Program: Collaborative Research Program for Alumni (CRA)
Field: Electrical and Electronics Engineering
Principal Investigator: Assoc. Prof. Dr. Ha Duyen Trung
Sending University: Hanoi University of Science and Technology (HUST)
Japanese Co-Investigator: Prof. Dr. Tomoaki OHTSUKI
Japanese University: Keio University
This research has the benefits of employing multiple apertures at the transmitter, multiple photodetectors at the receiver and additional relay nodes and provides model design guidelines under various turbulence regimes. Therefore, improved methods have a strong potential impact on performance evaluation for free-space optical communications in particularly. As its first contribution, this project provides a new system model of multi-hop relaying FSO communication system employing SC-QAM signals over different atmospheric turbulence and misalignment channels; this proposed system model can provides better performance compared with that of direct single-hop FSO transmission. In addition, this technique has a longer link distance when APD receiver is used. Secondly, the proposed project provides a novel MIMO FSO configuration in order to utilize its spatial diversity characterization on the performance of such systems. In this approach, the ergodic capacity characterization of MIMO FSO systems over atmospheric turbulence-induced fading and misalignment error channels is also provided. Moreover, APD receiver-based multi-hop relaying MIMO FSO systems is investigated as well for selecting an appropriate APD gain value to achieve the best performance. In the third contribution of the research, we provide in-depth simulation foundations to tackle the validation of the theoretical evaluation. In this approach, two atmospheric turbulence models of log-normal and gamma-gamma together with misalignment errors are taken into account. In currently existing researches, only parts of these aspects are solved. This research project bring me to connect with Japanese Professors and scientific researchers through joining and presenting the outputs at the international conference and workshop. This research project has been supporting to training and research of Vietnamese undergraduate (4th and 5th year students) and graduate (Master and PhD) students in the research group at Hanoi University of Science and Technology for high quality scientific research levels in the field of electronics and telecommunications engineering. Researchers and students who involved in this project, are gaining experience with international research and development trends. Through the research project, new models and analytical methodologies with performance results have been delivered. Three (03) papers have been published, where 01 paper in National Scientific Journal and 02 papers in the proceedings of international conferences that technically supported by IEEE. One (01) article has been accepted for publication at the international journal indexed by ISI. One (01) article has been submitted at the other international journal indexed by ISI.