Receiver Architectures for MIMO-OFDM Based on a Combined VMP-SP Algorithm

Iterative information processing, either based on heuristics or analytical frameworks, has been shown to be a very powerful tool for the design of efficient, yet feasible, wireless receiver architectures. Within this context, algorithms performing message-passing on a probabilistic graph, such as the sum-product (SP) and variational message passing (VMP) algorithms, have become increasingly popular. In this contribution, we apply a combined VMP-SP message-passing technique to the design of receivers for MIMO-ODFM systems. The message-passing equations of the combined scheme can be obtained from the equations of the stationary points of a constrained region-based free energy approximation. When applied to a MIMO-OFDM probabilistic model, we obtain a generic receiver architecture performing iterative channel weight and noise precision estimation, equalization and data decoding. We show that this generic scheme can be particularized to a variety of different receiver structures, ranging from high-performance iterative structures to low complexity receivers. This allows for a flexible design of the signal processing specially tailored for the requirements of each specific application. The numerical assessment of our solutions, based on Monte Carlo simulations, corroborates the high performance of the proposed algorithms and their superiority to heuristic approaches

Electrodialytic upgrading of MSWI APC residue from hazardous waste to secondary resource

Relatório editado por: Pernille E. Jensen; Gunvor M. Kirkelund; Raimon Parés Viader; Catia Magro; Kristine B. Pedersen; Celia Ferreira, e Lisbeth M. Ottosen.Environmental project No 1884info:eu-repo/semantics/publishedVersio

Mercury levels in fly ash and APC residue from municipal solid waste incineration before and after electrodialytic remediation

Fly ash (FA) and Air Pollution Control (APC) residues collected from three municipal solid waste incinerators (MSWI) in Denmark and Greenland were treated by electrodialytic remediation at pilot scale for 8 to 10 h. The original residues and the treated material were analysed for mercury (Hg) in order to assess the influence of the electrodialytic treatment on the concentrations of this element. Mercury levels varied with the MSWI residue, ranging from 0.41 mg kg1 in FA sample from electrostatic precipitator (ESP) to 8.38 mg kg1 in MSWI residues from a semi-dry system with lime and activated carbon. Two distinct behaviours were observed for mercury as a result of the electrodialytic treatment. This element became enriched in the MSWI residues from the semi-dry system with activated carbon, whereas it decreased in ESP's and cyclone's FA. This work presents for the first time information about the effect of electrodialytic treatment on mercury levels and discusses the valorisation options for these MSWI residues. © 2016 WIT Press