Teknik Modulasi Pertemuan 07

Presentasi berjudul: "Teknik Modulasi Pertemuan 07"— Transcript presentasi:

1 Teknik Modulasi Pertemuan 07
Matakuliah : H0484/Jaringan Komputer Tahun : 2007 Teknik Modulasi Pertemuan 07

2 Pada akhir pertemuan ini, diharapkan mahasiswa akan mampu :
Learning Outcomes Pada akhir pertemuan ini, diharapkan mahasiswa akan mampu : Menjelaskan teknik modulasi Bina Nusantara

3 Outline Materi Teknik Modulasi Modulasi analog Modulasi digital
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4 Analog data, carrier analog signal Digital data, carrier analog signal
Encoding Techniques Analog data, carrier analog signal Digital data, carrier analog signal Analog Modulation Analog data, carrier digital signal Digital Modulation Digital data, carrier digital signal Encoding Bina Nusantara

5 Analog Data, Analog Signals
Why modulate analog signals? Higher frequency can give more efficient transmission Permits frequency division multiplexing Types of modulation Amplitude Frequency Phase Bina Nusantara

6 Analog Modulation Bina Nusantara

7 Memperbesar jarak jangkau sinyal informasi.
Modulasi Tujuan: Mengubah sinyal komputer yang digital menjadi sinyal analog yang diperlukan oleh saluran komunikasi. Memperbesar jarak jangkau sinyal informasi. Modem merupakan perangkat keras untuk kedua proses ini Bina Nusantara LST/FASKD/CINQ

8 Type Modulasi Digital /Analog
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9 Modulation Techniques
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10 Frequency Shift Keying
Most common form is binary FSK (BFSK) Two binary values represented by two different frequencies (near carrier) Less susceptible to error than ASK Up to 1200bps on voice grade lines High frequency radio Even higher frequency on LANs using coax Bina Nusantara

11 Phase of carrier signal is shifted to represent data Binary PSK
Phase Shift Keying Phase of carrier signal is shifted to represent data Binary PSK Two phases represent two binary digits Differential PSK Phase shifted relative to previous transmission rather than some reference signal Bina Nusantara

12 Each element represents two bits
Quadrature PSK More efficient use by each signal element representing more than one bit e.g. shifts of /2 (90o) Each element represents two bits Can use 8 phase angles and have more than one amplitude 9600bps modem use 12 angles , four of which have two amplitude Bina Nusantara

13 4-PSK Constellation Bina Nusantara

14 Quadrature Amplitude Modulation
QAM used on asymmetric digital subscriber line (ADSL) and some wireless Combination of ASK and PSK Logical extension of QPSK Send two different signals simultaneously on same carrier frequency Use two copies of carrier, one shifted 90° Each carrier is ASK modulated Two independent signals over same medium Demodulate and combine for original binary output Bina Nusantara

15 4-QAM and 8-QAM Bina Nusantara

16 PULSE AMPLITUDE MODULATION
Pulse amplitude modulation has some applications, but it is not used by itself in data communication. However, it is the first step in another very popular conversion method called pulse code modulation. Bina Nusantara

17 Pulse Code Modulation (PCM)
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