1. Contributions to the Improvement
of Multiuser PLC Home networks
unrestricted
Pierre ACHAICHIAPierre ACHAICHIAPierre ACHAICHIAPierre ACHAICHIA, October 12, Orange Labs Rennes
Orange Labs Supervisors
Marie Le BOT Pierre SIOHAN
Supélec Supervisor
Jacques PALICOT
2. 1. Motivations & Objectives
2. HomePlug Specifications Overview
3. The HPAV Modulation Scheme PHYPHYPHYPHY
Outline
INTROINTROINTROINTRO
unrestricted
4. Windowed OFDM vs OFDM/OQAM: Capacity Analysis
5. PLC Networks Multicast Issue
6. OFDMA for Point-to-Multipoint Transmissions
7. Conclusion
MACMACMACMAC
2 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
3. Motivations & Objectives
unrestricted3 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
Motivations & Objectives
4. Increased data rates offered to customers (FTTH), more and
more networking devices within the Home area, leading to:
– Increased Number of QoS demanding Services
– Heterogeneous traffic: services need to be prioritized
– Wi-Fi technology cannot answer all use cases: network coverage,
not necessarily appropriate to deliver QoS demanding applications
like IPTV…
Thesis Motivations
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like IPTV…
Powerline Communication (PLC) benefits:
– "No new wire" and easy to access network
– Quasi-static channels allowing fine link adaptation
– Increased home network coverage and reliability
– Low interference between neighboring networks
FTTH: Fiber To The Home
QoS: Quality of Service
IPTV: IP Television
5. Thesis Objectives
At the PHY layer:
Bandwidth extension up to 100 MHz
Show benefits of the OFDM/OQAM modulation for
next-generation PLC networks
Anticipate evolution of broadband PLC networks
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At the MAC layer:
Identify lacks of current PLC standards (HPAV-based)
Propose novel allocation techniques to improve
network efficiency in a multi user context
PHY: Physical
MAC: Medium Access Control
7. A Little Background…
The home power grid is a harsh communication medium:
Multi-path channels due to impedance mismatch, resulting
in reflection signals
Quasi-static nature
Severe attenuation, typically comprised between 20 and 60
dB
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Various interference sources:
• Colored background noise
• Impulsive noise sources: home appliances, such as hair
dryer, vacuum cleaner… Error bursts
8. • Windowed OFDM modulation in the [1.8; 30]
MHz frequency range: 3072-point FTT size, 917
active subcarriers, up to 200 Mbps PHY rate
• Fine channel adaption through the definition of
tone maps (bit-loading) -> BPSK to 1024-QAM,
various FEC rates, GI…
• Beacon-based synchronization, controlled by a
CCo (Central Coordinator), providing scheduled
channel accesses (TDMA)
HomePlug Specifications
Evolution of Broadband PLC Specifications
Capacity
• OFDM modulation in the [4; 21] MHz
frequency range
• CSMA/CA : Distributed and prioritized
channel Access, error detection and
• Uses HPAV as baseline technology
• Introduction of an ISP protocol to
handle dual-PHY
• Bandwidth extension up to 50 MHz
(4096-point FFT), possibility to use
4096-QAM
• Up to 500 Mbps PHY rate
Bandwidth extension up to 86 MHz
(8192-point FFT), combined with
MIMO PLC
Between 750 Mbps and 1.5 Gbps
PHY rates, fully compliant with
P1901 standard
1.51.51.51.5 GbpsGbpsGbpsGbps
unrestricted
• Coexistence with HP 1.0 devices, but not
backward compatible!
