September 18, 2020
The Fraunhofer Heinrich Hertz Institute (HHI) is a pioneer in the research and development of LiFi technology. A research team from the "Photonic Networks and Systems" department has now created a new toolkit for the simulation of networked LiFi systems. The release of this software suite is an important milestone for the communications and lighting industries to accelerate the adoption of LiFi in practical applications.
LiFi technology is based on modulated LED-light and considered a promising supplement to radio-based systems, like WiFi. Light propagates along the line of sight and it can be confined more precisely than radio inside rooms. In this way, user data can be protected more effectively against unauthorized access and external interference (jamming). The LiFi software suite, which was developed by the Fraunhofer HHI for the simulation of LiFi systems and networks, offers LiFi channel models as well as Physical Layer (PHY) reference implementations for current and upcoming communication standards, including ITU-T G.9960 (G.hn), ITU-T G.9991 (G.vlc), IEEE P802.15.13 and P802.11bb
The LiFi channel models simulate the propagation of light in the optical free space channel as well as the analog components of LiFi transmitters and receivers. Line-of-sight (LOS) and non-line-of-sight (NLOS) channels of mobile users can be simulated in 3D scenarios, both for single-input single-output (SISO - one transmitter and one receiver module) and for multiple-input multiple-output (MIMO - multiple transmitter and receiver modules) LiFi systems. By using efficient algorithms, the simulation is significantly faster than with conventional ray tracing.
In addition to the LiFi channel models, complete, standard-compliant data transmission simulations are supported. Information bits are transmitted via the optical free space channel by using the physical layer. In the LiFi software suite, both the LiFi transmitter and the LiFi receiver signal processing for the respective PHY are completely implemented in MATLAB. Depending on the PHY, different modulation formats are used, including Orthogonal Frequency-Division Multiplexing (OFDM) and On-Off-Keying (OOK) with Frequency Domain Equalization (FDE).
The research team's implementations are based on a long-term developed MATLAB signal processing toolbox with algorithms being verified by numerous simulations, laboratory experiments, and tests. The LiFi software suite can be used to realize complete link level simulation chains and to validate LiFi transmit and receive components. When used for system-level (multilink) simulations, it is possible to optimize LiFi for different applications, e.g. for conference rooms, operating rooms or industrial production environments. This also supports the further development of standards.
LiFi software suite components can be used individually or as a complete package and can be adapted to specific requirements. Different licensing models depending on individual customer needs are available.
The software was developed within the German research projects OWICELLS , SESAM, AIRBORNE, ERIKA and OTB-5G+ and the European projects VISION and ELIoT.