On-off keying (OOK) denotes the simplest form of amplitude-shift keying (ASK) modulation that represents digitaldata as the presence or absence of a carrier wave. In its simplest form, the presence of a carrier for a specific duration represents a binary one, while its absence for the same duration represents a binary zero. Some more sophisticated schemes vary these durations to convey additional information. It is analogous to unipolar encodingline code.
OOK is more spectrally efficient than frequency-shift keying, but more sensitive to noise. BANDWIDTH: For a given data rate,the bandwidth of a BPSK(Binary Phase Shift keying) signal and the bandwidth if OOK signal are EQUAL.