A modem is connected to a 4,800 bit/s data terminal. Assuming that a 50-percent roll-off pulse shaping is used for all cases, calculate the required transmission bandwidth BT at the modem output for...

A modem is connected to a 4,800 bit/s data terminal. Assuming that a 50-percent roll-off pulse shaping is used for all cases, calculate the required transmission bandwidth BT at the modem output for each of the following schemes:

a) Frequency-shift keying (FSK) transmission with a frequency deviation of +- 3,600 Hz around the carrier frequency.

b) Amplitude-shift keying (ASK) transmission

c) 16-level quadrature amplitude modulation (QAM)

Which scheme is the optimum modulation for this transmission?