It is well-known that node cooperation can yield sig- nificant performance gains in wireless networks. However, it is not known ap rioriwhich nodes are able to cooperate in many practical cases. In this paper, we address the problem of nonco- herent distributed space-time block code (DSTBC) designed for this scenario. We show that the proposed noncoherent DSTBCs can guarantee a certain diversity order regardless which nodes in the network cooperate. Neither the intended receiver nor the cooperating nodes require channel state information. I. INTRODUCTION