Jun 212009
Q: What is Eb/N0?
Eb/No is S/N (Signal to Noise ratio) divided by spectral efficiency.
“SNR per bit”
Q: Why is Eb/N0 important in digital communication?
Motivation:
- analog waveform is a power signal (infinite energy, finite average power)
- digital waveform is an energy signal (zero average power, non-zero finite energy) since a waveform is transmitted only during each symbol duration.
- the digital waveform represents a digital message. The message may contain 1 bit(binary) 2 bit(4-ary)…
- suppose we are told that the waveform S/N=20…
- if the waveform had 1 bit meaning, then all 20 units of S/N ratio are allocated to that 1 bit
- if the waveform had 10 bit meaning, then each bit has 2 unit of S/N.
