The symmetric information rate is used to define the relationship between the APSK constellation parameters, the code rate, and the average and peak Eb/N0 . Minimizing the average Eb/N0 reproduces the DVB-S2 constellation parameters for 16- and 32-APSK. Minimizing the peak Eb/N0 produces DVB-S2 constellation parameters for 16- and 32-APSK that minimize the peak-to-average power ratio. The peak-to-average power ratio gains are less than 1 dB, but when used on coded systems with very steep decoded bit error probability vs. Eb/N0 curves, the gains can be significant.