Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU) B-Tech 5th Semester (Fifth Semester) 2018-2019 REC 502 Principles Of Communication Question Paper
Paperld 3 n?n- Roll No.
B. TECH
THEORY EXAMINATION ( SEM-V) 2018-19
PRINCIPLES OF COMMUNICATION
Tue: 3 Hours Max. Marks: 70
Nate : Be precise in your answer. In case of numerical problem auume dqta wherever not
provided
SECTION ~ A
l. Attempt all parts of the following questions: 2X7=l4
(a) What is the function of limiter and frequency discriminator?
(h) De?ne Modulation? List different types of AM
(0 Draw the waveforms of PAM PPM and PWM.
(d) De?ne Power Spectral Density? What IS the PSD _of AWGN?
(e) W hat Is noise? Discuss superposition of noise
(I) What is [inc coding? lee its types?
(g) Give Carson?s mlc'? Find the bandWIdth ofNarrowband FM
SECI?ION B , .
Attempt any three parts of the foildwing questions: Jx7=2l
(11) Derive the mathematical expression for single? ?tone FM
Delermine the frequency deviation and camer 5w mg for a frequency-modulated (FM)
sIgnal thch has a resting frequency of 105 00 MHz and whose upper frequency is
105 007 MHz when modulated by a pamcular wave Find- the lowest frequency
reached by the FM wave
(b) What are the dIsadvanIages of PAM and PWM signals? D1scuss the generatxon of
PPM s1gnals using PWM signa1s. List the advantages 01 PPM.
(c) Given that the bit sequence given below 15 to be transmitted
BIt sequence: 10110010
Draw the resulting waveform, 1f the sequence is transmitted using.
(1) Jnipolar R2
(11) Polar R2
(111 ) AMI
1V 1 Split Dhase Manchester
(v) M~aIy where m=4 (Pom Quatemary).
(d) A television signal having a bandwidxh of 10.2 MHz is transmitted using bmary PCM
system. Given that the number 01" quantuation levels is 512. Determine:
(1) Codeword length
(ii) Transmission bandwidth
(iv) Final bit rate
(v) Output signal to quantization noise ratio,
(e) De?ne Figure of merit. Derive the [mthematical expression of ?gure of merit for FM
system
SECTION C
Attempt any one part of the following question: l><7=7
3. (a) State and prove Sampling theorem. What is the criteriOn to remove Aliasing effect?
Detemu'nc the Nyquist rate and Nyqnist interval for a continuous-tlme signal
x(t) = 6cos 501tt + 20 sin3001rt * 10 cos 100m
(1]) Explain in detail Superheterodyne AM Receiver with labelled block diagram
Attempt any one part of the following question: : IX7=7
4. (a) Explain the indirect method (Armstrong method) of generation of FM.
(b) W hat1s multiplexing? Explain TDM Hierarchy for digital communication in detail.
List the advantages of d1 glta! meltipl?xing
Attempt any one part of the following qileetion: 1X7=7
5. (a) Explain the working 9f PLI -FM demodulator with supporting diagrams and
mathema?cal express1ons?r ,
(b) What is delta modulation? Discuss the errors in Delta Modulation How thev are
overcome in Adaptive Delta Modutation?
Attempt any one part of the following question: _ ,_ 1X7=7
6. (3) Define F ?gure of Merit. Derive an expression of ?g?te?of merit for AM system.
(b) What are vocoders? List various types of voeoderi and discuss them brie?y
Attempt any one part of the following question: 1 IX7=7
?7. (a) W hat is the need for modulation? Li?t?the differences between AM and FM.
(b) Explain TRF receiver in detail: What are the drawbacks of TRF receivers?
This post was last modified on 29 January 2020