* Pulse-density modulation== قراءات إضافية ==* PCM description on MultimediaWiki* Ralph Miller and Bob Badgley invented multi-level PCM independently in their work at Bell Labs on SIGSALY: filed in 1943: N-ary Pulse Code Modulation.
==Notes====References====Further reading====External links==* PCM description on MultimediaWiki* Ralph Miller and Bob Badgley invented multi-level PCM independently in their work at Bell Labs on SIGSALY: filed in 1943: N-ary Pulse Code Modulation.