Download TRANSMISI

Modul – 2
Sistem Transmisi
TE-09-1313
2 sks
Tim Bidang Studi
Telekomunikasi Multimedia
(Achmad Ansori, Devy Kuswidiastuti, Gatot Kusrahardjo, M Aries Purnomo)
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TRANSMISI
• The transfer of
information from one
point to one or more
other points by means
of signals
( Rec ITU-R V.662-3-2000 )
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TRANSMISI - (1)
• Simplex
Pemancar
Penerima
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TRANSMISI - (2)
• Duplex / Full Duplex
Pemancar
Penerima
Penerima
Pemancar
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TRANSMISI - (3)
• Half / Semi Duplex
Pemancar
Penerima
Penerima
Pemancar
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TRANSMISI - (4)
• Point to point
• Communication provided by a link, for example, a
radio-relay link between two stations located at
specified fixed points.
• STL ( Studio to Transmitter Link )
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TRANSMISI - (5)
• Point to Multipoint
• Communication provided by links, for example, radio-relay
links between a single station located at a specified fixed
point and a number of stations located at specified fixed
points.
Contoh :
TV Cable
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TRANSMISI - (6)
• Point to Area
• Communication provided by links between a station located
at a specified fixed point and any number of stations located
at non-specified points in a given area which is the coverage
area of the station located at the fixed point.
Contoh :
Stasiun Radio FM
Stasiun Televisi
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TRANSMISI – (7)
• Multipoint to Point ( Data Collecting )
Contoh :
Wireless sensor
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TRANSMISI - (8)
• Conference
Contoh :
Teleconference
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SINYAL
A physical phenomenon one or
more of whose characteristics
may vary to represent information.
NOTE – The physical phenomenon may be for
instance an electromagnetic wave or acoustic wave
and the characteristic may be an electric field,
a voltage or a sound pressure.
( Rec ITU-R V.662-3-2000 )
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Jenis Sinyal
• Analog
• Diskrit
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Sinyal Analog (1)
• A signal one of whose characteristic quantities follows
continuously the variations of another physical quantity
representing information.
• ITU T G.701 : vocabulary of digital transmission and
multiplexing, and pulse code modulation (PCM) terms,
Karakteristik :
• Amplitudo
• Frekuensi
• Phase
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Sinyal Analog (2)
+
Amplitudo
t
T = periode = 1/f
1 Hertz (Hz) = 1 cps
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Sinyal Analog (3)
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Discretely-timed signal (1)
• A signal composed of successive elements in time, each
element having one or more characteristics which can
convey information, for example, its duration, its waveform
and its amplitude.
• ITU T G.701 : vocabulary of digital transmission and
multiplexing, and pulse code modulation (PCM) terms,
Karakteristik :
• Amplitudo
• Lebar ( durasi )
• Bentuk gelombang
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Discretely-timed signal (2)
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Sinyal Digital (1)
• A discretely timed signal in which information is represented
by a number of well-defined discrete values that one of its
characteristic quantities may take in time.
• NOTE – The term may be qualified to indicate the digit rate,
for example: “140 Mbit/s digital signal”.
• ITU T G.701 : vocabulary of digital transmission and
multiplexing, and pulse code modulation (PCM) terms,
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signal element
A part of a digital signal, characterized by its discrete timing
and its discrete value, and used to represent a digit.
Digit
A member selected from a finite set.
binary figure
One of the two figures (that is, 0 or 1) used in the representation
of numbers in binary notation.
binary digit (bit)
A member selected from a binary set
NOTES
1. Bit is an abbreviation for binary digit.
2. In the interest of clarity, it is recommended that the term “bit” should not be used in
two-condition start-stop modulation instead of “unit element”.
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Octet
A group of eight binary digits or eight signal elements
representing binary digits operated upon as an entity.
code word [character signal]
A set of signal elements representing the quantized value of a
sample in PCM.
NOTE – In PCM, the term “PCM word” may be used in this
sense.
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Sinyal :
A physical phenomenon one or more of whose
characteristics may vary to represent information.
NOTE – The physical phenomenon may be for instance
an electromagnetic wave or acoustic wave and the characteristic may
be an electric field, a voltage or a sound pressure.
( Rec ITU-R V.662-3-2000 )
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Informasi
Information :
• Intelligence or knowledge capable of being represented in
forms suitable for communication, storage or processing.
• Suara / Voice : percakapan (speech) , musik
• Tanda-tanda / isyarat
• Tulisan ( text )
• Gambar : diam , bergerak ( video )
• Gabungan ( Multimedia )
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Characteristics of signal
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NOTE – The physical phenomenon may be for instance
an electromagnetic wave or acoustic wave and
the characteristic may be an electric field, a voltage or
a sound pressure.
