说明：  Energy efficiency is the most important design goal for wireless sensor networks (WSNs). In this paper, we propose an energy-efficient cooperative MIMO scheme, which combines energy-efficient LEACH (EE-LEACH) protocol and cooperative MIMO. We name it as EE-LEACH-MIMO scheme. EE-LEACH is an improved LEACH algorithm, in which the network is partitioned to sectors with equal angle for avoiding the distribution non-uniformity of cluster heads. In EE-LEACH-MIMO scheme, the location and the residual energy of each node are considered when the cluster heads for clustering and cooperative nodes for MIMO system are chosen. For comparisons, LEACH, EE-LEACH, the simple cooperative scheme with LEACH and MIMO (LEACHMIMO), and EE-LEACH-MIMO scheme are simulated. The result shows that EE-LEACH-MIMO scheme can well balance the network load, save energy and prolong the network lifetime