Efficient hierarchical embedded signaling scheme for nodes identification in cooperative wireless networks with relay selection

In cooperative wireless systems, a data packet transmitted by a source node is forwarded by relay nodes before reaching the destination node. In actual technologies, the destination recovers the identities of the sources and relays of received signals by using signaling information exchange before the data exchange and by including identities information (addresses) in data sequences. This leads to a waste of energy and spectral resources as well as an additional transmission delay. In this paper, we propose a novel blind nodes identification scheme in a cooperative wireless system where a relay node is selected to forward a source node data sequence. Two different relay selection schemes are considered: the Opportunistic Relay Selection (ORS) and the Partial Relay Selection (PRS). The proposed identification scheme is based on embedding precoding sequences into the data sequence at each source and relay node. The choice of the precoding sequences and the destination processing are based on classical coding theory. The proposed identification scheme allows the destination to recover hierarchically the relay nodes and the source nodes by allocating to them different modulation alphabets. Our technique is efficient since it avoids explicit signaling information exchange and allows the destination node to recover the nodes identities without using additional signaling bits. Numerical results validate the proposed identification scheme performance.