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In wireless communication systems, error control coding is necessary to provide reliable communications over fading channels. Turbo code is used practically in third generation due to good error correcting capability. However, it has error floor at high signal-to-noise ratio (SNR). Concatenation of another code as an outer code is an alternative to reduce turbo codepsilas error floor. In this paper,...
Since the apparition of Voice over IP (VoIP), many standards (mainly signaling protocols and codecs) have arisen with the aim of enabling voice calls through data networks. This paper describes a comparative study to evaluate the performance of a representative set of these standards when transmitting voice streams in a packet network. Asterisk PBX software is employed to define a testbed that allows...
A peer-to-peer (P2P) technology is applied for various systems because it enables to construct a system with high scalability and robustness. We have proposed a distributed cooperative storage system that can construct huge storage space by providing it on a P2P network. The storage system is based on an overlay network construction, and its hash space is created in an application layer. Each peer...
The use of broadcast TV channels is growing considerably so that the number of users (scalability) and the need to manage traffic (bandwidth) are challenges for network design and dimensioning. Broadcast and live channels show strict requirements to operate on a continuous basis in content distribution scenarios in terms of delay, huge demand of bandwidth and characterized by very dynamic variations...
In a ubiquitous network society, information on mobile nodes such as pedestrians with cell phones in a target region is useful for network configuration, communication control, and so on. In this paper, we propose a novel method to estimate in real time the number of pedestrians in video sequences using a stationary camera. The proposed method extracts moving regions from video frame grabs using background...
In this paper we put forward a scheme for suppressing narrowband interference by the use of adaptive narrowband filtering. We compare this method with other schemes for the suppression of complex narrowband interference in OFDM UWB systems, such as the frequency excision method and complex narrowband interference identification and cancelation algorithms. The study shows that the three schemes give...
A 4+12+16 amplitude phase shift keying (APSK) modulation outperforms other 32-APSK modulations such as rectangular or cross 32-quadrature amplitude modulations (QAMs) which have a high peak to average power ratio that causes non-negligible amplitude modulation to amplitude modulation (AM/AM) and amplitude modulation to phase modulation (AM/PM) distortions when the signal is amplified by a high-power...
Detection of skin pixels in arbitrary images is addressed in this paper. We have combined texture and color information to segment skin regions. First, a pixel-based boosted skin detection method is used to locate skin pixels. To further improve the detect performance, skin region texture features are employed using the non-subsampled contourlet coefficients. For the candidate skin pixels, the set...
An efficient super resolution (resolution enhancement) method for low resolution images is proposed in this paper. The algorithm is mainly based on a mathematical theorem (inhibition principle) for over determined scenario of superresolution. The proposed method aims at achieving a fast and computationally efficient resolution enhancement. Performance of the proposed method is compared to the conventional...
High-grade narrowband speech security for high frequency (HF) transmissions can be achieved using low rate speech coders and encryption algorithms. This paper presents test results for an HF channel and the structure of a test system that uses a mixed excitation linear prediction (MELP) vocoder for digital plain and secure speech transmission. The system is tested for bit error percentage in the received...
This paper presents an emotion recognition framework based on sound processing could significantly improve human computer interaction. One hundred thirty three (133) speech features obtained from sound processing of acting speech were tested in order to create a feature set sufficient to discriminate between seven emotions. Following statistical analysis in order to assess the significance of each...
This paper presents a new approach to enhance the quality of separated source in blind source separation problem. We consider the general case where the total number of sources is larger than the number of sensors and the number of sources is not known. The method is based on a principal point that we can use the signals of the ldquovirtual sensorsrdquo that do not exist in practice but generated...
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