Log-Likelihood Ratio Calculation for Iterative Decoding on Rayleigh Fading Channels Using Padé Approximation

Figure 4

Comparison of bitwise True LLR and approximated LLRs for the 8-PAM with Gray labeling (SNR=7.91 (𝜎=1.699)).

(a) Bit 1

(b) Bit 2

(c) Bit 3

(d) Bit 3 (detail for Taylor3)

(e) Bit 3 (detail for Pade41 and Pade34)

(f) Bit 3 (Pade45)