“…We observe that, as for linear transmission, when γ → ∞, we haveD d,2 = σ 2 v (1 − 2/π), and when γ → 0, we havē D d,2 = σ 2 v . From (17), one can check that the slope of the average distortion for BPSK transmission as γ → 0 is −4σ 2 v /π 2 , whereas the slope for linear transmission, obtained from (13c), is −2σ 2 v /π. This means that linear transmission has a decline in the distortion in the low SNR regime; therefore, it outperforms BPSK transmission, in this regime.…”