Performance analysis of 2-1-1 relaying protocol in wireless sensor networks

A power-and-bandwidth efficient cooperative communications protocol where a sensor node assists two others for their data transmission to a clusterhead in WSNs (wireless sensor networks) using LEACH (low-energy adaptive clustering hierarchy) is proposed in this paper. Its closed-form BER expression which generalizes BER one for the decode-and-forward protocol (DF) is also derived. We proved that the proposed protocol performs the same as the conventional DF but achieves higher bandwidth efficiency. A variety of numerical results reveal the cooperation can provide a performance gain of up to 11 dB over direct communications at BER of 10/sup -3/.