Impact Statement:Analogue pre-equaliser has been proposed to extend LEDs' 3-dB bandwidth to increase the VLC system's data rates. We first point out that the use of analogue pre-equaliser...Show More
Abstract:
Visible light communication (VLC) systems are highly constrained by the limited 3-dB bandwidth of light-emitting diodes (LEDs). Analogue pre-equalisers have been proposed...Show MoreMetadata
Impact Statement:
Analogue pre-equaliser has been proposed to extend LEDs' 3-dB bandwidth to increase the VLC system's data rates. We first point out that the use of analogue pre-equalisers with excess attenuation may be unnecessary, especially when multi-carrier modulation with bit-loading has been used already and the analogue pre-equaliser introduces too much SNR loss to achieve extended 3-dB bandwidth. We reached the above conclusion from theoretical analysis and confirmed by experiment.
Abstract:
Visible light communication (VLC) systems are highly constrained by the limited 3-dB bandwidth of light-emitting diodes (LEDs). Analogue pre-equalisers have been proposed to extend the LED's bandwidth at the cost of reduced signal-to-noise ratio (SNR). Compared with the pre-equaliser, the multi-carrier modulation with bit-loading can efficiently use the spectrum beyond the LED's raw 3-dB bandwidth without incuring SNR penalties by employing multiple narrow quasi-flat sub-bands to eliminate the need for equalisation. In this work we show by means of theoretical and experimental investigation that VLC with multi-band carrierless amplitude and phase modulation with bit-loading can outperform VLC with analogue pre-equalisers.
Published in: IEEE Photonics Journal ( Volume: 12, Issue: 2, April 2020)
Contents