Hugo S. Carrer

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Multi-mode fibers (MMF) are typically used in LAN applications, in links which may reach or exceed 300 meters. Widespread use of electronic dispersion compensation (EDC) for MMF is prompted by the ratification of the 10GBASE-LRM standard [1]. A number of studies have demonstrated the superiority of MLSD for this application (see [2] and references therein).(More)
This paper discusses the investigation of maximum-likelihood sequence estimation (MLSE) receivers operating on intensity-modulated direct-detection optical channels. The study focuses on long-haul or metro links spanning several hundred kilometers of single-mode fiber with optical amplifiers. The structure of MLSE-based optical receivers operating in the(More)
Chromatic dispersion (CD) and polarization mode dispersion (PMD) severely limit the performance of optical transmission systems operating at data rates of 10 Gb/s and beyond. Electrical equalization techniques have been proposed to compensate dispersion in both coherent and intensity modulation/directdetection (IM/DD) systems. The former benefit from the(More)
Optical communication technology in long-haul and metropolitan links is experiencing a transition to coherent techniques and high spectral efficiency modulation formats such as dual-polarization (DP) QPSK, DP-QAM and OFDM. The combination of coherent demodulation and DSP allows costly optical signal processing hardware used to compensate fiber optic(More)
This paper presents an efficient parallel architecture for high-speed maximum a posteriori (MAP) probability detectors. The parallel systolic scheme proposed here builds upon a sliding window approach, and is capable of providing very high throughput. The implementation of an 8-state MAP decoder on an off-the-shelf field programmable gate array (FPGA)(More)
In this paper we present a new reduced complexity maximum likelihood sequence detector for intensity modulation / direct detection (IM/DD) fiber optic systems. The proposed detector takes into account the presence of thermal and amplified spontaneous emission (ASE) noise. The results presented here show a negligible performance degradation from the optimum(More)
In this paper, we propose new closed-form approximations to the probability-density function (pdf) of the received signal in intensity-modulation/direct-detection (IM/DD) optical channels. These approximations greatly simplify the problem of channel estimation. This is an important problem in the implementation of maximum-likelihood sequence-estimation(More)