An Enhanced Scaled Selection Combiner(ESSC)is proposed for Decode-and-Forward(DF)cooperative networks,where different modulation levels are adopted by the source and relay nodes to improve spectral efficiency. When the ESSC is used to combine signals from different diversity branches,the source-relay-destination branch is weighted by varying scale factors.As a result,the performance degradation caused by erroneous relaying in DF networks can be effectively mitigated by ESSC.Towards this end,the Bit-Error-Ra...