8 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
OFDM: Orthogonal Frequency Division Multiplexing
CSMA/CA: Carrier Sense Multiple Access/Collision Avoidance
FFT: Fast Fourier Transform
BPSK: Binary Phase Shift Keying
QAM: Quadrature Amplitude Modulation
Years
channel Access, error detection and
Automatic Repeat Request (ARQ)
mechanisms
• Up to 14 Mbps PHY rate, further enhanced
by Intellon with the proprietary HP 1.0 turbo
• Up to 500 Mbps PHY rate
FEC: Forward Error Correction
TDMA: Time Division Multiple Access
IEEE: Institute of Electrical and Electronics Engineers
ISP: Inter System Protocol
MIMO: Multiple Input Multiple Output
14141414 MbpsMbpsMbpsMbps
200200200200 MbpsMbpsMbpsMbps
500500500500 MbpsMbpsMbpsMbps
2001: HP 1.02001: HP 1.02001: HP 1.02001: HP 1.0 2005: HPAV 12005: HPAV 12005: HPAV 12005: HPAV 1 2010: IEEE P19012010: IEEE P19012010: IEEE P19012010: IEEE P1901 2012: HPAV 22012: HPAV 22012: HPAV 22012: HPAV 2
9. The HPAV
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Modulation Scheme
10. OFDM principles
Multicarrier modulations are the appropriate answer to cope
with the multipath nature of PLC channels
Attenuation
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ffffminminminmin ffffmaxmaxmaxmax Frequency
11. OFDM principles
Multicarrier modulations are the appropriate answer to cope
with the multipath nature of PLC channels
– OFDM: Orthogonal Frequency Division Multiplexing
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T0 (FFT Size)
t
T0 (FFT Size)
t
ISI+ICI
t
CHANNELCHANNELCHANNELCHANNEL
ISI: Inter-symbol Interference
ICI: Inter-Carrier Interference
12. OFDM principles
Multicarrier modulations are the appropriate answer to cope
with the multipath nature of PLC channels
– CP-OFDM: OFDM with Cyclic prefix
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t
ISI+ICI
t
CHANNELCHANNELCHANNELCHANNEL
T0GI T0GI T0GI
t
T0GI T0GI T0GI
ISI+ICI free
GI: Guard Interval
13. OFDM principles
CP-OFDM allows interference-free transmissions, thanks to the
addition of a guard interval (counterpart: losslosslossloss in the spectralin the spectralin the spectralin the spectral
efficiencyefficiencyefficiencyefficiency)
HoweverHoweverHoweverHowever, PLC equipments must comply with a restrictive
spectral mask
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Because of the bad spectral containment of the subcarriers,the
classic CPCPCPCP----OFDMOFDMOFDMOFDM scheme is notnotnotnot suitedsuitedsuitedsuited for broadband PLC
14. The Windowed OFDM Modulation
To improve the spectral containment of the subcarriers, HPAV
introduces a Windowed OFDM modulation scheme
Windowed OFDM Pulse-Shaped OFDM
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SameSameSameSame spectral efficiency as CP-OFDM:
RI: Roll-off Interval
15. The Windowed OFDM Modulation
HoweverHoweverHoweverHowever,,,, looking at the receiver side:
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ProblemProblemProblemProblem:::: in strongly dispersive channels, an interference term
remains present in the demodulated symbol
The effective protectioneffective protectioneffective protectioneffective protection against interference is reducedreducedreducedreduced in
proportion of the RI effective GI = GIeffective GI = GIeffective GI = GIeffective GI = GI----RIRIRIRI
remaining interference
16. Link Adapation
Broadband PLC specifications allow to adapt the signal to the
transmission path, using bit-loading techniques:
Signal toSignal toSignal toSignal to InterferenceInterferenceInterferenceInterference plus Noise Ratioplus Noise Ratioplus Noise Ratioplus Noise Ratio
Noise variance
Complex QAM symbol
variance
ISI+ICI power
Channel Coefficient
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SINR gap:
CapacityCapacityCapacityCapacity formulaformulaformulaformula
ToneToneToneTone mapmapmapmap
Ex: in HPAV,
SER: Symbol Error Rate
17. Broadband PLC specifications allow to adapt the signal to the
