Uplink Cluster-Based Radio Resource Scheduling and Allocation for HetNet mMTC Scenarios
Scheduling , Resource Allocation , Heterogeneous Networks , NB-IoT , Poisson Cluster Processes , 4G , 5G , OFDMA , NOMA
Current telecommunication networks face a surge in the number of connected Machine-type Communication (MTC) devices, creating an unprecedented disproportionate demand for existing resources, especially when working with a Heterogeneous Network (HetNet). This demand cannot be addressed adequately as the infrastructure's transition process between different generations is slow. Fourth Generation (4G) relies on Orthogonal Multiple Access (OMA), where a single user occupies its assigned sub-channel, and orthogonality offers interference-free communication for normally loaded scenarios but underperforms in overloaded scenarios. Whereas Fifth Generation (5G) is targeting more spectral efficiency by using the Non-orthogonal Multiple Access (NOMA) which is proposed to be used in future releases, allowing MTC devices to share the same resources in frequency and time. However, NOMA medium access techniques, in general, have a complex scheduler design as they group users/devices with aligned correlations, and then a challenging process is needed at the receiving side to decode messages from different devices. In this study, we formulate and simulate a 4G/5G Uplink scheduler that is based on dual NOMA-OMA. The objective is to achieve a tangible improvement in the spectral and scheduling efficiency of the network. We are able to optimize the system under HetNet objectives and clustering constraints in overloaded scenarios, to examine the limitations of both NOMA and OMA.