Equalization and Pre-distorted Schemes for Increasing Data Rate in In-door Visible Light Communication System

Abstract

We propose and demonstrate using signal pre-distortion and equalization schemes for increasing the data rate of the white-light LED communication system. Bit-error-rate of <10 -10 at 10-Mb/s operation was achieve using 1-MHz bandwidth white-light LED.

Advances in access networks - from long-reach (LR) to short-reach (SR), and from TDM/WDM to OFDM

“…The structure and design can be found in [19]. In addition, the wireless SR system can be implemented using the LED lighting system [20][21]. And they will be discussed in this talk.…”

Investigation of 4-ASK modulation with digital filtering to increase 20 times of direct modulation speed of white-light LED visible light communication system

“…According to the previous studies, the transmission data rate of LED VLC could only be increased by 2 to 10 times [6][7][8] of the direct modulation speed of the white-light LED if using electrical equalization only. An important modeling of VLC channel was also done in [12].…”

“…Recently, using high brightness light emitting diode (LED) for the lighting and visible light communication (VLC) simultaneously has attracted much attenuation, since this is costeffective, and can provide electromagnetic-interference (EMI) free, license-free and high signal-to-noise ratio (SNR) link with high security [1][2][3][4][5][6][7][8][9]. Using separated red, green, blue (RGB) LEDs [9] and using blue LED with phosphor [10,11] are the two main methods to implement the white-light LED.…”

Time division duplex for preventing reflection interference in visible light communication

“…Besides, if the modulation bandwidth of the transmitter LED is not enough, the intersymbol interference caused by plural LED with the same information being transmitted is not the most significant limitation for high speed visible light communication. There are different techniques in increasing available bandwidth of LED in VLC system, such as using multiple-resonant equalization [2], optical blue filter [3], post-equalization [3,4], and electrical pre-distortion [4]. To achieve higher data rate within the limited bandwidth and signal to noise ratio, the orthogonal frequency division multiplexing (OFDM) or discrete multi-tone (DMT) can be used [5,6].…”