Antonio Caballero (1st year PhD student), Darko Zibar, and Idelfonso Tafur Monroy have produced a paper that has been accepted as a postdeadline contribution at the European Conference on Optical Communication (ECOC) being held in Vienna, Austria, on September 20 – 24, 2009.
New possibilities in speed and capacity
The Authors from the Metro-Access and Short Range Communication group demonstrated that optical coherent detection technologies in combination with sophisticated digital signal processing (DSP) algorithms open new horizons for high speed and high capacity optical wireless systems.
System simplification gets simpler
In this paper, the authors successfully demonstrated demodulation of a 40 GHz frequency carrier with 16 QAM modulation format up to 3.2 Gbit/s, with low bandwidth electronics (No 40 GHz components are required) for radio-over-fibre links (RoF). To the best of our best knowledge, this is the first report on demodulation of advanced modulation formats at high carrier frequencies where no highly linear and complex high radio frequency components are needed. This is an advance in system simplification required in order to move radio-over-fibre concepts from the present state closer to real application in high capacity hybrid optical-access networks.
Uplink of RoF links
Another important contribution of the presented research is that it addresses the uplink channel of RoF links, whose simplification and versatility of detection of high carrier frequencies and complex modulation formats in the central office has not been considered so far. Furthermore, demonstrating that optical down-sampling and coherent detection is suitable for wireless-on-fibre systems, encourages further research efforts on realizing versatile receivers for both baseband digital signals and hybrid optical-wireless systems in photonic integrated circuits
The paper is entitled ”Digital Coherent Detection of Multi-Gigabit 16-QAM Signals at 40 GHz Carrier Frequency using Photonic Downconversion”.