Very low-complexity filter lookup-table design with non-uniform spacing for SOA linearisation

• Published in: IET optoelectronics Vol. 14; no. 5; pp. 306 - 311
• Main Authors: Younes, Mohamad, Telescu, Mihai, Azou, Stéphane, Morel, Pascal, Tanguy, Noël
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 01.10.2020; Institution of Engineering and Technology
• Subjects: bit error rate; digital predistortion algorithms; Engineering Sciences; error statistics; filter‐lookup‐tables; nonlinear phenomena; nonuniform spacing; OFDM modulation; optical communication systems; optical‐orthogonal frequency‐division multiplexing systems; power amplifier; power amplifiers; Research Article; semiconductor optical amplifiers; Signal and Image processing; SOA linearisation; table lookup; very low‐complexity filter lookup‐table design; wireless microwave networks; filter-lookup-tables; power amplifier; optical-orthogonal frequency-division multiplexing systems; optical communication systems; digital predistortion algorithms; bit error rate; table lookup; very low-complexity filter lookup-table design; wireless microwave networks; semiconductor optical amplifiers; OFDM modulation; power amplifiers; error statistics; nonuniform spacing; SOA linearisation; nonlinear phenomena
• ISSN: 1751-8768; 1751-8776
• DOI: 10.1049/iet-opt.2019.0044

Non-linearities introduced by power amplifiers in communication systems have been a subject of interest for industry and academia for a long time. On one hand, the search for increased range intrinsically incites operators to boost input power. On the other hand, this leads to stronger non-linear phenomena in amplifiers, which in turn increase the bit error rate. The situation led to the emergence of digital predistortion algorithms that compensate for the power amplifier's non-linearities and improve the overall performance of the link. A rich corpus of literature exists on this topic but it mainly addresses wireless microwave networks. The case of digital predistortion specifically tailored for optical communications is much less explored. This study focuses on predistortion via filter-lookup-tables and tackles the issue of non-uniform spacing. The work is mainly aimed at coherent optical-orthogonal frequency-division multiplexing systems including low-cost semiconductor optical amplifiers.