Physical Layer Security for Mobile Optical Wireless Communications Systems

Optical wireless communication (OWC) is a highly directive communication system. This directivity hinders its practical implementation in mobile applications. Short-range OWC systems, which integrate lighting and communication functionalities and support multiple users using LED sources, are commonly referred to as visible light communication (VLC). In comparison, long-range device-to-device OWC systems that utilize laser sources are known as free space optical (FSO) communication. While the directive nature of OWC has been believed to offer security advantages, it does not guarantee security in multiuser VLC systems as the authenticity of users is not guaranteed. Although the narrow laser beam in an FSO system expands 1000 times less than RF-based long-range communications beam (such as satellite systems) and it can be controlled using optics, very narrow beam divergence is undesirable because it causes misalignment errors due to sway, vibration, and jitter. With the advances in photodetectors, a 10 cm receiver aperture can interrupt the broad optical beam and align with the transmitter, which exposes the FSO link to security threats. Securing OWC links by cryptography, which relies on the computational complexity of the code used to encrypt the transmission, has yet to be noticed. This is likely due to the prevailing consensus within the research community that it is not a significant threat because of the narrow optical beam. This assumption should not be taken for granted for long-range systems. Physical layer security (PLS) was investigated for OWC. This technology employs the information theory concept depending on the supremum of the difference between the lower bound on the legitimate channel capacity and the upper bound on the wiretapping channel capacity across all input laws. Assuming perfect knowledge of the channel states, the transmitter beamforms the transmission into the null space of the eavesdropper. However, research activities have investigated PLS for OWC, but all previous PLS schemes considered static (fixed) OWC systems. In mobile systems, the dynamic environment nature is continuously changing channel conditions. Hence, novel techniques are required to sense the channel and beamform the transmission into the null space of the eavesdropper.

<p>Formal applications for research degree study should be made online through the <a href="https://www.leeds.ac.uk/research-applying/doc/applying-research-degrees">University's website</a>. Please state clearly in the Planned Course of Study section that you are applying for <em><strong>PHD Electronic & Electrical Engineering FT</strong></em> and in the research information section that the research degree you wish to be considered for is <em><strong>Physical Layer Security for Mobile Optical Wireless Communications Systems</strong></em> as well as <a href="https://eps.leeds.ac.uk/electronic-engineering/staff/14162/dr-farah-al-sallami">Dr Farah Al-Sallami</a> as your proposed supervisor. Please state in the Finance section that the funding source you are applying for is <em><strong>School of Electronic & Electrical Engineering Studentship 2025/26.</strong></em></p> <p>If English is not your first language, you must provide evidence that you meet the University's minimum English language requirements (below).</p> <p><em>As an international research-intensive university, we welcome students from all walks of life and from across the world. We foster an inclusive environment where all can flourish and prosper, and we are proud of our strong commitment to student education. Across all Faculties we are dedicated to diversifying our community and we welcome the unique contributions that individuals can bring, and particularly encourage applications from, but not limited to Black, Asian, people who belong to a minority ethnic community, people who identify as LGBT+ and people with disabilities. Applicants will always be selected based on merit and ability.</em></p> <p class="MsoNoSpacing" style="text-align:start; margin-bottom:24px">Applications will be considered on an ongoing basis until 31 January 2025.  Potential applicants are strongly encouraged to contact the supervisors for an informal discussion before making a formal application.  We also advise that you apply at the earliest opportunity as the application and selection process may close early, should we receive a sufficient number of applications or that a suitable candidate is appointed.</p> <p><strong>Please note that you must provide the following documents in support of your application by the closing date of 31 January 2025:</strong></p> <ul> <li>Full Transcripts of all degree study or if in final year of study, full transcripts to date</li> <li>Personal Statement outlining your interest in the project</li> <li>CV</li> </ul>

Applicants to research degree programmes should normally have at least a first class or an upper second class British Bachelors Honours degree (or equivalent) in an appropriate discipline. The criteria for entry for some research degrees may be higher, for example, several faculties, also require a Masters degree. Applicants are advised to check with the relevant School prior to making an application. Applicants who are uncertain about the requirements for a particular research degree are advised to contact the School or Graduate School prior to making an application.

The minimum English language entry requirement for research postgraduate research study is an IELTS of 6.0 overall with at least 5.5 in each component (reading, writing, listening and speaking) or equivalent. The test must be dated within two years of the start date of the course in order to be valid. Some schools and faculties have a higher requirement.

<p class="MsoNoSpacing" style="text-align:start; margin-bottom:24px">A highly competitive School of Electronic & Electrical Engineering Studentship consisting of the award of fees, together with a tax-free maintenance grant (£19,237 in academic session 2024/25) per year for 3.5 years.  Training and support is also provided.</p> <p>This opportunity is open to all applicants.  All candidates will be placed into the School Electronic & Electrical Engineering Studentship Competition and selection is based on academic merit.</p> <p>You will be responsible for paying the overtime fee in full in your writing up/overtime year (£320 in Session 2024/25), but the scholarship maintenance allowance will continue to be paid for up to 6 months in the final year of award.</p> <p><strong>Important:</strong> Please note that that the award does <em><strong>not</strong></em> cover the costs associated with moving to the UK.  All such costs (<a href="https://www.leeds.ac.uk/international-visas-immigration/doc/applying-student-visa">visa, Immigration Health Surcharge</a>, flights etc) would have to be met by yourself, or you will need to find an alternative funding source. </p> <p>Please refer to the <a href="https://www.ukcisa.org.uk/">UKCISA</a> website for information regarding Fee Status for Non-UK Nationals.</p>

<p>For further information about this project, please contact Dr Farah Al-Sallami by email to <a href="mailto:F.Al-Sallami@leeds.ac.uk">F.Al-Sallami@leeds.ac.uk</a></p> <p>For further information about your application, please contact PGR Admissions by email to <a href="mailto:phd@engineering.leeds.ac.uk">phd@engineering.leeds.ac.uk</a></p>