We consider probabilistic shaping as a means of increasing the spectral efficiency of fiber-optic communication systems. In contrast to previous works in the literature, we consider probabilistic shaping with hard decision decoding (HDD). In particular, we extend the probabilistic amplitude shaping (PAS) scheme recently introduced by B\"ocherer \emph{et al.} to a coded modulation (CM) scheme with HDD that uses a staircase code as the forward error correction code. We show that the proposed CM scheme with PAS and staircase codes yields significant gains in spectral efficiency with respect to the baseline scheme using a staircase code and a standard, uniform constellation. Using a single staircase code, the proposed scheme achieves performance within $0.56$--$1.55$ dB of the corresponding achievable information rate for a wide range of spectral efficiencies. 查看全文>>