Flashcards in NCT 5 16 Deck (15):
the “measuring” of the analog signal at specific intervals
the assigning of a specific value to each of the samples
The process of varying the amplitude, frequency, or phase of a carrier to be in step with the instantaneous value of the modulating waveform.
Data transmission scheme wherein the carrier is shifted in amplitude.
Amplitude Shift Keying (ASK)
Digital modulation scheme wherein the frequency of the carrier is shifted
Frequency Shift Keying (FSK)
Digital modulation scheme wherein the carrier is shifted in 90 degree steps. There are four possible phase states and the magnitude is constant.
quadrature phase shift keying (QPSK)
A network architecture where nodes, hubs, or headends may be connected with fiber optic cables to provide redundancy or increase services.
An extra bit added to help check if the data that is being transferred is correct.
used in synchronous transmission to maintain synchronization between transmitter and receiver.
Data Over Cable Service Interface Specification
The voltage required to “ring” the phone, typically between
70 and 90 volts AC
What does Nyquist’s Rule state?
The C/N gets worse by 3 dB each time the number of amplifiers doubles.
How many phase angles are there in QAM?
4 (0°/360°, 90°, 180° and 270°)
A stream of atomic nuclei that enter the earth’s atmosphere from outer space at speeds approaching that of light.