Abstract

Recently, higher order modulation formats are intensively investigated to further increase spectral efficiency for building next generation optical transport networks. Direct detection receivers are capable of detecting arbitrary modulation formats with differentially encoded phases such as differentially phase shift keying (DPSK) and star shaped quadrature amplitude modulation (Star QAM) formats. In an earlier publication of the authors (M. Seimetz , “Optical systems with high-order DPSK and star QAM modulation based on interferometric direct detection,” J. Lightw. Technol. , vol. 25, no. 6, pp. 1515–1530, Jun. 2007) a system analysis was performed where performance was mainly characterized by eye opening penalties. Here, these investigations are extended. A tool for semi-analytical BER estimation is developed allowing to calculate the BER down to small values such as $10^{-9}$ for a wide range of modulation formats, as well as for different receiver structures. Using this module, the back-to-back OSNR requirements are calculated. CD and SPM tolerances are characterized by optical signal-to-noise ratio (OSNR) penalties at ${\hbox {BER}} = 10^{-9}$. As far as the authors know, this is the first analysis of the transmission characteristics of optical 16DPSK and Star 16QAM based on the BER. Moreover, further novel aspects such as optimization of the optical and electrical receiver filter bandwidths are investigated.

© 2009 IEEE

Generalized data-aided multi-symbol phase estimation for improving receiver sensitivity in direct-detection optical m-ary DPSK

Xiang Liu
Opt. Express 15(6) 2927-2939 (2007)

Performance analysis of coherent optical 8-star QAM systems using decision-aided maximum likelihood phase estimation

Hongyu Zhang, Pooi-Yuen Kam, and Changyuan Yu
Opt. Express 20(8) 9302-9311 (2012)

Semi-analytical approach for performance evaluation of direct-detection OFDM optical communication systems

Tiago M. F. Alves and Adolfo V. T. Cartaxo
Opt. Express 17(21) 18714-18729 (2009)

Noise statistics of and BER estimation using demodulated signals for direct detection differential polarization-phase-shift keying

Yan Han and Guifang Li
Opt. Express 13(7) 2761-2766 (2005)

Flexible high-order QAM transmitter using tandem IQ modulators for generating 16/32/36/64-QAM with balanced complexity in electronics and optics

Guo-Wei Lu, Takahide Sakamoto, and Tetsuya Kawanishi
Opt. Express 21(5) 6213-6223 (2013)