Papr Reduction Techniques for Coherent Optical Ofdm Transmission
ICTON 2009
Mo.B2.4
PAPR Reduction Techniques for Coherent Optical OFDM Transmission
Bernhard Goebel, Graduate Student Member, IEEE, Stephan Hellerbrand, Graduate Student Member, IEEE, Norman Haufe, Norbert Hanik, Member, IEEE Institute for Communications Engineering, Technische Universität München, D-80290 Munich, Germany E-mail: Bernhard.Goebel@tum.de ABSTRACT In coherent optical OFDM systems, the large peak-to-average power ratio (PAPR) gives rise to signal impairments through the nonlinearity of modulator and fiber. We review the most prominent PAPR reduction techniques that have been proposed for mitigating the impairments with regard to their reduction capability, computational complexity and redundancy. Simulation results are presented for Clipping, Selected Mapping, Active Constellation Extension and Trellis Shaping. Keywords: modulation, OFDM, coherent detection, nonlinear fiber effects, PAPR, coding. 1. INTRODUCTION Orthogonal frequency division multiplexing (OFDM) is considered one of the most promising transmission schemes for future 100 Gigabit Ethernet (100 GbE) networks. In combination with coherent detection, it offers virtually unlimited electronic compensation of chromatic dispersion and PMD [1] as well as record spectral efficiencies [2]-[3]. One major drawback of OFDM signals is their large peak-to-average power ratio (PAPR) which gives rise to distortions caused by nonlinear devices such as A/D converter, external modulator and transmission fiber [4]. Upon transmission along the fiber, the Kerr effect creates distortions through four-wave mixing (FWM) between OFDM subcarriers; the strength of these FWM products depends on the signal’s PAPR [5]. Various PAPR reduction techniques have been proposed in a wireless communications context [6] and for optical OFDM systems [5], [7]-[10]. In Section 2, we review the most important PAPR reduction methods for coherent optical OFDM systems with respect to their performance, complexity and introduced
Mo.B2.4
PAPR Reduction Techniques for Coherent Optical OFDM Transmission
Bernhard Goebel, Graduate Student Member, IEEE, Stephan Hellerbrand, Graduate Student Member, IEEE, Norman Haufe, Norbert Hanik, Member, IEEE Institute for Communications Engineering, Technische Universität München, D-80290 Munich, Germany E-mail: Bernhard.Goebel@tum.de ABSTRACT In coherent optical OFDM systems, the large peak-to-average power ratio (PAPR) gives rise to signal impairments through the nonlinearity of modulator and fiber. We review the most prominent PAPR reduction techniques that have been proposed for mitigating the impairments with regard to their reduction capability, computational complexity and redundancy. Simulation results are presented for Clipping, Selected Mapping, Active Constellation Extension and Trellis Shaping. Keywords: modulation, OFDM, coherent detection, nonlinear fiber effects, PAPR, coding. 1. INTRODUCTION Orthogonal frequency division multiplexing (OFDM) is considered one of the most promising transmission schemes for future 100 Gigabit Ethernet (100 GbE) networks. In combination with coherent detection, it offers virtually unlimited electronic compensation of chromatic dispersion and PMD [1] as well as record spectral efficiencies [2]-[3]. One major drawback of OFDM signals is their large peak-to-average power ratio (PAPR) which gives rise to distortions caused by nonlinear devices such as A/D converter, external modulator and transmission fiber [4]. Upon transmission along the fiber, the Kerr effect creates distortions through four-wave mixing (FWM) between OFDM subcarriers; the strength of these FWM products depends on the signal’s PAPR [5]. Various PAPR reduction techniques have been proposed in a wireless communications context [6] and for optical OFDM systems [5], [7]-[10]. In Section 2, we review the most important PAPR reduction methods for coherent optical OFDM systems with respect to their performance, complexity and introduced
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