Hardware-Efficient Coherent Digital Receiver Concept With Feedforward Carrier Recovery for $M$ -QAM Constellations

This paper presents a novel digital feedforward carrier recovery algorithm for arbitrary M-ary quadrature amplitude modulation (M-QAM) constellations in an intradyne coherent optical receiver. The approach does not contain any feedback loop and is therefore highly tolerant against laser phase noise. This is crucial, especially for higher order QAM constellations, which inherently have a smaller phase noise tolerance due to the lower spacing between adjacent constellation points. In addition to the mathematical description of the proposed carrier recovery algorithm also a possible hardware-efficient implementation in a parallelized system is presented and the performance of the algorithm is evaluated by Monte Carlo simulations for square 4-QAM (QPSK), 16-QAM, 64-QAM, and 256-QAM. For the simulations ASE noise and laser phase noise are considered as well as analog-to-digital converter (ADC) and internal resolution effects. For a 1 dB penalty at BER = 10-3, linewidth times symbol duration products of 4.1 x 10-4 (4-QAM), 1.4 x 10-4 (16-QAM), 4.0 x 10-5 (64-QAM) and 8.0 x 10-6 (256-QAM) are tolerable.

[1]  Ut-Va Koc.  PLL-Free Quadrature-Amplitude Modulation in Coherent Optical Communication , 2007, 2007 IEEE International Symposium on Circuits and Systems.

[2]  Kuang-Tsan Wu,et al.  Real-time measurements of a 40 Gb/s coherent system. , 2008, Optics express.

[3]  D. Sandel,et al.  Coherent Digital Polarization Diversity Receiver for Real-Time Polarization-Multiplexed QPSK Transmission at 2.8 Gb/s , 2007, IEEE Photonics Technology Letters.

[4]  T. Ellermeyer,et al.  DA and AD converters for 25 GS/s and above , 2008, 2008 Digest of the IEEE/LEOS Summer Topical Meetings.

[5]  Augusto Gutierrez-Aitken,et al.  An Ultra-Wideband 7-Bit 5 Gsps ADC Implemented in Submicron InP HBT Technology , 2007, 2007 IEEE Compound Semiconductor Integrated Circuits Symposium.

[6]  B. Jalali,et al.  Digital adaptive phase noise reduction in coherent optical links , 2006, Journal of Lightwave Technology.

[7]  Alan Pak Tao Lau,et al.  Coherent detection in optical fiber systems. , 2008, Optics express.

[8]  T. Sakamoto.  50Gb/s 16 QAM by a quad-parallel Mach-Zehnder modulator , 2007 .

[9]  David Hanson,et al.  Performance of a 46-Gbps Dual-Polarization QPSK Transceiver in a High-PMD Fiber Transmission Experiment , 2008 .

[10]  M. Seimetz.  Laser Linewidth Limitations for Optical Systems with High-Order Modulation Employing Feed Forward Digital Carrier Phase Estimation , 2008, OFC/NFOEC 2008 - 2008 Conference on Optical Fiber Communication/National Fiber Optic Engineers Conference.

[11]  D. Hanson,et al.  Performance of a 46-Gbps Dual-Polarization QPSK Transceiver With Real-Time Coherent Equalization Over High PMD Fiber , 2009, Journal of Lightwave Technology.

[12]  Steven A. Tretter,et al.  Estimating the frequency of a noisy sinusoid by linear regression , 1985, IEEE Trans. Inf. Theory.

[13]  R. Noe,et al.  Phase noise-tolerant synchronous QPSK/BPSK baseband-type intradyne receiver concept with feedforward carrier recovery , 2005, Journal of Lightwave Technology.

[14]  H. Louchet,et al.  Improved DSP algorithms for coherent 16-QAM transmission , 2008, 2008 34th European Conference on Optical Communication.

[15]  Masataka Nakazawa,et al.  Polarization-multiplexed 1 Gsymbol/s, 128 QAM (14 Gbit/s) coherent optical transmission over 160 km using a 1.4 GHz Nyquist filter , 2008, OFC/NFOEC 2008 - 2008 Conference on Optical Fiber Communication/National Fiber Optic Engineers Conference.

[16]  J. Kahn,et al.  Feedforward Carrier Recovery for Coherent Optical Communications , 2007, Journal of Lightwave Technology.

[17]  Jack E. Volder.  The CORDIC Trigonometric Computing Technique , 1959, IRE Trans. Electron. Comput..

[18]  Reinhold Noe,et al.  13 Gsamples/s 5-bit analogue-to-digital converter for coherent optical QPSK receiver , 2008 .

[19]  W. Weber,et al.  Differential Encoding for Multiple Amplitude and Phase Shift Keying Systems , 1978, IEEE Trans. Commun..

[20]  S. Walther.  A unified algorithm for elementary functions , 1899 .

[21]  R. Noe.  PLL-free synchronous QPSK polarization multiplex/diversity receiver concept with digital I&Q baseband processing , 2005, IEEE Photonics Technology Letters.

[22]  Arne Svensson,et al.  Estimation of Phase Noise for QPSK Modulation over AWGN Channels , 2003 .

[23]  K. Kikuchi,et al.  Polarization-demultiplexing algorithm in the digital coherent receiver , 2008, 2008 Digest of the IEEE/LEOS Summer Topical Meetings.

[24]  Noriaki Kaneda,et al.  A real-time CMA-based 10 Gb/s polarization demultiplexing coherent receiver implemented in an FPGA , 2008, OFC/NFOEC 2008 - 2008 Conference on Optical Fiber Communication/National Fiber Optic Engineers Conference.

[25]  S. Bigo,et al.  Transmission of 16.4-bit/s Capacity Over 2550 km Using PDM QPSK Modulation Format and Coherent Receiver , 2008, Journal of Lightwave Technology.

[26]  E. Cacciamani,et al.  Phase-Ambiguity Resolution in a Four-Phase PSK Communications System , 1971 .

[27]  Peter J. Winzer,et al.  Monolithic InP 16-QAM Modulator , 2008 .

[28]  Hideyuki Nosaka,et al.  A 24-Gsps 3-Bit Nyquist ADC Using InP HBTs for DSP-Based Electronic Dispersion Compensation , 2005, IEICE Trans. Electron..

[29]  T. Sakamoto,et al.  50-Gb/s 16 QAM by a quad-parallel Mach-Zehnder modulator , 2011 .