1 Institut TELECOM, TELECOM Bretagne, UMR CNRS 3192 Lab-STICC, Technopôle Brest-Iroise CS 83818, 29238 Brest Cedex∼3, France 2Université Européenne de Bretagne, (UeB), France 3 Institut TELECOM, TELECOM Bretagne, Technopôle Brest-Iroise CS 83818, 29238 Brest Cedex∼3, France 4Laboratoire CRISTAL, Ecole Nationale de Sciences de L’Informatique (ENSI), Campus Universitaire de la Manouba, 2010 Manou...

A durational modelling technique is proposed for CDHMM-based connected digit recognition. This reduces the insertion error rate, which is typically the most frequent recognition error observed when no grammar constraint is applied. Insertion errors can be attributed in part to the acknowledged weakness of the acoustic models for accurate temporal modeling of speech signals. Two forms of duratio...

This paper proposes a novel method to detect Furon’s asymmetric watermark by using a correlation detector that is mathematically tractable and simple. The performance of the proposed method is tested under various conditions. The experimental results matched the theoretical results well, showing that the correlation detector can indeed be used for the detection of asymmetric watermark. The prop...

We introduce a scheme that achieves a diversity gain for coded systems under static fading conditions by using multiple antennas and random signal mapping. In a two-antenna system, the BER performance of the proposed scheme approaches that of Alamouti’s scheme when the channel is perfectly known. In the presence of channel mismatch, the proposed scheme outperforms Alamouti’s scheme significantl...

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Simultaneously pressing two keys on a keyboard (Zero Time keystrokes) is a unique typing occurrence. To understand the cause of Zero Time keystrokes, typing data were collected from young children and undergraduate computing students. The results show that, in both students and children, the most frequent cause of Zero Time keystrokes were errors in aiming for the intended key, resulting in the...

—Radio-Frequency (RF) recharging of sensor nodes is a promising way to minimize maintenance and prolong the operational life of wireless sensor networks. In this paper, we present a simple MAC protocol based on polling that includes provisions for on-demand recharging using the same RF band as normal data communications, and we develop a probabilistic performance model to evaluate the impact o...

This study uses the joint receive antenna selection and symbol detection (JRAS/SD) technique to simultaneously improve the bit error rate and channel capacity while reducing the cost of the radio-frequency chains in multipleinput multiple-output (MIMO) systems. Optimal antenna selection methods in the literatureare based on the criteria of maximal capacity or minimal bit error rate. Either of t...

Digital speech transmission systems use source coding to reduce the bit rate and channel coding to correct transmission errors. Furthermore, in periods of a very poor channel quality error concealment of residual bit errors becomes necessary as channel decoding fails. However, if the channel is clear, channel coding would not be required at all and the speech quality could be improved by allowi...

A beamforming algorithm is introduced based on the general objective function that approximates the bit error rate for the wireless systems with binary phase shift keying and quadrature phase shift keying modulation schemes. The proposed minimum approximate bit error rate (ABER) beamforming approach does not rely on the Gaussian assumption of the channel noise. Therefore, this approach is also ...