Carrier Frequency Offset Estimation using Data-Dependent Superimposed Training

In this letter we propose, for the first time, a solution to the problem of carrier frequency offset (CFO) estimation within the data dependent superimposed training (DDST) framework for channel estimation. While time division multiplexed (TDM) trained systems can use the TDM sequence to determine the CFO, the original attraction of DDST for channel estimation was that it avoided any TDM training. So in this letter we show how CFO estimation can still be very effectively performed with the DDST algorithm, while continuing to preclude the need for any additional bandwidth-consuming TDM training. Finally, simulations are presented that verify the theoretical results.     

Spectroscopic,morphological, thermal and dielectrical analysis of composite of polythiophene with photoactive transition metal complex of W(IV)

The present work involves the synthesis of polythiophene–potassium octacyanotungstate(IV) dihydrate composite via in-situ oxidative chemical polymerization method using \(\hbox {FeCl}_{3}\) as an oxidant. The resulting composite has been subjected to Fourier transform infrared, X-ray diffraction (XRD) and scanning electron microscopy characterization techniques, which confirm the successful synthesis of the composite. XRD shows that the crystalline structure of \(\hbox {K}_{4}[\hbox {W(CN)}_{8}]\cdot \hbox {2H}_{2}\hbox {O}\) has been retained in the composite. Thermogravimetric analysis data confirm the higher thermal stability of the composite in comparison with pure polythiophene, thus allowing it to be used as a promising material for high-temperature application purposes. Dielectric studies reveal that the dielectric constant and ac-conductivity of the composite increased by several orders of magnitude as compared with pure polythiophene at all frequencies, thus showing that the material can be used for various applications in the fields of charge storage devices and high-frequency device applications, and can also serve as a potential candidate for solar cell applications.     

Synthesis and characterization of PPY/K[Fe(CN)3(OH)(en)] nanocomposite: Study of photocatalytic,sorption, electrical,and thermal properties

This work involves the synthesis of nanocomposite of Polypyrrole (PPY) with photoadduct {K[Fe(CN)₃(OH)(en)]} via in‐situ oxidative chemical polymerisation. Photoadduct is synthesized by irradiating equimolar mixture of potassium hexacyanoferrate (III) and ethylenediamine (en) and is then reduced to nanosize by high energy ball mill. Successful synthesis of nanophotoadduct is confirmed by elemental analyser, UV–Vis, and FTIR. The nanocomposite of PPY and photoadduct has been characterised by SEM, TEM, FTIR, XRD, TGA, UV–Vis spectroscopy, I–V characteristics, and dielectric analysis for structural, thermal, optical, electrical, and dielectric properties. The average particle size of nanophotoadduct and nanocomposite has been found to be 80 and 84 nm, respectively. The thermal stability of nanocomposite is enhanced. The nanocomposite shows high value of dielectric constant (5 × 10³ at10³ Hz) and ac conductivity (7.0 × 10⁸ Sm^?1 at 10⁶ Hz) as compared with pure PPY. The high value of dielectric constant can make the material suited for energy storage applications. The nanocomposite shows higher photocatalytic activity as compared with pure PPY and a high value of distribution coefficient (K_d) has been obtained for Pb²⁺, Zn²⁺, and Cd²⁺ ions, hence, can act as an efficient material for removal of dyes and heavy metal ions in waste water. Thus, photoadduct of K₃[Fe(CN)₆] and ethylenediamine(en), a new kind of filler, has succeeded in improving the properties of PPY with respect to thermal stability, high dielectric constant, high ac conductivity, efficient photocatalytic activity, and high K_d value for toxic metal ions. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43487.