130 



BELL SYSTEM TECHNICAL JOURNAL 



VALUE Aie =0 

 2.5 ' 



2.0 



1.5 



ij 



0.5 

 r 0.25 



[ 0.1 



0.05 



0.025 



0.01 



0.005 



0.0025 



0.001 



0.1 



0.2 0.3 0.4 0.5 0.1 



0.8 1 



V3e'/(/3-ir) 



4 5 6 



Fig. 5 — Probability density of time derivative of phase angle. 



p{&) dB' = probability that the value of dd/dt at an instant selected at random lies be- 

 tween 6' and d' + dd' . The power spectrum of In is constant in band of width 

 /3 centered on fq and is zero outside this band. 



99.99 



99.95 

 99.9 



V 



^ 99.5 



•o 



> 99 



95 



90 



60 



i 70 



0.1 



0.2 



0.3 0.4 0.5 0.6 0.8 1 2 



YTei/Cp-ir) 

 Fig. 6— Cumulative distribution of time derivative of phase angle. 

 Notation explained in Fig. 5. 



4 5 6 8 10 



