Faculty of Engineering, LTH

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Wireline communications in a wireless world


Examples of the hybrid deployment of fiber and copper cables

Yezi Huang

It is possible to get a fiber-like Internet speed without bothering about pulling a fiber home. Ultra-fast Internet speeds are coming through the regular copper based phone lines. The latest technology behind this buzz is The main idea of is to make fibers and phone lines complement each other in a hybrid fiber-copper network: using fiber to guarantee the high-speed backbone over long distance, and using the copper lines to cover the last-mile transmission.

The first half of the Yezi Huang’s PhD thesis focuses on the copper segment of the network, and makes sure that the Gbps-level network speeds brought by the fiber are effectively forwarded to the end users. As the world becomes more wireless, the thesis also illustrates the feasibility of using the fixed lines to improve the radio coverage. The studies in the thesis ensure that the fixed lines will not introduce additional interference to the carried radio signal, and that the radio signal will not bring too much redundant information.

Before coming to Sweden, a PhD degree was not in Yezi Huang’s wish list. 
– I like signal processing and felt that I had learned a lot by working with Thomas Magesacher, who supervised my Master’s thesis. So when he introduced a PhD position on the topic to me I thought, why not, says Yezi Huang.
–  The interesting part of doing copper line communication is that it is a small community. Shortly after the position started, I got acquainted with most of the European-based industrial and academic people in this area. Directly from them, I kept learning very relevant problems and interesting topics, she continues.  

Analog film and spicy food
Yezi Huang comes from the city Yibin, where the Yangtze river starts, in the Sichuan Province of China, – also a place famous for spicy food. 

– Cooking Sichuan food with the ingredients bought in Sweden has become one of my favorite activities that I can get relaxed from the tense research work. Regarding hobbies, I like photographing with my analog film camera. I am not good at using all the fancy techniques to take and post-process photos. The film camera nicely covers my shortage with its amazing combination of light and color tones. 

Why Lund University?
– I did my Master’s degree also at LTH, Lund university at the Department of Electrical and Information Technology. After I decided to continue my studies in Sweden, Lund University was on the top of my list, for its historical environment and giving good education in telecommunication, Yezi Huang continues.

Commuting from Stockholm
The special setting of this PhD position placed Yezi Huang in Stockholm to have a close cooperation with the industrial partners of the project. 
– It was an excellent advantage. But the negative side was the frequent travelling to Lund to take courses and perform department duties. One can count how many trips would the 90 credits and hundreds of teaching hours equal to. Leaving home at 5:00 am during the Swedish winter time was not pleasant. Cold sandwiches at Malmö airport after a full working day were not enjoyable either. But now when I sit warmly indoor and start recalling the four and half years’ experience, I feel proud that I made it, she says. 

This October Yezi Huang started a new career at Ericsson Research in Stockholm. 
– It was a natural move for me, and I continued with the work that was presented in the last piece of the thesis. Recently, a new project starts which is more related to the upper layers, quite a challenge for me. I did wireless communication during my Master’s degree, and then wireline communication with my PhD. But both are in physical layer. It seems that my telecommunication background will be enriched again with the new assignment, Yezi Huang concludes.