Abstract: In this paper present review study on optical communication with OFDM system by MIMO technique. At reviewing background knowledge that includes fundamentals of modulation and communication, signal propagation and channel modeling. In this paper ideas behind formulas, rather than mathematical derivations, are emphasized and several examples are provided to allow easy comprehension of the concepts. in-depth treatment of two essential signal processing tasks synchronization and channel estimation–is discussed. Then, MIMO (multiple-input multiple output) techniques with their application to optical OFDM systems are also delineated. This part also aims to present the readers with modern signal-processing algorithms in optical OFDM baseband receivers talks about hardware design, from design methodology to design of essential blocks with a couple of examples that cover the latest OFDM receiver and its developments.