Alamouti coding

Alamouti Coding is a spatial-time block code (STBC) which exploits the spatial diversity at the transmitter for a two-transmitter(antenna) system. It was proposed by Siavash M. Alamouti in 1998.

The transmitter output is given by the following equation:

$s={\begin{bmatrix}s_{0}&s_{1}\\-s_{1}^{*}&s_{0}^{*}\end{bmatrix}}$

where columns represent the transmit antennas and the rows represent time. $s_{0}$ and $s_{1}$ are two consecutive symbol inputs into the Alamouti encoder.