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APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY

FIRST SEMESTER M.TECH DEGREE EXAMINATION, DECEMBER
2015

(Electronics and Communication Engineering Department)

(Signal Processing)

(01 EC6205 ==ADVANCED DIGITAL COMMUNICATION)

Max. Marks : 60 Duration:3 hours

Answer any two full questions from each pan
PARTA

1. (a) Prove that if signal s(t) in corrupted by AWGN, the filter with an impulse response
matched to s(t) maximizes the output signal-to-noise ratio (5)

(b) Considering a signal communication system that transmits information in QAM over a

voice band telephone channel at a rate of 2400 symbols/sec and assuming the noise to
be white and Gaussian.

(i)Determine the Eb[No required to achieve an error probability of at 4800bits/sec and
19200 bits/sec.

(ii)What conclusions do you arrive from these results? (4)

2. (೩) With necessary diagrams explain 8PSK and 8QAM.Highlight the differences between
them. (5)

(b) Compare ASK,FSK and PSK. (4)

3.The telephone line which is having a bandwidth of 3KHz is used for full duplex

transmission of digital signals.What is the maximum rate of transmission(in bits per
second)if, (aJ)ASK,(b)FSK (c)PSK is used.

Assume that only the fundamental component is permitted to pass through the telephone line.

(9)