (MPM) in the FD
Np
H  f   A pi  f   e


 a0  a1 f K di
 e  j 2 fdi 
i 1
Propagation phase shift
Cable attenuation
Reflection effects
 IDEA: introduce the variability into the model
N p : Poisson random variable with intensity L
max
pi  f  : log-normal frequency-dependent r.v. with a random sign flip
di : Erlang random variable
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
30
Fare clic per modificare
Path Gains
lo stile del titolo
 In some channels, the attenuation does not strictly increase as a
function of the frequency
– It can be traced back to the coupling effects between wires
without electrical continuity (e.g., cross-phase channels)
[5]
 We include this effect in the path gains
as
follows
0
pi  f   gi  ci f
-10
K2
-20
gi : log-normal random variable with
a random sign flip
ci : log-normal random variable with
a random sign flip
K 2 : constant
PLC for the Smart Grid – IEEE SmartGridComm 2011
Path Loss (dB)
-30
-40
-50
-60
-70
-80
-90
-100
0
20
40
60
Frequency (MHz)
80
A. Tonello, M. Katayama
100
31
Fare clic
Fitting
per modificare
the Top-Down
lo stile
Model
del titolo
 The MPM can be fitted to the experimental measures
– It requires the knowledge of the average path loss profile and the RMS delay
spread of the measured channels
 Example: fit the model to the results of a measurement campaign reported in
Omega and the literature [6]
Percentage
No. of
(%)
channels
 Use a finite set of class of parameters
Class 1
3.49
5
 Provide a certain probability to each class
0
Class 9
-10
Class 2
16.78
24
Class 3
18.18
27
Class 4
11.88
17
Class 5
11.88
17
Class 6
12.58
18
Class 7
9.79
14
Class 8
7.69
11
Class 9
7.69
11
Path Loss (dB)
-20
-30
-40
144
measures
-50
-60
-70
-80
0
Target Path Loss
20
Class 1
40
60
Frequency (MHz)
80
PLC for the Smart Grid – IEEE SmartGridComm 2011
100
A. Tonello, M. Katayama
32
Fare clic per
Average
modificare
Channel
lo stile
Gaindel titolo
 We define the Average Channel Gain as
N2
 1

*
G  10log10 
H  if  H  if  

 N 2  N1 i  N1

 Figure to be added
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
33
Fare clic perRMS
modificare
Delay Spread
lo stile del titolo
 We define the Root Mean Square Delay Spread as
 
N 1
  iTc 
i 0
2
2
 N 1

2
P  i     iTc P  i   , P  i   h  iTc 
 i 0

N 1
 h  iTc 
2
i 0
 Figure to be added
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
34
Fare clic per
Coherence
modificare
Bandwidth
lo stile del titolo
 We define the Coherence Bandwidth as [5]
Bc  l f
s.t.
N2
R  l f    R  0 
R  k f    f H  if  H *  if  k f

