Estimation of fast time-varying channels in OFDM systems using two-dimensional prolate

Abstract

The fractional amount of sodium chloride, potassium sorbate and sodium bisulphite were evaluated in mango slices immersed in limited volumes of syrup at 25, 50 and 70 °C. The syrup contained 250 g sucrose, 1.5 g sodium chloride, 0.5 g potassium sorbate and 0.25 g sodium bisulphate per kilogram of solution. The sodium chloride concentration in the syrup was confirmed with a flame photometer, and the concentrations of potassium sorbate and sodium bisulphite were determined using high-performance liquid chromatography (HPLC). Fick's second law was used to calculate effective diffusion coefficients and to predict solute content in the mango slices. Diffusion coefficients were affected by temperature and were correlated by the Arrhenius equation. The experimental data fit the proposed mathematical model well, allowing prediction of the system's behavior at different temperatures. The resultant diffusivities ranges were 2.63-3.54 10-9 m2/s for sodium chloride, 3.88 10-9-8.3 10-10 m2/s for potassium sorbate and 1.83 10-7-5.98 10-8 m2/s for sodium bisulphite. " 2008 Elsevier Ltd. All rights reserved.",,,,,,"10.1016/j.jfoodeng.2008.08.032",,,"http://hdl.handle.net/20.500.12104/41303","http://www.scopus.com/inward/record.url?eid=2-s2.0-56349121134&partnerID=40&md5=2062a3c2c8c94a68e47658e4be1f7ffe",,,,,,"2",,"Journal of Food Engineering",,"211

216",,"91",,"Scopus

WOS",,,,,,"Diffusivity; Hurdle technology; Mango; Potassium sorbate; Sodium bisulphite; Sodium chloride",,,,,,"Estimation of the diffusivities of sodium chloride, potassium sorbate and sodium bisulphite in mango slices processed by hurdle technology",,"Article" "43079","123456789/35008",,"Pena-Campos, F., Department of Electrical Engineering, Communications Section, CINVESTAV-IPN, Guadalajara, Jalisco, 45019, Mexico; Carrasco-Alvarez, R., Department of Electronic Engineering, University of Guadalajara-CUCEI, Guadalajara, Jalisco, 44430, Mexico; Longoria-Gandara, O., Department of Electronics, Systems and IT, ITESO, Periferico sur Manuel Gomez Morin 8585, 45604, Tlaquepaque, Jalisco, Mexico; Parra-Michel, R., Department of Electrical Engineering, Communications Section, CINVESTAV-IPN, Guadalajara, Jalisco, 45019, Mexico",,"Pena-Campos, F.

Carrasco-Alvarez, R.

Longoria-Gandara, O.

Parra-Michel, R.",,"2013",,"Modern communication systems are based on orthogonal frequency division multiplexing (OFDM). They are designed for dealing with frequency selective channels considering invariance within the time-span of an OFDM symbol. However, this assumption is no longer valid when the transceivers operate in higher mobility scenarios or higher carrier frequencies. This condition provokes inter-carrier interference (ICI) that greatly degrades system performance. State-of-the-art approaches that satisfactorily mitigate this problem have a complexity of O(N3), which makes them infeasible with current technology. In this paper, a novel channel estimation algorithm to cope with this problem is presented. It is based on a subspace approach using two-dimensional Prolate functions, achieving a complexity of only O(N2). It depends only on the maximum delay spread and maximum Doppler spread while being robust in the sense that it is independent of the particular channel scattering function. Performance analysis of the proposed algorithm is presented. Simulation results under the WiMAX standard show that this algorithm improves previous results, achieving a bit error rate (BER) close to the one obtained with perfect channel state information (CSI) in very-fast transceiver mobility, as high as 874 Km/h over a 2.4 Ghz carrier frequency. " 2012 IEEE.