PAM3 is 3 levels per unit interval (~1.58 bits), not 3 bits per cycle as reported in this article. Although I suppose if you count a cycle as both edges of the

PAM3 is 3 levels per unit interval (~1.58 bits), not 3 bits per cycle as reported in this article. Although I suppose if you count a cycle as both edges of the clock it's 3.17 bits.