DATA AND SIGNALS

DATA AND SIGNALS

analog signals
1. periodic
  1. continous repetitive pattern whitin time frame
2. non- periodic
  1. composite perioddic analog signal is composed of multiple sine waves
sine wave
1. amplitude
2. period
3. frequency
4. phase
composite signals
1. a single frequency sine wave is not useful in data communication, we need to send a composite signal
digital signals
1. described by bit interval(instead of period) and bit rate (instead of frequency)
Nyquist bit rate
1. BitRate = 2 x bandwidth x log2 L (L=the number of signal level used)
shannon capacity
1. Capacity = B x log2 (1 + SNR) SNR=the signal-to-noise ratio
transmission impairment
1. noise
  1. thermal noise
  2. induced noise
  3. crosstalk
  4. impulse noise or spike
2. distortion
3. attenuation
performance of network
1. troughput
2. propagation and transmission time
3. queuing time
4. bandwith
5. latency
digital to digital convertion
1. line coding
2. block coding
3. scrambling

Resource summary

	Created by Umar Amiruddin S over 11 years ago