OFDM systems are sensitive to Carrier Frequency Offsets (CFO) that results in performance's degradation. Researchers have proposed various CFO compensation techniques. Some estimates the CFO's value then compensates for it using preamble methods. Others estimate the CFO value using the inherent construction of the time-domain OFDM symbol. Our proposed technique changes the conventional structure of the OFDM symbol to allow estimating the CFO values over a wide range. CFO estimation range, accuracy, transmitted data-rate, system complexity, and the compatibility of a specific estimator to be used in different applications are the most important parameters to be considered in researches. In this paper, a comparative analysis between preamble techniques (Moose, Training Symbol) and the OFDM internal construction-based estimators including blind and proposed schemes will be discussed. Simulations show the trade-offs between those techniques.