Blind Cooperative Communications for Multihop Ad Hoc Wireless Networks

Cooperative communications enhance the performance of wireless networks by allowing nodes to cooperate with each other to achieve spatial diversity gains. To obtain cooperation gains, appropriate relay node(s) should be selected according to network topology and channel state information (CSI). However, in ad hoc wireless networks, the CSI is random, and the network topology is dynamic. This complicates relay selection, and in turn, makes it difficult to implement cooperative communications in ad hoc wireless networks. To tackle the issue, this paper proposes blind cooperative communications (BCC) for multihop ad hoc wireless networks. In BCC, intermediate nodes and the destination node in a multihop path first listen and cache the data from two-hop-away upstream nodes, and then combine the cached data with the data forwarded by the upstream to obtain diversity gains. The performance of BCC is evaluated by analysis and simulations to show that BCC can significantly increase the packet delivery ratio (PDR) and the average end-to-end throughput (AET). Compared with existing cooperation methods, BCC requires neither CSI and topology information nor additional signaling overheads, making it extremely easy to implement in dynamic multihop ad hoc wireless networks.