i  N1
 Figure to be added
 Higher probability to
find low coherence
bandwidths for the
generated channels
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
35
Bottom-up channel modeling
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
36
In-Home
Fare clic :per
Bottom-Up
modificare
Statistical
lo stile del
Modeling
titolo
 Random topology generation
– Regular structure: the area can be divided in
clusters (typically one room/cluster)
– Each cluster has a derivation box
– National practices and norms can also be
implemented (e.g., UK ring topology)
 Applying Trasmission Line theory we
can compute the CTF among any pair
of outlets for a topology realization
– Efficient method based on voltage ratio
approach has been developed
: outlets
: derivation boxes
PLC for the Smart Grid – IEEE SmartGridComm 2011
Ref: Tonello, Versolatto, IEEE Tr. Power Del. 2010
A. Tonello, M. Katayama
37
Fare clic per
TL Theory
modificare
Application
lo stile del titolo
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
38
In-Home
Fare clic
: Some
per modificare
Channel Statistics
lo stile del
(B=30
titolo
MHz)
Cumulative Distribution Function of RMS Delay Spread
Quantile-Quantile Plots of Average Channel Gain
0.8
CDF
0.6
0.4
Af = 100 m2
0.2
Af = 200 m2
dB Average Channel Gain quantiles
1
0
-20
-40
-60
-80
Af = 100 m2
Af = 200 m2
-100
Af = 300 m2
0
0.2
0.4
0.6
0.8
RMS Delay Spread (s)
1
1.2
Af = 300 m2
-3
-2
-1
0
1
Standard Normal Quantiles
2
3
B
 The delay spread and average channel gain G = 1/ B ò | H (f ) |2 df
0
are approximately log-normal, (mean: 0.1/0.3 µs, and -25/-50 dB).
 The bottom-up approach allows the connection to physical reality
(topology, distance, time variant loads …). But more complex.
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
39
Fare clic per
Outdoor
modificare
LV Topology
lo stile del titolo
from PLC Wiley
 Low Voltage (230/400 V)
3-phase distribution system
divided in supply cells
 Each supply cell is connected to
a single MV/LV transformer
station and it serves up to 300
households via branches (30
households/branch)
 A branch typically extends to a
maximal length of 1 km
 In-depth Investigation provided by Open PLC European
Research Alliance (OPERA)
Ref: PLC Book – Wiley 2010
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
40
Fare
Outdoor
clic per
LVmodificare
vs. In-Home
lo PLC
stileChannel
del titolo
 Comparison between an OPERA reference channel and
a typical In-Home channel
0
 In-Home channels have high
frequency selectivity and
low attenuation
-20
-40
Path Loss (dB)
-60
– Very high number of branches,
discontinuities and unmatched
loads
– Short cables
150 m
-80
-100
-120
In-Home
Outdoor LV
-140
250 m
350 m
-160
-180
-200
0
10
30
20
frequency (MHz)
40
50
 Outdoor LV channels have
high attenuation but
negligible fading
– Cable attenuation dominates
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
41
Fare clic per
Outdoor
modificare
MV Channel
lo stile del titolo
 MV channels exhibit in general (but not always!) lower
attenuation than Outdoor LV PLC
– Further investigations have to be done
 The multipath model can be specialized for overhead
cables (effect of high-loss earth)
 Coupling effects have also to be considered
– Inductive / Capacitive coupling
– RESULTS FROM MEASUREMENTS to BE ADDED
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
42
MIMO
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
43
An
Fare
Approach
clic per modificare
to MIMO Channel
lo stile del
Modeling
titolo
 To be added
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
44
Noise Characterization and Modeling
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
45
Main noise sources,
In-home and outdoor noise sources
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
46
FareNoise
clic per
Generated
modificare
by Typical
lo stile del
Loads
titolo
 To be added recent results fn a measurement campaign in
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
47
Noise Characteristics
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
48
Fare clic PLC
per Noise
modificare
Classification
lo stile del titolo
 Stationary Noise
– Colored Background Noise
– Narrowband Noise
 Unstationary Noise
– Periodic Impulsive Noise
– Aperiodic Impulsive Noise
Ref: Zimmermann, Dostert, ISPLC 2000
Esmalian, Kschischang, Gulak, IJCS 03
PLC Book – Wiley 2010
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
49
Narrow-band
Fare clic
Characteristics
per modificare
of lo
PLC
stile
noise
del titolo
 Peculiar characteristics of power-line noise
– mainly caused by appliances
• non-stationary
• non-white
– Statistic Feature of PLC noise
– Simple, Tractable, and Accurate
Mathematical Model
PLC for the Smart Grid – IEEE SmartGridComm 2011
Narrow Band
(10Hz - 450kHz)
A. Tonello, M. Katayama
50
Fare Background
clic per modificare
Noise Comparison
lo stile del titolo
Noise PSD Comparison
-60
Outdoor MV
Outdoor LV
In-Home
-70
PSD (dBm/Hz)
-80
-90
-100
-110
-120
-130
 MV PLCs experience the
highest level of noise
(approximately 20/30 dB
higher than In-Home)
 Overhead MV background
noise due to corona
discharges
-140
– The strong electric fields
-150
determine the avalanche
0
10
20
30
40
50
frequency (MHz)
generation of free charges in the
 Background noise has an exponential PSD
sorrounding air, which in turn
induce current pulses in the
 Narrowband interference exhist
conductors
– FM disturbances (> 87.5 MHz)
–
–
AM (< 1.6 MHz)
Radio amateur (up to 30 MHz)
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
51
Wide-band
Noise
Fare clic per modificare lo stile del titolo
in time-frequency plane
・Non-white: concentrated in lower
frequency band.
・Cyclic change synchronous with a
period TAC/2.
TAC
TAC
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
52
Modeling of NB PLC Noise
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
53
Fare clicMeasurement
per modificare System
lo stile del titolo
Reference @300kHz
<1.9MHz
10 M
samples/s
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
54
Pick-up circuit
 Fare clic per modificare stili del testo dello schema
– Secondo livello
• Terzo livello
– Quarto livello
» Quinto livello
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
55
Fare clic per
modificare Noise
lo stile del titolo
Normalized
Noise-to-Signal Ratio
 ( iTS ) 
Instantaneous Noise Lev el at iTS
Av arage Ref erence Signal Lev el (  TS  sec.)
  400 [samples]
  40 [ s]
Normalized Noise-to-Signal Ratio
 ( iTS )
 ( iTS ) 
 2 ( iTS )

Instantaneous Noise Level


Normalized by Reference Signal Level
with unit power
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
56
FareTypical
clic perNB-PLC
modificare
NoiseloWaveform
stile del titolo
 (iTS )
ＴＡＣ：a cycle duration of the AC voltage (1/60 [s])
Noise characteristics change synchronous with a period TAC/2.
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
57
Fare clic per
CDFmodificare
of PLC Noise
lo stile
(1) del titolo
 If noise is measured at random timings,
PLC Noise is Impulsive:
– Higher Probability
for Low-level noise
and High-level noise
– Lower Probability
for Medium-level noise

than Gaussian Noise
Non-Gaussian: if samples taken randomly
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
58
Fare clic per
CDFmodificare
of PLC Noise
lo stile
(2) del titolo
 PLC Noise is Gaussian
– if sampled
synchronously with
mains AC
 If Gaussian
– only (time-dependent)
variance (instantaneous power)
 2 (iTS )  E[ 2 (iTS )]
is necessary.
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
59
Variance (Instantaneous Power)
Fare clic per modificare lo stile del titolo
as a cyclic function
Noise Waveform
 (iTS )
PLC for the Smart Grid – IEEE SmartGridComm 2011
Cyclic Averaged Noise Power
1 2 m1 2
 (iTS ) 
 (iTS  jT C)

