A system and method are provided for framing messages in a forward error correction (FEC) structure for data streams encoded with redundant signal conditioning information. The method accepts signal conditioning-encoded words at a first bit rate, and eliminates redundant information in the signal conditioning-encoded words, creating N reduced-bit words of k bits. The k-bit words are mapped into a payload field of N*(k/p) p-bit words. Overhead (OH) and FEC parity fields are generated, and a frame is created including the OH field, payload field, and FEC parity field. The bit values in the frame are then pseudorandomly scrambled and the scrambled frame is transmitted at the first bit rate. A system and method are also presented for recovering the signal conditioning-encoded words from an FEC frame.