Portable visible light communication transmitter and receiver using core-shell CdSe/ZnS quantum dots white light-emitting diode

A portable visible light communication (VLC) system using core-shell CdSe/ZnS quantum dots (QDs) as light converter was presented. The absorption peak wavelength of the fabricated QDs locates at 540 nm, and the emission peak wavelength locates at 570 nm. Owning to a short fluorescent life of QDs, a wide modulation bandwidth as well as a fast data transmission rate can be achieved. A portable transmitter and receiver based on digital signal processors (DSPs) were developed and the related communication experiments were carried out. Under an optimum direct bias voltage of 2.70 V, the achieved maximum communication distance is ~ 1.3 m, and the maximum transmission rate is 267 Kb/s under the premise that the bit error ratio (BER) is <;10 -3 due to a slow turnover speed of the DSP input/output pin. At a 133 Kb/s data transmission rate, high stability was observed through measuring the BER results over 5 h at the two communication distances of 0.5 and 0.7 m.