Important RGPV Question
CSIT-402 Â Analog & Digital Communication
IV Sem, CSIT
UNIT 1- Signals and Systems:
Q.1) Consider the following signal
i) Determine if the signal is periodic or not
ii) If signal is periodic, find its fundamental period and sketch one period of the signal.
iii) If the signal is non-periodic, explain why?
RGPV Nov 2023
Q.2)
RGPV Nov 2023
Q.3) Explain the working of a two station data communication circuit with a block diagram. RGPV June 2020
Q.4) Write short note on
(i) Transform of gate
(ii) Shifting property of delta function.
RGPV June 2020
Q.5) Write short note on fourier transform and its properties.
RGPV December 2020
Q.6) What is the process of the fourier transform? How fast does fourier transform work? explain.
RGPV December 2020
Q.7) Define signal and explain the following signals-
(i) unit step
(ii) unit Ramp.
RGPV May 2019
Q.8) What is Fourier transform? Write and proof any two properties of Fourier transform.
RGPV November 2019.
Q.9) Explain the following signals with suitable diagrams-
(i) Periodic
(ii) Non periodic
(iii) Energy
(iv) Power
RGPV November 2019
Q.10) Draw electromagnetic spectrum and discuss the applications of different frequencies in our daily life.
RGPV May 2018
Q.11) Draw and explain sinusoidal signal.
RGPV May 2018
Q.12) Draw and explain unit step and Ramp signals.
RGPV May 2018
Q.13) Draw and explain impulse (delta) signal.
RGPV May 2018
Q.14) Draw and explain rectangular pulse and Signum signals.
RGPV May 2018
Q.15) Draw a block diagram of communication system and explain it.
RGPV May 2018
Q.16) Write any five properties of Fourier Transform and explain any one in detail.
RGPV May 2018
Q.17) Write conditions for existence of Fourier Transform and also write equations for inverse Fourier Transform.
RGPV May 2018
Q.18) What do you mean by convolution of two functions ? Write and explain time and frequency convolution theorems.
RGPV May 2018
Q.19) Prove the following relations- RGPV May 2018
Q. 20) What is Fourier Transform ? Write and prove any two properties of Fourier transform.
RGPV May 2019
Q. 21) Find out the Fourier transform of Gate and impulse function.
RGPV May 2019
UNIT 2- Amplitude Modulation:
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Q.1)Â What is the principle of Amplitude modulation? Derive expression for the AM wave and draw its spectrum.
RGPV November 2023
Q.2)Â A modulating signal of 2Cos(5000t) is amplitude modulated over a carrier signal of 5Cos(20000t). Derive the expression for modulation index, LSB and VSB frequencies, Bandwidth and the ratio of side band power in the Total Power of AM wave.
RGPV November 2023
Q.3) A 107.6 MHz carrier signal is frequency modulated by a 7 kHz sine wave. The resultant FM signal has a frequency deviation of 50 kHz. Determine:
i) The carrier swing of the FM signal.
ii) The highest and the lowest frequencies attained by the modulated signal.
iii) The modulation index of the FM wave.
RGPV November 2023
Q.4) What is analog modulation ? compare analogue modulation and digital modulation.
RGPV December 2020
Q.5) What is modulation? why we need modulation?
RGPV November 2019, December 2020
Q.6) Draw the spectrum of an AM signal.
RGPV June 2020
Q.7) Â Define modulation index for amplitude modulation. Describe over modulation and envelope distortion.
RGPV May 2018
Q.8) Define modulation index. What is over modulation?
RGPV May 2019
Q.9) What is modulation index? Draw waveform of a modulated signal when modulation index is
RGPV November 2019, December 2020
Q.10) Derive the expression for the instantaneous voltage of AM wave.
RGPV December 2020
Q.11) What is transmission efficiency? What determines the bandwidth of a transmitted AM signal what will happen if modulation index is greater than 100%?
