A simple asynchronous distributed STBC network scheme with full diversity

Abstract

In this article, we propose a simple distributed space-time block code (STBC) network scheme for asynchronous relay network, where every two traditional relay nodes are combined to one node to amplify and forward the processed signals via the same transmission antenna. In the proposed distributed network scheme, we consider a wireless scenario with frequency selective fading channels. The orthogonal frequency division multiplexing (OFDM) symbols are broadcast from source to relay nodes in the first step, and in the second step, the received signals at the relay nodes are implemented with a simple operation and mixed partially and forwarded to destination. In this network scheme, the four by four quasi-orthogonal STBC (QO-STBC) is applied, and the orthogonal decoding algorithm can be used at the receiver because of the orthogonality of the re-constructed equivalent transmission matrix. Thus, the full rate and the full diversity are achieved at the transmitter and the receiver of the proposed distributed network scheme, respectively. Simulation result shows that the proposed distributed STBC network scheme has better performance than other network schemes.