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Visible light communication (VLC) is an emerging technology that has been gaining attention over the last few years. Transmission of data at higher rates in a VLC system is mainly limited by the modulation bandwidth of the employed LED. To alleviate this limitation, equalization is frequently employed. This is usually achieved by either using discrete circuit elements or in digital form. In this paper, we present a power-efficient VLC receiver as a system-on-chip, implemented in 130 nm CMOS technology. The proposed receiver supports LEDs with different bandwidths thanks to the switchable equalizer. We tested the proposed receiver using phosphorescent white LEDs with different bandwidths on an experimental VLC link. For each tested LED, around 20 fold improvement in data rate was achieved compared to the original bandwidth of the LED. For the LED with a modulation bandwidth of 1.6 MHz, data rates of 32 Mbps and 50 Mbps at a BER of $10^{-2}$ were obtained at a distance of 2 meters without and with a blue filter, respectively. [ABSTRACT FROM AUTHOR]

In this study, the authors demonstrate that transmission rate in white phosphorescent light emitting diode (LED) transmitter communication‐illumination system can be increased significantly by simultaneous transmission of an additional infrared (IR) channel. Unlike in typical colour multiplexing, the IR channel does not require a dedicated receiver filter as the channel crosstalk can be removed using digital signal processing. Both channels can operate in synchronous or asynchronous mode. The experimental results in this study demonstrate a significant increase in the data rate. [ABSTRACT FROM AUTHOR]

In this paper, we present a high-speed visible light communication (VLC) system based on a single commercially available phosphorescent white light-emitting diode (LED). In this system, a preequalization circuit is used to extend the modulation bandwidth, and a differential output receiver is utilized to reduce the system noise. With adaptive bit and power allocation and orthogonal frequency-division multiplexing (OFDM), we experimentally demonstrated a 2.0-Gb/s visible light link over 1.5-m free-space transmission, and the BER is under a preforward error correction limit of 3.8×10-3. To the best of our knowledge, this is the highest white-light VLC data rate using a single phosphorescent white LED.

Light-emitting diodes (LEDs), which will be increasingly used in lighting technology, will also allow for distribution of broadband optical wireless signals. Visible-light communication (VLC) using white LEDs offers several advantages over the RF-based wireless systems, i.e., license-free spectrum, low power consumption, and higher privacy. Mostly, optical wireless can provide much higher data rates. In this paper, we demonstrate a VLC system based on a white LED for indoor broadband wireless access. After investigating the nonlinear effects of the LED and the power amplifier, a data rate of 1 Gb/s has been achieved at the standard illuminance level, by using an optimized discrete multitone modulation technique and adaptive bit- and power-loading algorithms. The bit-error ratio of the received data was $1.5\cdot 10^{-3}$, which is within the limit of common forward error correction (FEC) coding. These results twice the highest capacity that had been previously obtained.

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. [ABSTRACT FROM AUTHOR]

A research in extending bandwidth of the visible light communication (VLC) system that uses phosphorescent white LED has been reported in this letter. Slow response of the phosphorescent component limits the modulation bandwidth of white LED to the lower MHz range. In this letter, we present a post-equalization circuit that contains two passive equalizers and one active equalizer. With blue-filtering and the post-equalization circuit, a bandwidth of 151 MHz has been achieved in our VLC system, which allows OOK-NRZ data transmission up to 340 Mb/s. The VLC link operates at 43 cm using a single one Watt white LED, and the bit-error-ratio was below 2×10-3, which is within the forward error correction limit. [ABSTRACT FROM PUBLISHER]