( Rec ITU-R V.662-3-2000 )
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Satuan (1)
• Daya ( Power ) :
kiloWatt (kW), Watt (W),milliWatt (mW)), mikroWatt
(µW), picoWatt (pW)
1 kW = 1.000 W = 10E3 W =
1.000.000 mW = 10E6 mW =
1.000.000.000 W = 10E9 W =
1.000.000.000.000.000 pW = 10E15 pW
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Satuan (2)
1 pW = 0,000.001 W = 10E-6 W =
0,000.000.001 mW = 10E-9 mW =
0,000.000.000.001 W = 10E-12 W =
0,000.000.000.000.001 kW = 10E-15 kW
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Satuan (3)
• Tegangan ( Voltage ) :
kiloVolt (kV), Volt (V), milliVolt (mV), mikroVolt (µV)
• Arus ( Current ) :
Ampere (A), milliAmpere (mA), mikroAmpere (µA)
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Satuan (4)
• Frekuensi :
Hertz (Hz), kiloHz (kHz), MegaHz (MHz),
GigaHz (GHz), TeraHz (THz)
1 THz = 1.000 GHz = 10E3 GHz =
1.000.000 MHz = 10E6 MHz =
1.000.000.000 kHz = 10E9 kHz =
1.000.000.000.000 Hz = 10E12 Hz
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Satuan (5)
• Kuat Medan Listrik :
Volt/meter ( V/m ), µVolt/meter ( µV/m )
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Daya, Tegangan dan Arus
• Daya = Tegangan x Arus
• Satuan :
Daya : Watt , Tegangan : Volt , Arus : Ampere (Amp)
• P=VxI
• V=IxR
dimana R : tahanan, Ohm ()
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Model Sistem Komunikasi Listrik
Pemancar
Media
Penerima
- Wire / kawat / kabel
- Wireless / radio / optik
Transducer
Transducer
Informasi
Informasi
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Elements of a Communication System
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Noise (in telecommunication);
Any variable physical phenomenon apparently not conveying
information and which may be superimposed on, or combined
with, a wanted signal.
Interference (to a wanted signal):
Disturbance of the reception of a wanted signal caused by
interfering signals, noise or electromagnetic disturbance.
NOTE :
The term “radio-frequency noise” and
“radio-frequency interference” are defined in Rec ITU-R V.573.
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Radio (frequency) noise :
A time-varying electromagnetic phenomenon having components
in the radio-frequency range, apparently not conveying
Information and which may be superimposed on, or combined
with, a wanted signal.
Radio-frequency disturbance :
Any electromagnetic phenomenon having components in the
radio-frequency range, which may degrade the performance of
a device, equipment or system, or affect adversely living or
inert matter.
Note :
A radio-frequency disturbance may be a radio-frequency noise,
an unwanted signal or a change in the propagation medium itself.
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Radio-frequency interference (RFI) :
Degradation of the reception of a wanted signal caused by
a radio-frequency disturbance.
Interfering source :
An emission, radiation, or induction which is determined to be
a cause of interference in a radiocommunication system.
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Signal-to-interference ratio; signal/interference ratio :
The ratio, generally expressed in decibels, of the power of the
wanted signal to the total power of interfering signals and noise,
evaluated in specified conditions at a specified point of a
transmission channel.
Note 1 : A distinction is made, for example, between:
– at the receiver input,
the radio-frequency (RF) signal-to-interference ratio;
– at the receiver output,
the audio-frequency (AF) signal-to-interference ratio
and the video-frequency (VF) signal-to-interference ratio.
Note 2 : In each individual case, the noise and interfering signals
taken into account should be specified.
Note 3 : The term “signal-to-disturbance ratio” or its abbreviated
form “signal/disturbance ratio”, which is already used for
electromagnetic compatibility, may be used as a synonym.
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Spot noise temperature (of a one-port network) :
The exchangeable noise power spectral density at a given
frequency of a one-port electrical network, divided by
Boltzmann’s constant. ( k = 1,3803.10e-23 J/ºK )
Note 1 : This definition assumes that quantum effects are negligible.
Note 2 : The spot noise temperature has the sign of the real part of the
network impedance.
Note 3 : If the network has an impedance with a positive real part,
its noise temperature at a given frequency equals the
thermodynamic temperature to which a resistor equal in
value to the real part of the impedance should be brought
in order to obtain an available power of thermal noise equal to
the available power of the noise of the network at the same
frequency.
Note 4 : A receiving antenna can be regarded as a one-port electrical
network when viewed from its output port.
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Equivalent (spot) noise temperature
(of a linear two-port network) : Symbol: T( f )
The amount by which at a given frequency the noise temperature
of a one-port electrical network connected to the input of a given
linear two-port electrical network would have to be increased, if
the noise due to this two-port network was temporarily
suppressed, in order to cause the noise power spectral density
at the output frequency corresponding to input frequency, to be
the same as that of the total noise of the one-port and two-port
networks.
Note 1 – This definition assumes that quantum phenomena are
negligible.
Note 2 – The equivalent spot noise temperature of a two-port network
is dependent on the impedance of the one-port network
connected to input.
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Spot noise factor, spot noise figure
(of a linear two-port network) :
Symbol: F( f )
The ratio of the exchangeable power spectral density of the
noise appearing at a given frequency at the output of a given
linear two-port electrical network, to the spectral density which
would be present at the output if the only source of noise were
the thermal noise due to a one-port electrical network connected
to the input and which is assumed to have at all frequencies a
noise temperature equal to the reference thermodynamic
temperature fixed, by convention, around 290 K.
290 K = 17ºC
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Note 1:
The spot noise factor F( f ) is related to the equivalent spot
noise temperature T( f ) as follows:
where Tₒ is the thermodynamic reference temperature.
Note 2 :
The value of the ratio F( f ) may be expressed in decibels.
In English, the term “noise factor” is generally employed when
the ratio is expressed arithmetically, and “noise figure” is
employed when the ratio is expressed in decibels.
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