On the Definition and Measurement of Occupied Bandwidth

Measurement of the occupied bandwidth is not a simple matter as the term is now defined. This is particularly true for emissions which are measured at a great distance from the transmitter. The emission class studied here is frequency modulation with noise as the modulating signal. The emitted spectrum is first separated into three parts, namely, spurious emissions, harmonic emissions, and the fundamental emission. The first of these is discussed qualitatively, whereas the second and the third are treated quantitatively. An equation is given for computing the maximum expected amplitude of the harmonic emissions. A probability density function has been found that links the Laplacian and the Gaussian probabilities. This function is then used to demonstrate the practicality of a measurement method and to aid in the justification for a modification to the existing definition of occupied bandwidth.