Offloading of Users in NOMA-HetNet Using Repulsive Point Process

TL;DR

This paper models an improved HetNet with NOMA and carrier sensing, demonstrating significant outage probability reductions through offloading and intelligent user pairing, validated by simulations.

Contribution

It introduces a mathematical model combining NOMA, carrier sensing, and offloading in HetNets, with novel analysis of outage probability improvements under various conditions.

Findings

74.04% outage reduction for cell center users at low FBS density

48.65% outage reduction for cell edge users at low FBS density

99.60% outage reduction for both user types at high FBS density

Abstract

Ever increasing number of cellular users and their high data requirements, necessitates need for improvement in the present heterogeneous cellular networks (HetNet). Carrier sensing prevents base stations within a certain range of the transmitter from transmitting and hence aids in reducing the interference. Non-orthogonal multiple access (NOMA) has proven its superiority for the 5th generation (5G) networks. This work proposes a mathematical model for an improved HetNet with macro base station (MBS) and femto base station (FBS) tier. The FBS tier is equipped to support NOMA and carrier sensing for its transmissions. Offloading is performed for load balancing in HetNet where the macro users (MU) from congested MBS tier are offloaded to the FBS tier. The FBS tier pairs the offloaded MU (OMU) with an appropriate pairing user (PU) to perform NOMA. The performance of the OMU is studied under different channel conditions with respect to the available PU at the FBS and some useful observations are drawn. A decrease in outage probability by $74.04\%$ for cell center user (CCU) and $48.65\%$ for cell edge user (CEU) is observed for low density FBS. The outage probability decreases by $99.60\%$, for both the CCU and CEU, for high density FBS using the proposed carrier sensing in NOMA. The results are validated using simulations.