Efficient D2D Discovery Scheme for Channel Measurement of Interference Alignment

Co-channel interference among Device-to-device (D2D) users is major issue to be solved when utilizing the same frequency bands. Consequently, interference alignment (IA) as an effective interference management approach has been implemented to D2D communications for the frequency sharing. However, the measurement of channel state information (CSI) between transmitter and receiver of a D2D pair and cross-channel state information (C-CSI) among D2D pairs are the major issues that need to be resolved for the implementation of IA from theory to practical. Therefore, in this paper, we propose an effective D2D discovery scheme to overcome this problem, which can measure the CSI and C-CSI based on the discovery messages. Simulation results show that, under perfect conditions, even though the proposed D2D discovery scheme increases the needed time slots to establish D2D communications by 6.2% compared with the conventional D2D discovery without considering IA, it increases the throughput up to 50% than the conventional D2D without considering IA, i.e., it improves the spectrum efficiency.