Communicatoin theory

Explain what is meant y narrowband FM and wideband FM using the expression? 3. Explain any two techniques of demodulation of FM. 4. Explain the workings of reactance tube modulator and derive an expression to show how the variation of the amplitude of the infix signal changes the frequency of the output signal of the modulator. 5. Draw the frequency spectrum of FM and explain. Explain how Varactor diode can be used for frequency modulation. 6. deal the indirect method of generating a wide-band FM signal. 7. Draw the circuit plat of Foster-Seelay discriminator and explain its working.Define internal resound. 2. Define shot randomness. 3. Define thermal noise. 4. Define narrow band noise. 5. Define noise fgure. 6. Define noise equivalent bandwidth. 7. Define a random variable. Specify the sample place and the random variable for a coin tossing experiment. 8. What is white noise? separate its characteristics. 9. When is a random process called deterministic? 10. Define flicker n oise. 11 . State the reasons for higher noise in mixers. 1 . Derive the efficacious noise temperature of a fall amplifier and explain how various noises are generated in the method of representing them. Explain the following terms (i) random variable (it) Random process (iii)Gaussian process 3. Explain how various noises are generated and the method of representing them. 4. spell out notes on noise temperature and noise figure. 5. Derive the noise figure for cascade stages. 6. What is narrowband noise? Discuss the properties of the quadrature components of a narrowband noise? 7. Write short notes on thermal noise and short noise. 8. Explain in detail approximately white and filtered noise.Define image frequency. 3. Define Tracking 4. What is meant by FOM of a recipient role? 5. What is doorsill effect? 6. Draw the Phasor representation of FM noise. 8. Define SNR. 9. What is the SNR at the output of DSB system with coherent demodulation? 10. Define CSNR. 1 1 . What is sensibil ity and selectivity of pass receiver? 1 . Explain the working of Super heterodyne receiver with its parameters. 2. Discuss the noise performance of AM system using gasbag detection. 3. Compare the noise performance of AM and FM systems. 4. Calculate the noise power of a DSB-SC system using coherent detection. Discuss in detail the noise performance in SSB-SC receiver. 6. Explain the significance of pre-emphasis and de-emphasis in FM system. 7. Derive the noise power spectral density of the FM demodulation and explain its performance with diagram. 8. a. Draw the block diagram of FM sensing element and explain the effect of noise in detail. b. Explain the FM threshold effect and capture effect in FM. UNIT V selective information THEORY 1. What is prefix commandment? 2. Define information rate. 3. What is contrast subject of binary synchronous channel with error opportunity of 4.State channel cryptography theorem. . Define data for a discrete memory less reference. 6. What is code circumlocution? 7. Write down the construction for the mutual information. 8. Name the source coding techniques. 9. What is Data compaction? 10. Write the expression for code capacity in terms of entropy. PART-B (16 Marks) 1 . Explain the significance of the entropy H(XN) of a communication system where X is the transmitter and Y is the receiver. 2. An event has sextet possible outcomes with probabilities Find the entropy of the system. 3.Discuss Source coding theorem, give the good and disadvantage of channel oding in detail, and discuss the data compaction. 4. Explain the properties of entropy and with suitable example, explain the entropy of binary memory less source. 5. quintuple symbols of the alphabet of discrete memory less source and their probabilities are accustomed below. the symbols using Huffman coding. 6. Write short notes on Differential entropy, derive the channel capacity theorem and discuss the implications of the information capacity theorem. 7. What do you mean by binary symmetric channel? Derive channel capacity formula for symmetric channel. . Construct binary optical code for the following probability symbols using Huffman procedure and calculate entropy of the source, average code Length, efficiency, redundancy and variance?