Cooperative Communications Based on Harmonic Means of Channel Responses

In the cooperative communication, the destination node combines the received signals from source and relay nodes such that a better performance can be achieved due to diversity. However, the channel responses from the source to relay nodes also affect the combination effect at the destination. In this work, we apply the harmonic mean of the channel responses between source-relay and relay-destination to replace the original relay-destination channel response. The harmonic mean operation can reflect the overall effects of these two channels. With this we observe that the error rates in the destination can be reduced. We consider the schemes of maximum ratio combining (MRC) and the selection combining (SC) and the hybrid types. In these schemes, we all observe that with the harmonic mean of channel responses, better performance can be achieved.