2m j  0
2
m
A. Tonello, M. Katayama
60
Noise
Power
FareInstantaneous
clic per modificare
lo stile
del titolo
Assumption: Cyclic-Stationary Process
 Instantaneous Normalized Noise Power
– Requires ensemble average
 2 (iTS )  E[ 2 (iTS )]
 If Noise is Cyclic-Stationary Process
– Cyclic-Average of m/2 cycles of AC
2 m 1
1
2
 m2 (iTS ) 

(iTS  jT C)

2m j  0
 2 (iTS )  lim  m2 (iTS )
m
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
61
Approximation of
Fare clic
per modificare lo stile del titolo
Instantaneous Power of PLC Noise
Approximated Instantaneous
2
Power of PLC Noise ˆ (t )
Cyclic Averaged Instantaneous
2
Power of PLC Noise  m (iTS )
L3
L 1
ˆ (t )   Al sin(t
2
l 0
TC  l )
PLC for the Smart Grid – IEEE SmartGridComm 2011
nl
l
0
Al
0.23
1
2
l

nl
0
1.38
6
1.91
7.17
 35
1.57 105
[deg]
A. Tonello, M. Katayama
62
Convergence
of the Derived
Parameters
Fare
clic per modificare
lo stile
del titolo
0
10
20
30
40
about 40-50 cycles (1 second)
is enough
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
63
Power
Density of
Fare
clicSpectrum
per modificare
loNB-PLC
stile delNoise
titolo
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
64
Approximation
of Power Spectrum
Density
Fare
clic per modificare
lo stile del
titolo

Noise Power for a given
time-frequency
 2 (t ,
f )   2 (t ) ( f )
 Linear Approximation of
PSD in dB
ln  ( f )  af  C
for  f
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
65
Fare
Computer
clic per modificare
Simulated NB-PLC
lo stile del
Noise
titolo
L  3 a  1.2 10 5
l
0
1
2
PLC for the Smart Grid – IEEE SmartGridComm 2011
Al
0.23
1.38
7.17
l
[deg]

6
 35
nl
0
1.91
1.57 105
A. Tonello, M. Katayama
66
Fare clic
per modificare
lo stile del titolo
Robustness
of Parameters
Measured
Simulated
Parameters ? Parameters
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
67
Fare clic per modificare
Summarylo stile del titolo
Narrow-band
 Approximations
– Cyclostationary Gaussian
– Linear Function for PSD in dB
 Simple Mathematical Representation of
Narrow-Band PLC noise
– 8-parameters
– Necessary Observation: about 1second
 Benefits
– Benchmark for Design/Evaluation of PLC Systems
– Better Understandings of PLC Noise
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
68
Correlations of Noise Waveforms
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
69
Fare clic per modificare
PLC Noiselo stile del titolo
 Noise Source
– Wireless Systems: thermal noise at receiver amplifiers.
– PLC Systems:
machine-made noise by electric appliances.
• Interference from electric appliances, rather than simple noise
• Estimation, Adaptation, and Cancellation are possible.
 Features
– Non-Gaussian (less entropy)
– Non-White (Frequency Dependent)
– Non-Stationary (Time Dependent)
– Noise waveforms at different frequencies,
at different time-slots, and
at different locations
may have correlations.
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
70
Wide-band
Noise
Fare clic per modificare lo stile del titolo
in time-frequency plane
・Non-white: concentrated in lower
frequency band.
・Cyclic change synchronous with a
period TAC/2.
TAC
TAC
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
71
Instantaneous Power of Band-Limited Noise
Fare clicat per
modificare lo stile del titolo
different frequency sub-bands.
Measured at 22:00 on Nov. 25 2002.
(3.197MHz,54kHz)
(3.305MHz,54kHz)
•Cyclo-Stationary with a period TAC/2.
•Instantaneous noise power in different frequency looks alike.
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
72
Farenon-white/non-stationary
clic per modificare lo stileNoise
del titolo

Estimation of noise statistics is possible


by cyclic features
by the observation
at vacant frequency/time slots.
TAC
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
73
of noiselowaveforms
FareRelationship
clic per modificare
stile del titolo
 Noise waveforms at different outlets
mainly caused by the same electrical appliances
Noise waveforms may have correlations
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
74
Measures
of the
correlation
characteristics
Fare clic per
modificare
lo stile
del titolo
 Tree types of correlation coefficients
1.instantaneous noise voltages
2.instantaneous noise powers
3.cyclic-averaged noise powers
Correlation coefficients
 ( X  X )  (Y  Y )
 ( X  X )   (Y  Y )
2
PLC for the Smart Grid – IEEE SmartGridComm 2011
2
A. Tonello, M. Katayama
75
Noise voltage
Noise voltage
1. Correlations coefficients
Fare clic of
per
modificare
lo
stile
del
titolo
instantaneous voltages
t
t
Noise sampled @outlet B:n [i ]
2
Noise sampled @outlet A: n1[i ]
T /  1

