Performance analysis of double-threshold based multi-relay selection with differential modulation for cooperative D2D network

In this paper, we analyze the performance of the proposed double threshold-based multi-relay selection for cooperative device-to-device (D2D) communication networks using differential modulation with distance constraints. The mathematical model of the proposed scheme is discussed and the proposed double-threshold based relay selection scheme consists of input threshold fixed at the relay based on the distance between the source, relay and destination nodes and the output threshold at the output of the combiner at the destination. Differential modulation with threshold-based relay selection using Differential AF (DiffAF) relaying is applied in the proposed scheme to overcome the full CSI requirement and it reduces complexity at the relays and destination. The performance analysis of double-threshold based multi-relay selection with different relay scenario for different cases based on the distance constraints and it shows improved performance for higher relay scenario compared to the direct transmission.