PhD Defense of Mohammad ASGHARZADEH

The Internet of Things (IoT) is a new approach in which the Internet connection extends into real-world objects to make them communicate with each other. The communication for IoT can be established using cellular networks or the licence-free frequencies in the Industrial, Scientific and Medical (ISM) bands. There are many communication standards for IoT applications. There are also many modulation techniques. Nevertheless, there is no perfect solution for all the needs and requirements in all domains. The choice of the right communication standard and modulation technique is unique for each use-case and depends on each specific application.
In this research, instead of developing a new communication standard or a new modulation technique, we improved the receiver sensitivity while using the existing modulation technique and communication standards. Improving the receiver sensitivity increases the link budget. A better link budget, under certain propagation conditions, increases the communication distance. Different radio communication standards and conventional techniques based on Low Power Wide Area Networks (LPWAN) are presented in the first chapter.
The theoretical basis of the time-synchronous averaging (TSA) method as a powerful signal processing method to improve the sensitivity of the RF receiver and the simulation methodologies are presented in chapter two. We also study the impact of phase noise on the MSK modulator in this chapter.
The synchronisation problem, as well as the different solutions to improve it, are presented in chapter three. Synchronisation in phase and frequency are studied separately, and an innovative method has been developed to combine the synchronisation process with averaging.
The performance of the synchronised averaging method with and without new synchronisation techniques was measured, and the results are presented in chapter four. The processing gain from the theoretical calculation is compared with the measurement results too.