Improving Millimetre Wave Coverage in Indoor Environments using Convex Passive Reflectors

The growth in connectivity using wireless communication systems is causing spectral congestion in both licensed and unlicensed frequency bands. The ever-increasing need for greater capacity and data rates is driving the exploration of higher frequency spectrum. Millimetre wave frequencies are being proposed as potential candidate bands due to the higher bandwidths and low latency this spectrum can offer. However, at these frequencies, transmissions are highly susceptible to shadowing, resulting in reliance on predominantly line-of-sight propagation. In indoor environments this can become particularly problematic as there are often many obstacles which can potentially form shadow regions. As a high density of devices are expected to be found within such environments, there is a need for solutions to improve coverage at millimetre wave frequencies. This thesis presents an investigation into low-cost, practical solutions for providing additional ray paths for coverage using convex passive reflectors. A geometrical optics model has been developed to analytically evaluate coverage in office and straight corridor environments using convex spherical reflectors. Various reflector deployment strategies have been investigated by changing reflector location, curvature and quantity within each environment. Deployment in locations further away from the source is seen to be advantageous, allowing additional coverage around obstacles, and in some cases may be more favourable than using additional reflectors. Meanwhile, use of multiple reflectors provides additional reflected field components, increasing the amplitude of received power. In finding optimal solutions for each case, the trade-off between increased reflected power and reduced angular spread is considered, as well as a balance between achieving additional ray paths and the cost of deployment. Following the analytical investigation, experimental measurements have been conducted at Ka band to validate the findings using cylindrical reflectors. The findings from this work have been used to derive generalised guidelines for consideration during design of reflector solutions. In addition, recommendations for future investigation have also been suggested.

Name thesis:degree_name

PhD

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Electrical and Electronic Engineering

Grantor dc:publisher

ResearchSpace@Auckland

Year dc:date.issued

2025

Author dc:creator

• Qualtrough Mittal, Priya Anjali

Advisors dc:contributor.advisor

• Neve, Michael
• Austin, Andrew

• Millimetre wave
• Passive Reflector

Statement dc:rights

• Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Licence dc:rights.uri

• https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm

Handle dc:identifier.uri

https://hdl.handle.net/2292/76459

OAI identifier oai:identifier

oai:researchspace.auckland.ac.nz:2292/76459