Abstract: oint estimation of the carriers frequency offsets and channels of OFDM system is considered. A computationally efficient joint estimator of carriers frequency offsets (CFO) and channels is developed to overcome the drawbacks of single estimation and improve estimation accuracy. By utilizing the constant amplitude zero autocorrelations (CAZAC) sequence, CIR parameters are estimated with the maximum likelihood criterion. And then CFO is calculated and modifies channel estimators. In addition, the frequency offsets CramerRao bound is proposed. Numerical simulations indicate the proposed low complexity estimators having less mean square errors outperform the least square (LS) joint estimation algorithm.