(a(i))[1]
State the meaning of attenuation.
(a(ii))[2]
State the meaning of noise.
(b)[1]
Using (a)(ii) as a reference, explain why transmitting the signal in digital form has an advantage over analogue form.
(c)
Fig. 4.1 shows part of an analogue signal.
(c(i))[1]
At time $t = 3.0\,\text{ms}$, underline the least significant bit (LSB) of the digital number.
(c(ii))[2]
State the digital numbers for the sampling times between $t = 4.0\,\text{ms}$ and $t = 6.0\,\text{ms}.
(d)[3]
The digital signal being sent is converted back into an analogue signal by a digital-to-analogue converter (DAC). On Fig. 4.3, show how the DAC output levels vary with time $t$ for $t = 0$ to $t = 4.0\,\text{ms}$. Assume that the transmission line delay is negligible.