On phaser-based processing of impulse radio UWB over fiber systems employing SOA

Abstract

In this study, we adopt a phaser-based processing to enhance the performance of impulse radio over fiber system utilizing SOA. The amplifier has been placed at a distance in the optical link, so as to extend the coverage area of proposed transceiver. Operating in the linear or saturation region for SOA, adds ASE noise or strong nonlinearities acting on the propagated pulses, respectively. Both lead to a degradation in the power efficiency and bit error rate performance. By applying up and down analog chirping technique, we have reduced the ASE power and nonlinearity simultaneously. Based on the 5th Gaussian pulse and Abraha's combination of doublets, a significant improvement has been achieved at extremely low and high input powers entering the amplifier (<-15 dBm and 0 dBm), recording a very good bit error rate performance and power efficiency. Better signal quality was observed after photo-detector, due to the fact that waveforms with lower frequency components are less affected by SOA nonlinearity. Our scheme has proved to be effective for 1 Gbps OOK and 0.5 Gbps PPM transmissions, while reaching a distance of 160 km in the optical fiber.

Chirping techniques for enhancing the performance of SOA-based UWB over fiber systems: An experimental demonstration

“…Chirping scheme has shown to be effective in our previous simulations, a very good power efficiencies being obtained for the 5 th Gaussian pulse besides to Abraha's combination of Doublets [8]. Here we examine the potential of chirping in a real SOA-based optical system so as to confirm the effectiveness of this scheme, while up/down chirping is performed in offline processing via simple phaser models in Matlab.…”

“…Here we examine the potential of chirping in a real SOA-based optical system so as to confirm the effectiveness of this scheme, while up/down chirping is performed in offline processing via simple phaser models in Matlab. Due to the band limitation of the AWG used, it was not possible to generate the same waveforms as in [8], on the other side, dealing with pulses having a frequency diversity is much easier to see the benefits of chirping. Therefore, we have proposed a combination of 2 modulated basic Gaussians g 1 and g 2 , with different carrier frequencies f 1 and f 2 , in order to see the original signal as two overlapped waveforms which could be separated via chirping.…”

“…A particular scenario of UWB is the Impulse Radio, which is a cost effective approach offering a low order of generation complexity [5] together with a simple design at the receiver side if a non-coherent detection is adopted [6]. With the view to get a reach extension in the optical access network, a low cost Semiconductor Optical Amplifier (SOA) has been recently employed [7,8]. However, a performance degradation may occur due to the nonlinear effects and Amplified Spontaneous Emission (ASE) noise inherent to SOA.…”

“…However, a performance degradation may occur due to the nonlinear effects and Amplified Spontaneous Emission (ASE) noise inherent to SOA. In [8], we have overcome these two impairments via phaser-based processing techniques [9], a significant improvement in the power efficiency and bit error rate has been carried out, due to symmetrical up and down chirping performed at the transmitter and receiver respectively. The key concept is that a lower order of four wave mixing and cross gain modulation is obtained against signals with less frequency diversity.…”

A Compact CPW Fed Uwb Antenna With Quad Band Notch Characteristics for Ism Band Applications

“…In 2002, the Federal Communication Commission (FCC) gave license to propagate signals in the UWB spectrum (3.1 GHz-10.6 GHz) with a fractional bandwidth (FBW) of more than 100% for civilian communication applications [1]. The UWB systems have many advantages, such as low operating power, high data rate, and low profile.…”