docsis 3.1 –technischer Überblickeach carrier corresponds to a narrow-band modulated transmission...
TRANSCRIPT
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Walter FischerRohde&Schwarz Trainingszentrum München
DOCSIS 3.1 – Technischer Überblick
DOCSIS = Data over Cable Service Interface Specification
Vortrag anlässlich der Cabletech 2017, Spielberg, März 2017
Cablemodem
RF
IP
Phone
16.3.2017
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Referent
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Dipl. Ing. (FH) Walter FischerRohde&Schwarz
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AgendaDOCSIS Intro and Principle
Single Carrier Modulation Principle
Time Domain and Spectrum Domain
QAM and SNR Requirement
OFDM in CATV
DOCSIS 3.1 Physical Layer Parameters
DOCSIS 3.1 Demo Transmission
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DOCSIS Intro and PrincipleDOCSIS Intro and Principle
Single Carrier Modulation Principle
Time Domain and Spectrum Domain
QAM and SNR Requirement
OFDM in CATV
DOCSIS 3.1 Physical Layer Parameters
DOCSIS 3.1 Demo Transmission
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Broadband Internet & Telephone via CATV
CMTSCable
modemtermination
systemIP RF
RF
Cablemodem
RF
Coax/HFC
IP
Phone
DOCSIS
Return channel
Downstream
Upstream
DOCSIS – Data-over-Cable Service Interface Specification
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DOCSIS – Data over Cable Service Interface Specification
DOCSIS 1.0 1997 Cable Labs, ITU-T spec. ITU-T J.112DOCSIS 1.1 1999 QoS capabilitiesDOCSIS 2.0 2001 enhanced upstream speeds ITU-T J.122DOCSIS 3.0 2006 increase of both up and downstream speed, IPv6 ITU-T J.222DOCSIS 3.1 2013 10Gbit/s downstream, 1Gbit/s upstream, OFDM, 4096QAM
DOCSIS standard =bidirectional transmission of high-speed data over broadband cable networks using hybrid fiber-coaxial infrastructure
all DOCSIS standards are backward compatible
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DOCSIS Physical Layer
DOCSIS 1.0 ... 3.0:Downstream = ITU-T J83B [US] Single Carrier 64QAM/256QAMor ITU-T J83A (DVB-C) [EURO-DOCSIS] Single Carrier 64QAM/256QAM
Upstream = Single Carrier, QPSK ... 64QAM, TDMA, CDMA
DOCSIS 3.1:Downstream = OFDM, 4096 (4K) QAM and higher (16K QAM)4K/8K OFDM, 50/25 kHz carrier distance
Upstream = OFDM, minislots in time and frequency domainup to 4096 (4K) QAM, 2K/4K OFDM, 50/25 kHz carrier distance
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DOCSIS 1.0 ... 3.0 Downstream Data Rates
Standard Data rate per down stream channel
DOCSIS, J83B, 64QAM, 6 MHz 26.97 Mbit/s
DOCSIS, J83B, 256QAM, 6 MHz 38.81 Mbit/s
EURO-DOCSIS, DVB-C, 64QAM, 8 MHz 38.15 Mbit/s
EURO-DOCSIS, DVB-C, 256QAM, 8 MHz 51 Mbit/s
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Single Carrier Modulatin PrincipleDOCSIS Intro and Principle
Single Carrier Modulation Principle
Time Domain and Spectrum Domain
QAM and SNR Requirement
OFDM in CATV
DOCSIS 3.1 Physical Layer Parameters
DOCSIS 3.1 Demo Transmission
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IQ Modulator / Single Carrier Modulation
+ iqmod(t)data(t) Mapper
90°
q(t)
i(t)
I
Q
Carrier lo(t)
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Single Carrier Modulation … very short Symbols
Example: DVB-C, 6.9 MS/s; Symbol duration = 1/6.9 µs = 144 ns
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Constellations QPSK, 16QAM, 64QAM, 256QAM
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DVB-C FEC
ScramblerReed-
Solomonencoder
Inter-leaver
MPEG-2TransportStream
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Time Domain and Spectrum DomainDOCSIS Intro and Principle
Single Carrier Modulation Principle
Time Domain and Spectrum Domain
