This chapter presents one of the primary contributions of this dissertation: a mathematical model to analyze and evaluate noise-like spectrum-sliced systems which employ conventional PIN receivers, or as proposed in this dissertation, optical preamplifier receivers. As discussed in previous chapters, spectrum-slicing provides a low-cost alternative to the use of multiple coherent lasers for WDM...

The focus of this chapter is to consider the case of spectral-slicing when Frequency-Shift Keying (FSK) is used as the modulation scheme. Although the majority of lightwave systems use conventional On-Off Keying (OOK) or intensity modulation, FSK is preferred in certain situations and this chapter will discuss where transmission using FSK may prove advantageous in the context of a noise-like sp...

Abstract Single-carrier (SC) transmission is an appropriate transmission scheme for uplink transmission because of its low peak-to-average power ratio (PAPR). Spread spectrum (SS) transmission achieves higher frequency diversity gain and hence improves the bit error rate (BER) performance. The authors have recently proposed SC with frequency-domain spread spectrum (SC-FDSS) transmission with or...

the development of green approaches for the biosynthesis of silver nanoparticles (agnps) is of prime significance in the field of nanotechnology research. a fast and eco-friendly protocol for the biosynthesis of extracellular agnps using culture supernatant (cs) from the fungus cunninghamella phaeospora was studied in this work. this cs was proved as a potential new source for the extracellular...

This study focuses on the deposition and growth mode of rhodium (Rh) on gold (Au) seed nanorods (NRs). Using a combination of scanning transmission electron microscopy imaging, energy-dispersive X-ray spectroscopy, and UV-visible absorption spectroscopy, we show that Rh deposition results in an uneven overlayer morphology on the Au NR seeds, with a tendency for Rh deposition to occur preferenti...

---------------------------------------------------------------------***--------------------------------------------------------------------Abstract Here, in this paper spectrum sensing method is proposed for full duplex cognitive radio. Spectrum sensing performs essential part in spectrum allocation. Cognitive radio is the very useful option now a days, as the traffic of user increase and less...

In this paper we demonstrate that the sonication-driven exfoliation of aggregates and bundles of single-wall carbon nanotubes (SWNTs) in an aqueous surfactant solution can be easily monitored by UV-vis spectroscopy. The different stages of the exfoliation process were directly visualized by cryogenic temperature transmission electron microscopy, showing an excellent correspondence with the spec...

Abstract Single-carrier (SC) transmission is a transmission equipped with frequency-domain equalization (FDE) is suitable for uplink transmission because of its low peak-to-average power ratio (PAPR) property. Square-root Nyquist filtering is widely used, where the filter shape is controlled by the roll-off factor  from 0 to 1. Nyquist filtering with =1 occupies twice bandwidth of the origina...

The key idea to spectrum decision in Cognitive Radio Networks (CRN) is the selection of the best available spectrum band to satisfy Secondary Users (SUs) Quality of Service (QoS) requirements, without interfering with transmission of the licensed or Primary Users (PU). This challenging task requires a very good cooperation between users with different demands for the best use of spectrum channe...

Spectrum handover is a significant topic in the cognitive radio networks to assure an efficient data transmission in the cognitive radio user’s communications. This paper proposes a comparison between three spectrum handover models: VIKOR, SAW and MEW. Four evaluation metrics are used. These metrics are, accumulative average of failed handover, accumulative average of handover performed, accumu...