Important RGPV Question
EX- 604 (C) Analog & Digital Communication
VI Sem, EX
UNIT 1- Time domain And Frequency Domain Representation Of Signal
Q.1) Time domain and frequency domain representation of signal.
(RGPV Dec 2020)
Q.2) Determine the Fourier transform of the following signals
i) u(t)
ii) sgn(t)
iii) coscot
iv) Gτ(t)
(RGPV Dec 2020)
Q.3) State and prove Parseval theorem for power signals.
(RGPV Dec 2020)
Q.4) Discuss about the impulse response of ideal low pass filter.
(RGPV Dec 2020)
Q.5) Draw the block diagram of communication system and mention the name of each block.
UNIT 2- Base Band Signal, Need Of Modulation
Q.1) Discuss about generation and detection of Amplitude modulated signal. Also determine its efficiency.
(RGPV Dec 2020)
Q.2) Explain briefly about Vestigial side band transmission.
Q.3) Explain about following modulation.
a) NBFM
b) WBFM
(RGPV Dec 2020)
Q.4) Define modulation, amplitude modulation and angle modulation.
Q.5) What is frequency deviation of FM signal?
Q.6) Define modulation index and percentage modulation in case of FM.
Q.7) Why is modulation needed?
Q.8) Differentiate between narrowband FM and wideband FM with their frequency spectrum and suitable mathematical expressions.
Q.9) Why super heterodyne receiver is better than the TRF receiver? Explain.
Q.10) An arbitrary modulating signal consisting of two modulating frequencies of 1 kHz and 2 kHz modulated a carrier signal having peak amplitude level of 1 V and frequency of 1 MHz, with amplitude modulation index of 0.5 and 0.2 respectively. Write the resultant expression for complex AM signal and sketch its frequency spectrum.
Q.11) An FM modulator operates at carrier-signal frequency of 500 kHz having peak amplitude of 10 V. A modulating frequency (fm) of 10 kHz modulates it with a peak frequency deviation (δ) of 10 kHz. From the Bessel function table, it is observed that a frequency modulation index of one yield three sets of significant sidebands. Compare actual minimum bandwidth as obtained using Bessel function and the approximate minimum bandwidth using Carson’s rule.
UNIT 3- Sampling Of Signal, Sampling Theorem For Low Pass And Band Pass Signal
Q.1) Determine the channel bandwidth for PAM-TDM signal.
(RGPV Dec 2020)
Q.2) Explain Sampling theorem for Band pass signal.
(RGPV Dec 2020)
Q.3) Explain about Delta modulation system.
(RGPV Dec 2020)
Q.4) Explain about Adaptive Delta modulation system.
(RGPV Dec 2020)
Q.5) Discuss Nyquist criteria for sampling.
Q.6) Draw the signal waveform of PAM, PWM and PPM.
Q.7) Explain briefly, quantization process.
Q.8) What is electronic commutator in TDM system?
Q.9) Explain coherent method of generation and detection of PAM signal with suitable mathematical expressions.
Q.10) Explain Time Division Multiplexing (TDM) technique with suitable diagram.
Q.11) Let the maximum spectral frequency component (fm) in an analog information signal is 3.3 kHz. Illustrate the frequency spectra of sampled signals under the following relationships between the sample frequency, fs and maximum analog signal frequency, fm–
- fs= 2fm
- fs> 2fm
Q.12) What is pulse code modulation (PCM)? Explain briefly, generation and detection of PCM.
Q.13) Explain T-1 carrier system with the help of block diagram.
UNIT 4- Digital Modulations Techniques, Generation, Detection
Q.1) Explain the working principle of the following.
a) Binary phase shift keying
b) Quadrature phase shift keying
(RGPV Dec 2020)
Q.2) Explain briefly, signal to noise ratio.
Q.3) Compare ASK, PSK and FSK: Also give the advantages and disadvantages of ASK, PSK and FSK.
Q.4) Explain the working of delta modulation. How adaptive delta modulation improves the performance of delta modulation?
UNIT 5- Information Theory And Coding
Q.1) What do you understand by Shannon Hartley theorem?
Q.2) What is noise? Explain various forms of noise and its sources.
Q.3) A discrete memoryless source X has five symbols (S0, S1, S2, S3, S4) and their probabilities of occurrence are given as 0.40, 0.20, 0.20, 0.10, 0.10, respectively. Construct Huffman code and calculate efficiency.
Q.4) Consider 8 different alphabet source with probability of occurrence are given in Table 2:
According to Shannon-Fano technique generates binary code and calculates average word length, Entropy, and efficiency.
Extra Questions-
Q.1) Write short notes on any two of the following.
a) Quadrature Amplitude modulation
b) Shannon theorem
c) Huffman coding
(RGPV Dec 2020)
— Best of Luck for Exam —