RGPV December 2020
Q.12) Discuss the square law modulator method of generation of AM wave.
RGPV June 2017
Q.13) Â Draw the circuit diagram for ring modulator for generating DSB-SC AM signal.
RGPV December 2020
Q.14)  Define DSB – SC and SSB-SC systems.
RGPV May 2018
Q.15) Explain the phasing method of generation of SSB – SC signal.
RGPV June 2020
Q.16) Derive an expression for figure of merit for SSB – SC system.
RGPV June 2017
Q.17) Write short note on VSB – SC system.
RGPV May 2018
Q.18) Explain the term VSB with advantages of VSB transmission.
RGPV December 2017
Q.19) Differentiate SSB – SC and DSB – SC modulation techniques.
RGPV May 2019
Q. 20) Compare the following modulation systems
(i) DSB – SC
(ii) SSB – SC
(iii) AM-FC
 RGPV November 2019
Q. 21) Write short note on TRF receiver.
RGPV May 2018, November 2019
Q. 22) Write short note on TRF and superheterodyne receivers.
RGPV December 2020
Q. 23) Explain the function of superheterodyne road dine receiver. Also, write its merits and demerits.
RGPV December 2017
Q. 24) Draw block diagram of superheterodyne receiver an explain concept of intermediate frequency.
RGPV May 2018
Q. 25) Differentiate the following-
(i) TRF and superheterodyne receiver
 (ii) Sensitivity and selectivity
(iii) Low and high power am transmitters.
RGPV May 2019
Q. 26) Drop block diagram of superheterodyne receiver and explain it. Define sensitivity and selectivity.
RGPV November 2019
UNIT 3- Â Angle modulation:
Q.1)Â Explain frequency modulation. Derive the relation between frequency modulation and phase modulation.
RGPV Nov 2023
Q.2) Discuss the advantages and disadvantages of angle modulation.
RGPV June 2019
Q.3) Define phase deviations and frequency deviations.
RGPV December 2017
Q.4) Define modulation index.
RGPV December 2017
Q.5) Explain the following terms related to FM
(i) Carson’s rule
(ii) Frequency deviation
(iii) Deviation ratio
(iv) Modulation index
RGPV November 2019
Q.6) Explain the terms frequency deviation modulation index and deviation ratio in FM.
RGPV May 2019
Q.7) Â Comment on frequency deviation deviation ratio and Carson’s rule.
RGPV May 2018
Q.8) Explain and NBFM v/s WBFM term related to FM.
RGPV November 2019
Q.9) Write an explain Carson’s rule for bandwidth of FM.
RGPV May 2019
Q.10) What is angle modulation question mark discuss the various type of angle modulation.
RGPV June 2017
Q.11) Discuss the difference between FM and PM.
RGPV June 2017
Q.12) How the FM signal can be generated from PM signal? Explain with block diagrams.
RGPV December 2017
Q.13) Â With the help of suitable diagrams explain direct and indirect methods of FM generations.
RGPV May 2018
Q.14) Draw and explain direct and indirect methods of FM generation.
RGPV May 2019
Q.15) Draw the block diagram of Armstrong indirect FM transmitter and describe its operation.
RGPV June 2020
Q.16) Write short note on Faster-Seely discriminator.
RGPV May, June 2020
Q.17) Write short note on ratio detector.
RGPV November 2019
Q.18) Discuss pre-emphasis and de-emphasis in FM.
RGPV June 2017
UNIT 4- Â Sampling of signal:
Q.1)Â State and explain sampling theorem in time domain. Explain about Nyquist rate.
RGPV Nov 2023
Q.2)Â Find the Nyquist rate and Nyquist interval for the signal. RGPV Nov 2023
Q.3) Write short note on natural and flat top.
RGPV June 2020
Q.4) What is the various pulse modulation techniques give one method for the generation of PAM.