 (n [i ]  n [i ])  (n [i ]  n [i ])
i 0
T /  1
1
1
 (n1[i ]  n1[i ]) 2 
i 0
2
2
T /  1
 (n [i ]  n [i ])
i 0
1
2
1
Sampling interval of ADC: 
Measured samples :
T /
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
76
tt
At outlet A:
n1[i ]
At outlet B:
square
t
T /  1
 power 
t
 (n [i ]
1
i 0
T /  1
 (n [i ]
i 0
1
PLC for the Smart Grid – IEEE SmartGridComm 2011
2
2
n2 [i ]
square
Instantaneous
noise power
Instantaneous
noise power
Noise voltage
Noise voltage
2. Correlations coefficients
Fare clic per modificare lo stile del titolo
of instantaneous noise powers
t
 n1[i ]2 )  (n2  n2 [i ]2 )
 n1[i ]2 ) 2 
2
T /  1
 (n [i ]
i 0
2
2
 n2 [i ]2 ) 2 ) 2
A. Tonello, M. Katayama
77
3. Correlations coefficients
Fare clic
per
modificare
lo
stile
del
titolo
of cyclic-averaged noise powers
cyclic-averaged
noise power
t
( )2
 1 [i ]
2
2 T / TAC 1
~ 

i 0
2 T / TAC 1

i 0
PLC for the Smart Grid – IEEE SmartGridComm 2011
t
 2 2 [i ]
( 1 [i ]   1 [i ] )  ( 2 [i ]   2 [i ] )
2
2
( 1 [i ]   1 [i ] ) 2 
2
TAC/2
cyclic-averaged
powers
a half of
a mains
AC cycle
cyclic-averaged
powers
TAC/2
average
 2 (t )
2
2
2 T / TAC 1

i 0
2
( 2 [i ]   2 [i ] ) 2
2
2
A. Tonello, M. Katayama
78
Benefits
of noise correlations
Fare clic
per modificare
lo stile del titolo
If noise at different outlets have correlations
 Noise at each receiver has correlations,
 Noise at a transmitter has correlations to that at each
receiver.
 Transmitter can
have knowledge of the noise at the receivers,
transmit data with
modulation/coding adaptive to the noise at the receivers.
If Transmitter know the Correlations in
instantaneous noise voltages
instantaneous noise powers
cyclic-averaged noise powers
PLC for the Smart Grid – IEEE SmartGridComm 2011
noise waveforms
time varying SNR
SNR as a periodic function
A. Tonello, M. Katayama
79
Noise voltage
Scattering diagram
Fare clic per modificare lo stile del titolo
of the instantaneous noise voltages
t
Noise voltage
t
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
80
Measurement system
 Fare clic per modificare stili del testo dello schema
– Secondo livello
A • Terzo livello
pickup
– Quarto livello
» Quinto livello
T=1[s]
B
pickup
UPS: Uninterruptible Power Supply
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
81
Typical cable structure in Japan
 Fare clic per modificare stili del testo dello schema
– Secondo livello
to outlet
• Terzo livello
– Quarto livello
» Quinto livello

to outlet
Three-wire single-phase
AC frequency: 60Hz
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
82
Measurement locations
 Fare clic per modificare stili del testo dello schema
– Secondo livello
• Terzo livello
– Quarto livello
» Quinto livello
Cases
outlet pair
I
II
PLC for the Smart Grid – IEEE SmartGridComm 2011
Outlets
open
A. Tonello, M. Katayama
83
Noise at Outlet-1
Noise at Outlet-3
Noise voltage
at Outlet-3 [mV]
Case
Fare Iclic
(same
per mains
modificare
phaselo/stile
open
del
outlets)
titolo
Correlation coefficients
Noise voltage
at Outlet-1 [mV]
  86%
High

power

77
%
instantaneous noise powers:
correlations
~
cyclic-averaged noise powers :   98%
instantaneous noise voltages:
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
84
Noise at Outlet-1
Noise at Outlet-2
Correlation coefficients
Noise voltage
at Outlet-2 [mV]
Case
(different
mains phase
/ open
Fare IIclic
per modificare
lo stile
del outlets
titolo )
Noise voltage
at Outlet-1 [mV]
Low


0
.
68
%
instantaneous noise voltages:
correlation
instantaneous noise powers:
cyclic-averaged noise powers :
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
85
Fare
clic per modificare
lo stile/ open
del titolo
Case
II (different
mains phase
outlets)
Noise at Outlet-1
Noise at Outlet-2
cyclic-averaged noise
powers at Outlet-1
cyclic-averaged noise
powers at Outlet-2
Correlation coefficients
  0.68%
instantaneous noise voltages:
instantaneous noise powers:  power  24%
~
cyclic-averaged noise powers :   97%
PLC for the Smart Grid – IEEE SmartGridComm 2011
High
correlation
A. Tonello, M. Katayama
86
Noise voltage
at Outlet-2 [mV]
Noise at Outlet-1
with
Noise voltage
at Outlet-3 [mV]
Cases
III &
IV modificare
(vacuum cleaner
Outlet-1)
Fare clic
per
lo stileatdel
titolo
as a strong noise source
Correlation coefficients
Noise voltage
at Outlet-1 [mV]
Noise voltage
at Outlet-1 [mV]
Case III
Case IV
same mains phase different mains phase
instantaneous noise voltages:
  48%
  1.3%
instantaneous noise powers:


cyclic-averaged noise powers :
~  69%

PLC for the Smart Grid – IEEE SmartGridComm 2011
power
 24%
power
 8.7%
~  78%

A. Tonello, M. Katayama
87
Physical Layer
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
88
Fare clicSingle
per modificare
Carrier Modulation
lo stile del titolo
 Code division multiple access has been investigated
 Frequency shift keying (FSK) has been implemented in NB
modems
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
89
FareUnified
clic perView
modificare
of MC lo
Modulation
stile del titolo
 b(k)(mN):
QAM data symbols
 g(k)(n):
sub-channel pulses, obtained from the modulation
of a prototype pulse
 N:
interpolation factor N ≥ M number of sub-channels
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
90
Fare clicCyclically
per modificare
Prefixed
lo OFDM
stile del titolo
 M tones (sub-channels)
 Rectangular sub-channel pulse (window) of duration N > M samples
 Cyclic prefix (CP) of length µ=N-M samples (typically longer than the channel
duration)
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
91
Fare clic per modificare
Notchinglo stile del titolo

