Rapid Dynamic Power Rail Switching of OFDM Signal Amplifiers

Global resource usage and allocation is becoming an increasingly critical topic. Efficiency is at the heart of a plethora of current research fields from reducing energy consumption in the manufacturing industry, to increasing energy generation from renewable sources, or reusing waste materials for alternative applications. The telecommunications industry is no different, OFDM as a modulation format is ubiquitous and popular due to its spectral efficiency and robustness to interference but its major drawback is its high peak-to-average power ratio (PAPR) meaning that its efficiency is compromised. A review of existing methods for improving OFDM signal amplifier efficiency showed a lack of innovative techniques for power supply control for such amplifiers. This thesis proposes two unique solutions to innovate efficiency for a range of applications. Firstly, a novel power supply control technique to improve the efficiency of OFDM signal amplifiers based on probabilistic analyses. The probability density function of an OFDM signal was analysed and optimum switching thresholds were determined to maximise the efficiency of the power supply. The proposed mechanism considers the theory of Golomb rulers and perfect difference sets, specifically the conversion from linear rulers to modular to achieve a much greater system implementation efficiency. The result is a dynamic fast-switching multi-level power supply which achieves the main benefits of Doherty and Chireix amplifiers but without requiring multiple amplifiers. This class A-G amplifier topology can achieve a 63% efficiency increase compared to amplifiers with single-level voltage supplies. Secondly, a generalised resource management technique known as Total Resource Utilisation Shuffling Technique (TRUST) to tackle the wider issue of resource utilisation and management. The focus for TRUST in this work is on batteries but it could be applied to a wide range of resources, not necessarily in the technology sector. Keywords: Chireix, Class A-G, Doherty, Golomb, OFDM, PAPR, PDF