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Doctoral Thesis
Author of thesis: Ing. Jan Pospíšil, Ph.D.
Acad. year: 2025/2026
Supervisor: doc. Ing. Radek Fujdiak, Ph.D.
Reviewers: doc. Mgr. Josef Horálek, Ph.D., prof. Ing. Miroslav Vozňák, Ph.D.
The core of this dissertation is the study and verification of a method for controlled superposition of frames with different spreading factors, aimed at increasing the user data throughput of LoRa technology. The work is based on the assumption that, by appropriately splitting user data into two frames that overlap in time and frequency, parallel transmission can be achieved within a single channel without a substantial degradation of reception reliability. The proposed approach uses a controlled overlap of two transmission branches and, at the receiver, assumes standard detection extended by successive interference cancellation. Both the choice of the spreading-factor pair and an isochronous split of the data play a key role, with the aim of equalizing the time-on-air and maintaining both branches with sufficient signal-to-noise ratio margin above the demodulation threshold. The method is formalized, implemented, and experimentally verified under controlled laboratory conditions. Attention is given to identifying suitable combinations of spreading factors, estimating practical operating settings for the power offset between branches, and evaluating the benefit of successive interference cancellation. Furthermore, a single-header and single-preamble concept is introduced as a mechanism to reduce protocol overhead. The results show that the proposed controlled superposition can provide a significant increase in the transmitted user data volume while causing only marginal degradation of link robustness and maintaining compliance with regulatory limits in unlicensed bands. The work therefore offers a systematic treatment of superposition in the LoRa context and describes the conditions under which its benefits are practically achievable.
LoRa; controlled frame superposition; power offset; signal-to-noise ratio margins; successive interference cancellation; isochronous payload partitioning and time-on-air; robustness/demodulation threshold; single-header superposition; user throughput enhancement.
Date of defence
08.04.2026
Result of the defence
Defended (thesis was successfully defended)
Process of defence
Disertant jasně a stručně objasnil základní vědecké výsledky a zodpověděl všechny otázky oponentů a členů komise.
Language of thesis
Czech
Faculty
Fakulta elektrotechniky a komunikačních technologií
Department
Department of Telecommunications
Study programme
Teleinformatics (DKC-TLI)
Composition of Committee
prof. Ing. Zdeněk Smékal, CSc. (předseda) doc. Ing. Petr Mlýnek, Ph.D. (člen) doc. Ing. Zdeněk Martinásek, Ph.D. (člen) doc. Ing. Jan Jeřábek, Ph.D. (člen) Ing. Ondřej Krajsa, Ph.D. (člen) doc. Mgr. Josef Horálek, Ph.D. (člen) prof. Ing. Miroslav Vozňák, Ph.D. (člen)
Supervisor’s reportdoc. Ing. Radek Fujdiak, Ph.D.
Reviewer’s reportdoc. Mgr. Josef Horálek, Ph.D.
Reviewer’s reportprof. Ing. Miroslav Vozňák, Ph.D.
Responsibility: Mgr. et Mgr. Hana Odstrčilová