Seb J. Savory

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The achievable transmission capacity of conventional optical fibre communication systems is limited by nonlinear distortions due to the Kerr effect and the difficulty in modulating the optical field to effectively use the available fibre bandwidth. In order to achieve a high information spectral density (ISD), while simultaneously maintaining transmission(More)
Superchannel transmission spaced at the symbol rate, known as Nyquist spacing, has been demonstrated for effectively maximizing the optical communication channel capacity and spectral efficiency. However, the achievable capacity and reach of transmission systems using advanced modulation formats are affected by fibre nonlinearities and equalization enhanced(More)
We experimentally demonstrate ultra-long haul transmission of 24-D extended Golay coded modulation with LDPC. Compared with LDPC coded DP-BPSK, an increase of 15% in reach was shown, with a 3 dB increase in launch power margin at a transmission distance of more than 16,000 km. This work may not be copied or reproduced in whole or in part for any commercial(More)
We experimentally examine the maximum achievable transmission performance of a 7 channel Nyquist-WDM system with 10GBd per carrier. Back-to-back, a maximum of 11.9 bit/sym and 13.8 bit/sym can be transmitted for DP-64QAM and DP-256QAM respectively, while after 2 spans of transmission, a maximum of 12.4 bit/sym and 11.6 bit/sym can be achieved. This work may(More)
—The potential of optimum selection of modulation and forward error correction (FEC) overhead (OH) in future transparent nonlinear optical mesh networks is studied from an information theory perspective. Different network topologies are studied as well as both ideal soft-decision (SD) and hard-decision (HD) FEC based on demap-and-decode (bit-wise)(More)
We demonstrate a baud-rate sampled 3.125GBd QPSK digital coherent transceiver employing pulse shaping and interpolation. Compared to an over-sampled receiver, a fixed penalty of 1.4dB is measured being independent of sampling phase or chromatic dispersion. This work may not be copied or reproduced in whole or in part for any commercial purpose. Permission(More)
We present a statistical inference based multi-pilot aided CPE algorithm and analyze its performance via simulations. We experimentally verify LDPC coded back-to-back performance using 10 GBd DP-64QAM and DP-256QAM modulation, with transmitter and receiver linewidths of 100 kHz. This work may not be copied or reproduced in whole or in part for any(More)
—In this Letter we analyze the benefit of digital compensation of fiber nonlinearity, where the digital signal processing is divided between the transmitter and receiver. The application of the Gaussian noise model indicates that, where there are two or more spans, it is always beneficial to split the nonlinearity compensation. The theory is verified via(More)
—Current research efforts are focussed on overcoming the apparent limits of communication in single mode optical fibre resulting from distortion due to fibre nonlinearity. It has been experimentally demonstrated that this Kerr nonlinearity limit is not a fundamental limit; thus it is pertinent to review where the fundamental limits of optical communications(More)