Abstract: A theoretical study of the symbol error rate (SER) for orthogonal space-time block codes (OSTBC) was presented while there existed non-ideal channel state information (CSI). it was proved that the squaring method to simplify the decoding of OSTBC could be used. Both signal-to-noise ratio and SER expressions for OSTBC, using this squaring method, got derived under the above conditions. Numerical simulation shows that the performance with non-ideal CSI is poorer than that with ideal one, and also shows that the more estimation errors there exist, the more performance losses. It is concluded that the SER bound decreases slowly when the variance of estimation errors is less than some small values (say 0.2).

Key words: channel codes, orthogonal space-time block codes, diversity technology