Cooperative communication or distributed multi- input multi-output (DMIMO) system is an emerging paradigm for increasing spectral efficiency, coverage extension, small cell deployment. In such a system, the signal received at the destination is characterized by multiple carrier frequency offset (MCFO) and channel gains as relays are distributed over space. On the other hand, as orthogonal frequency division multiplexing (OFDM) is very sensitive to frequency offset. DMIMO-OFDM system faces a fundamental problem of synchronization. In this paper, we propose two iterative algorithms based on expectation conditional maximization (ECM) and space alternating generalized expectation maximization (SAGE) to jointly estimate MCFOs and channel gains for a quasi-static channel in estimate-and-forward (EF) multi-relay cooperative communication system. The performances of the estimators are evaluated by means of mean square error (MSE) and system bit error rate (BER). The results indicate that in the high SNR regime, the BER performance of the system with SAGE algorithm results in 1 dB SNR improvement as compared to that with ECM.