Taipei Tech Professor Hai-Han Lu led an inter-university research team to pioneer the use of polarization orthogonal modulation technology to simplify the construction of 5G bidirectional systems, which can be applied to the telecommunications industry in the future to support multi-media high-bandwidth applications such as ultra-high-definition video and audio streaming.

Taipei Tech Department of Electro-Optical Engineering tenure-track professor Hai-Han Lu led an inter-university research team to lead the world's first bi-directional fiber optic broadband, wireless optical communication, and 5G wireless communication system using polarization orthogonal modulation technology, Taipei Tech announced in a press release today. The research results have been published in the international journal "Communications
Communications Engineering".

Hai-Han Lu pointed out that the polarized orthogonal modulation technology is generally used to double the transmission capacity, can only be transmitted in one direction, not bidirectional transmission, because the return of the uplink optical carrier will be carried at the same time the uplink and downlink optical modulation signals, resulting in signal interference and distortion caused by each other, "like wearing myopic glasses and presbyopia at the same time," the focus is not in the same place, the image will be blurred and distorted.

The research team innovated the system architecture by supplying lower bias voltage for downlink transmission, carrying y-axis optical modulation signals and x-axis optical carriers, and using the x-axis optical carriers as uplink optical carriers at the downlink receiving end, as well as carrying uplink optical modulation signals, which is "just like bifocal glasses", and can be used for both purposes at the same time, eliminating the need to wear nearsightedness glasses and presbyopia glasses alternately, thus simplifying the construction of the 5G bi-directional system.

Hai-Han Lu said that in addition to optimizing system transmission performance, the team also built a 1-kilometer-long FSO (wireless optical communication) link, which can replace dozens to hundreds of 5G base stations and reduce the cost of base station construction; the relevant technology has already been transferred to communications equipment suppliers, and can be applied to the telecommunications industry in the future to support multimedia and high-bandwidth applications such as ultra-high-definition video and audio streaming, as well as high-speed drones or self-propelled vehicles, industrial automation, and smart healthcare industries.

Chinese Source：https://www.cna.com.tw/news/ahel/202312210031.aspx