RAJALAKSHMI ENGINEERING COLLEGE, THANDALAM.DEPARTMENT OF ECE

EC2307 COMMUNICATION SYSTEMS LAB

VIVA QUESTIONS

1. Define Modulation.2. Need for modulation.3. Define AM.4. Merits and demerits of AM.5. Applications of AM6. Define FM.7. Merits and demerits of FM.8. Applications of FM9. Differentiate between AM and FM10.Define pulse modulation11.Define PAM.12.Define PWM.13.Define PPM.14.Differentiate between phase and frequency modulation15.Define pulse code modulation (PCM).16.Define delta modulation.17.Define adaptive delta modulation.18.Distinguish between DM and ADM.19.Define ASK, PSK and FSK.20.Differentiate ASK and FSK.21.What is meant by PLL?22.Applications of PLL.23.Define pre-emphasis & de-emphasis.24.Why is ASK called as ON-OFF keying?25.What are the advantages of digital transmission?26.What is meant by frequency synthesizer?27.Applications of frequency synthesizer.28.What is meant by line coding?29.Define polar encoding.30.Define bipolar encoding.31.Define unipolar encoding.32.Define Manchester encoding.

33.Differentiate between RZ,NRZ,NRZI,AMI codes34.Explain about error detection and error correction.35.Purpose of error control coding.36.Explain ARQ,FEC.HARQ37.What is sampling?38.State sampling theorem.39.What is aliasing?40.How to avoid aliasing effect.41.Define Nyquist Criteria.42.Purpose of sampling.43.Explain TDMA.44.Explain FDMA.45.Explain CDMA.46.Explain SDMA.47.Differentiate between TDMA,FDMA,CDMA,SDMA48.Merits and demerits of TDMA49.Merits and demerits of FDMA50.Merits and demerits of CDMA51.Merits and demerits of SDMA52.Explain about GSM technique.53.Define dipole antenna.54.Applications of dipole antenna.55.Different dipole types.56.What is meant by balun?57.Define yagi uda antenna58.Applications of yagi uda antenna.59.Define loop antenna.60.Which antenna is to be used for TV transmission?