Should Analogue Pre-Equalisers be Avoided in VLC Systems?
- Resource Type
- Periodical
- Authors
- Li, X.; Ghassemlooy, Z.; Zvanovec, S.; Perez-Jimenez, R.; Haigh, P.A.
- Source
- IEEE Photonics Journal IEEE Photonics J. Photonics Journal, IEEE. 12(2):1-14 Apr, 2020
- Subject
- Engineered Materials, Dielectrics and Plasmas
Photonics and Electrooptics
Light emitting diodes
Modulation
Visible light communication
Bandwidth
Signal to noise ratio
Lighting
Impedance
Visible light communications (VLC)
channel capacity
equaliser
CAP.
- Language
- ISSN
- 1943-0655
1943-0647
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.