Distributed concatenated Alamouti code designs for one-way relay networks using uniquely-factorable PSK constellation

This paper develops a novel uniquely-factorable constellation pair (UFCP) by carefully factorizing phase-shift keying (PSK) constellation. With this unique factorization, a new distributed concatenated Alamouti code is proposed for a one-way relaying network consisting of two single-antenna terminals and one relay having two antennas. This design allows the relay to transmit its own information while forwarding the source information which it has received to the destination. By making use of the Alamouti coding scheme twice and jointly processing the signals from the two antennas at the relay node, such a code design also renders the equivalent channel between source and destination be a product of the two Alamouti channels and therefore, is called distributed concatenated Alamouti space-time block code (STBC). In addition, the asymptotic symbol error probability (SEP) formula is derived with the maximum likelihood (ML) detector, showing that the optimal diversity gain function is achieved and proportional to ln SNR/SNR².