QAM and SNR Requirement
OFDM in CATV
DOCSIS 3.1 Physical Layer Parameters
DOCSIS 3.1 Demo Transmission
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Continuous Streams and Bursted Streams
Downstream
Upstream
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Spectral Rolloff Filtering in DVB-C (r=0.15)
f
∆f
∆f
∆f
∆f2BN = BS
2cos2cos
2cos 2cos
r=∆f/BN
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Spectrum, CATV Network
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RF Characteristics
Frequency
Leve
l PAL system level-12 dB -6 dB -4…-6 dB0…2 dB
DVB-C64QAM
DVB-C256QAM
DVB-C21024QAM
DVB-C24096QAM
ATV
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QAM and SNR RequirementDOCSIS Intro and Principle
Single Carrier Modulation Principle
Time Domain and Spectrum Domain
QAM and SNR Requirement
OFDM in CATV
DOCSIS 3.1 Physical Layer Parameters
DOCSIS 3.1 Demo Transmission
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Required SNR(QAM Order)
SNR4+6dB SNR16+6dB SNR64+6dB SNR256+6dB
4QAM, 16QAM, 64QAM, 256QAM, 1024QAM, 4096QAM, ...
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Mainly used Modulation in Cable: 64QAM, 256QAM
64QAM 256QAM
SNR64+6dB = SNR256
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OFDM Basics, OFDM in CATVDOCSIS Intro and Principle
Single Carrier Modulation Principle
Time Domain and Spectrum Domain
QAM and SNR Requirement
OFDM in CATV
DOCSIS 3.1 Physical Layer Parameters
DOCSIS 3.1 Demo Transmission
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Interferences in a CATV Network
• Linear distortions (amplitude response, group delay)• Non-linear distortions (... amplifiers ...)• Intermodulation (multi-channel load and non-linearity)• Short echos (micro-reflections)• Noise (AWGN)• Noise, frequency selective interferer• Ingress noise• Leakage (in both directions ...)• ...
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Amplitude Response in CATV - Tilt
A(f)
f
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Interferer in CATV (Ingress, DVB-T/T2 Interferer, ...)
A(f)
f
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Unused, ... Forbidden Frequencies ... in CATV („Notches“)
A(f)
f
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OFDM – Orthogonal Frequency Division Multiplex
COFDM
Coded Orthogonal Frequency DivisionMultiplex
FEC
Forwarderror
correction(Channel coding)
Distribution of data tomany subcarriers
No crosstalkbetween
subcarriers
∆f = 1/∆t
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COFDM Principle
X
XMap
per
+
X
XMap
per
+
..... COFDM
symbolΣ
Data+
FEC
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Mapping of OFDM carrier
Data stream: 0110 1110 0001 1010 1111 0011 0000 1010 0101
Forming of
groups of
4 bit
at 16QAMcarrer no. 0 1 2 3 4 5 6 7 8
mapped
carrier vector
each carrier is described via a (I,Q) pair
in the frequency domain
each carrier corresponds to a narrow-band modulated transmission channel
∆f∆f = 1/∆t = carrier spacing
at DVB-T: 6817 or 1705 carriers in a distance of approx. 1kHz or 4kHz
6817 or 1705 carrier plus guard band = 2 N carrier = 8192 or 2048 carrier
IFFT = Inverse Fast Fourier Transformation
OFDM symbol in time domain
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IFFT and I/Q Modulator
+ ofdm(t)
Re(f)
Im(f)
IFFT
90
im(t)
re(t)
I
Q
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OFDM Symbols with Guard Interval
Symbol n Symbol n+1
Guard interval
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OFDM Symbols with Guard Interval
Symbol n+1Symbol n
Guard interval (CP = cyclical prefix)
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Guard Interval – Cyclical Prefix
OFDM Symbol
Copy of end of symbol Guard Interval
