Using Higher Order Cyclostationarity to Identify Space-Time Block Codes

Research in cognitive radios has renewed interest in tools, such as spectrum estimation and modulation identification, to characterize the Radio Frequency (RF) environment. The use of multiple antennas for Multiple-Input Multiple-Output (MIMO) communications presents a new challenge in detecting and classifying signals. In this paper, the authors propose a cyclostationarity-based statistical test to detect space-time block codes, focusing on the two transmitter Alamouti Space-Time Block Code (STBC). Their test exploits a new characterization of the Alamouti code using fourth order cyclic frequencies.