Using LED lights for visible light communication (VLC) has received a great deal of interest because of a wide range of new applications such as location-based wireless broadcasting through LED lightings, signs with LED backlights and digital LED displays, as well as indoor positioning and navigation utilizing LED lights as location beacons. Recently, a number of VLC systems have been reported with focus ranging from functionality demonstration to using various modulation schemes for data rate improvement. However, systematic analysis and design methodologies for implementing a VLC system fulfilling certain specifications have been largely overlooked.

This work presents, for the first time, a systematic approach to VLC transceiver design based on an analytical study of system d...[ Read more ]

Using LED lights for visible light communication (VLC) has received a great deal of interest because of a wide range of new applications such as location-based wireless broadcasting through LED lightings, signs with LED backlights and digital LED displays, as well as indoor positioning and navigation utilizing LED lights as location beacons. Recently, a number of VLC systems have been reported with focus ranging from functionality demonstration to using various modulation schemes for data rate improvement. However, systematic analysis and design methodologies for implementing a VLC system fulfilling certain specifications have been largely overlooked.

This work presents, for the first time, a systematic approach to VLC transceiver design based on an analytical study of system design considerations and optical wireless link budget analysis. To obtain the signal-to-noise ratio (SNR) at the receiver, the received signal power is predicted by modeling the transmitted optical power and the channel path loss while the input-referred noise is estimated by characterizing the noise contribution from each of the receiver building blocks. To validate the proposed approach, a VLC transceiver using discrete components has been designed, achieving a data rate of 2.5 Mb/s and a communication distance of ~2m. Furthermore, another VLC system using a fully integrated CMOS transmitter SoC compliant with IEEE 802.15.7 standard is implemented. The SoC integrating a DC-DC power converter, a VLC modulator and a baseband unit measures a record energy efficiency of ~5nJ/bit.