Ngoc T. Dang

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SUMMARY In this paper, a novel model of Gaussian pulse propagation in optical fiber is proposed to comprehensively analyze the impact of Group Velocity Dispersion (GVD) on the performance of two-dimensional wavelength hopping/time spreading optical code division multiple access (2-D WH/TS OCDMA) systems. In addition, many noise and interferences , including(More)
SUMMARY We analyze the beat noise cancellation in two-dimensional optical code-division multiple-access (2-D OCDMA) systems using an optical hard-limiter (OHL) array. The Gaussian shape of optical pulse is assumed and the impact of pulse propagation is considered. We also take into account the receiver noise and multiple access interference (MAI) in the(More)
—We propose a novel multiwavelength optical code-division multiple-access (OCDMA) system using multi-code modulation (MCM) signaling. For the multicode de-modulator, we employ a maximum-likelihood detection and optical hard limiters. The work in this paper theoretically analyzes the performance of the proposed system over linear dispersive channels, while(More)
SUMMARY We propose turbo-coded two-dimensional (2-D) free-space optical (FSO) CDMA systems for broadband access networks. The performance bound for the proposed system over atmospheric turbulence channels is obtained considering multiple-access interference (MAI) and receiver noise. The results show that the proposed system offers a better performance than(More)
A number of studies recently have proposed optical spatial modulation (SM) as a simple, power- and bandwidth efficient modulation scheme for free-space optical communication (FSO) systems. In these studies, it was assumed that an active laser source only sends the signal to one targeted photodetector (PD). However, undesirable PDs still can receive the(More)
—In this paper, we newly propose and theoretically analyze the performance of all-optical amplify-and-forward (OAF) relaying free-space optical (FSO) systems using erbium-doped fiber amplifier (EDFA) combined with optical hard-limiter (OHL) over atmospheric turbulence channels. The use of OHL enables OAF relaying FSO systems to remove accumulated background(More)
The authors propose a relay-assisted atmospheric optical code-division multiple-access (AO/CDMA) system for secured, multiuser optical communications. Chip detect-and-forward (CDF) scheme is used at relay nodes so that the complex multiuser decoding process can be avoided. The proposed system performance, in terms of bit-error rate (BER) and transmission(More)