transmission path, using bit-loading techniques:
– Ex. : HPAV OFDM bit-loading (917 subcarriers, [1.8: 30] MHz)Each tone map:
• is defined on a specific link
• is defined for a one-way communication
Link Adapation
Channel frequency response Dedicated Tone Map (TM)
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Allows to approach the theoretical capacity of the channel
19. OQAM: Offset Quadrature Amplitude Modulation
Multicarrier Modulation with frequency spacing F0
As classic OFDM systems, FFT-based implementation is
possible
MainMainMainMain principleprincipleprincipleprinciple:
The transmissions of the real and imaginary parts of the complex
The OFDM/OQAM Modulation
unrestricted
The transmissions of the real and imaginary parts of the complex
symbols cm,n are delayed of one half symbol duration T0/2
The constraint is to keep a phase shift of π/2 between adjacent
symbols in time and frequency
19 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
T0 (FFT Size)
t
T0 (FFT Size)
t
Re{cm,n}
Im{cm,n}
ClassicClassicClassicClassic OFDMOFDMOFDMOFDM OFDM/OQAMOFDM/OQAMOFDM/OQAMOFDM/OQAM
real or imaginary part of cm,n
prototype filter Phase term
T0/2
20. MainMainMainMain benefitsbenefitsbenefitsbenefits::::
No GI same spectral efficiency as OFDM without CP with
lower interference
Relaxing the orthogonality constraint by only imposing it in the
real field gives an additional degree of freedom to shape
transmitted symbols
For a distortion-free channel, the interference only affects the
The OFDM/OQAM Modulation
unrestricted
For a distortion-free channel, the interference only affects the
imaginary part of the symbols, and is therefore removed by the
real-part extraction
For a realistic channel, it can be well contained if the prototype
filter is appropriately selected, and using a 3-tap (ASCET [Alhava et
al., 2001]) Zero Forcing (ZF) equalizer
20 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
ASCET: Adaptive Sine/Cosine-modulated filter bank Equalizer for Transmultiplexer
21. How can we efficiently exploit the additional degree of freedom
offered by OQAM in the particular context of PLC?
Ex.: comparison between a prototype filter optimized upon the
FS (Freq. Selectivity) criterion and the HPAV window
The OFDM/OQAM Modulation
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22. How can we efficiently exploit the additional degree of freedom
offered by OQAM in the particular context of PLC?
The association of OFDM/OQAM with frequency selective filters
allows to activate more than 917 subcarriers (windowed OFDM)
FCC mask:
windowed OFDM: 917 active subcarriers
OFDM/OQAM + FS4: 968 active subcarriers
The OFDM/OQAM Modulation
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OFDM/OQAM + FS4: 968 active subcarriers
CENELEC mask (draft standard)
windowed OFDM: [503, 767] active subcarriers
OFDM/OQAM + FS4: [632, 871] active subcarriers
22 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
FCC: Federal Communications Commission
CENELEC: Comité Européen de Normalisation
23. Simulation parameters for the capacity analysis:
3 classes of PLC channels (Class 2, 5 and 9) [Tlich et al., 2010]
with:
Capacity (class 9)>Capacity(class 5)>Capacity(class 2)
100 channel realizations
Colored background noise [Omega D3.2, 2010]
Target SER=10-2
Windowed OFDM vs OFDM/OQAM: HPAV 1 Context
unrestricted
Target SER=10-2
FCC spectral mask:
• 917 active subcarriers for windowed OFDM
• 968 active subcarriers for OFDM/OQAM
ZF per-channel equalizers:
•1-tap for windowed OFDM
• 3-tap (ASCET) for OFDM/OQAM
23 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
24. Some results on class 9 channels (transmitted PSD is
increased from -120 to -50 dBm/Hz ):
Windowed OFDM vs OFDM/OQAM: HPAV 1 Context
Transmission capacity
(infinite granularity)
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Achievable throughput
(finite granularity)
