Authors:
Petr Chvojka
1
;
Paul Anthony Haigh
2
;
Stanislav Zvanovec
1
;
Petr Pesek
1
and
Zabih Ghassemlooy
3
Affiliations:
1
Faculty of Electrical Engineering and Czech Technical University in Prague, Czech Republic
;
2
Faculty of Engineering and University of Bristol, United Kingdom
;
3
Faculty of Engineering and Environment and Northumbria University, United Kingdom
Keyword(s):
Carrier-less Amplitude and Phase Modulation, Roll-off Factor, Filters, Visible Light Communications
Related
Ontology
Subjects/Areas/Topics:
Optical Communication Systems
;
Optical Modulation and Signal Processing
;
Optical Networks Performance Modeling
;
Telecommunications
Abstract:
In multi-band carrier-less amplitude and phase modulation (m-CAP), the transmitter and receiver pulse shaping filters have a significant impact on the signal performance. Since m-CAP is an emerging and promising modulation format for visible light communications (VLC), it is necessary to balance the system performance and the filter length, due to limited integration density in field programmable gate arrays (FPGAs). In this paper we investigate the m-CAP VLC system performance for different number of sub-bands m = {2, 5, 10} under varying finite impulse response (FIR) filter parameters, such as the filter length Lf and the roll-off factor β. We show that increasing both β and Lf improves the bit error rate (BER) performance of the system substantially. We demonstrate that a BER target of 10-4 is achieved using Lf ≤ 12 symbols for m = 5 and 10 for low order subcarriers. Moreover, the BER limit is attained for β = 0.2 by all subcarriers, except the last two for m = 5 and 10, which is
a significant improvement, even considering the slightly increased excess bandwidth in comparison to the literature.
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