Development of a dc-ac power conditioner for wind generator by using neural network

This project present of development single phase DC-AC converter for wind generator application. The mathematical model of the wind generator and Artificial Neural Network control for DC-AC converter is derived. The controller is designed to stabilize the output voltage of DC-AC converter. To verify the effectiveness of the proposal controller, both simulation and experimental are developed. The simulation and experimental result show that the amplitude of output voltage of the DC-AC converter can be controlled

Joint distribution of polarization-multiplexed UWB and WiMAX radio in PON

In this paper, the feasibility of the joint distribution of ultra-wideband (UWB) and WIMAX wireless using polarization multiplexing as a coexistence technique is proposed and experimentally demonstrated within the framework of passive optical networks (PON). Four single- and orthogonal-polarization multiplexing schemes are studied targeting to reduce the mutual interference when UWB and WiMAX are distributed jointly through standard single-mode fiber (SSMF) without transmission impairments compensation techniques and amplification. Experimental results indicate successful transmission up to 25 km, in SSMF exceeding the range in typical PON deployments. The radio link penalty introduced by optical transmission is also investigated in this paper

Nonlinearity and Noise Effects in Multi-level Signal Millimeter-Wave over Fiber Transmission using Single- and Dual-Wavelength Modulation

We transmit multilevel quadrature amplitude modulation (QAM) data-IEEE 802.16 schemes-at 20 MSps and an orthogonal frequency-division multiplexing (OFDM) 802.11 g signal (54 Mbps) with a 25 GHz millimeter-wave over fiber system, which employs a dual wavelength source, over 20 km of single mode fiber. Downlink data transmission is successfully demonstrated over both optical and wireless (up to 12 m) paths with good error vector magnitude. An analysis of two different schemes, in which data is applied to one (single) and both (dual) of the wavelengths of a dual wavelength source, is carried out. The system performance is analyzed through simulation and a good match with experimental results is obtained. The analysis investigates the impact of Mach-Zehnder modulator (MZM) and RF amplifier nonlinearity and various noise sources, such as laser relative intensity noise, amplified spontaneous emission, thermal, and shot noise. A comparison of single carrier QAM IEEE 802.16 and OFDM in terms of their sensitivity to the distortions from MZM and RF amplifier nonlinearity is also presented

Ultra-wideband radio signals distribution in FTTH networks

The use of an ultra-wideband (UWB) radio technique is proposed as a viable solution for the distribution of high-definition audio/video content in fiber-to-the-home (FTTH) networks. The approach suitability is demonstrated by the transmission of standards-based UWB signals at 1.25 Gb/s along different FTTH fiber links with 25 km up to 60 km of standard single-mode fiber length in a laboratory experiment. Experimental results suggest that orthogonal frequency-division-multiplexed UWB signals exhibit better transmission performance in FFTH networks than impulse radio UWB signals

Full duplex 60 GHz millimeter wave transmission over multi-mode fiber

Copyright @ 2010 IEEENew wireless subscribers are signing up at an increasing demand of more capacity for ultra-high data rate transfers at speeds more than 1 Gbps, while the radio spectrum is limited. Millimeter wave communication system offers a unique way to resolve these problems. In this paper, the performance of a full duplex transportation system is reported for 1.5 Km of multi-mode fiber length for a sample 10 Gbit/s pseudo random sequence data, with quadrature amplitude modulation mapping and orthogonal frequency division multiplexing modulation with 60 GHz RF and coherent 1550 nm optical carrier. The analysis and simulation results show that the system's quality of service depends on nonlinearity of electro optical modulator, dispersion and signal attenuation impairment of the multi-mode fiber cable

Performance of MB-OFDM UWB and WiMAX IEEE 802.16e converged radio-over-fiber in PON

Experimental results about the performance of converged radio-over- fiber transmission including multiband- OFDM UWB and WiMAX 802.16e wireless over a passive optical network are reported in this paper. The experimental study indicates that UWB and WiMAX converged transmission is feasible over the proposed distribution set-up employing a single wavelength. However, the results indicate that there is an EVM penalty of 3.2 dB for a UWB 10 km SSMF transmission in presence of WiMAX wireless

Integrated performance analysis of UWB wireless optical transmission in FTTH networks

The optical transmission of full standard ECMA_368 OFDM_UWB signals 400 Mbit/s per single user over 50 km SSMF, and the impact of optical transmission in the radio performance experimentally analyzed in this paper

480Mbit/s UWB bi-directional radio over fiber CWDM PON using ultra-low cost and power VCSELs

Radio-over-fiber (RoF) schemes offer the possibility of permitting direct access to native format services for the domestic user. A low power requirement and cost effectiveness are crucial to both the service provider and the end user. Here, we present an ultra-low cost and power RoF scheme using direct modulation of commercially-available 1344 nm and 1547 nm VCSELs by band-group 1 UWB wireless signals (ECMA-368) at near broadcast power levels. As a result, greatly simplified electrical-optical-electrical conversion is accomplished. A successful demonstration over a transmission distance of 20.1 km is described using a SSMF, CWDM optical network. EVMs of better than-18.3 dB were achieved. © 2011 Optical Society of America

Dual-drive LiNbO_3 interferometric Mach-Zehnder architecture with extended linear regime for high peak-to-average OFDM-based communication systems

A dual-drive LiNbO3 architecture modulator with chirp management is proposed and developed offering SFDR > 25 dB in a 1.4 V bias excursion compared to only 0.5 V bias excursion in a conventional Mach-Zehnder electro-optical modulator (MZ-EOM). The architecture effectively extends the linear regime and enables the optical transmission of wireless systems employing orthogonal division multiplexing (OFDM) modulation such as ultra-wide band (UWB) which require high linearity over a broad frequency range due to their high peak-to-average power ratio (PARP). Radio-over-fiber UWB transmission in a passive optical network is experimentally demonstrated employing this technique, exhibiting an enhancement of 2.2 dB in EVM after 57 km SSMF when the dual-drive developed modulator is employed. © 2011 Optical Society of America