Ciena Corporation
Forward Error Correction with Outer Multi-Level Code and Inner Contrast Code

Abstract:

In data communications, a suitably designed contrast coding scheme, comprising a process of contrast encoding (108) at a transmitter end (101) and a process of contrast decoding (120) at a receiver end (103), may be used to create contrast between the bit error rates `BERs` experienced by different classes of bits. Contrast coding may be used to tune the BERs experienced by different subsets of bits, relative to each other, to better match a plurality of forward error correction `FEC` schemes (104, 124) used for transmission of information bits (102), which may ultimately provide a communications system (100) having a higher noise tolerance, or greater data capacity, or smaller size, or lower heat.