It is fundamental to generate low radiations in certain parts of
the spectrum, e.g., Radio amateur signals

Further notching can be done beyond 30 MHz to grant
coexistence with other systems
Notching Mask
PSD [dBm/Hz]
-40
-50
-60
- 80 dBm/Hz
FM
-70
-80
917 tones out of 1536
-90
0
10
20
30
PLC for the Smart Grid – IEEE SmartGridComm 2011
40
50
f [MHz]
60
70
80
90
100
A. Tonello, M. Katayama
92
Fare clic per modificare lo stile del titolo

It is fundamental to generate low radiations in certain parts of
the spectrum, e.g., Radio amateur signals

Further notching can be done beyond 30 MHz to grant
coexistence with other systems
Notching Mask
PSD [dBm/Hz]
-40
-50
-60
FM
-70
-80
917 tones out of 1536
-90
0
10
20
30
PLC for the Smart Grid – IEEE SmartGridComm 2011
40
50
f [MHz]
60
70
80
90
100
A. Tonello, M. Katayama
93
FareSpectrum
clic per modificare
of OFDM and
lo stile
PS-OFDM
del titolo
PS-OFDM
OFDM
Pulse Shaped OFDM - Spectra of three adjacent sub-channels
OFDM - Spectra of three adjacent sub-channels
0
0
-10
-10
-20
|G(f)| (dB)
-30
2
2
|G(f)| (dB)
-20
-40
-30
-40
-50
-50
-60
-60
-70
-70
-80
-4
-3
-2
-1
0
f  MT
1
2
3
4
-80
-4
-3
-2
-1
0
f  MT
1
2
3
4
 Use a root-raised-cosine window (or other), to fulfill the
mask with a higher number of active tones.
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
94
Fare clic per
Pulse
modificare
Shaped OFDM
lo stile del titolo
 It is a filter bank system with a prototype pulse equal to the window
 If no symbol overlapping exists, we obtain windowed OFDM
 It introduces a transmisison rate penalty. Overhead β=µ+α=N-M
 The transmission rate is
M
R= M =
N M + m+ a
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
95
Fare clic Filter
per modificare
Bank Approaches
lo stile del titolo
 Can we increase the sub-channel frequency selectivity ?
 Yes, by privileging the frequency confinement
 What schemes are available ?
 Wavelet OFDM (solution adopted by IEEE P1901)
 Filtered Multitone Modulation (FMT)
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
96
Fare clic per modificare
FMT Basics
lo stile del titolo
FMT - Spectra of three adjacent sub-channels
0
-10
2
|G(f)| (dB)
-20
-30
-40
-50
-60
-70
-80
-4
-3
-2
-1
0
f  MT
1
2
3
4
 Pulses obtained from modulation of a prototype pulse
 Root-raised-cosine
 Time/Frequency confined pulses
 Perfect reconctruction solutions provided that N > M
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
97
Fare clic per
Efficient
modificare
Realization
lo stile del titolo
Synthesis
 M point IDFT and Cyclic extension to M2  l.c.m.(M, N )  L1M  L2N
 Pulses: PP components of order N, i.e., g ( i ) (nN )  g(i  nN ) i  0,..., N  1
 Sample with period L2
Analysis
 Dual operations
 Complexity: M log2M + Lg,h (pulse length) operations/sample
Ref: Moret, Tonello, EURASIP JASP 2010
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
98
FareHow
clic per
to Increase
modificare
Performance
lo stile del ?titolo
 Increase bandwidth (up to 100 MHz)
 Use high order QAM (beyond 10 bits/symbol)
 Perform adaptation of the transmitter parameters to
the channel
 All respecting the stringent mask requirements !
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
99
What
Fare
Can
clic
We
per
Gain
modificare
with Increased
lo stile del
Bandwidth
titolo ?
1600
Channels Class 5
1400
OFDM, 100 MHz, -50 dBm/Hz
1000
600
400
40


41
42
OFDM,100 MHz, -80 dBm/Hz
-80
800
-50 dBm/Hz
Rate (Mbit/s)
1200
43
OFDM, 30 MHz, -50 dBm/Hz
44
45
46
channel realization
47
48
49
50
4096 Tones in 100 MHz, fixed CP=5.57 us, PSD noise -110 dBm/Hz
PSD signal: -50 dBm/Hz + HPAV notching 0-30 MHz, -50/-80 dBm/Hz 30-87.5 MHz
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
10
What
Fare
Can
clic
We
per
Gain
modificare
with Increased
lo stile del
Bandwidth
titolo ?
1600
Channels Class 5
1400
Capacity
margin
1000
OFDM, 100 MHz, -50 dBm/Hz
Capacity
800
margin
Rate (Mbit/s)
1200
600
OFDM,100 MHz, -80 dBm/Hz
Capacity
400
OFDM, 30 MHz, -50 dBm/Hz
40


