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Shama Naz Islam,M. A. Mahmud,Aman Oo 한국통신학회 2017 Journal of communications and networks Vol.19 No.4
In this paper, we consider device to device (D2D) communicationoverlaying cellular network where a group of D2Dusers exchange messages among themselves. We investigate thecase when the channel conditions of the direct links among theseD2D users are not strong enough to support direct communicationand hence, an intermediate relay node assists the communicationamong the D2D users. Here we consider capacity achieving latticecodes at the D2D users along with compute-and-forward protocolat the relay. Based on these, we derive the received signal to noiseratio (SNR) at the relay, as well as the D2D users and formulateupper bounds on the achievable sum rate. We also investigate theachievable sum rate when the devices communicate using the directlinks and compare with that of the relay aided D2D communication. We find that when the D2D users are closer to the relay, relayaided communication achieves better performance compared to directcommunication. However, for the same distances, the sum ratedegrades more for relay aided communication. It is also shown thatwhen the links between most of the D2D users and the relay havegood channel conditions compared to the direct links, relay aidedcommunication can achieve better sum rate performance than thedirect communication.