Question #2

An analog signal that has been sampled to form a PAM waveform can be recovered by a low pass filter.  The output of the low pass filter is the original analog signal.

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a.   Explain in words why this is possible.   (i.e. What feature of the PAM signal spectrum allows the recovery of the original signal at the output of the LPF?)

b.   What is the advantage of using impulse sampling rather than square wave sampling?

Question #3

An analog voice signal occupies a bandwidth of 300 – 3,400 Hz.

a.  What is the Nyquist sampling frequency for this signal?

b.  A sampling system operates at 1.2 times the Nyquist frequency.  What is the sampling rate?

c.  The sampled signal is transmitted as a PCM signal from a 10 bit ADC to a receiver that has a low pass filter.  What cut off (maximum pass band) frequency should this filter have?

Question #4

The output of a video surveillance camera is an analog signal with a bandwidth that extends from 0 Hz to 1.5 MHz.  The signal is sampled at 1.2 times its Nyquist rate.  Packets are

transmitted serially over a twisted pair used as the cable for data transmission.

a.   What is the sampling frequency?

b.   Each sample is encoded as 6 bit PCM.  What is bit rate of the transmission on the twisted pair?

c.   If the digital outputs of three identical video cameras are combined onto a single cable using time division multiplexing, what is the bit rate on the cable.