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One of the most commonly used tools in systems science is that of nonlinear filtering. Applications can be found in control engineering, telecommunications, radar tracking, environmental systems, economics and many other areas. However, despite the wide spread use of these tools, there remain several unresolved issues. The goal of this paper is to give a brief overview of nonlinear filtering. We give...
The paper deals with the synchronization of two chaotic Sigma-Delta Modulators. The synchronization is reached via two modulators: one of the modulators is used to code the input information into a bitstream, while the second demodulator is used to decode the obtained bitstream into the original state of the applied input signal. In this way, the system could also be used for chaotic encryption; current...
It is well known that the availability of M transmit antennas at the base station enables to serve K single-antenna users (K ≤ M), under the assumption of perfect channel state information (CSI) at the base station. However, in practical frequency division duplex (FDD) systems, the channel knowledge available at the base station is not perfect since it is obtained through a limited feedback in the...
In this paper, we provide a simple method for analyzing the GOP structure of an MPEG-2 or H.264/AVC decoded video without having access to the bitstream. Noise estimation is applied on the decoded frames and the variance of the noise in the different I-, P-, and B-frames is measured. After the encoding process, the noise variance in the video sequence shows a periodic pattern, which helps in the extraction...
Hybrid video coding algorithms, e.g. H.264/MPEG-4 AVC [1], apply prediction and subsequent prediction error coding introducing quantization noise. The quantized prediction error signal and the prediction signal are added for reconstruction. Deblocking filters reduce quantization noise of the reconstructed signal at block boundaries. To further reduce quantization noise, adaptive Wiener filters are...
Motion detection and tracking is an important vision topic for many applications such as video surveillance. When this process takes place during video encoding and transmission, Regions-of-Interest (RoIs) turn to be a very useful tool in order to favor the encoding of such regions compared to the fixed background. In this paper, we show that, in conjunction with effective spatio-temporal filters,...
In this paper, a robust watermarking scheme using singular value decomposition (SVD) and quantization is proposed. The SVD technique is used to extract important features from a host protected image; the important features are preserved in the singular values which are resistant to a rotation attack. Due to the sensitivity of singular values, the quantization technique is applied to find an appropriate...
We consider an environmental monitoring application where a scalar field (e.g., atmospheric pressure) is to be sensed by randomly distributed nodes. Each node takes a sample of a l-dimensional signal in its position and sends it to a collector entity through a wireless link. The latter performs signal reconstruction based on the received samples. Because of total bandwidth constraints, the transmission...
The SAR image data must be compressed efficiently so that the requirements for transmission bandwidth and storage space, which are brought by large amount of data on SAR image, can be reduced. The traditional methods of SAR image compression based on wavelet transformation can only decompose low frequency sub-bands, resulting in the loss of important information of high frequency sub-bands. Aiming...
Multi-gigabit per second wireless network devices are emerging for personal area networks (PAN) in the 60 GHz band. Such devices are typically power hungry, largely due to the requisite high speed analog to digital converters (ADCs) that can consume from tens to hundreds of milliwatts of power. This paper studies the use of analog equalization before the ADC to reduce the required ADC resolution....
We consider the oversampled noise-shaping subband quantizer (ONSQ) with the quantization noise being modeled as white noise. The problem at hand is to design an optimal feedback filter. Optimal feedback filters with regard to the current standard model of the ONSQ inhabit several shortcomings: the stability of the feedback loop is not ensured and the noise is considered independent of both the input...
This paper answers a question raised by Doyle on the relevance of the Witsenhausen counterexample as a toy decentralized control problem. The question has two sides, the first of which focuses on the lack of an external channel in the counterexample. Using existing results, we argue that the core difficulty in the counterexample is retained even in the presence of such a channel. The second side questions...
When compressing noisy image sequences, the compression efficiency is limited by the noise amount within these image sequences as the noise part cannot be predicted. In this paper, we investigate the influence of noise within the reference frame on lossy video coding of noisy image sequences. We estimate how much noise is left within a lossy coded reference frame. Therefore we analyze the transform...
Aiming for low-complexity encoding, distributed video coders still fail to achieve the performance of current industrial standards for video coding. One of most important problems in this area is the accurate modeling of the correlation between the predicted signal and the original video. In our previous work we showed that exploiting the quantization distortion can significantly improve the accuracy...
This paper addresses the feedback stabilization problem for linear time-invariant systems with non-Gaussian state and output noises, where sensors and controllers are connected via a noisy digital communication channel. A sufficient condition for stabilization of the unstable plant in the presence of data-rate constraints, is derived. It is found that there exists a quantization, coding and control...
Aim to avoid the deficiency of huge computation load and resource use in conventional fixed-point loop control method, base on the study of signal tracking method and accuracy of navigation receiver, an improved one is proposed, along with theoretical analysis and actual verification of the accuracy loss of signal tracking compared to the floating-point loop control method from the following two aspects...
This paper introduces an approach for quantizing intermediate values within an Multiple Constant Multiplication (MCM) implementation of a finite impulse response (FIR) filter. For a fixed-point Digital Signal Processing implementation, finite wordlength behavior in digital filter is very important. We proposed an approach to reduce the quantization noise at the filter output while maintaining performance...
This paper presents an implemented 4-bit phase ADC circuit. It introduces a model to calculate its dynamic range considering second order effects including non-linearity and offsets. The study also encompasses the phase resolution and validates the model with measurement results from the implemented chip. Our analysis shows that the phase ADC is extremely robust against circuit non-idealities and...
This paper provides a tutorial review of spread spectrum clock generators (SSCG). After explaining the various EMI reduction techniques, SSCGs which reduce EMI with frequency modulation are presented. The frequency modulation method and its implementation are also introduced. A low-cost SSCG design method that does not sacrifice EMI reduction is presented. The paper concludes with future trends of...
In this work we present a practical scheme for L-channel symmetric Multiple Description coding when one is only interested in receiving either a single description or all L descriptions. This scheme is based on oversampling and dithered Delta-Sigma quantization and is an extension of a scheme previously presented by Østergaard and Zamir. The oversampling process creates L redundant representations...
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