On orthogonal space-time block codes and transceiver signal linearization

We present a necessary and sufficient condition for any orthogonal space-time block code (STBC) to allow transceiver signal linearization (as in the well-known case of the Alamouti scheme). Then, we show that all square orthogonal STBC´s that satisfy the condition have rate that goes to zero linearly with the number of transmit antennas. Hence, multiple-antenna systems with orthogonal STBC´s and satisfactory rate are possible only If we abandon the linearization property or utilize non-square codes (except for the 2 times 2 Alamouti code)