We experimentally demonstrate a simple vector signal transmission architecture to realize the vector signal conversion from 8PSK to QPSK and optical carrier reuse based on radio over fiber system with fiber grating.A 5 GHz microwave carrying 1 Mbps 8PSK-vector signal is optical frequency doubled by employing double sideband carrier suppressed(DSB-CS) modulation scheme and up-converted to 10 GHz,optical carrier reuse is realized via a FBG in base station,and the finally demodulated vector signal is QPSK.As s...