Inter-cell Interference Reduction Scheme for Uplink Transmission in NB-IoT Systems

Abstract

In this paper, we propose an inter-cell interference (ICI) minimization scheme for uplink transmission in the narrowband internet of things (NB-IoT) systems. We first establish the theoretical ICI problem formulation and propose its corresponding solution for the orthogonal multiple access (OMA) NB-IoT system. Based on the theoretical formulation, we design a cooperative radio resource scheduler that reduces the impact of ICI and allocates transmit powers to reduce the energy consumption to the scheduled users in a multi-cell scenario. We compare the performance of the proposed scheme with that of some benchmark OMA schedulers. The results show that the proposed technique significantly reduces the impact of ICI and hence is more suitable for the massive connectivity of the NB-IoT system. For example, the users operating under the proposed approach experience up to 50% reduced energy consumption when compared to the best channel quality indicator (CQI) scheme. Furthermore, 30% and 35% improvements in terms of achieved user's data rates are obtained as compared to the MaxMin and round-robin schemes, respectively.

Cooperative Scheduler to Enhance Massive Connectivity in 5G and Beyond by Minimizing Interference in OMA and NOMA

“…In general, unlike the joint processing in coordinated multipoint (CoMP) in LTE systems where a UE at the cell-edge is served by two or more base stations to improve signals quality and increase throughput [23], in our proposed cooperative approach each base station serves its own users. The simulation parameters are similar as presented in [24], with some modifications adapted for the NOMA approach. The overview of the followed scheme is highlighted in Algorithms 1 and 2.…”