The goal of space-time coding is to achieve the maximum diversity of NM, the maximum coding gain, and the highest possible throughput. In addition, the decoding complexity is very important.

Alamouti code

N = 2 M = 1

To transmit b bits/cycle, we use a modulation scheme that maps every b bits to one symbol from a constellation with 2bsymbols

First, the transmitter picks two symbols from the constellation using a block of 2b bits. If s1 and s2 are the selected symbols for a block...