All RF Cafe quizzes would make perfect fodder for employment interviews for technicians or engineers - particularly those who are fresh out
of school or are relatively new to the work world. Come to think of it, they would make equally excellent study material for the same persons
who are going to be interviewed for a job.
Some of these books used in quizzes are available as prizes in the monthly
RF Cafe Giveaway.
Note: Many answers contain passages quoted in whole or in part from the text.
quiz is based on the information presented in OFDMA System Analysis and Design, by Samuel C. Young. Published by
Artech House. Note: Some of these books are available as prizes in the
RF Cafe Giveaway
Which of these are advantages of Frequency Division Multiplexing (FDM)?
at combating intersymbol interference (ISI) and multipath fading
b) Can adjust modulation and coding for each
c) Simple equalization
d) All the above2.
scheme has the highest spectral efficiency?
a) Frequency Division Multiplexing (FDM)
b) Orthogonal Frequency Division Multiplexing (OFDM)
c) Orthogonal Frequency Division Multiple Access (OFDMA)
d) Uber Orthogonal Frequency Division Multiple Access (UOFDMA)3.
signal computations, what is the "plane-earth" model?
a) A model used for airborne system calculations
b) A model that considers the earth surface to be flat
c) c) A model that neglects obstacles, i.e., "plane"
d) All the above4.
What are "linear block codes" in channel coding lingo?
a) A class of codes used for error detection or correction
b) Linear coding techniques that divide cells into city blocks
c) Coding schemes using a building block
d) None of the above5.
How does a high peak-to-average
power ratio (PAPR) affect OFDM systems?
a) Not at all
d) OFDM cannot be used with a high PAPR6.
What is the "physical layer" of a
a) It is the code (software/firmware) responsible for the actual transmission
across the medium
b) The actual cable or wireless link interconnecting the transmitter and receiver
c) Another name for the hardware
d) Another name for the MAC (Medium Access Control)
What is "receive diversity?"
a) Having a receiver capable of operating in a
b) Using all arriving bits regardless of signal quality
c) Giving preference to "0s"
over "1s" out of fairness
d) Dynamically selecting the best signal from multiple antennas
Which of the following are real names given to scheduling algorithms?
a) Round robin
Temporary removal scheduler
c) Proportional fairness
d) All the above9.
During a cell scanning interval, which neighboring station "association level" refers to
a) Association Level 0
b) Association Level 1
c) Association Level 2
d) Association Level 310.
What is a cryptographic "hash?"
a) Masking noise
b) A function that returns a fixed-size bit string from a variably-sized input
c) An algorithm that chops up messages to disguise them
d) Playful bantering between coders
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