Analysis of a Frequency-Hopping Millimeter-Wave Cellular Uplink

TL;DR

This paper analyzes uplink performance in 5G millimeter-wave cellular networks, focusing on frequency hopping, base station densification, and directional antennas using a novel propagation model and empirical data.

Contribution

It introduces a new millimeter-wave propagation model and assesses the impact of physical-layer features on uplink performance with real topology and empirical data.

Findings

Base-station densification improves uplink performance.

Frequency hopping enhances interference mitigation and diversity.

Directional sectorization and large bandwidth benefit uplink throughput.

Abstract

Fifth-generation (5G) cellular networks are expected to exhibit at least three primary physical-layer differences relative to fourth-generation ones: millimeter-wave propagation, massive antenna arrays, and densification of base stations. As in fourth-generation systems, such as LTE, 5G systems are likely to continue to use single-carrier frequency division multiple-access (SC-FDMA) on the uplink due to its advantageous peak-to-average power ratio. Moreover, 5G systems are likely to use frequency hopping on the uplink to help randomize interference and provide diversity against frequency-selective fading. In this paper, the implications of these and other physical-layer features on uplink performance are assessed using a novel millimeter-wave propagation model featuring distance-dependent parameters that characterize the path-loss, shadowing, and fading. The analysis proceeds by first fixing the location of the mobile devices and finding the performance conditioned on the topology. The spatially averaged performance is then found by averaging with respect to the location of the mobile devices. The analysis allows for the use of actual base-station topologies and the propagation model can leverage empirical millimeter-wave measurements. The benefits of base-station densification, highly directional sectorization, frequency hopping, a large available bandwidth, and a high code rate are illustrated. The minor importance of fractional power control is shown.