QAM Quadrature Amplitude Modulation

Presentasi berjudul: "QAM Quadrature Amplitude Modulation"— Transcript presentasi:

1 QAM Quadrature Amplitude Modulation
Sigit Kusmaryanto

2 Gambar-1 : Bagan Pemancar QAM
Modulator AM 2-4 level Converter fb/2 QAM Oscilator lokal I Data Pembagi Data fb  Biner Q 90º fb/2 2-4 level Converter Modulator AM

3 Gambar-2 : Pola Konstelasi Sinyal
Q • • • • I

4 Gambar-3 : Spektrum QAM Pita sisi bagian bawah Pita sisi bagian atas
f (Hz) fc - B fc fc + B BT = 2B

5 Gambar-4 : Diagram Modem QAM
Pentransmisi Cos ct ai Pembentukan Masukan biner Penyangga dan pengkode 1/T Luaran QAM R bit/detik 1/T simbol/detik bi Pembentukan T = n/R ( Menyimpan n bit ) Sin ct Penerima Luaran-luaran biner Masukan QAM Pengurai kode Filter lolos pita Penemu-penemu sinkron R bit/detik 1/T 1/T simbol/detik

6 Gambar-5 : Eye Patterns ( Pola Mata )
Normal Noise yang berlebihan

7 REFERENSI Feher, Kamilo Advanced Digital Communication . USA : prentice-Hall Haykin, Simon An Introduction to Analog and Digital Communications . Singapore : John Willey Lathi , B . P Modern Digital and Analog Communication System . USA : Holt – Saunders. Schwartz , Mischa Transmisi , Informasi , Modulasi dan Bising . Terjemahan Srijatno W., Ph.D. Jakarta : Erlangga. Smith , David R Digital Transmission Systems . New york :Van Nostrand Reinhold Company . Stallings , William Data and Computer Communications. Singapore : Maxwell Macmilan International Edition. Roddy , Denis and John Coolen Electronic Communication . New Delhi : Prentice-Hall.