= protection against intersymbol interference
in OFDM systems
Guard interval = „quasi-break“ =
Mechanism against problems in time domain at multipath reception
DVB-T
2K
∆f ~ 4kHz
∆t~250us
8K
∆f ~ 1kHz
∆t~1ms
∆t
Symbol
duration
∆t=1/∆f
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Intersymbol Interference (ISI)
Symboln+5
Symboln+2
Symboln+3
Symboln+4
Symboln
Symboln+1
Symboln+5
Symboln+2
Symboln+3
Symboln+4
Symboln
Symboln+1
∆t
∆t = Echo delay timeIntersymbol interference
+
=
Path1
Path2
Path1+2
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(Only) Micro Reflections in CATV
Time Attenuation
≤0.5 µs -20 dBc
≤1.0 µs -25 dBc
≤1.5µs -30 dBc
>2.0 µs -35 dBc
>3.0 µs -40 dBc
>4.5 µs -45 dBc
>5.0 µs -50 dBc
Micro-reflections in downstream(DOCSIS 3.1)
Time Attenuation
≤0.5 µs -16 dBc
≤1.0 µs -22 dBc
≤1.5µs -29 dBc
>2.0 µs -35 dBc
>3.0 µs -40 dBc
>4.5 µs -42 dBc
>5.0 µs -51 dBc
Micro-reflections in upstream(DOCSIS 3.1)
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OFDM Spectrum
∆f
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Orthogonality
∆t
∆f
tf
A(f)
sin(x)/xFouriertransform
∆f = 1/∆t
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OFDM Spectrum
∆f
Shoulder Shoulder
sin(x)/x functions
Carriers
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OFDM Spectrum
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OFDM – Edge Carriers switched off
2N carrier, but edge carriers are switched off: guard bandto attenuate the shoulders of the OFDM spectrum
Shoulders of OFDM spectrum
Channel M-1 Channel M Channel M+1
„Guard band“
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OFDM-Symbol
OFDMsymbol
duration ∆t
modulated OFDM carriers in time domain,discrete carriers ...
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OFDM SymbolOFDM carriers, in time domain, overlayed
OFDMsymbolduration ∆t
„noise-like“signal with highcrest factor
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Guard Interval / CP before and behind of the Symbol
OFDM Symbol
∆t
DOCSIS 3.1
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Guard Interval & Windowing
OFDM Symbol
∆t
DOCSIS 3.1
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Forward Error Correction (FEC)
Forward Error CorrectionFEC
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Transmission Channel – Channel Capacity
Channel bandwidth [Hz]
Cha
nnel
qua
lity
(SN
R [d
B])
Channel capacitydatarate
„Shannon“
CATV 6, 7, 8 MHz
Coax ... 32 dB .... HFC ... 40 dB ... 43 dB
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);1(log 2 N
SBC +⋅=
);log(10][
;3
1
N
SdBSNR
SNRBC
⋅=
⋅⋅≈
S/N>>1:
Example: B = 1GHz, SNR = 40 dBC = 13.3 Gbit/s;
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Channel codingChannel coding
Block codes
Convolutional codes
(1955: Elias,1967: Andrew Viterbi)
Concatenatedcodes
(1966: David Forney)
BCH(1960)
Reed-Solomon(1963)
Hamming(1950)
Turbocodes(1993:concat.convol. codes)
LDPC(1963: Gallager)
usinggroup/fieldtheoryof linearalgebra
Data Code
++
++ ++
in
out1
out2
Block code+interleaver+block code
Block code+interleaver+
Convol. code
Cyclicalgroup code
Generalblock code
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Block Code
Data
Algorithm(linear algebra)
Code
k lm
m = k + l
Example: DVB Reed-Solomon code:k = 188 byte, l = 16 byte, m = 204 byte
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Convolutional Coding
+
+ +
in
out1
out2
Shift registers
code rate =data rate in /data rate out;
EXOR
EXOR
Example: GSM, UMTS, DVB inner coder
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Typical FEC Structure
Basebandscrambler
FEC-1 Interleaver FEC-2Data
inDataout
FEC-1FEC-2
... brakes upones and zerossequences
... distributesinformation overtime ...
