- This paper investigates the effects of correlated multiple-input multiple-output (MIMO) channels on the performance of spatial modulation (SM) techniques. Bit error rate (BER) performance for SM, quadrature SM (QSM), and generalized QSM transmission schemes over correlated MIMO vehicle-to-vehicle (V2V) channels are presented. The results are compared with the conventional spatial multiplexing (SMux) transmission schemes. For all cases, the optimal maximum like-lihood (ML) detection criterion is used to detect the symbols at the receiver. Performace degradation due to the effects of spatial correlation of the MIMO V2V channels are then evaluated. The simulation results show significant degradations when SM techniques operate over correlated MIMO channels. Therefore, it can be concluded that SM techniques are very sensitive to the adverse effects of the propagation channels of modern mobile communication systems such as vehicular communications. © 2018 IEEE.