CDC Questions Flashcards
What is an example of analog-to-digital and digital-to-analog techniques?
Pulse code modulation (PCM) and continuously variable slope delta (CVSD) modulation
What converts analog signal information into an analog carrier signal?
Analog modulation
What convers analog signal information into a digital carrier signal?
Digital Modulation
The information-carrying components that occur on either side of a carrier are called…
sidebands
Amplitude modulation (AM) requires a bandwidth that is
twice that of the modulating signal
The upper sideband in a single-sideband suppressed carrier (SSBSC) modulation is eliminated by
filtering.
We can express the 6-to-1 improvement of the single-sideband suppressed carrier (SSBSC) modulation over conventional amplitude modulation (AM) as
8 db of improvement
The only basic waveform in nature is a
pure sine wave
A modulated waveform that contains a carrier plus two sidebands for each modulation frequency is a description of
an amplitude modulation (AM)
If 100% modulation is exceeded and there is distortion in the modulating signal, additional sidebands are generated. We identify these sidebands as what?
splatter
The amount of deviation in a frequency modulation (FM) signal is directly proportional to the modulating signal’s
amplitude
The amount of phase shift in a phase modulation (PM) signal is directly proportional to the
amplitude of the modulating signal
What form of modulation is insensitive to signal variations?
Binary-phase shift keying or bi-phase shift keying (BPSK)
In quadrature-phase shift keying (QPSK) the radio frequency (RF) bandwidth for a quadripphase signal is what of that required by a bi-phase signal, given the same data rate
half
What is the main advantage of differential phase shift keying (DPSK)?
It requires a less complex receiver than basic phase shift keying (PSK) signal
Which of the following is not considered an analog modulation techniques?
pulse-code modulation (PCM)
The form of pulse modulation in which the pulse is varied within a set range of positions is known as
pulse-position modulation (PPM)
Quantized analog modulation is actually
analog-to-digital conversion
How many bits per character of a 16-step pulse-code modulation (PCM) system are used to describe the quantized analog sample?
4
The process of coding pulse code modulation (PCM) quantized pulses to make them a constant duration and amplitude is
encoding
In time division multiplexing (TDM), the transmitting multiplexer will put a bit or a byte from each of the incoming lines into a specifically allocated what?
time slot
The two major types of frame structures are
CCITT and low speed
The method of multiplexing the T1 multiplexer uses is
time division
Wave-division multiplexing (WDM) creates the virtual channels for multiplexing them together for transmission by using different
wavelengths or lambdas