... adds dataoverhead tothe data stream
... adds dataoverhead tothe data stream
code ratecode rate
data rate in data
rat
e ou
t
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DVB-T FEC Structure
Basebandscrambler
Reed-Solomon188, 204
Forneyinterleaver
Convol.coder &
puncturing
Datain
Dataout
FEC-1FEC-2
... brakes upones and zerossequences
... distributesinformation overtime ...
... adds dataoverhead tothe data stream
... adds dataoverhead tothe data stream
188/204code rate
data rate in data
rat
e ou
t
„squeeze“puncturing
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DVB-T2 & DOCSIS3.1 FEC Structure
Basebandscrambler
BCHcoder
LDPCcoder
Bitinterleaver
Datain
Dataout
FEC-1FEC-2
... brakes upones and zerossequences
... distributesinformation overtime ...
... adds dataoverhead tothe data stream
... adds dataoverhead tothe data stream„Low Density ParityCheck Coding“
code ratedata rate in da
ta r
ate
out
BCH=Bose-Chaudhuri-HocquenghemLDPC=Low Density Parity Check Code
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OFDM Subcarriers
f
Channel bandwidth
∆f
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Orthongonality
∆f
Orthogonality condition: ∆f = 1/∆t
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OFDM ... Pilots ... (Example: DVB-T)
TPS=TransmissionParameterSignalling;BPSK modulated;signalling ofDVB-T transmissionparameters
Scattered pilots =„sweep signal“(channel estimation andcorrection)
Continual Pilots,fixed position inspectrum andin constellationdiagram(AFC =AutomaticFrequencyControl)
Rotating constellationsin the receiver in case of afrequency deviation;� frequency correction (AFC)using continual pilots
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Constellations Diagram, showing Pilot Signals
Example: DVB-T
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Pilot Pattern
….
….
0 i
Frequency (carrier no.)
….
….
d1
d2
d3
d1 = distance between scattered pilot carrier positionsd2 = distance between scattered pilots in one symbold3 = symbols forming one scattered pilot sequence
Time
Edgepilot
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Bulding OFDM Frames ... (1)
OFDMsymbol
duration ∆t
Modulated OFDM carrier signals in time domain,discrete carriers shown ...
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Building OFDM Frames ... (2)OFDM carriers, in time domain, overlayed
OFDMsymbolduration ∆t
„noise-like“signal with high„crest factor“
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Building OFDM Frames ... (3)
Symbol n+1Symbol n
Guard intervalcyclical prefix (CP)
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From a OFDM Symbol to a OFDM Frame (4) ...
....
OFDMframe
S1 SnS2
S1 ... Sn = OFDM symbols incl. guard interval
n symbols = 1 frame
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From a OFDM symbol to a OFDM Frame ... (5)
....
DVB-TOFDMframe
S1 S68S2
....
DABOFDMframe
S1 S76S2TFPR
67 TPS bits, scattered pilots ...
Nullsymbol
....
DVB-T2OFDMframe
S1 SnS2P1 P2 Payload symbols
Preamble symbols
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OFDM in Time and Frequency Domain (6)
„Slot“
Time
Frequency
n OFDMcarriers
m OFDM symbols
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DOCSIS 3.1 Upstream
DOCSIS3.1Upstream
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From DVB-C2 to DOCSIS 3.1DOCSIS Intro and Principle
Single Carrier Modulation Principle
Time Domain and Spectrum Domain
QAM and SNR Requirement
OFDM Basics, OFDM in CATV
DOCSIS 3.1 Physical Layer Parameters
DOCSIS 3.1 Demo Transmission
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From DVB-C2 ... to ... DOCSIS 3.1
DVB-C2 based on DVB-T2• narrow-band channel design (6, 8 MHz) with wide-band channel-bonding option• Long interleaver design for broadcast applications• Narrow OFDM subcarrier distance 1.7/2.2 kHz (4K mode in 6, 8 MHz)• Only downstream, no upstream defined
