III B.Tech I Semester Supplementary Examinations, November 2005 DIGITAL COMMUNICATIONS ( Common to Electronics & Communication Engineering and Electronics & Telematics) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) With neat diagrams, explain the principle of working a sample and hold circuit. List out its applications. [8] ∞ ∞ P P (b) Show that x(RTs ) = fs X(nfs ) , where x(t) is a signal band R=−∞
n=−∞ 1 Ts
= 2f1 is the Nyquist [8]
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limited to f1 , X(f) is the spectrum of x(t), and fs = sampling rate.
2. (a) Describe the synchronization procedure for PAM, PWM and PPM signals. (b) Discuss about the spectra of PWM and PDM signals.
[10+6]
3. (a) Why the overall transfer function of the duo-binary filter is called as Half-cycle cosine function. [8]
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(b) Give the Impulse response of the duo-binary filter and sketch the amplitude and phase response. [8] 4. Write short notes on the following: (a) Adaptive equalizer. (b) Scrambler
(c) Characteristics of eye pattern.
[5+5+6]
5. (a) Draw the block diagram of PCM Generator and explain each block. [8+8]
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(b) Determine the Transmission Bandwidth in PCM.
6. In a single-integration DM system, the voice signal is sampled at a rate of 64kHz.The maximum signal amplitude is Amax=1. (a) Determine the minimum value of the step size σ to avoid slope over load error.
Aj
(b) Determine the granular noise power if the voice signals bandwidth is 3.5 kHz. (c) Assuming that the voice signal is sinusoidal, determine output signal power and SNR
(d) Determine the minimum transmission bandwidth.
[4+4+4+4]
7. (a) A bandpass data transmission scheme uses a PSK signaling scheme with S2 (t) = A cos Wc t, 0 ≤t ≤ Tb , Wc =10π/Tb S1 (t) = - A cos Wc t 0 ≤t ≤ Tb , Tb =0.2 msec 1 of 2
NR
Code No: NR310405
The carrier amplitude at the receiver input is 1mv and the psd of the additive white Gaussian noise at the input is 10−11 Watt/Hz. Assume that an ideal correlation receiver is used. Calculate the average bit error rate of the receiver.
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8. The convolutional encoder is given below Figure1:
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(b) Compare the average power requirements of binary non-coherent ASK, coherent PSK, DPSK signaling schemes operated at a data rate of 1000 bits/sec over a bandpass channel having a bandwidth of 3000Hz, η/2=10−10 Watt/Hz and Pe=10−5 . [8+8]
Figure 1:
(a) Find the code sequence for input message.
[6]
(b) Construct a code tree for the convolutional encoder for 3-bit input data. [10]
NR310405 III B.Tech I Semester Supplementary Examinations ...
8. The convolutional encoder is given below Figure1: · Figure 1: ... (b) Construct a code tree for the convolutional encoder for 3-bit input data. [10] · âââââ.
4. (a) Explain how eye patterns are used for monitoring the performance of base ... Eb/No. [8] · (b) Specify a matched filter receiver for the signal S(t) shown in ...
(b) The ground water level in a deposit of fine sand is 1.5 m below ground level. Above the water table ... is 21 kN/m3. Calculate the total stress, the neutral stress.
(b) Explain the following particle size measurement techniques. i. Sedimentation ... compaction. [6]. (b) Define Sintering and how is it different from hot pressing.
III B.Tech I Semester Supplementary Examinations, November 2005. AERO SPACE ... (b) Maximum energy theory. [16] ... plain with live examples. (b) Write a ...
4. What are the objectives of wage and salary administration function? [4+6+6] · 5. Write short notes on: · [4x4=16] · (a) Speculative purchasing · (b) Rate contract ...
(a) What are the different problems associated with measurement of low resis- · tances. Explain. (b) How these problems are eliminated by using Kelvins double ...
(b) What is score boarding and its use in RISC? [10] · 5. (a) Explain the salient features of Pentium architecture. [6] · (b) Draw the schematic blocks of Floating ...
Which one you are saving by using statistical time-division multiplexing and prove · it. [16M] · 8. Give two full duplex protocols and explain their operation? [16M].
(a) Pattern plating process. (b) Tenting process. [8+8] · 7. (a) Draw the schematic diagram of magnetic amplifier with a center tapped trans- · former and D.C. ...
A reversible engine operating between a reservoir at 600 K and the ambient at- · mosphere at ... Determine the ratio of energy rejected by both the devices to the.
What is degree of reaction of a gas turbine; how it can be controlled, derive its ... A single stage free vortex turbine is designed for zero degree of reaction at root.
(b) Discuss the help of computers in Cardio vascular evaluation in ICU. [8] · 7. Discribe the use of computers for handicapped persons. Give two examples and.
(a) Explain the pre-anesthetic care and preparation undertaken in a hospital. Why it is important? Explain. [8] · (b) How the patients are monitored during surgery ...
III B.Tech I Semester Supplementary Examinations, November 2005. POWER ELECTRONICS · (Electrical & Electronic Engineering) · Time: 3 hours · Max Marks: 80 · Answer any FIVE Questions · All Questions carry equal marks · ***** · 1. (a) Explain the oper
(c) Explain inverted paging method of memory management. [4+4+8] · 4. (a) Explain banker's algorithm for deadlock detection. (b) What are the criteria for a ...
(a) Discuss the path sensitization in a combinational circuit. shown in figure1 · (b) Find the test set to detect A1- SA0 and A1- SA1 faults using Boolean difference.
i. plain carbon steel with 4% carbon and 0.8% manganese, ... (a) It is required to design a square key for fixing a gear on a shaft of 30 mm · diameter; to transmit ...
TECHNIQUES OF METAL JOINING · (Metallurgy & Material Technology) · Time: 3 hours · Max Marks: 80 · Answer any FIVE Questions · All Questions carry equal ...
Figure 1 shows two views of a tripod bracket. All connections are pinned. Find · the forces in magnitude and nature in the three memebers due to a vertical load ...
(b) Explain the bridge type of thermocouple arrangement and mention its ... 3. The standard resistor arm of a Wheatstone bridge has a range from 0 to 100 ohm.
