中文摘要：

讨论了一个四节点无线网络，并将该四节点无线网络划分MIMO，MAC，Broadcast，Cooperative模型。讨论了四种不同模型的DMT上界。理论结果表明该模型可获得的最大分集值为4，最大复用值为2；协作可以有效地提高系统的分集值或者复用值，但是，协作并不能完全模拟MIMO系统。当复用增益较低时，协作模型与MIMO模型具有相同的DMT。当复用增益较高时，受复用增益的限制，分集增益为零。

英文摘要：

A four-node wireless network is discussed and divided into MIMO,MAC,broadcast,cooperative models. The di-versity-multiplexing tradeoff（DMT）upper bounds of four different models are discussed. The theoretical results show that the maximum diversity order of these four models is 4,and their maximum multiplexing order is 2,and cooperation can effectively improve the models＆#39; diversity order or multiplexing order,but it can not fully simulate MIMO system. Cooperative model and MIMO model have same DMT when the multiplexing gain is low. However,the diversity gain is zero when the multiplexing gain is high,because of the limitation of multiplexing gain.