Answer Happy

QUESTION TWO [25 MARKS A. i) Briefly describe two methods that can be used to generate Wideband FM. [2 marks] ii) Explain with appropriate spectrum diagram(s) how VSB is generated from DSB-SC waveform. B. i) Draw a block diagram of a typical digital communication system. Briefly explain what any three of the blocks does in the communication process. [4 marks] ii) Contrast the advantages and disadvantages of digital transmission [3 marks] iii) What is the purpose of guard bands in frequency-division multiplexing? [3 marks] C. A message x(t) with bandwidth 200 Hz and signal power Sx = 0.5 W is to be transmitted by modulating a 20 kHz carrier of amplitude A = 15. a) If the modulation scheme employed is USSB, what is the signal power Sy of the transmitted signal and between what frequency limits does the transmitted signal power lie (consider only positive frequency space). [5 marks] b) If the modulation scheme is DSB-FC with m=0.8, determine the following: i. Carrier power, P [2 marks] ii. Power of the sideband, Ps [3 marks) iii. What frequency limits does the transmitted signal power lies (consider only positive frequency space) [3 marks]