Schemes integrating inter-carrier interference (ICI) self-cancellation and common phase error (CPE) compensation for coherent optical orthogonal frequency division multiplexing (CO-OFDM) systems are investigated. The purpose of our research is to counteract the impacts of laser phase noise and fiber nonlinearity. We propose two ICI self-cancellation-based CO-OFDM schemes, and adopt a pilot-aided decision feedback (DFB) loop for CPE compensation. The proposed schemes are compared with conventional CO-OFDM schemes at the same spectral efficiency. Simulations show that our schemes can not only enhance laser linewidth tolerance of the CO-OFDM system, but also present strong robustness against fiber nonlinearity.