Zipper - a Duplex Method for VDSL based on DMT

We present a new duplex scheme, called Zipper, for discrete multitone (DMT)-based very high bit-rate digital subscriber line (VDSL) systems on copper wires. This scheme divides the available bandwidth by assigning different subcarriers for the upstream and downstream directions. It has high flexibility to divide the capacity between the up and downstream, as well as good coexistence possibilities with other systems such as ADSL. Simulation results show the high bit-rate performance in different environments such as mixed ADSL and VDSL traffic under radio frequency interference and with different background noise source

Simultaneous channel and symbol maximum likelihood estimation in Laplacian noise

This paper treats channel estimation and signal detection in Laplacian noise. The received signal is assumed to be a transmitted signal which has been corrupted by an unknown channel, modeled as a FIR filter, the output being further disturbed by additive independent Laplacian noise. The transmitted signal is assumed to depend on an unknown parameter belonging to a known finite set. The simultaneous maximum likelihood (ML) estimator of the unknown parameter, as well as of the FIR filter coefficients, is derived. The ML estimate of the channel can be obtained by using a linear programming approach and the decision about the parameter is based on the output from a set of generalized matched filters. Simulation results are included in order to illustrate the performance of the proposed receiver

A method for evaluation of QRS shape features using a mathematical model for the ECG

Automated classification of ECG patterns is facilitated by careful selection of waveform features. This paper presents a method for evaluating the properties of features that describe the shape of a QRS complex. By examining the distances in the feature space for a class of nearly similar complexes, shape transitions which are poorly described by the feature under investigation can be readily identified. To obtain a continuous range of waveforms, which is required by the method, a mathematical model is used to simulate the QRS complexes

Symbol time offset estimation in coherent OFDM systems

This paper presents a symbol time offset estimator for coherent OFDM systems. This estimator exploits both the redundancy in the cyclic prefix and the pilot symbols used for channel estimation. The estimator is robust against frequency offsets and is suitable for use in dispersive channels. We base the estimator on the ML estimator for the AWGN channel. Simulations of an example system indicate a system performance as close as 0.3 dB to a perfectly synchronized system. Compared to an estimator not using pilots, our estimator's performance could allow a shorter cyclic prefix and thus a more spectrally efficient syste

Common Mode Characterization and Channel Model Verification for Shielded Twisted Pair (STP) Cable

This paper investigates common-mode propagation in shielded twisted pair cables. The common mode exhibits great potential for improving the throughput in emerging wireline systems. The design of corresponding transmission schemes over multipair copper cables requires accurate knowledge of the channel properties. We present measurement and modeling results and investigate the feasibility of using standard differentialmode models for data fitting in multiconductor transmission-line modelling of common-mode paths

Шоп-туризм: проблемы и перспективы развития в Республике Беларусь

Материалы XV Междунар. науч.-техн. конф. студентов, аспирантов и молодых ученых, Гомель, 23–24 апр. 2015 г

Synchronization in OFDM systems sensitivity to the choice of pulse shape

Problème traité : dans cette publication, nous nous intéressons au problème de la synchronisation dans les systèmes à porteuses multiples : estimation du début du symbole et de l'écart de fréquence. Nous utilisons la redondance introduite par le temps de garde ainsi qu'une fonction de mise en forme des symboles. Originalité de la contribution : Les performances d'un système utilisant uniquement la corrélation introduite par le temps de garde ont été évaluées dans un article précédent dans le cas d'un canal gaussien. Dans cette contribution, nous introduisons une fonction de mise en forme sur les symboles OFDM et nous évaluons les performances du système ainsi obtenu. Résultat nouveaux : Nous avons déterminé les performances du système proposé pour différentes fonctions de mise en forme