Quiz 1

Consider the following statements regarding differential pulse-code modulators:

1. The differential pulse-code modulator system employs a predictor.

2. It needs far fewer bits per each error sample than what would have been needed for the original

samples themselves.

3. It will have larger dynamic range than the original message itself.

Select the correct statements using the code given below,

• 1 & 3 only

• 2 & 3 only

• 1 & 2 only

• 1,2,3

Which of the following statements is correct?

• 1. 1. Bandwidth requirement of DPCM is more than PCM

• 2. Bandwidth requirement of DPCM is equal to PCM

• 3. Bandwidth requirement of DPCM is less than PCM

• 4. Both DPCM and PCM have no Bandwidth requirement

In digital transmission, the modulation technique that requires the minimum bandwidth is:

• PCM

• PAM

• DPCM

• Delta modulation

Which one of the following statements about differential pulse code modulation (DPCM) is true?

• 1. The sum of message signal sample with its prediction is quantized 

• 2. The message signal sample is directly quantized and its prediction is not used

• 3. The difference of message signal sample and a random signal is quantized

• 4. The difference of message signal sample with its prediction is quantized

DPCM suffers from

• a) slope over load distortion
  

• b) quantization noise
  

• Neither a) nor b)

• a) an d b)

An audio signal comprising of a single sinusoidal term s(t) = 3cos (2π1000t) is quantized using DM. What is the signal-to-quantization noise ratio?

• 120

• 170

• 107

• 100

In Delta Modulation, the slope overload distortion can be minimized by

• keeping the step size constant

• Vary the pulse inbetween

• keeping the step size zero

• Increasing the step size

Which of the following is responsible for generating quantization error in delta modulation?

I. Slope overload distortion 

II. Granular noise 

III. White noise 

• I only

• II only

• II and III only

• 1 and II Only

Delta modulation system Input applied 10 kHz, 1Vp-p. The signal Is sampled ten times more than Nyquist rate. What is the minimum step size required to prevent slope overload?

• 0.157 V

• 1.57 V

• . 15.7 V

• . 0.0157 V

The adaptive delta modulation avoids

• 1. Quantization error

• 2. Slope overload error 

• 3. Both 1 and 2 

•   4. Speckle error