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PAGE 1 PAGE 10 COE 342 – Data Communications (Sec. 1) Fall 001 Exam II Exam is closed book and notes Date : Tuesday 21 November, 2000. Time : 8:00 pm - 8:30 pm. Location : Rooms 24/120-121 Name : ID Number : QuestionGradeQn. 1. (10)Qn. 2. (20)Qn. 3. (20)Qn. 4. (20)Qn. 5. (35)Qn. 6. (05)Qn. 7. (10)Qn. 8. (15)Total (125) Instructor : Dr. Habib Youssef Qn.1. (10 pts.) For the statements listed below, mark with T if the statement is completely true, and with F if the statement is partially or completely False. AM modulation requires twice the bandwidth of the carrier signal. For AM modulation, the DSBSC and SSB signals require less power to transmit and are easier to demodulate than DSBTC signals. To economize on bandwidth and power requirements, SSB is preferred, where the AM DSBTC signal is amplified, the carrier and one of the sidebands suppressed, and finally the resulting signal transmitted. FM requires five to ten times the carrier bandwidth. A PCM-CODEC performs the reverse process of a MODEM. FM and PM are special cases of angle modulation. The bandwidth requirement of angle modulation increases with the amplitude of the data signal. Balanced signal transmission is more immune to noise than unbalanced transmission. Manchester encoding has a problem with long streams of alternating 0s and 1s. One disadvantage of Non-Return-to-Zero (NRZ) signal encoding is the difficulty of synchronization for data signals that have long streams of 0s or long streams of 1s. Qn.2. (20 pts.) Select the correct option. A modulated signal is formed by changing the modulating signal by the carrier wave changing the carrier wave by the modulating signal sampling of the data signal at the frequency of the carrier sampling of the data at the Nyquist rate In ASK the strength of the carrier signal is varied to represent binary 0 and 1 the strength of the data signal is varied to represent binary 0 and 1 the peak amplitude of the carrier s