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We consider a dual-hop amplify-and-forward relaying system where the channel state is unknown to both the transmitter and the receiver. Our objective is to derive the penalty of the information rate due to the unknown channel state information. We focus on determining the compound effects of fixed-gain relaying and unknown time-varying channels on the achievable information rates of the system. We...
It is difficult to track targets in grayscale videos especially for small targets because of the lack of the target image information. A tracking algorithm was proposed to track small targets in grayscale videos whose size was from 7×7 pixels to 25×25 pixels. The algorithm included six steps: (1) enlarge the target and the surrounding region by bilinear interpolation; (2) enhance the target features...
Recently, wireless mesh networks (WMNs) have received enormous attention for wireless backbone network as well as sensor network due to its flexibility and cost-effectiveness in deployment. Particularly, IEEE 802.16-2004 based on time division multiple access (TDMA) with orthogonal frequency division multiplexing (OFDM) air interface supports mesh mode operation for last-mile connection to backhaul...
Spatio-temporal motion field descriptors for the hierarchical action recognition system have been developed. At the lower level, blurred motion fields representing local features such as speed and direction are estimated from video sequences. At the higher level, feature vectors are calculated by applying a parallel updating scheme to measure the similarity between the input video sequences and so-called...
This paper presents a system for speaker independent keyword spotting (KWS) in continuous speech using a spoken example template. The approach, based on Dynamic Time Warping (DTW) for matching the template to a test utterance, does not require any modelling or training as required in alternative techniques such as the Hidden Markov Model (HMM). This is of particular relevance to applications such...
Major drawback in orthogonal frequency division multiplexing (OFDM) systems is that the transmit signal exhibits high peak-to-average power ratio (PAPR). In this paper, a phase sequence blind estimation method is presented for PAPR reduction based on a selected mapping (SLM) or a partial transmit sequence (PTS) in multi-input multi-output (MIMO) coded OFDM systems, where low density parity check (LDPC)...
One of the most important areas of study in wireless sensor networks (WSNs) is security. This work presents how to maximize data survivability in unattended WSNs (UWSNs) where sensed data cannot be off-loaded to a sink in real time. The characteristics of this network are the presence of intermittent sink and operation in possibly hostile settings. The major goal in this study is to improve the availability...
In this paper, we present and analyse a spread spectrum chaos-based communication system in a multipath channel. The propagation model considers the direction of arrival and the polarization of each version of a transmitted signal. To increase the performance of the chaos-based communication system, monopoles with different orientations and no space diversity are proposed in the receiver side. In...
A dominant-noise identification system used on images corrupted by content-independent noises without a priori information has been developed. As representative examples of content-independent noises additive white Gaussian noise (AWGN) and random impulse noise (RIN) are used. The system uses two noise detectors to estimate the intensity component of either AWGN or RIN in an image. For this purpose...
For fulfilling new tasks of the regulator, we propose a novel mobile spectrum monitoring network. The huge amount of measurement data contains besides thermal noise also noise induced by the Automatic Gain Control (AGC). As a result the occupancy results based on normal energy detection are significantly biased. In order to assess the spectrum occupancy more accurately, we employ an eigenvalue based...
Spherical harmonics serve as basis functions on the unit sphere and spherical harmonic transform is required in analysis and processing of signals in the spectral domain. We investigate the possibility of parallel computation of spherical harmonic transform using Compute Unified Device Architecture (CUDA) with no communication between parallel kernels. We identify the parallel components in the widely...
Wireless sensor networks (WSN) that require bridging to other networks or extending sensor coverage must keep high link availability to reduce energy wasted on error control. This paper first details the relationship of individual link probability of availability to Eb/No and to upper protocol layers. Then the efficient computation of the network probability of availability is shown, and applied to...
This paper proposes a novel limb-based technique for semantic description of motion capture data. The goal is to create a motion segmentation and classification technique that is easily extensible by recognizing the actions of a limb instead of the whole body. This provides a highly detailed metadata that can be extended as needed to include additional motion classes by either adding a new limb submotion...
Real-time audio-visual communication requires a packet-loss recovery mechanism due to inevitable packet loss characteristics of the transmission channel such as the Internet. Especially for interactive applications e.g. real-time audio-visual communication, the delay for the recovery and enhancement technology must be minimized. Among the low-delay packet-loss recovery techniques, Multiple Description...
The major objective of this paper is to reveal the performance of the turbo equalization using doped accumulator (TEQ-ACC) when it is combined with channel estimation, in broadband single carrier signalling. It is shown that the accuracy of the channel estimate in TEQ-ACC is inferior to that in conventional turbo equalization (TEQ-CVT), if TEQ-ACC generates the soft replica only from the soft information...
A visible light communication system including various signal types transmitted among the system's respective cells needs to be considered as a viable option for indoor localization-based services and positioning systems. In order to mitigate inter-cell interference, a carrier allocation-visible light communication system (CA-VLC), adopting various carriers among the system's respective cells, is...
In this paper, we present several fusion approaches to merge speed limits reported in digital maps with detected speed limit signs using an onboard camera. Digital maps holding speed limits signs are required to be updated to cover speed limit changes and are unable to support variable speed limits. On the other hand, a camera system placed onboard a vehicular can detect variable speed limits as well...
In this paper, we consider a downlink two-tier network comprising of a multiple-antenna macrocell base station and a single femtocell access point, each serving multiples users with a single antenna. In this scenario, we treat the total transmit power minimization problem and mean-square error balancing problem. In the presence of perfect channel state information (CSI), we formulate the optimization...
A new maximum ratio combining (MRC) Wavelet Rake (WR) receiver is presented in this paper. The WR receiver makes use of the huge bandwidth accompanied with the Ultra-Wideband (UWB) system. The proposed WR receiver uses the continuous wavelet transform (CWT) of the transmitted pulse at different scales (frequency resolutions) as the Rake fingers template pulses. Where, the Rake fingers delays are the...
With the increasing deployment of autonomous machine type devices which highly surpass in number the devices directly controlled by humans, the wireless environment should support efficiently and in a scalable manner the Machine-2-Machine (M2M) type of communication enabling new services and business opportunities. However, the current mobile network architecture is designed for human interaction,...
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