In-band amplify and forward cooperative diversity for the orthogonal complementary coded CDMA networks

This study proposes synchronous in-band amplify and forward relaying for the orthogonal complementary coded Code Division Multiple Access (CDMA) networks. In any relay assisted system, in order to achieve diversity, the destination terminal should combine the replicas of the information signal from the source and relay terminals. The two replicas should be sent in orthogonal channels such as either in different time slots or different frequency bands for successful detection at the destination. Unlike the previous studies, in this paper we propose amplify and forward cooperative diversity strategy where the relays operate in the same band and in the same time slot for the direct sequence complementary coded CDMA (DS/CC-CDMA) networks. In traditional CDMA networks with conventional code sets, it is not possible for the relays operate in the same band and in the same time slot. This work shows that the complementary coded CDMA networks can accommodate in-band and in-time relay terminals without any interference.