9/26/2004 5. Analog Transmisison - Lin 1 CPET/ECET 355 CPET/ECET 355 5. Analog Transmission Data Communications and Networking Fall 2004 Professor Paul I-Hai Lin Electrical and Computer Engineering Technology Indiana University-Purdue University Fort Wayne www.ecet.ipfw.edu/~lin
CPET/ECET 355. 5. Analog Transmission Data Communications and Networking Fall 2004 Professor Paul I-Hai Lin Electrical and Computer Engineering Technology Indiana University-Purdue University Fort Wayne www.ecet.ipfw.edu/~lin. Analog Transmission - Outlines. Modulation of Digital Data - PowerPoint PPT Presentation
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9/26/20045. Analog Transmisison - Lin1
CPET/ECET 355CPET/ECET 3555. Analog Transmission
Data Communications and NetworkingFall 2004
Professor Paul I-Hai LinElectrical and Computer Engineering TechnologyIndiana University-Purdue University Fort Wayne
www.ecet.ipfw.edu/~lin
9/26/20045. Analog Transmisison - Lin2
Analog Transmission - OutlinesAnalog Transmission - Outlines1. Modulation of Digital Data
Bit rate and Baud rate Carrier signal Amplitude Shift Keying (ASK) Frequency Shift Keying (FSK) Phase Shift Keying (PSK) Quadrature Amplitude Modulation (QAM)
5.1 5.1 Modulation of Digital DataModulation of Digital Data (cont.)(cont.)
Bandwidth of ASK– BW = (1 +d) * Nbaud
Where d: modulation factor, Nbaud = baud rate If d = 0, BW = Nbaud
– Bit rate = baud rate
From p. 119, Figure 5.4 of Data Communications and Networking, Forouzan, McGrawHill
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5.1 5.1 Modulation of Digital DataModulation of Digital Data (cont.)(cont.)
Example 3– Find the min BW for an ASK signal
transmitting at 2000 bps. The transmission mode is half-duplex.
– Ans: BW = Nbaud = 2000 Hz Example 4
– Given a bandwidth of 5000 Hz for an ASK signal, what are the baud rate and bit rate?
– Ans: In ASK, Bit rate = Baud rate = 5000 bps
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5.1 5.1 (cont.)(cont.) Example 5
– Given a BW of 10,000 Hz (1000 to 11,000 Hz), draw the full-duplex ASK diagram of the system. Find the carriers and the BWs in each direction. Assume there is no gap between bands in the two directions.
From p. 119, Fig 5.5, Data Communications and Networking, Forouzan, McGrawHill
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5.1 Frequency Shifting Keying 5.1 Frequency Shifting Keying (FSK)(FSK) Varying frequency of carrier signal to
represent 1 or 0 Amplitude and phase remain
constant
From p. 120, Fig 5.6, Data Communications and Networking, Forouzan, McGrawHill
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5.1 FSK 5.1 FSK (cont.)(cont.)
Bandwidth = Fc1 – Fc0 + Nbaud
From p. 121, Fig. 5.7, Data Communications and Networking, Forouzan, McGrawHill
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5.1 FSK 5.1 FSK (cont.)(cont.)
Example 6: Find the min BW for an FSK signal transmitting at 2000 bps. Transmission is in half-duplex mode, and the carriers are separated by 3000 Hz.– Ans:
BW = Nbaud + Fc1 – Fc0 = 2000 + 3000 = 5000 Hz Example 7: Find the maximum bit rates for an
FSK signal if the BW of the medium is 12kHz and difference between the two carriers is 2000 Hz. Transmission is in full-duplex mode.– Ans: