19
Signal Bandwidth
¥A baseband signal is any signal which transmits data in the form of the amplitude of the signal voltage.  The bandwidth of a baseband signal is measured from zero frequency upwards to fmax .
¥A modulated signal transmits data by modifying the amplitude, frequency, or phase of a carrier signal.  The bandwidth of a modulated signal is measured from the minimum frequency fmin  (below the carrier frequency) upwards to fmax  (above the carrier frequency).

¥The full bandwidth of a signal is the frequency range that includes all spectrum lines of the signal.
¥The absolute bandwidth (ABW) of a signal is the width of the spectrum that contains 98% of the signalÕs total power. 

¥The effective bandwidth (EBW) (bandwidth) of a signal is the width of the spectrum that contains at least 50% of the signalÕs total power.  This is the part of the signal whose power is within 3 dB of the complete signal.