Embodiments of the invention provide time-domain link adaptation in power line communications. In one embodiment, the cyclic prefix length and position is adjusted with an OFDM symbol to overlap a periodic impulse noise pulse, thereby allowing the data carried in the symbol to be detected at a receiver. The cyclic prefix may be adjusted to provide a pattern that yields an integer number of OFDM symbols in one zero crossing period. The data rate used for the symbols overlapping the zero-crossing period may be zero or very low. A high data rate may be used for symbols outside the zero-crossing period because those symbols will not be affected by the periodic impulse noise.