In this paper,we address the Alamouti code in Filter-Bank Multicarrier with Offset Quadrature Amplitude Modulation (FBMC/OQAM) and propose a novel block-wise Alamouti code,in which a repeated block is designed to eliminate the imaginary interference among FBMC/OQAM symbols.The proposed approach exhibits a higher spectral efficiency than the conventional block-wise Alamouti scheme,as only one column of zero symbols is used as a guard interval instead of two.Furthermore,compared to the conventional scheme,the bit error ratio is improved in the proposed block-wise Alamouti,as the assumption on channel invariance at two adjacent sub-carriers is not required.Simulation results indicate that,with a significantly reduced overhead,the proposed Alamouti scheme achieves better performance over the conventional block-wise Alamouti scheme.