Fig. 1. Practical scheme utilizing multiple LEDs to achieve full-range illumination and VLC.

Fig. 2. Sub-band mapping with (a) localized and (b) interleaved schemes.

Fig. 3. DSP schemes at the receiver side for (a) CCE and (b) QR-CE.

Fig. 4. Experimental setup of the 2 m free-space VLC system with delay-line interference. OSC: oscilloscope; LPF: low-pass filter^[11,12].

Fig. 5. Measured channel response of the signal under various (a) relative delays with power ratio of one and (b) power ratios with a relative delay of 3 m.

Fig. 6. BER performances of the DFT-S OFDM signal with QR-CE and CCE, and a normal OFDM versus (a) relative delays at power ratio of one and (b) power ratios at a relative delay of 3 m under different sub-band mapping schemes.

Fig. 7. BER performances of the QR-CE with (a) a different number of sub-bands and (b) a different number of pilots for the QR-CE.

Fig. 8. Complementary cumulative distribution function (CCDF) versus PAPR for a normal and DFT-S OFDM with a different number of sub-bands, respectively.