41
42
43
44
45
46
channel realization
47
48
49
50
4096 Tones in 100 MHz, fixed CP=5.57 us, PSD noise -110 dBm/Hz
PSD signal: -50 dBm/Hz + HPAV notching 0-30 MHz, -50/-80 dBm/Hz 30-87.5 MHz
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
10
Fare clicAdaptive
per modificare
OFDM and
lo stile
FMT
del titolo

We can adapt the pulse shape and the overhead β = N-M such that
capacity is maximized
1
R (b ) =
(M + b )T
æ SINR(k ) (b )÷
ö
çç
÷
log2 ç1+
÷
å
÷
ç
G
÷
k Î KON
è
ø
[bit / s ]
channel response
 For example, in CP-OFDM we adapt the CP to the channel response
CP
CP
t
t
CP
t
Ref: Tonello, D’Alessandro, Lampe, IEEE TCOM 2010
Pecile, Tonello, IEEE ISPLC 2009
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
10
Example
Fare clic
of per
Performance:
modificareSystem
lo stile del
Parameters
titolo

Number of carriers: M={256,512,1024,2048,4096}

SNR Gap for Pe=10-2: G=3.4 dB

PSD of the transmitted signal: -50 dBm/Hz (in 0-100 MHz)

PSD of the Gaussian background noise: -140 dBm/Hz

Test channel response of class 5

Average SNR at the receiver: 44, 24 or 4 dB

Pulse-Shaped OFDM: Raised-cosine window

FMT: Truncated root-raised-cosine pulse

Single tap equalization

Fractionally spaced sub-channel equalization
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
10
Achievable
Fare clic per
Rate
modificare
as a Function
lo stile
of N.
deloftitolo
Tones
Masked
2-100
MHz
A:
MHz
Band,
B:Masked,
Masked,2-28
2-100
MHz
Band,
A: Masked, 2-100 MHz Band,
Average SNR=44 dB
Masked
2-28
MHz
B:
MHz
Band,
C:Masked,
Masked,2-28
2-100
MHz
Band,
AverageSNR=44
SNR=24dB
dB
Average
C: M
Average
SNR=4 dB
dB
Average
SNR=24
30
Target
1000
below
Pulse-ShapedOFDM
OFDM
Pulse-Shaped
FMTEqual.
Equal.1 1Tap
Tap
FMT
FMTFS
FSEqual.
Equal.2 2Taps
Taps
FMT
FMTFS
FSEqual.
Equal.10
10Taps
Taps
FMT
FMTFS
FSEqual.
Equal.20
20Taps
Taps
FMT
300
500
250
450
-70
-80
-90
0
10
400
200
800
700
20
25
30
40
50
f [MHz]
60
70
80
90
100
100
350
60
30
250
100
500
40
80
150
300
600
Achievable Rate [Mbit/s]
-60
Notching Mask
Achievable Rate [Mbit/s]
Achievable Rate [Mbit/s]
-50
60
140
120
50
Achievable Rate [Mbit/s]
Achievable Rate [Mbit/s]
PSD [dBm/Hz]
-40
Achievable Rate [Mbit/s]
900
160
Pulse-ShapedOFDM
OFDM
Pulse-Shaped
FMTEqual.
Equal.11Tap
Tap
FMT
FMTFS
FSEqual.
Equal.22Taps
Taps
FMT
FMTFS
FSEqual.
Equal.10
10Taps
Taps
FMT
FMTFS
FSEqual.
Equal.20
20Taps
Taps
FMT
10
0
PLC for the Smart Grid – IEEE SmartGridComm 2011
4096
4096
2048
2048
(OverallSystem
SystemCarriers)
Carriers)
MM(Overall
256
256
512
512
1024
1024
4096
2048
1024
256
512
M (Overall System Carriers)
0
(OverallSystem
SystemCarriers)
Carriers)
MM(Overall
4096
4096
50
150
20
2048
2048
300
10
5
256
256
512
512
1024
1024
400
15
40
20
200
20
A. Tonello, M. Katayama
M (O
256
512
1100
Pulse-Shaped OFDM
FMT Equal. 1 Tap
FMT FS Equal. 2 Taps
notching
mask
FMT FS Equal.
10 Taps
FMT
FS
Equal.
20 Taps
30 MHz: HPAV
10
Fare clic perFMT
modificare
vs. PS-OFDM
lo stile del titolo

The lower the SNR the higher is the advantage of FMT w.r.t. PS-OFDM

FMT has better notching capability

FMT achieves the maximum rate with a smaller number of tones

Achievable rate can be used as a design metric to choose properly the
number of carriers and the equalization method in the system


