Chapter 3 Flashcards
Analog signal
Continuous values
Digital signal
Discrete values
Periodic signal
Continuous after the fixed time (simple or composite)
Repeating
ex: Single sine wave
Non-periodic signal
Discrete levels which do not repeat
Levels presented as 0 or 1
Sine wave
Peak amplitude, frequency and phase
Peak amplitude
distance between highest peak and 0
Period
amount of time a signal takes to complete 1 cycle
measured in seconds
t = 1/f
Frequency
Rate of change with respect to time
Change in short span = high frequency
change over long span = low frequency
no change = zero frequency
instant change = infinite frequency
Phase
position of waveform relative to time
Phase 0: starts at 0
Phase 90: Starts quarter way through wave
Phase 180: Starts half way through wave
Wavelength
Distance covered in 1 cycle
Wavelength = propagation speed / frequency
Composite signal
Combination of multiple sine waves with different frequencies, amplitudes and phases
Periodic or non periodic
Bandwidth
Difference between highest and lowest frequencies
Bit rate
Number of bits sent in 1s
bits per second
Bit length
Distance one bit occupies on the transmission medium
bit length = propagation speed * bit duration
Baseband
digital signaling over single wire
bidirectional
send and recieve data using single cable, but not at the same time
