Abstract
In this paper, we study the performance of the optimum receiver for nonlinear distorted OFDM signals in RoF applications, which is composed by a demodulator followed by an ML detector. The demodulator observes the various intermodulation products to compute a set of sufficient statistics, while the detector observes the sufficient statistics to compute an estimate of the original data. Particularly, we concentrate on the uplink of intensity modulation/direct detection RoF system where the OFDM signal suffers from linear distortion (fading), nonlinear distortion and noise. We demonstrate that the optimum receiver outperforms the conventional OFDM receiver by several orders of magnitude.

Abstract
We assess the performance of a coherent optical system employing a phase estimation algorithm combined with a least mean square decision-directed equalizer in a feedback configuration and compare it to the constant modulus algorithm with an independent carrier phase estimation approach for 16-quadratic-amplitude-modulation transmission. Both series and parallel implementations are discussed. Hardware issues regarding a recursive implementation of the estimation filter are also reported.

Abstract
Type S thermocouples were assembled in situ by applying high intensity electric are discharges to the contact junction of two platinum (Pt) and Pt-10% rhodium (Pt-10% Rh) wires, inserted on a silica capillary. The electrically insulated thermocouples built in this way were afterwards employed to estimate the temperature of an optical fiber subjected to arc discharges. For typical values of the arc discharge parameters used to arc-induce long-period fiber gratings (electric current I = 9 mA and arc duration t = 1 s), a capillary peak temperature value of 1420 degreesC +/- 400 degreesC was obtained by extrapolation of the experimental data for the limit situation of having a thermocouple with negligible diameter. The temperature profiles in the capillary and in an optical fiber were calculated based on a heat transfer model implemented by a finite element algorithm and fitted to the experimental temperature distribution in the Pt and Pt-10% Rh wires. The correspondent peak temperatures computed for the capillary and for the fiber were 1450 degreesC and 1320 degreesC, respectively. A good agreement between the capillary temperature values determined graphically and numerically was obtained.

Abstract
The options to implement a coherent optical system employing a phase estimation algorithm combined with adaptive linear equalization are investigated. Several carrier phase estimator strategies are discussed, in terms of parallelization, performance and implementation complexity.

Abstract
The electrical compensation of chromatic dispersion (CD) and polarization mode dispersion (PMD) in a coherent optical system exploiting polarization multiplexing is discussed in this paper. The benefits of combining a phase estimation algorithm with a decision directed least-mean-square equalizer in a feedback configuration is reported.

Abstract
One compact printed monopole antenna with a chip inductor for dual-band WLAN is presented. The proposed antenna has a two-armed structure and an electrically small size. The equivalent circuit structure of the chip inductor is studied and a simplified circuit structure is proposed. This simplified circuit structure was introduced into the electromagnetic (EM) simulation model by assigning a boundary condition, and the experimental results show that with this model, the simulation can provide an accurate prediction of the antenna radiation performance. The measurement results show that the proposed monopole antenna has a VSWR 2: 1 bandwidth over 2.41-2.49 and 5.2-5.6 GHz with omnidirectional radiation patterns. The simulation results suggest that the proposed antenna has a directivity around 1.5 dB at both bands with relatively high radiation efficiency. The antenna is designed and optimized by using Ansoft HFSS.