:''This article deals with {{About|coherent space–time block codes (STBCs). For |differential space–time block codes, see [[differential|Differential space–time code]]s.}}
'''Space–time block coding''' is a technique used in [[wireless|wireless communications]] to transmit multiple copies of a data stream across a number of [[antennaAntenna (radio)|antenna]]s and to exploit the various received versions of the data to improve the reliability of data- transfer. The fact that the transmitted signal must traverse a potentially difficult environment with [[scattering]], [[reflectionReflection (physics)|reflection]], [[refraction]] and so on and may then be further corrupted by [[thermal noise]] in the [[receiverReceiver (radio)|receiver]] means that some of the received copies of the data will be 'better' than others. This redundancy results in a higher chance of being able to use one or more of the received copies to correctly decode the received signal. In fact, [[space–timeSpace–time code|space–time coding]] combines ''all'' the copies of the received signal in an optimal way to extract as much information from each of them as possible.