PSD: Power Spectral Density
25. How can we efficiently increase the capacity of PLC networks?
Bandwidth extension: in the scope of OMEGA, simulations were
conducted in the [1,8: 87.5] MHz bandwidth (~AV2) (3072 8192-
point FFT)
Enable higher modulation orders: the 4096-QAM (12 bits) is
allowed by AV 2
Number of active subcarriers:
Windowed OFDM vs OFDM/OQAM: HPAV 2 Context
unrestricted
Number of active subcarriers:
• Windowed OFDM : 917 (HPAV) + 2428 = 3354
• OFDM/OQAM : 968 (HPAV) + 2440 = 3408
25 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
26. Some results on class 9 channels (transmitted PSD is
increased from -120 to -50/-80 dBm/Hz ):
Windowed OFDM vs OFDM/OQAM: HPAV 2 Context
Transmission capacity
(infinite granularity)
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Achievable throughput
(finite granularity)
27. Some results on class 2 channels (transmitted PSD is
increased from -120 to -50/-80 dBm/Hz ):
Windowed OFDM vs OFDM/OQAM: HPAV 2 Context
Transmission capacity
(infinite granularity)
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Achievable throughput
(finite granularity)
28. HPAV 1 context: a significant throughput gain can be achieved
by OFDM/OQAM using a frequency selective prototype filter,
together with a 3-tap equalizer (ASCET)
Up to 20 % increase in the data rates using the FCC mask
More than 40 % increase is shown considering the new
CENELEC mask (cf. dissertation)
HPAV 2 context: The OMEGA project has shown that Next-
PHY Layer Contributions Summary
unrestricted
HPAV 2 context: The OMEGA project has shown that Next-
generation PLC networks(HPAV 2) could reach the Gbps
connectivity, thanks to the bandwidth extension (+MIMO)
Main ContributionsMain ContributionsMain ContributionsMain Contributions (cf. dissertation):
Computation of the analytical expression of the interference term
of the Windowed OFDM signal
Generalized expression of the OFDM/OQAM interference power,
analytical expression of the noise power at the output of ASCET
28 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
29. Multicast Issue in PLC
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Networks
30. Multicast Issue
Broadband PLC specifications allow to adapt the signal to the
transmission path, using bit-loading techniques
HoweverHoweverHoweverHowever, a problem arises if we want to simultaneously reach
several stations
Tone maps allow to approach the theoretical
capacity of the channel.
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HPAV / IEEE P1901:HPAV / IEEE P1901:HPAV / IEEE P1901:HPAV / IEEE P1901: Multicast/broadcast services must be
handled as multiple unicast streams (unicast conversion)
Stations areStations areStations areStations are isolatedisolatedisolatedisolated fromfromfromfrom oneoneoneone anotheranotheranotheranother
31. Known solution: LCG (Lowest Channel gain)
Computation of an equivalent channel among the K
stations to reach
In PLC networks, LCG can be directly applied at the
transmitter side by computing a multicast tone map:
