678 



THE BELL SYSTEM TECHNICAL JOURNAL, MAY 1957 



power ill db hclow that cuiTcspoiuliiig to u full load sine wave is simply 



10 logic 



^ 



10 logio [C72] = 20 logio C - 3 db (34) 



It must be emphasized that C varies inversely with the rms signal voltage, 

 so that weak signals are characterized bj^ large values of C and strong 

 signals by small values of C. 



4. Average Ahsohde Signal Amplitude (I e |) 



The proljability density of the signal manifests itself in the value as- 

 signed to the average absolute signal parameter, A = \ e \ /\/^- This 



10^ 



e 



6 



102 



8 

 6 



Z 



10 



4 6 8 



10 



4 6 8 



c = v//e2 



10' 



4 6 8 



10-^ 



Fig. 6 — Variation of the rms error to signal voltage ratio (D) with relative 



signal strength, C = V/w e^, as given by equation (27) for various degrees of 

 logarithmic companding. 



