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Question # 2
(a) A random signal $m(t)$ with a highest frequency component of 30 kHz is
required to be converted to a digital signal using an Analog-to-Digital
Converter (ADC). The amplitude probability density function of the random
input signal is uniform in [-2, +2]. The bits from the ADC are required to be
stored on a digital computer for further processing.
Design an ADC system that meets the following specifications: i) Signal-to-
Quantization Noise Ratio (SQNR), of 42 dB or better; (ii) Sampling rate equal
to 3 times that of the Nyquist rate of sampling of $m(t)$; and (iii) NRZ signaling
is used to transmit binary data over the channel to the computer [Bit '0' \rightarrow
+1V and Bit '1' \rightarrow -1V, $0 \leq t \leq T_b$], where $T_b$ is the bit duration.
Specifically, determine the number of bits, $b$, required to represent each
sample and determine the bit rate, $f_b$, of the system. What is the memory
requirement of the digital computer if we are required to store the digital
signal for a period of 1 minute?
Draw the block diagram of the ADC system and specify characteristics of
each subblock of the system. Sketch the output of the ADC if the binary output
sequence is 01010101....
[10 Marks]
b=____ bits
$f_b$=____ bits/sec
Memory Requirement:____ bits
Block diagram of ADC
Output waveform of ADC
