This paper proposes two efficient peak-to-average power ratio (PAPR) reduction algorithms for OFDM signals based on the principle of tone reservation. The first algorithm is performed in the time domain, whereas the second algorithm is a new clipping-and-filtering method. Both algorithms consist of two stages. The first stage, which is done off-line, precomputes a set of canceling signals based on the settings of the OFDM system. In particular, these signals are constructed to cancel signals at different levels of maximum instantaneous power that are above a predefined threshold. The second stage, which is online and iterative, reduces the signal peaks using modified versions of the canceling signals constructed in the first stage. When the reserved tones are distributed among the data tones, analysis and simulation results obtained with Data Over Cable Service Interface Specifications (DOCSIS) parameters show that the proposed algorithms achieve slightly better PAPR reduction performance and with significantly lower complexity when compared to the conventional algorithms.