RGPV June 2020
Q.5) Output noise power from an amplifier is 80 nW, the available power gain of the amplifier fire being 40dB and the equivalent noise bandwid being 25 MHz. Find the noise figure assuming room temperature to be 27° C.
RGPV June 2020
Q.6) Write short note on compare delta modulation and adaptive delta modulation.
RGPV December 2020
Q.7) Â Explain in detail about the function of each layer in a Bluetooth system.
RGPV December 2020
Q.8) Define mutual information and mention its properties.
RGPV June 2020
Q.9) List the source of internal and external noise.
RGPV June 2020
Q.10) Discuss about the generation of PAM and its modulation.
RGPV June 2020
Q.11) Drawing explain PPM, PAM and PWM schemes.
RGPV November 2019, December 2020
Q.12) Draw a block diagram of PCM system and explain it.
RGPV November 2019
Q.13) Write short note on delta modulation (DM).
RGPV may 2019, November 2019
Q.14) Differentiate natural and flat top sampling full stop define aperture effect.
RGPV may 2019
Q.15) Define the terms natural and flat top sampling, aperture effect.
RGPV November 2019
Q.16) Write an explain functioning of pulse code modulation system. Comment on its bandwidth.
RGPV May 2018
Q.17) In 24 telephone channels each band limit did to 3.4 kHz are to be time division multiplexed by using PCM. Calculate the bandwidth of the PCM system for the 128 quantization level and an 8 kHz sampling frequency.
RGPV may 2018
Q.18) Write a short note on differential PCM.
RGPV may 2018
Q.19) Determine the channel bandwidth required for transmitting in number of PAM- TDM signal.
RGPV December 2017
Q. 20) With the help of block diagram explain the generation of delta modulated signal.
RGPV December 2017
Q. 21) Compare PAM, PPM and PDM.
RGPV December 2017
Q. 22) Write short note on PWM systems.
RGPV June 2017
Q. 23) State and prove sampling theorem for low pass signal.
RGPV June 2017
UNIT 5– Digital modulations Techniques:
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Q.1)Â Explain DPSK. With the help of block diagram explain generation and detection of DPSK.
RGPV Nov 2023
Q.2)Â Describe with the help of neat diagram, the operation of QPSK modulator. Draw its phasor and constellation diagram.
RGPV Nov 2023
Q.3) Write short note on BPSK.
RGPV December 2017, May 2019
Q.4) Explain the QAM transmitter and receiver.
RGPV June 2020
Q.5) Explain the method of generation of QAM and the demodulation of the same.
RGPV June 2020
Q.6) Write short note on QAM.
RGPV May 2019, November 2019, December 2020
Q.7) Job block diagram of 8-QAM transmitter and explain its working.
RGPV December 2020
Q.8) What is probability of error?
Q.9) Compare the various digital modulation techniques.
RGPV December 2020
Q.10) Draw the block diagram of CDMA encoder and decoder and briefly explain.
RGPV December 2020
Q.11) Draw the ASK, FSK, PSK waveform for the digital data 10100110.
RGPV June 2020
Q.12) Draw the ASK, FSK, BPSK and QPSK waveforms for the bit stream 10110001.
RGPV December 2020
Q.13) Draw the block diagram for explaining the working of coherent binary FSK transmitter and receiver.
RGPV June 2020
Q.14) Explain different PSK (phase shift keying) system. The bandwidth requirement in QPSK reduces to half as compared to BPSK justify it.
Q.15) Write short note on QP SK.
RGPV May 2018, 2019
Q.16) What are the advantages of digital modulation techniques? describe BPSK system.
RGPV May 2018
Q.17) Draw the block diagram of DPSK transmitter and receiver. Describe the working along with the waveforms showing recovery of binary message.
RGPV June 2017
Q.18) Explain ASK FSK and PSK modulation techniques.
RGPV June 2017Â Â Â Â Â Â
 — Best of Luck for Exam —
