a. A cable TV company delivers video signals over coaxial cable to individual houses. Video signals occupy a bandwidth of 6 MHz and are stacked in frequency from 50 MHz to 656 MHz without guard bands. There are 100 video channels numbered 1 through 100. Is this system using FDM or FDMA?
b. When NTSC analog TV signals are sent over the cable, the video portion of the signal occupies the lower 5.7 MHz of the 6 MHz channel as a VSB-AM signal and an FM audio signal with a bandwidth of 100 kHz is located between 5.8 and 5.9 MHz. Are the channels using FDM or FDMA to deliver the video and audio portions of the TV signal?
c. A broadcast TV station would like to transmit the same 100 analog TV channels described in part (b) above that the cable TV company distributes via coaxial cable. The radio spectrum available to this station lies between 470 MHz and 840 MHz. Give two reasons why the TV station cannot transmit 100 TV channels.
d. A direct broadcast satellite television (DBS-TV) company competes with the cable TV company to transmit the same 100 TV channels to all households in the US using a large geostationary satellite. The TV transmissions are digital and one transponder on the satellite can transmit eight pre-recorded TV signals or four live TV signals in an RF bandwidth of 30 MHz. The 100 TV channels include 12 live TV signals and 88 pre-recorded signals
How many transponders are needed on the satellite? If guard bands of 6 MHz are needed between the RF signals, what is the total RF bandwidth occupied by the 100 TV channel?