Question 1

Which of the following allows complex,periodic waveforms to be broken down into a series of sine and cosine terms?

Accepted Answer

A) Flat-top sampling 
B) Quantization 
C) Reconstruction 
D) Fourier analysis 
A) Flat-top sampling 
B) Quantization 
C) Reconstruction 
D) Fourier analysis D

Question 2

In _______________,the pulse amplitude is made proportional to the amplitude of the modulating signal.

Accepted Answer

A) pulse-width modulation (PWM) 
B) pulse-amplitude modulation (PAM) 
C) pulse-position modulation (PPM) 
D) pulse-code modulation (PCM) 
A) pulse-width modulation (PWM) 
B) pulse-amplitude modulation (PAM) 
C) pulse-position modulation (PPM) 
D) pulse-code modulation (PCM) B

Question 3

Techniques that allow correction at the receiver are called forward error-correcting codes.Which of the following is an example of an FEC?

Accepted Answer

A) Nyquist 
B) Hamming 
C) Schmitt 
D) Fourier 
A) Nyquist 
B) Hamming 
C) Schmitt 
D) Fourier B

Question 4

What is the primary advantage of the flash ADC?

Accepted Answer

A) It uses little power. 
B) It's simplicity. 
C) It is inexpensive. 
D) It is very fast. 
A) It uses little power. 
B) It's simplicity. 
C) It is inexpensive. 
D) It is very fast.

Question 5

With codes and data,error detection is accomplished through some form of ___________.

Accepted Answer

A) redundancy 
B) modulation 
C) coding 
D) quantization 
A) redundancy 
B) modulation 
C) coding 
D) quantization

Question 6

Why do high-quality capacitors have polyethylene,polycarbonate,or Teflon dielectrics?

Accepted Answer

A) They minimize voltage variations resulting from capacitor characteristics. 
B) They limit the maximum input frequency that the S/H circuit can accurately process. 
C) They convert quantized waveforms into stepped analog signals. 
D) They isolate the input signal from the S/H circuit and provide proper impedance matching. 
A) They minimize voltage variations resulting from capacitor characteristics. 
B) They limit the maximum input frequency that the S/H circuit can accurately process. 
C) They convert quantized waveforms into stepped analog signals. 
D) They isolate the input signal from the S/H circuit and provide proper impedance matching.

Question 7

What is required to increase the resolution of a digitizing system?

Accepted Answer

A) The number of quantization levels to be increased. 
B) The aperture and acquisition times must limit the maximum input frequency. 
C) The maximum input or output voltage level to the smallest voltage level be quantized and/or reproduced by the converters. 
D) The input amplitude must be increased with reference to the quantizing error. 
A) The number of quantization levels to be increased. 
B) The aperture and acquisition times must limit the maximum input frequency. 
C) The maximum input or output voltage level to the smallest voltage level be quantized and/or reproduced by the converters. 
D) The input amplitude must be increased with reference to the quantizing error.

Question 8

What is the chief disadvantage of analog communication?

Accepted Answer

A) Simplicity 
B) Bandwidth requirements 
C) Susceptibility to noise 
D) Cost 
A) Simplicity 
B) Bandwidth requirements 
C) Susceptibility to noise 
D) Cost

Question 9

Which of the following is the conversion of quantized waveform into a stepped analog signal?

Accepted Answer

A) Regeneration 
B) Digitizing 
C) Modulation 
D) Reconstruction 
A) Regeneration 
B) Digitizing 
C) Modulation 
D) Reconstruction

Question 10

Which of the following did Harry Nyquist in 1928 first demonstrate mathematically?

Accepted Answer

A) An analog signal can be reconstructed from periodic samples. 
B) Pulses can be time-division multiplexed over a single communication channel. 
C) The sample rate must be at least twice the highest frequency of the intelligence or information signal to be sampled. 
D) Analog signals are quantized to the closest binary value provided in the digitizing system. 
A) An analog signal can be reconstructed from periodic samples. 
B) Pulses can be time-division multiplexed over a single communication channel. 
C) The sample rate must be at least twice the highest frequency of the intelligence or information signal to be sampled. 
D) Analog signals are quantized to the closest binary value provided in the digitizing system.

Question 11

What does error detection and correction techniques rely heavily on?

Accepted Answer

A) Digital signal processing 
B) Baseband transmission 
C) Pulse modulation 
D) Capacitance 
A) Digital signal processing 
B) Baseband transmission 
C) Pulse modulation 
D) Capacitance

Question 12

What is the most common method of error detection?

Accepted Answer

A) Block check character 
B) CRC dividing circuit 
C) Parity 
D) Cyclic redundancy check 
A) Block check character 
B) CRC dividing circuit 
C) Parity 
D) Cyclic redundancy check

Question 13

Which of the following forms the basis for class D power amplification?

Accepted Answer

A) PCM 
B) PPM 
C) PAM 
D) PWM 
A) PCM 
B) PPM 
C) PAM 
D) PWM

Question 14

In what terms is dynamic range typically expressed?

Accepted Answer

A) Decibels 
B) Bits 
C) Ohms 
D) Farads 
A) Decibels 
B) Bits 
C) Ohms 
D) Farads

Question 15

__________ involves the use of mathematical functions such as addition and multiplication to control the characteristics of a digitized signal.

