Gb/s Visible Light Communication With Low-Cost Receiver Based on Single-Color LED

The exhausted radio frequency spectrum in mobile networks calls for light-based wireless solutions. However, visible light communication builds on dedicated receiver sub-systems. As an alternative to traditional photodetectors, we exploit low-cost commercial light emitting diodes (LED) that enjoy abundance in consumer electronics. In particular, surface-mounted LEDs with emission in the yellow spectrum are employed as photodetectors in a line-of-sight optical wireless communication link that is sourced by a green laser diode as a pencil beam emitter. Together with their corresponding transimpedance amplifiers, the LED-based receivers show an opto-electrical 3-dB bandwidth of up to 260 MHz, which enables data rates of 3.1 Gb/s using orthogonally frequency division multiplexed signal transmission over in-door distances. We further show that costly digital signal processing functions can be omitted through a fully analogue design of the optical link. Passive frequency response equalization in combination with simple duobinary signaling allows for 1.25 Gb/s transmission over the same link distance. Moreover, we prove that there is neither a rate nor a quality-of-experience penalty when collapsing an Ethernet connection over the optical wireless link in order to transfer large amounts of data or to stream high-definition video. The high-speed properties of commercial LEDs, together with their established role as a transmitter, promise to open new application possibilities in low-cost, short-reach segments.