8/8/2019 LaSalle Final

1/24

26/06/2001

Design of Systems on SiliconDesign of Systems on Silicon

DS2PLC Technology

Juan Carlos RiveiroJuan Carlos Riveiro

System Architecture ManagerSystem Architecture Manager

8/8/2019 LaSalle Final

2/24

26/06/2001

IndexIndex

DS2 Profile and Strategy

DS2 PLC Technology

8/8/2019 LaSalle Final

3/24

26/06/2001

DS2 Profile andDS2 Profile andStrategyStrategy

8/8/2019 LaSalle Final

4/24

26/06/2001

DS2 ProfileDS2 Profile

Fabless silicon design house

Mission: to become the leading supplier ofIPR (silicon and software) for high speedPowerline Communications (PLC)

Experienced in advanced communicationschipsets: QAM, OFDM, FFT, IFFT, FEC, ADCs,DACs, etc.

8/8/2019 LaSalle Final

5/24

26/06/2001

DS2 ProfileDS2 Profile

Incorporated 1998/February/15

Key shareholder: ENDESA (the largestelectricity utility in Spain and South America)

Experienced management and key personnel:IBM, HP, Philips, Matra-MHS, Telefnica, EC-R&D programs, INITEC, etc.

Experience in state-of-the-art large critical

projects

8/8/2019 LaSalle Final

6/24

26/06/2001

DS2 StrategyDS2 Strategy

DS2

DS2 is a fabless silicondesign house.

Foundry

Selected foundries produceDS2 chipsets

OEM

DS2s customers are OEMswho integrate DS2 chipsets

in their systems

... to whom DS2 sells andSUPPORTS

OEMs produce...

HE CPE

HomeGatewa

y

Customer PremisesEquipment which is placed

in users devices inhouseholds

and HomeGateways allowing

in-home LANservice

Utility

OEMs supply DS2 PLC andtelecom equipment to

utilities

... and turn them intoNetwork Service Providers...

End-User

... for a 3000million End-Usersmarket worldwide

Head Ends which areinstalled in each MV/LV

transformer

8/8/2019 LaSalle Final

7/24

26/06/2001

DS2 StrategyDS2 Strategy

Capitalize on company skills (communications,DSP, electronic design, silicon,etc.)

Alliances and joint developments with customers:

Router and Telecom manufacturers: CISCO, Ascom, PACE, Nokia, Mitsubishi, Vayris...

Silicon foundries, core providers: Samsung, AMS,...

Electricity utilities: Endesa, EDF, ENEL, Sydkraft, TEPCO, EnBW...

Electrical equipment supply: Schneider, Schlumberger, ABB...

8/8/2019 LaSalle Final

8/24

26/06/2001

DS2 PLCDS2 PLCTechnologyTechnology

8/8/2019 LaSalle Final

9/24

26/06/2001

DS2 PowerlineDS2 PowerlineTopologyTopology

8/8/2019 LaSalle Final

10/24

26/06/2001

Powerline advantagesPowerline advantages

Lowest cost equipment compared to competitorstechnologies

Ubiquitous due to electricity grid capillarity

No new cabling is needed Shared bus means shared cost

New business opportunities diversifying activities

In-home LAN allowing multiple new applications

Real broadband access to home at the lowest cost

8/8/2019 LaSalle Final

11/24

26/06/2001

Powerline problemsPowerline problems

Different cables used:

Underground cable.

Twisted overhead cable.

Bare overhead line.

Unstable medium, designed to carry power signal notcommunications signal.

Time-Variant (plug and unplug).

Noisy medium (power supplies).

Input impedance is a function of frequency and time, not flatand invariant.

Different topology per country, distance up to 1km.

Point to Multipoint, with lots of taps and mismatching.

8/8/2019 LaSalle Final

12/24

26/06/2001

CommunicationsCommunicationscharacteristicscharacteristics

Impulse Response: Time Spread and Variation.

Slow frequency selective

channel.

Noise: Background, Ingress and Impulsive.

Attenuation is a function of frequency,

distance and time.

8/8/2019 LaSalle Final

13/24

26/06/2001

WidebandWidebandcharacteristicscharacteristics

Multipath propagation Dispersion of the received signal in time domain. (Time spread, Ts)

Frequency selectivity in frequency domain.

If Tsignal < Ts Intersymbol interference (ISI)

Limits the maximum usable symbol rate (data rate).

QAM constellations with (a) no ISI, (b) 3% ISIand (c) 10% ISI

8/8/2019 LaSalle Final

14/24

26/06/2001

Wideband modulationWideband modulation

Single carrier with an equalizer: High complexityand cost(silicon area)

The channel must be known ( or accurately estimated).