LCG Solution
unrestricted
Ex: K = 4 HPAV 2 tone maps
31 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
32. Is LCG always better than the Unicast Conversion?
From the PHY layer point of view: YES
• Study conducted for the HPAV TWG (measured PLC channels in 3 countries):
LCG Solution
unrestricted
HoweverHoweverHoweverHowever,,,, from the MAC layer point of view: not necessarily
32 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
HPAV TWG: HPAV Technical Working Group
33. If we want each one of the K adressed stations to acknowledge
the Multicast transmission:
LCG Solution
LCGLCGLCGLCG cancancancan degradedegradedegradedegrade the MACthe MACthe MACthe MAC efficiencyefficiencyefficiencyefficiency
Unicast transmissionUnicast transmissionUnicast transmissionUnicast transmission
The transmission window
is limited to 2.5 ms
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Unicast transmissionUnicast transmissionUnicast transmissionUnicast transmission
Multicast transmissionMulticast transmissionMulticast transmissionMulticast transmission
The K 1 additional ACK frames
must be taken into account
MACMACMACMAC efficiencyefficiencyefficiencyefficiency decreasesdecreasesdecreasesdecreases asasasas KKKK increasesincreasesincreasesincreases
34. IdeaIdeaIdeaIdea:
Instead of defining a unique "multicast" tone map, the KKKK stations are
classified into NNNN multicast subsets
Each multicast subset is associated with an exclusive multicast tone
map, contructed by applying the LCG principle among the tone maps
contained in the subset
A tradeoff must be made between the number of simultaneously
Smart Merging Approach
unrestricted
A tradeoff must be made between the number of simultaneously
addressed stations and the transmission window length
A smart merging algorithm has been developped (cf. manuscript),
considering both PHY and MAC layers:
Assessing the correlation between tone maps before merging them
Taking into account the reduction of the transmission window
34 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
35. Multicast tone maps allow major improvement of the transmission
efficiency (cf. manuscript and the study conducted for the HPAV
TWG)
HoweverHoweverHoweverHowever, special care must be taken when considering the MAC
overhead:
If we want the K adressed stations to acknowledge the frame, the
transmission window is reduced
Multicast Summary
unrestricted
transmission window is reduced
The creation multiple multicast subsets may be more appropriate in
such a case
Complementary studies need to be made to assess:
The multiple overhead sources: frame headers, segmentation, inter-
frame spaces…
The impact on system complexity and reactivity
35 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
37. The Interest of Point-to-Multipoint
STA 3:
Bridge to
STA 1:
Bridge to set-
unrestricted
If More than 2 Stations in the network:
Point-to-multipoint transmissions = Frequent use case
37 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
Bridge to
computer 1
Bridge to set-
top box 1
STA 0 (CCo):
Bridge to
Home GW
STA 2:
Bridge to set-
top box 2
Distant
Services
Home GW: Home Gateway
38. STA 3:
Bridge to
computer 1
STA 1:
Bridge to set-
top box 1
Taking advantage of the Multiuser Diversity
unrestricted38 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
STA 2:
Bridge to set-
top box 2
Distant
Services
STA 0 (CCo):
Bridge to
Home GW
PLC channels have a multi-path nature, and are
quasi-static:
Bit-loading algorithms result in the creation of
tone maps, specific to each link
Home GW: Home Gateway
39. Taking advantage of the Multiuser Diversity
unrestricted
How can we take advantage of this multiuser diversity?
OFDMA:OFDMA:OFDMA:OFDMA: distribution of the MMMM subcarrierssubcarrierssubcarrierssubcarriers amongamongamongamong the Kthe Kthe Kthe K usersusersusersusers
39 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
OFDMA: Orthogonal Frequency Division Multiple Access
40. If we apply the σ permutation s.t.:
increasesincreasesincreasesincreases on {1,..,M}
How can we optimally orthogonalize tone maps?
Ex.: K = 2K = 2K = 2K = 2 tone maps to orthogonalize
The Tone Maps Orthogonalization Problem
unrestricted
with:
and
40 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
41. How can we optimally orthogonalize tone maps?
K = 3K = 3K = 3K = 3 ?