Adaptation of the parameters is beneficial
The achievable rate increases significantly using 100 MHz band
(depending, however, on the transmitted PSD beyond 30 MHz)
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
10
Other Modulation Schemes
PLC for the Smart Grid – IEEE SmartGridComm 2011
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10
Fare clic per modificare
I-UWB lo stile del titolo
 For low data rate: Impulsive UWB
PSD of Transmitted Signal and Noise
-80
T
cL -1
signal
(u,i)
frame format for user u and spreading code i
Tf
Tg
 Gaussian monocycle D=75 ns, Tf = 2 us,
R = 0.5 Mpulses/s.
 Symbol energy is spread in frequency by
the monocycle (frequency diversity)
 The monocycle is spread in time via a
binary code (time diversity)
 Coexistence with broadband systems is
possible
PLC for the Smart Grid – IEEE SmartGridComm 2011
-90
PSD (dBm/Hz)
c0(u,i)
-100
-110
noise
-120
-130
-140
0
20
40
60
frequency (MHz)
80
100
Ref: Tonello, EURASIP JASP 2007
A. Tonello, M. Katayama
10
Fare
Comparison
clic per modificare
of I-UWB with
lo stile
NB-OFDM
del titolo
 To be done based on SGComm paper
PLC for the Smart Grid – IEEE SmartGridComm 2011
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10
optimum design of PLC modem
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
10
Receiver using
Correlations of Noise
at Different Frequencies
PLC for the Smart Grid – IEEE SmartGridComm 2011
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11
Performance Improvement under
Fare clicnon-white/non-stationary
per modificare lo stile
del titolo
Noise

If noise statistics of each
frequency-time cell (at a receiver) are known



by a receiver → optimum reception .
by a transmitter → adaptive modulation/coding
Estimation of noise statistics is possible


by cyclic features
by the observation
at vacant frequency/time slots.
PLC for the Smart Grid – IEEE SmartGridComm 2011
TAC
A. Tonello, M. Katayama
11
Instantaneous Power of Band-Limited Noise
Fare clicat per
modificare lo stile del titolo
different frequency sub-bands.
Measured at 22:00 on Nov. 25 2002.
(3.197MHz,54kHz)
(3.305MHz,54kHz)
•Cyclo-Stationary with a period TAC/2.
•Instantaneous noise power in different frequency looks alike.
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
11
Farenon-white/non-stationary
clic per modificare lo stileNoise
del titolo

Estimation of noise statistics is possible


by cyclic features
by the observation
at vacant frequency/time slots.
TAC
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
11
Fare clic perSimple
modificare
Example
lo stile del titolo



OFDM: frame =TAC/2
Intentional vacant
sub-channels
FEC


Interleaver


Mapping of a coded bit
as far as possible in
time-frequency plane
FEC Decoder


Simple M repetition
Estimates of noise variance of each cells used for weighting.
Estimation of noise variance



