Density-Based Spatial Clustering of Applications with Noise for Modulation Order Blind-Detection in Non-Orthogonal Multiple Access

Successive Interference Cancellation (SIC) receiver is used to eliminate the co-channel interferences in non-orthogonal multiple access (NOMA) scenario. During the SIC procedure, some physical layer parameters including user equipment’s (UE’s) modulation order are required to decode and reconstruct the interference signal. These kinds of parameters would increase the signaling overhead. To address this issue, this paper provides a novel modulation order blind-detection algorithm with Density-Based Spatial Clustering of Applications with Noise in NOMA systems. The proposed algorithm adopts a spatial cluster to extract the characteristics of the samples. A novel cluster center location feature is introduced to modulation order blind-detection to enhance the detection performance. Specifically, the novel algorithm consists of two parts: one is performing the spatial cluster for samples, another is processing distance eigenvalue for the centroid of the cluster. Simulation results show that the proposed scheme is capable of improving the blind-detection correction rate and reducing the downlink signaling overhead compared with previous work. In addition, it is corroborated that the proposed scheme requires low computational complexity.