Broadband data services are demanded even under high mobility environment, such as high-speed railway. In this paper, we consider single-carrier (SC) linearly distributed antenna network (DAN). The distributed antenna-mobile terminal (MT) link will be a line-of-sight link and therefore, fading can be characterized as the frequency-selective Nakagami-Rice fading. Distributed antenna diversity using single frequency network (SFN) can mitigate the impacts of path and shadowing losses as well as the frequency-selective fading. In this paper, frequency-domain space-time block coded-joint transmit/receive diversity (FD-STBC-JTRD) is employed as SFN linearly distributed antenna diversity. It is confirmed by computer simulation that FD-STBC-JTRD is a powerful diversity to improve the transmission performance under a high mobility environment.