Abstract:

Different transmission strategies for decode-and-forward parallel relay networks based on superposition coding are investigated. In particular, an optimal-cooperation (OC) strategy is proposed to minimize the aggregate power consumption for a target transmission rate, which requires strict synchronization at the destination node to achieve its optimal performance. A non-information-overlapping (NIO) strategy is then proposed to avoid the synchronization problem. Compared with OC strategy, NIO strategy is more suitable for actual relay networks. Furthermore, a reduce-relay-selection method involving only 2-level superposition coding is given to trade off between complexity and performance. Analysis shows that the performance gap between NIO strategy and OC strategy is negligible. the best two relay nodes are selected in adequating to achieve most performance gain of NIO strategy even if the number of relay nodes is large.