Single-Symbol ML Decodable Distributed STBCs for Cooperative Networks

In this correspondence, the distributed orthogonal space-time block codes (DOSTBCs), which achieve the single-symbol maximum likelihood (ML) decodability and full diversity order, are first considered. However, systematic construction of the DOSTBCs is very hard, since the noise covariance matrix is not diagonal in general. Thus, some special DOSTBCs, which have diagonal noise covariance matrices at the destination terminal, are investigated. These codes are referred to as the row-monomial DOSTBCs. An upper bound of the data-rate of the row-monomial DOSTBC is derived and it is approximately twice higher than that of the repetition-based cooperative strategy. Furthermore, systematic construction methods of the row-monomial DOSTBCs achieving the upper bound of the data-rate are developed when the number of relays and/or the number of information-bearing symbols are even.