Resource Allocation in Virtualized CoMP-NOMA HetNets: Multi-Connectivity for Joint Transmission

TL;DR

This paper introduces a generalized joint transmission CoMP-NOMA model for virtualized multi-infrastructure networks, proposing schemes to optimize power allocation and user association, improving sum-rate and reducing SIC complexity.

Contribution

It proposes a novel UNC and LNC NOMA clustering schemes within a virtualized CoMP-NOMA framework, along with optimization algorithms for resource allocation.

Findings

WNV and LNC improve sum-rate by up to 35%.

LNC reduces SIC complexity by up to 46%.

Proposed algorithms are suitable for open radio access networks.

Abstract

In this work, we design a generalized joint transmission coordinated multi-point (JT-CoMP)-non-orthogonal multiple access (NOMA) model for a virtualized multi-infrastructure network. In this model, all users benefit from multiple joint transmissions of CoMP thanks to the multi-connectivity opportunity provided by wireless network virtualization (WNV) in multi-infrastructure networks. The NOMA protocol in CoMP results in an unlimited NOMA clustering (UNC) scheme, where the order of each NOMA cluster is the maximum possible value. We show that UNC results in maximum successful interference cancellation (SIC) complexity at users. In this regard, we propose a limited NOMA clustering (LNC) scheme, where the SIC is performed to only a subset of users. We formulate the problem of joint power allocation and user association for the UNC and LNC schemes. Then, one globally and one locally optimal solution are proposed for each problem based on mixed-integer monotonic optimization and sequential programming, respectively. Numerical assessments reveal that WNV and LNC improves users sum-rate and reduces users SIC complexity by up to $35\%$ and $46\%$ compared to the non-virtualized CoMP-NOMA system and UNC model, respectively. Therefore, the proposed algorithms are suitable candidates for the implementation on open and intelligent radio access networks.