Question

A source outputs data at the rate of 1,000,000 bits/sec. The transmitter uses binary PAM with raised cosine pulse shaping. If the ideal baseband channel has a cutoff frequency of 850 kHz, what is the maximum roll-off factor that can be applied to the pulse shaping?

Answer 1

Answer:

maximum roll-off factor is 0.7

Explanation:

given data

rate of output data  = 1,000,000 bits/sec

cutoff frequency fc = 850 kHz

solution

we know bandwidth frequency is same as that of bandwidth

we apply here fc formula that is

fc = ω ( 1 + α )     ..........1

here

ω = data rate ÷ 2   .............2

ω = 1000  ÷ 2  

ω = 500000 Hz

so put now value in eq 1

fc = ω ( 1 + α )

850000= 500000  ( 1 + α )

solve it we get

α = 0.7

so, maximum roll-off factor is 0.7