Amplify-and-forward cooperative relaying for single-carrier block transmission

In this paper, we consider amplify-and-forward relaying scheme with a single-relay framework, where the involved links between transmit-receive pairs may experience different delay spread. Without channel state information assumed or estimated at the destination terminal, unitary spacetime modulation (USTM) derived from complex orthogonal spreading sequence set was adopted for the distributed single-carrier block transmission. Our pairwise error probability (PEP) analysis indicates that the multipath diversity can be exploited based on the USTM in couple with the noncoherent demodulation rule. Numerical results vindicate the merit of multipaths under certain circumstances such as the link quality from the source to relay as well as power control at relay node.