High bit-rate signal Time spread >>> symbol time.

DS-SS (CDMA direct sequence spread spectrum): Using high bit-rate signal to achieve a high processing gain, a very

large bandwidth is required.

In PLC environment, an equalizer is requiredtoo.

OFDM:

The technique for high bit-rate applications.

High bit-rate signal Time spread

8/8/2019 LaSalle Final

15/24

26/06/2001

OFDM ModulationOFDM Modulation

Imperative need for speed. Competingagainst or complementing ADSL, Cablemodem and LMDS.

Imperative need for adaptiveness. EveryPowerline is different, with lots of taps andmultipath propagation.

Imperative need for low cost.

Solution OFDMTransmission medium shared in

time and in frequency

8/8/2019 LaSalle Final

16/24

26/06/2001

OFDM IntroductionOFDM Introduction

The tx bandwidth is divided into many narrowsubchannels which are transmitted in parallel.

Each subchannel is narrow enough so that the fading it

experiences is flat no ISI. OFDM increases the spectral efficientlyby allowing

subchannels to overlap

a) FD system

b) OFDM system

8/8/2019 LaSalle Final

17/24

26/06/2001

OFDM Introduction IIOFDM Introduction II

Guard interval is added to each OFDM symbol toeliminate ISI.

Adaptive loading

More bits/subchannel where SNR is sufficient. Could also adapt transmit power in each subchannel.

Orthogonality: Carrier spacing is a multiple of 1/T.

Carriers are linearly independent.

8/8/2019 LaSalle Final

18/24

26/06/2001

OFDM ModulationOFDM Modulation

Ideal for slow changing multipath channels withhigh time spread (Powerline case):

No need for time equalization (complex FIR Filters).

Simple frequency equalization (phase correction) Best Bps/Hz performance

Spectrally dense signal

Large number of carriers makes things easier: Synchronization is more robust and simple Easier to adapt to notches and ingress

Better immunity to impulsive noise Increase the robustness against frequency selective

fading channels

8/8/2019 LaSalle Final

19/24

26/06/2001

DS2 OFDMDS2 OFDM

1280 OFDM carriers

Data rate :

Up to 27 Mbps in downstream channel

Up to 18 Mbps in upstream channel

Data rate per subcarrier adaptable according SNRdetected

N bits per carrier : 0, 2, 4, 6 and 8

Different carriers transmit at different data rates

Modulation efficiency up to 7,25 bps/Hz

8/8/2019 LaSalle Final

20/24

26/06/2001

Low CostLow CostImplementationImplementation

Low cost digital implementation:

Only two major components:

FFT processor FEC encoder/decoder

0.25 m Process

304 plastic BGA package

Low cost analogue implementation

One ASIC (DSS7500) + Line Driver + Filters

ASIC implements LNA, PGA, Buffer, CPLD DAC, ADC

0.6 m Process

64 plastic QFP package

8/8/2019 LaSalle Final

21/24

26/06/2001

Access and In-homeAccess and In-homeLANLAN

Three different frequency ranges are used:

LINK 1: Low frequency band for ACCESS service

LINK 2: High frequency band for IN-HOME service

LINK LAN: IN-HOME service for xDSL, cable or wireless service

Frequency bands are fully programmable

Hardware needed will be:

HE: Manager in LINK1, LINK LAN

CPE: LINK1/2 and LINK LAN

Home Gateway: Manager in LINK2

8/8/2019 LaSalle Final

22/24

26/06/2001

SummarySummaryPerformancePerformance

Highest bit rates (up to 45 Mbps)

Highest efficiency (7,25 bps/Hz)

OFDM with 1280 carriers

Adaptive bpc depending on SNR

Lowest cost per bit (high integration) Adaptive QoS (users and services needs)

IP and SNMP 100% compatible

Access and In-Home service

IN-HOME service for xDSL, cable or wireless service

8/8/2019 LaSalle Final

23/24

26/06/2001

Product DescriptionProduct Description

HEs, CPEs and Home Gatewayshave the same block diagram.

DS2 chipsets integrate thesedifferent blocks.

8/8/2019 LaSalle Final

24/24

26/06/2001

Product DescriptionProduct Description

Data processingblock

Digital Front EndAnalog Front

End

Line

Coupler

Data processingblock Digital Front End

Analog FrontEnd

DISTRIBUTIONPOWER LINE

DIG

ITALIN

TER

FACE

Digital Interface interacts

with incoming and outgoing

Packets are built adding error

correction and other data

OFDM digital modulation is

implemented

Interaction with powerline in

the analogue field

Protection and filter power

signal with maximum power