A network device implements a repetition scheme to generate a repetition-encoded FEC codeword for a FEC codeword. The repetition-encoded FEC codeword includes a set of bit sequences concatenated together. The set of bit sequences corresponds to a set of OFDM symbols. In some embodiments, each bit sequence is formed by M replicas of the FEC codeword and an offset is applied to shift the bit sequence where the offset is different for each bit sequence. In one embodiment, a right cyclic shift is used to offset the bits in each symbol. Each shifted bit sequence is allocated into subcarriers of an OFDM symbol over a frequency range indicative of an operating frequency band of a domain to form the respective OFDM symbol. The set of OFDM symbols is transformed into a time domain signal for transmission.