Define power efficiency and bandwidth efficiency.

48. Define power efficiency and bandwidth efficiency.

Power efficiency describes the ability of a modulation technique to preserve the fidelity of the digital message at low power levels.
ɳp = Eb/N0 = Bit energy / Noise power spectral density
Ability of a modulation scheme to accommodate data within a limited bandwidth is called bandwidth efficiency.
ɳB = R/B = Data rate / Bandwidth in bps/Hz