## Answer 5.1

#### For a baseband channel, a signalling rate of 2400 baud would imply a minimum bandwidth of 2400 / 2 Hz. ASK requires twice this bandwidth since the modulation process generates upper and lower sideband replicas of the baseband signal. The occupied bandwidth is thus 2400 Hz.

#### Alternatively we can use the formula,
Cbandpass = B log2M,
where M = 8 and the capacity is 2400 x 3 bps. Hence B = 2400 Hz.

#### For a raised cosine filter with a = 0.5, the bandwidth needed is increased by a factor (1 + a). This is true for baseband and bandpass signalling. The new occupied bandwidth is thus 2400 x (1.5) = 3600 Hz.