DOCSIS 3.1 design• wideband-band channel design (192 MHz) with narrow band option ( ... 24 MHz)• Optimized for short response time ... 1 ms• Wide OFDM subcarrier distance 25/50 kHz (4K / 8K mode in 192 MHz)• Downstream and upstream
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DOCSIS 3.1 Downstream, Upstream
CMTSCable
modemtermination
systemIP RF
RF
Cablemodem
RF
Coax/HFC
IP
Phone
DOCSIS
Return channel
Downstream
Upstream
DOCSIS – Data-over-Cable Service Interface Specification
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DOCSIS 3.1 Downstream
Parameter DOCSIS 3.1 DOCSIS 3.0
Type of modulation OFDM4K and 8 K FFT
single carrier(J.83/B, DVB-C)
Frequency range 108 MHz to 1218 MHz(1794 MHz)
45 MHz to1002 MHz
Channel bandwidth up to 192 MHz 6 MHz / 8 MHz
QAM constellations up to 4096, 8k, 16k up to 256
Cyclic prefix length 0.9375 µs to 5 µs n/a
Pilots scattered and continuous n/a
Forward Error Correction BCH-LDPC Reed-Solomon
DS capacity (bps) 8 G (10 G) 300 M (1 G)
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25 kHz / 50 kHz carrier spacing7680 / 3840 carriers in 192 MHz bandwidth
up to 16384QAM
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DOCSIS 3.1 Upstream
Parameter DOCSIS 3.1 DOCSIS 3.0
Type of modulation OFDM2K and 4 K FFT
single carrierTDMA, S-CDMA
Frequency range 5 MHz to 204 MHz 5 MHz to 85 MHz
Channel bandwidth up to 96 MHz up to 6.4 MHz
QAM constellations up to 4096 QPSK to 64
Cyclic prefix length 0.9375 µs to 6.25 µs n/a
Pilots complimentary and continuous
n/a
Forward Error Correction LDPC Reed-Solomon
DS capacity (bps) 400 M (1 G to 2.5 G) 100 M (300 M)
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25 kHz / 50 kHz carrier spacing3840 / 1920 carriers in 96 MHz bandwidth
up to 4096QAM
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DOCSIS 3.1 Frequency Plan
FM
sou
nd b
road
cast
88.5
...10
8 M
Hz
DOCSIS1.0...3.0Upstream5...65 MHz
f/MHz
f/MHz
Band I 47...68 MHzBand II 87.5...108 MHzS 104...174 MHz (Midband)Band III 174...230 MHzS 174...300 MHz (Superband)S 302...470 MHz (Hyperband)Band IV 470 ...582 MHzBand V 582...862 MHz
DOCSIS 3.1Upstream
5...204 MHz(42/65/85/117/204 MHz)
Air
traf
fic c
ontr
ol 1
18...
136
MH
z
ATV/DTV Broadcast108...862 MHz
862 MHz600 MHz
DOCSIS1.0..3.0Downstream450...862 MHz
DOCSIS 3.1Downstream
258 (108)...1218 (1794) MHz
Current CATV frequency occupation
DOCSIS 3.1 frequency plan
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DOCSIS 3.1 Channel Occupation
f/MHz
f/MHz
Current CATV frequency occupation
DOCSIS 3.1
FM
sou
nd b
road
cast
88.5
...10
8 M
Hz
DOCSIS 3.1Upstream
5...204 MHz(42/65/85/117/204 MHz)
DOCSIS 3.1Downstream
258...1218 (1794) MHz
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DOCSIS 3.1 Upstream Structure
Minislot Minislot Minislot
Minislot Minislot Minislot
Minislot Minislot Minislot
Minislot Minislot Minislot
Time
Frequency
n OFDMcarriers
m OFDM symbols
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DOCSIS 3.1 Downstream Spectrum
Center carriercarrier # m
Channelbandwidth
IFFTbandwidth
Signalband width
Carrier # e Carrier # w
4K/8K mode
max. 190 MHz 7600 or 3800 active
carriers)
Channel bandwidth192 MHz (7680 or
3840 totalno. of carriers)
25 kHz / 50 kHz carrier spacing7680 / 3840 carriers
configurabledownstream
channelspacing
from24 ... 192 MHz
downstreamoperating
frequency range54 ... 1002 MHz
(1218/1794 MHz)
204.8 MHz
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DOCSIS 3.1 Upstream Spectrum
Center carriercarrier # m
Channelbandwidth
IFFTbandwidth
Signalband width
Carrier # e Carrier # w
25 kHz / 50 kHz carrier spacing3840 / 1920 carriers
Channel bandwidthmax. 96 MHz (3840 or
1920 totalno. of carriers)
max. 95 MHz 3800/1900 active
carriers)
configurableupstreamchannelspacing
up96 MHz
upstreamoperating
