Performance Analysis of Transmitter-Side Cooperation–Receiver-Side-Relaying Schemes for Heterogeneous Sensor Networks

In this paper, we present two physical layer cooperative protocols for heterogeneous sensor networks. There is one cooperator near the transmitter and a second cooperator (as a relay) near the receiver. Although the focus is on heterogeneous sensor networks, the methods can be applied to homogeneous sensor networks as well. Analytical and simulation results show that, under an additive white Gaussian noise channel assumption for the links between the transmitter and its partner and between the receiver and its partner, the proposed protocols achieve a diversity order of three or four by using the amplify-and-forward cooperation strategy and maximal ratio combining in the receiver. In addition, the proposed methods outperform the noncooperative single-hop transmission in the clustered heterogeneous sensor network and save a considerable amount of energy relative to the noncooperative transmission.