Interference Management in Heterogeneous Networks with Blind Transmitters

TL;DR

This paper introduces two interference management schemes, BIA and a hybrid TIM-NOMA, for heterogeneous networks without CSI, demonstrating significant improvements in sum rate and Degrees of Freedom over traditional methods.

Contribution

The paper proposes novel interference management schemes using user-pairing and Kronecker Product representation for heterogeneous networks without CSI.

Findings

Both schemes double the rate of TDMA.

Hybrid scheme outperforms TDMA and BIA in DoF.

BIA offers better BER and sum rate for macrocell users.

Abstract

Future multi-tier communication networks will require enhanced network capacity and reduced overhead. In the absence of Channel State Information (CSI) at the transmitters, Blind Interference Alignment (BIA) and Topological Interference Management (TIM) can achieve optimal Degrees of Freedom (DoF), minimising network's overhead. In addition, Non-Orthogonal Multiple Access (NOMA) can increase the sum rate of the network, compared to orthogonal radio access techniques currently adopted by 4G networks. Our contribution is two interference management schemes, BIA and a hybrid TIM-NOMA scheme, employed in heterogeneous networks by applying user-pairing and Kronecker Product representation. BIA manages inter- and intra-cell interference by antenna selection and appropriate message scheduling. The hybrid scheme manages intra-cell interference based on NOMA and inter-cell interference based on TIM. We show that both schemes achieve at least double the rate of TDMA. The hybrid scheme always outperforms TDMA and BIA in terms of Degrees of Freedom (DoF). Comparing the two proposed schemes, BIA achieves more DoF than TDMA under certain restrictions, and provides better Bit-Error-Rate (BER) and sum rate performance to macrocell users, whereas the hybrid scheme improves the performance of femtocell users.