Ziad A. El-Sahn

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In this paper, we present a carrier phase recovery (CPR) algorithm using a modified superscalar parallelization based phase locked loop (M-SSP-PLL) combined with a maximum-likelihood (ML) phase estimation. Compared to the original SSP-PLL, M-SSP-PLL + ML reduces the required buffer size using a novel superscalar structure. In addition, by removing the(More)
We experimentally demonstrate the performance of a 10 Gb/s subcarrier multiplexed (SCM) wavelength-division multiplexed (WDM) passive optical network (PON) using 2.5 Gbaud 16-QAM transmission signals. Digital signal processing (DSP) and square-root raised cosine (SRRC) pulse shaping enable both the uplink and downlink channels to achieve net spectral(More)
We propose a training symbol based channel estimation (TS-EST) algorithm that estimates the 2 × 2 Jones channel matrix. The estimated matrix entries are then used as the initial center taps of the 2 × 2 butterfly equalizer. Employing very few training symbols for TS-EST, ultrafast polarization tracking is achieved and tap update can be initially pursued(More)
We propose a training symbol based algorithm that estimates the Jones channel matrix whose entries are used as the initial center taps of a decision-directed butterfly equalizer. With fewer than 40 training symbols, we experimentally demonstrate ultrafast polarization demultiplexing for 112 Gbps PDM-QPSK and 224 Gbps PDM-16QAM systems. Introduction(More)
We report on the experimental demonstration of single channel 28 Gbaud QPSK and 16-QAM zero-guard-interval (ZGI) CO-OFDM transmission with only 1.34% overhead for OFDM processing. The achieved transmission distance is 5120 km for QPSK assuming a 7% forward error correction (FEC) overhead, and 1280 km for 16-QAM assuming a 20% FEC overhead. We also(More)
We experimentally demonstrate the impact of equalization-enhanced phase noise (EEPN) on the performance of 56 Gbaud dual-polarization (DP) QPSK long haul transmission systems. Although EEPN adds additional noise to the received symbols, we show that this reduces the phase variance introduced by the LO laser, and therefore should be considered when designing(More)
Layered pulse amplitude modulation with discrete multitone (PAM-DMT) is proposed to improve the system spectral efficiency of existing passive optical networks (PONs) by modulating both the real and imaginary parts of the subcarriers through different layers. Signals from different layers are then combined for simultaneous transmission. At the receiver, an(More)
We demonstrate an improved overlapped-subcarrier multiplexed (O-SCM) WDM PON architecture transmitting over a single feeder using cost sensitive intensity modulation/direct detection transceivers, data re-modulation and simple electronics. Incorporating electronic equalization and Reed-Solomon forward-error correction codes helps to overcome the bandwidth(More)
A queuing subsystem is proposed to the round robin receiver/transmitter (RT ) optical code-division multiple-access (OCDMA) protocol. The corresponding state diagram and its mathematical model are outlined. We prove that significant improvement in terms of system throughput and blocking probability can be achieved by only adding a single buffer at each user(More)