# Clustered Millimeter Wave Networks with Non-Orthogonal Multiple Access

## TL;DR

This paper models clustered millimeter wave networks with NOMA, deriving analytical expressions for coverage and throughput, and demonstrates the benefits of large antenna arrays and optimal frequency choices through numerical analysis.

## Contribution

It introduces a realistic clustered mmWave NOMA network model with directional beamforming and provides tractable analytical expressions for key performance metrics.

## Key findings

- Large antenna arrays benefit near users but have fluctuating effects on far users.
- The proposed system outperforms traditional OMA and random beamforming NOMA scenarios.
- Optimal antenna element number and carrier frequencies improve system throughput.

## Abstract

We introduce clustered millimeter wave networks with invoking non-orthogonal multiple access~(NOMA) techniques, where the NOMA users are modeled as Poisson cluster processes and each cluster contains a base station (BS) located at the center. To provide realistic directional beamforming, an actual antenna array pattern is deployed at all BSs. We propose three distance-dependent user selection strategies to appraise the path loss impact on the performance of our considered networks. With the aid of such strategies, we derive tractable analytical expressions for the coverage probability and system throughput. Specifically, closed-form expressions are deduced under a sparse network assumption to improve the calculation efficiency. It theoretically demonstrates that the large antenna scale benefits the near user, while such influence for the far user is fluctuant due to the randomness of the beamforming. Moreover, the numerical results illustrate that: 1) the proposed system outperforms traditional orthogonal multiple access techniques and the commonly considered NOMA-mmWave scenarios with the random beamforming; 2) the coverage probability has a negative correlation with the variance of intra-cluster receivers; 3) 73 GHz is the best carrier frequency for near user and 28 GHz is the best choice for far user; 4) an optimal number of the antenna elements exists for maximizing the system throughput.