220ConceptsOccupied Bandwidth Measurement ConceptsOccupied Bandwidth Measurement ConceptsPurposeOccupied bandwidth measures the bandwidth containing 99.0 of the totaltransmission power.The spectrum shape of a signal can give useful qualitative insight into transmitteroperation. Any distortion to the spectrum shape can indicate problems in transmitterperformance.Measurement methodThe instrument uses digital signal processing (DSP) to sample the input signal andconvert it to the frequency domain. With the instrument tuned to a fixed centerfrequency, samples are digitized at a high rate with DSP hardware, and thenconverted to the frequency domain with FFT software.The total absolute power within the measurement frequency span is integrated for its100% of power. The lower and upper frequencies containing 0.5% each of the totalpower are then calculated to get 99.0% bandwidth.
