End-to-End Performance of a 4/16-QAM Hierarchical Modulation Scheme over Rician Fading Channels

In this paper, we derive an analytical expression for the average symbol error rate for the 4/16-QAM hierarchical modulation (HM), of the mapped signal at the relay during the up-link phase, for the HP and LP streams, respectively, in Rician fading environments. Furthermore, by utilizing HM for the proposed HM-PLNC system, we minimize the computational complexity at the relay node by reducing the number of Euclidean distance computations (EDCs) to 32 EDCs in fading channels. Performance evaluations show that the proposed system can significantly enhance E2E throughput for the TWRN systems compared to an equivalent 16-QAM based PLNC system. The results present a closed-form solution for HP and LP streams over slow, flat, Rician fading channels.