The Tone Maps Orthogonalization Problem
Problem:
If K>2If K>2If K>2If K>2, Finding a concave capacity
region is far from being straightforward
unrestricted41 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
2 solutions were developped:
A low-cost, nearly-optimal algorithm: TMSATMSATMSATMSA (Tone
Maps Splitting Algorithm)
An optimal resolution based on a geometrical
approach of the problem
region is far from being straightforward
42. Geometrical approach:
AllocationAllocationAllocationAllocation vectorvectorvectorvector::::
CapacityCapacityCapacityCapacity balance:balance:balance:balance:
The Tone Maps Orthogonalization Problem
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The ToneToneToneTone mapsmapsmapsmaps orthogonalisationorthogonalisationorthogonalisationorthogonalisation problemproblemproblemproblem comes down to
maximizemaximizemaximizemaximize , a K-dimentionnal vector directeddirecteddirecteddirected by
FDM: Frequency Division Multiplexing
43. Geometrical approach: K = 3
Noticing that the projection of the optimal allocation vector onto
the plane P2 , defined by vectors and is colinear to
Starting from K = 2:K = 2:K = 2:K = 2:
The Tone Maps Orthogonalization Problem
unrestricted
We extend the problem to K = 3K = 3K = 3K = 3 to create
43 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
Starting with the optimal allocationoptimal allocationoptimal allocationoptimal allocation vectorvectorvectorvector between links 1links 1links 1links 1 and 2222,
MaximizingMaximizingMaximizingMaximizing comes down to reallocatereallocatereallocatereallocate subcarrierssubcarrierssubcarrierssubcarriers maximizingmaximizingmaximizingmaximizing the
componentcomponentcomponentcomponent along basis vector , while minimizingminimizingminimizingminimizing thethethethe costcostcostcost on
44. Geometrical approach: K = 3
Intitialization:
What is the loss on after allocating a capacity ε on link 3 ?
The Tone Maps Orthogonalization Problem
unrestricted44 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
45. Geometrical approach: K = 3
Intitialization:
What is the loss on after allocating a capacity ε on link 3 ?
The Tone Maps Orthogonalization Problem
unrestricted
C2 increases with β2, while C1 decreases with β2
By always choosing the subcarrier ensuring the
minimal loss on , we maximize
45 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
46. Geometrical approach: K > 3
For K = 4, we can establish the following
cost functions:
The Tone Maps Orthogonalization Problem
unrestricted
with
and
46 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
47. Geometrical approach: K > 3
From which we deduce a general expression of the cost
function, for any K > 3. In the plane PK 1, the cost on link n is
expressed as follows:
The Tone Maps Orthogonalization Problem
unrestricted
with
and
47 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
48. Point-to-Multipoint Summary
The tone maps orthogonalization problem has been set and
solved using a geometrical approach
HoweverHoweverHoweverHowever, this method remains too complex to be incorporated in
real PLC systems. A fast orthogonalization algorithm has been
then developed: the Tone Maps Splitting Algorithm (TMSA)
TMSA has been integrated in a PLC network simulator, and we
have proposed an HPAV-compliant OFDMA access scheme:
unrestricted48 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
have proposed an HPAV-compliant OFDMA access scheme:
20% to 30 % improvement of the data rates will generally be
achieved using OFDMA (P1901, saturated throughput)
In future HPAV 2.0 systems, as the number of subcarriers will be
increased, so will be the multiuser diversity
Better gains have to be expected in the future
50. Main Contributions:Main Contributions:Main Contributions:Main Contributions:
On the PHY layer:On the PHY layer:On the PHY layer:On the PHY layer:
• Within the OMEGA project, we have shown that PLC systems
could benefit from a substantial troughput gain, by increasing the
bandwidth (up to 87.5 MHz for OMEGA, 86 MHz for AV 2)
• HoweverHoweverHoweverHowever, another modulation scheme than windowed OFDM,
called OFDM/OQAM, can further enhanced this capacity
Conclusion
unrestricted50 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
called OFDM/OQAM, can further enhanced this capacity
improvement
• Thanks to the assocation of OFDM/OQAM with prototype filters
optimized upon the FS criterion, it is possible to activate more
tones while still complying with the spectral mask
• Considering the CENELEC draft standard, the performance gap
between the two modulation schemes will be even more
important
51. Main Contributions:Main Contributions:Main Contributions:Main Contributions:
On the MAC layer:On the MAC layer:On the MAC layer:On the MAC layer:
• Since the release of the IEEE P1901 standard in 2010, the field
of broadband PLC has stabilized
• YetYetYetYet this thesis shows that current systems could still benefit
from significant improvement
The multicast issueThe multicast issueThe multicast issueThe multicast issue has been firstly adressed, where we
Conclusion
unrestricted51 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
The multicast issueThe multicast issueThe multicast issueThe multicast issue has been firstly adressed, where we
have shown that the definition of multicast tone maps could
bring major improvement in the data rates
PointPointPointPoint----totototo----multipointmultipointmultipointmultipoint transmissions have been then studied.
