Simulations were performed to evaluate performance of the proposed scheme. An indoor room environment as shown in Fig. 1 is considered for simulations. Four LED lamps, each consists of 60×60 LEDs, are installed at a height of 3m above the floor. The separation distance between the LEDs is 1cm. Fig. 3 shows the placement of the LED lamps at ceiling of the room. The center luminous intensity of an LED is 0.73 cd, and semi-angle at half power is 60 deg. The received optical power and illuminance level at the center each work place, and the total luminous flux of the lamps is computed. The required illuminance level is considered to be 400 lux; the BER is considered to be greater than 10−6. The simulation parameters are summarized in Table I [13], [14]. Figs. 4 and 5 show the illuminance and optical power distribution, respectively, computed on the desktop’s surface. Figs. 4 and 5 indicate that sufficient illuminance and optical power are obtained throughout the room, which, therefore satisfies the requirements for illumination and communication throughout room. Simulations were performed to demonstrate the total luminous flux of all the LED lamps for different levels of required illuminance. The proposed scheme is compared with conventional SC-4PPM scheme in terms of total luminous flux. The conventional SC-4PPM scheme is considered to have fixed modulation depths of a = 0,b = 1 andc = 1. Table II show the total luminous flux of LED lamps for the required illuminancelevels of 400lux−1000lux,andenergysavingsachieved
compared to conventional SC-4PPM. The proposed scheme reduces the total luminous flux of the luminaires, and achieves improvementin lighting energy savings. The proposed scheme satisfies the requirements for both illumination and communication while consuming less power compared with the conventional scheme. The proposed scheme can also satisfied different required lighting levels at different work places