frequency range5 ... 204MHz
2K/4K mode102.4 MHz
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Single Carrier Spectrum versus OFDM Spectrum
Typical single carrier spectrumwith roll-off
Typical OFDM spectrum
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Single Carrier Spectrum versus OFDM Spectrum
Typical single carrier spectrumwith roll-off
Wide-band DOCSIS OFDM „channel“
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Pilots in DOCSIS 3.1DOCSIS 3.1 spectrum contains
• data subcarriers, different modulation parameters due to profiles• continous pilots (fix position, for AFC)• scattered pilots (var. position for measurement purposes)• PLC subcarriers• exluded carriers that are set to zero
guard bandguard band
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Pilots in DOCSIS 3.1
guard bandguard band
f frequency
t time
Symbols
cont
inou
s pi
lots
PLC
car
riers
Sca
ttere
d pi
lots
preamble
NC
P n
ext c
odew
ord
poin
ter
excl
uded
car
riers
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PLC = physical layer link channel
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PLC – Physical Layer Link Channel
FFT size Subcarrier spacing Number of PLCsubcarriers per symbol
4096 50 kHz 8
8192 25 kHz 16
PLC contains physical layer parameters for the cable modem (CM)
PLC constists of preamble and PLC data
Modulation of PLC carriers is BPSK for preamble and 16QAM for PLC data
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Profiles
NCP = Next Codeword Pointer = lowest layer; QPSK, 16QAM, 64QAMNCP points to the beginning of the codewords of the profiles in a symbol
16 profiles (QPSK, ... 16KQAM)
Profile data are interleaved (interleaver depth 1...32)
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Profiles in DOCSIS 3.1 ...
CMTS
Headend
CM CM CM CM
CM CM CM CM
CM CM CM CM
different SNRup to 16profiles usingdifferent QAM
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DOCSIS 3.1 Downstream Spectrum
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DOCSIS 3.1 Modulation ParameterModulationmodedownstream
min CNR(AWGN)(... 1GHz)
min CNR(AWGN)(...1.2GHz)
16QAM 15.0 dB 15.0 dB
64QAM 21.0 dB 21.0 dB
128QAM 24.0 dB 24.0 dB
256QAM 27.0 dB 27.0 dB
512QAM 30.5 dB 30.5 dB
1024QAM 34.0 dB 34.0 dB
2048QAM 37.0 dB 37.5 dB
4096QAM 41.0 dB 41.5 dB
8192QAM
16384QAM
Modulationmodeupstream
min CNR(AWGN)
QPSK 11.0 dB
8QAM 14.0 dB
16QAM 17.0 dB
32QAM 20.0 dB
64QAM 23.0 dB
128QAM 26.0 dB
256QAM 29.0 dB
512QAM 32.5 dB
1024QAM 35.5 dB
2048QAM 39.0 dB
4096QAM 43.0 dB
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DOCSIS 3.1 Constellation Diagram, No Payload,only PLC and Pilots
PLC = physical layer link channel
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DOCSIS 3.1 Downstream, Pilots, Signalling and 64QAM Payload Profile
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DOCSIS 3.1 Downstream, Pilots, Signalling, 64QAM, 256QAM Payload Profile
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DOCSIS 3.1, ... 1024QAM
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DOCSIS 3.1 Downstream, ... 4096QAM
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DOCSIS 3.1, ... 16KQAM
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Guard Interval / CP before and behind of the Symbol
OFDM Symbol
∆t
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Guard Interval & Windowing
OFDM Symbol
∆t
Tukey-rised cosine windowingin DOCSIS 3.1
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DOCSIS 3.1 Cyclic PrefixCP lengthupstream2K / 4K mode
CP length in elementary periodes
0.9376 µs 96 • TSU
1.25 µs 128 • TSU
1.5625 µs 160 • TSU
1.875 µs 192 • TSU
2.1875 µs 224 • TSU
2.5 µs 256 • TSU
2.8125 µs 288 • TSU
3.125 µs 320 • TSU
3.75 µs 384 • TSU
5.0 µs 512 • TSU
6.25 µs 640 • TSU
CP lengthdownstream4K / 8K
CP length in elementary periodes
0.9376 µs 192 • TSD
