Secrecy outage probability of cooperative network through distributed Alamouti code

The cooperative diversity technique, combined with distributed space-time coding (DSTC), can efficiently improve the secrecy capacity and transmission reliability of wireless communication systems. In this paper, a multicast cooperative relaying system, based on distributed Alamouti space-time coding, is proposed, as a method of preventing an eavesdropper from accessing source data. A maximum likelihood (ML) decoder at the destination was chosen to receive the data, however, the ML decoder was unable to receive data at the eavesdropper. An analysis was carried out to synchronize DSTC, a Rayleigh fading channel, a Rician fading channel, and a combination thereof. It was assumed that channel state information (CSI) for the relay-destination link was known, although this was unknown for the relay-eavesdropper link. The theoretical results for the secrecy outage probability for the proposed scheme are then compared with existing results.