682 Mbit/s phosphorescent white LED visible light communications utilizing analog equalized 16QAM-OFDM modulation without blue filter

• The VLC link does not utilize optical blue filter.
• Optimal analog equalizers are designed for white light response.
• The 3-dB bandwidth of white light channel VLC link is enhanced from 3 to 143 MHZ.
• Data rate of 682 Mb/s is achieved based on analog equalized 16-QAM-OFDM modulation.
• Both transmitter and receiver modules are compact size.

In this paper, a 682 Mbit/s phosphorescent white LED visible light communication (VLC) system utilizing 16-quadrature-amplitude-modulation orthogonal frequency division multiplexing (16QAM-OFDM) modulation based on analog equalizers without blue filter is firstly experimentally demonstrated. The 3-dB bandwidth of white channel VLC link is enhanced from 3 to 143 MHz by using proposed optimal analog equalizers. On the basis of equalized modulation bandwidth, the maxim transmission data rate of 682 Mbit/s based on 16QAM-OFDM modulation could be achieved at the distance of 1 m and the resultant bit-error-ratio (BER) is 2.5×10−3. The VLC link also could be operated at illumination level of ~1000 lx with data rate of 520 Mbit/s and the BER is 3.76×10−3. All the BERs are below the forward-error-correction (FEC) limit 3.8×10−3. The results show that analog equalizers could be used in 16QAM-OFDM VLC system. In addition, our transmitter and receiver modules are with compact size. The proposed VLC link without blue filter provides a solution for high-speed low-complexity VLC application based on OFDM modulation.