;Differential spatial modulation (DSM) is a multi-antenna technique that uses only one antenna to transmit signals at a time and avoids pilot overhead. By selecting the transmitting antenna, additional data bits can be transmitted.DSM is extended to generalized DSM (GDSM) where more than one transmit antennas are activated each time. However, the transmission rate of the existing GDSM scheme is low. In this thesis, we propose a new GDSM scheme that uses symbol interleaving on differential space-time modulation. Properties and the number of valid interleaving patterns are shown as well. By selecting the interleaving patterns, the proposed scheme has higher data rates than the existing GDSM scheme.