Chair of Information and Coding Theory

Optical Multi-user Communication


With the steadily increasing use of LEDs as solid-state light sources replacing incandescent bulbs and energy-saving lamps, the interest in using LEDs for wireless data transmission, called visible light communication (VLC), is also growing. The light intensity is modulated with the data to be transmitted.

Wireless data transmission by light is a promising complement to radio transmission (e.g., WLAN) because, besides some other advantages, potentially a much wider bandwidth can be exploited. Also, a large number of individual LED chips can be installed in a single illumination fixture, which theoretically can be controlled separately.

At our chair, the latter point is given particular attention and an LED-based VLC system is regarded as a so-called massive MIMO system with a large number of transmission apertures. At the receiver side, several photodetectors can be exploited per user. In cooperation with the chair of communications, we are working on procedures to accomplish the achievable MIMO capacity.


[1] A. Krohn, P.A. Hoeher, and S. Pachnicke, "Visible light tricolor LED-to-camera data transmission suitable for internet-of-things and sensor applications," in Proc. 44th European Conference on Optical Communication (ECOC '18), Rome, Italy, Sep. 2018.

[2]  A. Krohn, S. Pachnicke, and P. A. Hoeher, "Visible light communication with multicarrier modulation utilizing a buck-converter circuit as efficient LED driver," in Proc. ITG Conference Photonic Networks, Leipzig, Germany, June 2018. 

[3] A. Krohn, G. J. M. Forkel, P. A. Hoeher, and S. Pachnicke, "Capacity-increasing 3D spatial demultiplexer design for optical wireless MIMO transmission," in Proc. European Conference on Optical Communication (ECOC), Gothenburg, Sweden, Sep. 2017. DOI


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