Smart Relaying for Selection Combining Based Decode-and-Forward Cooperative Networks

This letter proposes three smart relaying strategies, including power allocation, continuous power control, and discrete power control strategies, to mitigate the error propagation problem for single-relay decode-and-forward cooperative networks using selection combining at the destination. By fully exploiting the channel state information at the relay, these relaying strategies can optimize transmit power so as to minimize the bit error rate of the system, as well as allowing the source and relay nodes to use different modulation levels to improve spectral efficiency. Simulation results demonstrate that the proposed smart relaying strategies can effectively mitigate erroneous relaying and achieve diversity orders close to two.