A novel pulse modulation method is proposed to improve the data transmission rate and expand the applications of
indoor visible light communication. In our communication system, Red, Green and Blue LEDs are used
as the optical source. Combining with the simplicity of Space Shift Key and the energy efficiency of Pulse Position
Modulation, we propose an optimized Space Pulse Position Modulation (SPPM) for the special optical source. Its
fundamental purpose is to use Red Green and Blue LEDs to carry different data and then to transmit one of the colors as
a pulse signal in each time slot. We introduce this method in realizing a high capacity and data rate wireless light
communication system with the less average optical power. The experiment results show that Red, Green and Blue LEDs
with the proposed SPPM has higher data transmission rate than that of White LED under the same optical power.