cyclic average of the noise variance
at the vacant sub-channel
for K frames.
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
11
System parameters
Fare clic per
modificare lo stile del titolo
for the simple examples
The number of subcarriers
(communication band / outband)
The number of symbols in a frame
The number of frames
to estimate the noise
Code rate
2
(1/1)
450
1,5,
10,50
1/3
noise
Real measured power-line noise
•Environment A
•Environment B
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
11
Fare clic per modificare
Transmitter
lo stile del titolo
Repetition code
Code rate : 1/M
One frame = TAC/2
Mapping rule：
M code bits
each bit in a code word is
tried to be located as far as
possible in time-frequency
space
TAC/2
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
11
Fare clic per
Estimation
modificare
method
lo stile del titolo
Communication
band
Outband
.….
K frame
PLC for the Smart Grid – IEEE SmartGridComm 2011
The average of squared values
of these samples is used as the estimate
of the instantaneous noise power.
A. Tonello, M. Katayama
11
Fare clic per modificare
Receiverlo stile del titolo
1
1
PLC for the Smart Grid – IEEE SmartGridComm 2011
1
1
A. Tonello, M. Katayama
11
Fare
clicPerformance（Environment
per modificare lo stile del titolo
BER
A)
(99kHz,54kHz)
Instantaneous noise power
Correlation coefficient : 0.34
(45kHz,54kHz)
Cyclic-average noise power
Correlation coefficient : 0.75
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
11
Fare clic
BER
per
Performance
modificare lo
（Environment
stile del
B) titolo
(3.305MHz,54kHz)
Instantaneous noise power
Correlation coefficient : 0.99
(3.197MHz,54kHz)
Cyclic-average noise power
Correlation coefficient :0.99
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
12
Transmitter and Receiver using
Correlations of Noise
at the both ends of a PLC chanel
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
12
Relationship
of noiselo
waveforms
Fare clic
per modificare
stile del titolo
Noise waveforms at different outlet
– mainly caused by the same electrical appliances
– Noise waveforms may have correlations
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
12
data assignment
Fare clic Adaptive
per modificare
lo stile del titolo
Input
Data
Encoder
OFDM
Interleaver
Modulator
Noise Reference
at Rx
Power-line channel
Noise Reference
OFDM
Demodulator
PLC for the Smart Grid – IEEE SmartGridComm 2011
Deinterleaver
at Tx
Decoder
Output
Data
A. Tonello, M. Katayama
12
for numerical
examples
FareParameters
clic per modificare
lo stile
del titolo
Parameters
Number of Subcarriers
Symbols/Frame
Coding (Repetition) Rate
Freq. of the Lowest Subcarrier
Bandwidth
PLC for the Smart Grid – IEEE SmartGridComm 2011
4
450
1/3
250kHz
54kHz
A. Tonello, M. Katayama
12
FareBit
clic
per Rate
modificare
stile del titolo
Error
（High lo
Correlation）
周期的平均電力
相関係数：97％
ˆ 2 n,l   2 n,l
Tx
Rx
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
12
FareBit
clicError
per modificare
lo stile del titolo
Rate （Low Correlation）
周期的平均電力
相関係数：57％
ˆ 2 n,l   2 n,l
Tx
Rx
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
12
Medium Access Control and
Cooperation Techniques
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
12
Fare clic per MAC
modificare
in BB-PLC
lo stile del titolo
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
12
Fare clic per MAC
modificare
in NB-PLC
lo stile del titolo
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
12
Cooperative Algorithms
PLC for the Smart Grid – IEEE SmartGridComm 2011
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13
Fare clic perRelay
modificare
Techniques
lo stile del titolo
 To be done
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
13
Fare clic per modificare
Floodinglo stile del titolo
 To be done
PLC for the Smart Grid – IEEE SmartGridComm 2011
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13
Protocols for Sensing and Control
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
13
FareMultipoint
clic per modificare
cyclic data
lo gathering
stile del titolo
 Smart Grid/Energy Saving Context
 A base-station collects
(quasi) real time information
from many nodes in a wide area
– Energy consumptions
– Environmental information (ex. temperature, humidity, illumination)
– Electric generations (ex. photovoltaic, wind-power)
 Features
– Many nodes in wide area
– Cyclic observation in each node
( Cyclic packet generation)
– Small and constant packet size
– No retransmission
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
134
13
Faremultipoint
clic per modificare
data gathering
lo stilesystem
del titolo
 Base-station collects
(quasi) real time information in wide area
using a PLC network.
Energy consumptions
Cyclostationaly
Environmental
information
Electric
generations
environment
Long term change
Many nodes in wide area
Periodically generation
Small size data
t
t
Basestation
t
PLC network
t
nodes
PLC for the Smart Grid – IEEE SmartGridComm 2011
135
A. Tonello, M. Katayama
13
Fare
Access
clic control
per modificare
methodloforstile
thedel
system
titolo
 Demand assignment
× The overhead for assignment degrades channel efficiency.
 Random access
– CSMA
× Hidden terminal problem degrades the performance.
– ALOHA
• pure-ALOHA
• slotted-ALOHA
Basestation
Features of the system
Many nodes in wide area
Periodically generation
Small size data
Cyclostationaly
environment
Long term change
PLC network
nodes
PLC for the Smart Grid – IEEE SmartGridComm 2011
136
A. Tonello, M. Katayama
13
Fare
Access
clic control
per modificare
methodloforstile
thedel
system
titolo
 Random access
Mains AC voltage can be used
as a common clock
– ALOHA
• pure-ALOHA
Some nodes experience collisions periodically.
• slotted-ALOHA
t
t
Basestation
t
PLC network
t
nodes
PLC for the Smart Grid – IEEE SmartGridComm 2011
137
A. Tonello, M. Katayama
13
Fare clic per modificare lo stile del titolo
 To be done by Masaaki (adding from Ohtomo 2010/2011)
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
13
Standardization
PLC for the Smart Grid – IEEE SmartGridComm 2011
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13
Fare
Standard:
clic perIEEE
modificare
P1901 and
lo stile
ITU-T
delG.hn
titolo
 IEEE P1901 covers both indoor (in-home) and outdoor PLC (last mile)
– Two frequency bands
• 2-30 MHz: rate up to 200 Mbit/s. 2-60 MHz: rate up to 545 Mbit/s
– PHY 1: Windowed OFDM with turbo coding (from HPAV)
– PHY 2: Wavelet OFDM with RS/CC and LDPC (from Panasonic HD-PLC)
– MAC: TDMA for QoS traffic and CSMA for best effort traffic. The MAC is
technology dependent. Coexistence mechanism for interoperability.
 ITU-T G.9960 (G.hn)
– PHY and MAC for in-Home devices that use power line, coax, and phone lines.
– Frequency bands
• 2-50 MHz (optional 50-100 MHz): rate up to 1 Gbit/s
– PHY: scalable windowed OFDM (2048 tones for PLC)
– MAC layer: TDMA for QoS traffic, CSMA for best effort traffic
– Coexistence with IEEE P1901 devices but not interoperability
PLC for the Smart Grid – IEEE SmartGridComm 2011
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14
Standards:
Fare clic per
IEEE
modificare
P1901.2 lo
and
stile
ITUdel
G.hnem
titolo
 IEEE P1901.2: just started
– Narrow band (less than 500 kHz) PLC standard for both AC and DC lines:
• low voltage indoor/outdoor, as well as medium voltage in both urban
and in long distance (multi-kilometer) rural communications
– Scalable data rates up to 500 kbps depending on the requirements
– It addresses communication for:
• Grid to utility meter, management of local energy generation devices
• Electric vehicle to charging station
• In-home networking for command-and-control
 ITU-T G. hnem: started in 2010
– MAC & PHY for in-home energy management, LV only
PLC for the Smart Grid – IEEE SmartGridComm 2011
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14
Convergent SG Network
PLC for the Smart Grid – IEEE SmartGridComm 2011
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14
Fare clic per modificare lo stile del titolo
 Coexistence
 Interoperability
 Convergence with other technologies
 To be done ….
PLC for the Smart Grid – IEEE SmartGridComm 2011
A. Tonello, M. Katayama
14