In this work, we emphasize on the fact that the fine link
adaptation could be better exploited by defining an OFDMA
access mode
52. Contributions
Conference papers
– P. Achaichia, M. Le Bot, P. Siohan, "Windowed OFDM versus OFDM/OQAM: A
Transmission Capacity Comparison in the HomePlug AV Context," International
Symposium on Power Line Communications , ISPLC 2011, Udine, Italy, April
2011.
– P. Achaichia, M. Le Bot, P. Siohan, " An Efficient Technique for Merging
Transmissions in a Multicarrier Context ", IWCLD 2011, Rennes, France,
November 2011.
unrestricted52 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
November 2011.
– P. Achaichia, M. Le Bot, P. Siohan, "Frequency Division Multiplexing Analysis for
Point-to-Multipoint Transmissions in Power Line Networks," International
Symposium on Power Line Communications , ISPLC 2011, Udine, Italy, April
2011.
– P. Achaichia, M. Le Bot, P. Siohan, " Point-to-Multipoint Communication in Power
Line Networks: A Novel FDM Access Method", ICC 2012, Ottawa, Canada, June
2012.
– P. Achaichia, M. Le Bot, P. Siohan, ``Impact of CENELEC Transmission Spectrum
Mask on Current PLC networks,'' to be submitted, 2012.
53. Contributions
Journal papers
– P. Achaichia, M. Le Bot, P. Siohan, ``OFDM/OQAM: A Solution to Efficiently
Increase the Capacity of Future PLC Networks,'' Power Delivery, IEEE
Transactions on, vol. 26, no. 4, pp. 2443-2455, Oct. 2011.
– P. Achaichia, M. Le Bot, P. Siohan, ``Adrdessing the issue of FDM Resource
Allocation for Point-to-Multipoint Communication in PLC Networks'' to be submitted,
2012.
unrestricted53 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
Patents
– P. Achaichia, M. Le Bot, P. Siohan, ``Procédé de regroupement de stations pour
optimiser la diffusion d'un flux multicast/broadcast,'' 2011.
– P. Achaichia, M. Le Bot, P. Siohan, ``Procédé de distribution des sous-porteuses
d'un système multiporteuse entre différents liens de communication,'' 2011.
54. Contributions
Technical Contributions
– A. Tonello, S. D'Alessandro, M. Antoniali, M. Biondi, F. Versolatto, A. Maiga, J.-Y.
Baudais, F. S. Muhammad, P. Siohan, M. L. Bot, H. Lin, P. Achaichia, G. Ndo, G.
Mijic, B. Cerato, S. Drakul, E. Viterbo et O. Isson, " Performance report of
optimized PHY algorithms ", rap. tech., projet OMEGA, June 2010.
– P. Achaichia, M. Le Bot, P. Siohan, "Multicast Tone Maps: Gains to Expect," HPAV
face-to-face meeting, Lannion, March 2012.
unrestricted54 Pierre Achaichia - Contributions to the Improvement of Mulltiuser PLC Home Networks – 10/12/12
– P. Achaichia, M. Le Bot, P. Siohan, "FDM to Improve Point-to-Multipoint
Communications in Powerline Networks", HPAV face-to-face meeting, Lannion,
March 2012.
– P. Achaichia, M. Le Bot, P. Siohan and P.Pagani, "Multicast Tone Maps
Performance on Measured PLC Channels", HPAV TWG, April 2012.
– P. Achaichia, M. Le Bot, P. Siohan and P.Pagani, "Multicast Communications:
Practical Use Cases", HPAV TWG, May 2012.