Dynamic scheduling in system-level simulations for multi-hop D2D communications in LTE networks

Device-to-device (D2D) communication has attracted great attention and becomes a promising technology for future wireless networks. Besides two UEs communicating directly without going through the base station, D2D communication can be further broadened to multi-hop D2D communication, for example, a UE may serve as a relay for some D2D pair. In this work, we perform system-level simulation studies on multihop D2D communications overlay LTE networks with intra-cell and inter-cell interference from other D2D transmissions. We investigate dynamic scheduling for multi-hop D2D according to instantaneous channel and interference situation based on proportional fair metrics. Dynamic scheduling is a compromise between average and edge spectral efficiency, since using relays can increase edge performance but may decrease the average spectral efficiency as they consume more resources than direct D2D. In simulation studies, we can see that multi-hop D2D with dynamic scheduling outperforms direct D2D and multi-hop D2D with fixed scheduling for large D2D distance, and also increases edge spectral efficiency dramatically for small D2D distance with the expense of a little average spectral efficiency decrease.