A-005-09: Spread spectrum - frequency hopping, direct sequence
A-005-09-01:
What term describes a wide-band communications system in which the RF carrier varies according to some predetermined sequence?
Spread spectrum communication
Amplitude-compandored single sideband
AMTOR
Time domain frequency modulation
A-005-09-02:
What is the term used to describe a spread spectrum communications system where the centre frequency of a conventional carrier is altered many times per second in accordance with a pseudo-random list of channels?
Frequency hopping
Direct sequence
Time-domain frequency modulation
Frequency compandored spread spectrum
A-005-09-03:
What term is used to describe a spread spectrum communications system in which a very fast binary bit stream is used to shift the phase of an RF carrier?
Direct sequence
Frequency hopping
Phase compandored spread spectrum
Binary phase-shift keying
A-005-09-04:
Frequency hopping is used with which type of transmission?
Spread spectrum
AMTOR
Packet
RTTY
A-005-09-05:
Direct sequence is used with which type of transmission?
Spread spectrum
AMTOR
Packet
RTTY
A-005-09-06:
Which type of signal is used to produce a predetermined alteration in the carrier for spread spectrum communication?
Pseudo-random sequence
Frequency-compandored sequence
Quantizing noise
Random noise sequence
A-005-09-07:
Why is it difficult to monitor a spread spectrum transmission?
Your receiver must be frequency-synchronized to the transmitter
It requires narrower bandwidth than most receivers have
It varies too quickly in amplitude
The signal is too distorted for comfortable listening
A-005-09-08:
What is frequency hopping spread spectrum?
The carrier is altered in accordance with a pseudo-random list of channels
The carrier is amplitude-modulated over a wide range called the spread
The carrier is frequency-compandored
The carrier is phase-shifted by a fast binary bit stream
A-005-09-09:
What is direct-sequence spread spectrum?
The carrier is phase-shifted by a fast binary bit stream
The carrier is amplitude modulated over a range called the spread
The carrier is frequency-compandored
The carrier is altered in accordance with a pseudo-random list of channels
A-005-09-10:
Why are received spread-spectrum signals so resistant to interference?
Signals not using the spectrum-spreading algorithm are suppressed in the receiver
The receiver is always equipped with a special digital signal processor (DSP) interference filter
If interference is detected by the receiver, it will signal the transmitter to change frequencies
The high power used by a spread-spectrum transmitter keeps its signal from being easily overpowered
A-005-09-11:
How does the spread-spectrum technique of frequency hopping (FH) work?
The frequency of an RF carrier is changed very rapidly according to a particular pseudo-random sequence
If interference is detected by the receiver, it will signal the transmitter to change frequency
If interference is detected by the receiver, it will signal the transmitter to wait until the frequency is clear
A pseudo-random bit stream is used to shift the phase of an RF carrier very rapidly in a particular sequence
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