State two advantages of changing the signal to digital form for transmission.
Fig. 5.2 shows how the potential difference (p.d.) of the input signal varies with time. The ADC has a sampling frequency of $250\,\text{Hz}$ and is using 4-bit sampling, with the least significant bit equal to $1\,\text{mV}$. The signal is first sampled at time $0$, when the sampled bits are $0001$. State the sampled bits at time $4\,\text{ms}$ and time $8\,\text{ms}$.
Fig. 5.2 shows how the potential difference (p.d.) of the input signal varies with time. The ADC has a sampling frequency of $250\ \text{Hz}$ and is using $4$-bit sampling, with the least significant bit equal to $1\ \text{mV}$. The signal is first sampled at time $0$, when the sampled bits are $0001$. (i) State the sampled bits at time $4\,\text{ms}$ and time $8\,\text{ms}$.
A section of the signal received by the receiver, after the sampled signal has passed through the DAC, is shown in Fig. 5.3. On Fig. 5.3, finish the line to show the received signal from time $0$ to time $12\ \text{ms}$.
The ADC in (b) is replaced by one with a sampling frequency of $500\ \text{Hz}$ and $3$-bit sampling, with the least significant bit equal to $2\ \text{mV}$. On Fig. 5.4, sketch the signal that is now received, after passing through the DAC, from time $0$ to time $12\ \text{ms}$.