NOMA Aided Narrowband IoT for Machine Type Communications With User Clustering

Abstract

To support Machine Type Communications (MTC) in next generation mobile networks, NarrowBand-IoT (NB-IoT) has been released by the Third Generation Partnership Project (3GPP) as a promising solution to provide extended coverage and low energy consumption for low cost MTC devices. However, the existing Orthogonal Multiple Access (OMA) scheme in NB-IoT cannot provide connectivity for a massive number of MTC devices. In parallel with the development of NB-IoT, Non-Orthogonal Multiple Access (NOMA), introduced for the fifth generation wireless networks, is deemed to significantly improve the network capacity by providing massive connectivity through sharing the same spectral resources. To leverage NOMA in the context of NB-IoT, we propose a power domain NOMA scheme with user clustering for an NB-IoT system. In particular, the MTC devices are assigned to different ranks within the NOMA clusters where they transmit over the same frequency resources. Then, we formulate an optimization problem to maximize the total throughput of the network by optimizing the resource allocation of MTC devices and NOMA clustering while satisfying the transmission power and quality of service requirements. We prove the NP-hardness of the proposed optimization problem. We further design an efficient heuristic algorithm to solve the proposed optimization problem by jointly optimizing NOMA clustering and resource allocation of MTC devices. Furthermore, we prove that the reduced optimization problem of power control is a convex optimization task. Simulation results are presented to demonstrate the efficiency of the proposed scheme.

CDF-Based Multiuser Scheduling for Downlink Non-Orthogonal Multiple Access (NOMA)

“…We consider cellular downlink communication with one BS and IoT devices and the frequency bandwidth is divided into sub-bands [27], [28]. Each sub-band supports multiple devices simultaneously sharing the same bandwidth and time slot with different power levels as illustrated in Fig.…”

Energy consumption optimization for self‐powered IoT networks with non‐orthogonal multiple access

“…9 This is because the WPT operation can impair the signals. Shahini et al 36 presented a user clustering method for NOMA-based NB-IoTs, with the goal of maximizing the network throughput. Furthermore, for multiple end users, the access methods also play an important role for the system performance.…”

“…Shirvanimoghaddam et al 34,35 designed a random NOMA strategy for massive IoT networks where multiple devices are allowed to transmit data over the same sub-band. Shahini et al 36 presented a user clustering method for NOMA-based NB-IoTs, with the goal of maximizing the network throughput. Duan et al 37 discussed an optimal resource allocation method for multiple unmanned aerial vehicles (UAVs).…”

Maximizing Connection Density in NB-IoT Networks with NOMA

“…Reference [10] suggests a user clustering based approach where devices from two different device classes are bunched together into small groups and then considered for allocation, however, the emphasis of this work is to maximize the total throughput of the network by optimizing the resource allocation of MTC devices and NOMA clustering. Drawing from the insights of the solutions in existing literature, in this paper we propose a connectivity maximization framework which focuses on forming efficient device clusters through proper power allocation with the following salient contributions: 1) We propose a novel power filling based heuristic, the bottom-up power filling (BU) strategy, that is computationally efficient and can accommodate any kind of SIC constraints imposed by the system.…”