1.25 µs 256 • TSD
2.5 µs 512 • TSD
3.75 µs 768 • TSD
5 µs 1024 • TSD
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DOCSIS 3.1 Cyclic PrefixCP lengthdownstream4K / 8K
CP length in elementary periodes
0.9376 µs 192 • TSD
1.25 µs 256 • TSD
2.5 µs 512 • TSD
3.75 µs 768 • TSD
5 µs 1024 • TSD
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DOCSIS 3.1 FEC – Forward Error Correction
BCH InterleaverLDPCin out
Downstream - FEC
LDPCin out
Upstream - FEC
Interleaver depth 0...32
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FSW DOCSIS 3.1 Analysis
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From DVB-C2 to DOCSIS 3.1DOCSIS Intro and Principle
Single Carrier Modulation Principle
Time Domain and Spectrum Domain
QAM and SNR Requirement
OFDM Basics, OFDM in CATV
DOCSIS 3.1 Physical Layer Parameters
DOCSIS 3.1 Demo Transmission
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CLGD … Simulating Multichannel CATV Load
ATVDVB-CDOCSIS
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SFD … Single Channel DOCSIS 3.0/3.1/ARBGenerator
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R&S FSW-K192 DOCSIS 3.1 Downstream Measurement ApplicationR&S FSW-K193 DOCSIS 3.1 Upstream Measurement Application
DOCSIS 3.1 Signal Analysis … using R&S FSW
9912-2016 DOCSIS 3.1 Signal Analysis
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CATV Demo Transmission Link
DOCSIS 3.1 / DVB-C CATV lab network 10015.03.2017
Demo setup in Teisnach, Germany, June 2016
Source„CATV“ Headend
signal source:SFD
CLDGBTC
Sink„CATV“
enduser equipmentanalyzer:
ETLFSWOptical link
3 CATV amplifier pluscoax cable simulation
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CATV Demo Transmission Link
DOCSIS 3.1 / DVB-C CATV lab network 10115.03.2017
Optical fibre link
Laser Optical node
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CATV Demo Transmission Link
DOCSIS 3.1 / DVB-C CATV lab network 10215.03.2017
3 CATV amplifier pluscoax cable simulation
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DOCSIS3.1 – Signal from CLGD, measured with FSW
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CLGD Signal (DVB-C Multi-Channel and DOCSIS3.1)
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Single DVB-C Signal from SFU
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Signal before Optical Link at Network Input
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DOCSIS at Network Input
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MER = 48 dB
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DOCSIS - 1024QAM at the Input of the Cascade(CLGD Output)
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DOCSIS - 4kQAM at CLGD Output (Begin ofCascade)
15.03.2017 DOCSIS 3.1 / DVB-C CATV lab network 109
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DOCSIS - 16kQAM at CLGD Output (Begin ofCascade)
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Spectrum, after Optical Link
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Spectrum after 3rd Amplifier
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DOCSIS3.1 after Optical Link
15.03.2017 DOCSIS 3.1 / DVB-C CATV lab network 113
MER = 43 dB
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DVB-C at the End of the Cascade
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DOCSIS3.1 at the End of the Cascade
15.03.2017 DOCSIS 3.1 / DVB-C CATV lab network 115
MER = 37 dB
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1024QAM at the End of the Cascade
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4096QAM at the End of the Cascade
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16384QAM (16kQAM) at the End of the Cascade
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Walter FischerRohde&Schwarz
Training Center MunichEmail: [email protected]
Thank you very much!
16.3.2017