Accepted Answer

A) Flat-top sampling 
B) Interleaving 
C) Reed-Solomon coding 
D) Digital signal processing 
A) Flat-top sampling 
B) Interleaving 
C) Reed-Solomon coding 
D) Digital signal processing

Question 16

_________ is assigning one of a fixed number of numerical values to each pulse.

Accepted Answer

A) Coding 
B) Sampling 
C) Quantizing 
D) Decoding 
A) Coding 
B) Sampling 
C) Quantizing 
D) Decoding

Question 17

Conversion of the digital word to analog form consists of three steps: regeneration,decoding,and _______________.

Accepted Answer

A) modulation 
B) reconstruction 
C) distortion 
D) substitution 
A) modulation 
B) reconstruction 
C) distortion 
D) substitution

Question 18

What concept is represented by noise corrupted signals being periodically restored to their original values recreating an ideal,perfect representation of data at regular intervals and enabling transmissions over long distances?

Accepted Answer

A) Regeneration 
B) Coding 
C) Pulse modulation 
D) DSP processing 
A) Regeneration 
B) Coding 
C) Pulse modulation 
D) DSP processing

Question 19

What function does the sample-and-hold circuit perform in a PCM system?

Accepted Answer

A) Encoder 
B) Modulator 
C) Filter 
D) Decoder 
A) Encoder 
B) Modulator 
C) Filter 
D) Decoder

Question 20

PCM is a building block in many digital communication applications and consists of three steps: sampling,quantizing,and __________.

Accepted Answer

A) decoding 
B) coding 
C) error-detection 
D) retransmission 
A) decoding 
B) coding 
C) error-detection 
D) retransmission

Which of the following allows complex,periodic waveforms to be broken down into a series of sine and cosine terms?

In _______________,the pulse amplitude is made proportional to the amplitude of the modulating signal.

Techniques that allow correction at the receiver are called forward error-correcting codes.Which of the following is an example of an FEC?

What is the primary advantage of the flash ADC?

With codes and data,error detection is accomplished through some form of ___________.

Why do high-quality capacitors have polyethylene,polycarbonate,or Teflon dielectrics?

What is required to increase the resolution of a digitizing system?

What is the chief disadvantage of analog communication?

Which of the following is the conversion of quantized waveform into a stepped analog signal?

Which of the following did Harry Nyquist in 1928 first demonstrate mathematically?

What does error detection and correction techniques rely heavily on?

What is the most common method of error detection?

Which of the following forms the basis for class D power amplification?

In what terms is dynamic range typically expressed?

__________ involves the use of mathematical functions such as addition and multiplication to control the characteristics of a digitized signal.

_________ is assigning one of a fixed number of numerical values to each pulse.

Conversion of the digital word to analog form consists of three steps: regeneration,decoding,and _______________.

What concept is represented by noise corrupted signals being periodically restored to their original values recreating an ideal,perfect representation of data at regular intervals and enabling transmissions over long distances?

What function does the sample-and-hold circuit perform in a PCM system?

PCM is a building block in many digital communication applications and consists of three steps: sampling,quantizing,and __________.

Fundamental Communications Concept

Amplitude Modulation

Angle Modulation

Communications Circuits

Transmitters

Receivers

Digital Modulation and Demodulation

Telephone Networks

Wireless Communications Systems

Computer Communication and the Internet

Transmission Lines

Wave Propagation

Antennas

Waveguides and Radar

Fiber Optics

Filters

Exam 7: Digital Communications Techniques

Which of the following allows complex,periodic waveforms to be broken down into a series of sine and cosine terms?

In _______________,the pulse amplitude is made proportional to the amplitude of the modulating signal.

Techniques that allow correction at the receiver are called forward error-correcting codes.Which of the following is an example of an FEC?

What is the primary advantage of the flash ADC?

With codes and data,error detection is accomplished through some form of ___________.

Why do high-quality capacitors have polyethylene,polycarbonate,or Teflon dielectrics?

What is required to increase the resolution of a digitizing system?

What is the chief disadvantage of analog communication?

Which of the following is the conversion of quantized waveform into a stepped analog signal?

Which of the following did Harry Nyquist in 1928 first demonstrate mathematically?

What does error detection and correction techniques rely heavily on?

What is the most common method of error detection?

Which of the following forms the basis for class D power amplification?

In what terms is dynamic range typically expressed?

__________ involves the use of mathematical functions such as addition and multiplication to control the characteristics of a digitized signal.

_________ is assigning one of a fixed number of numerical values to each pulse.

Conversion of the digital word to analog form consists of three steps: regeneration,decoding,and _______________.

What concept is represented by noise corrupted signals being periodically restored to their original values recreating an ideal,perfect representation of data at regular intervals and enabling transmissions over long distances?

What function does the sample-and-hold circuit perform in a PCM system?

PCM is a building block in many digital communication applications and consists of three steps: sampling,quantizing,and __________.

Fundamental Communications Concept

Amplitude Modulation

Angle Modulation

Communications Circuits

Transmitters

Receivers

Digital Modulation and Demodulation

Telephone Networks

Wireless Communications Systems

Computer Communication and the Internet

Transmission Lines

Wave Propagation

Antennas

Waveguides and Radar

Fiber Optics

Filters