The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper presents a Genetic Algorithm (GA) based approach for Hardware/Software partitioning targeting an architecture composed of a processor and a dynamically reconfigurable datapath (FPGA). From an acyclic task graph and a set of Area-Time implementation trade offs points for each task, our GA performs HW/SW partitioning and scheduling such that the global application execution time is minimized...
Multiplierless filters are natural extensions of the low-sensitivity structures. Some low-sensitivity transformations are investigated for converting a prototype lowpass filter into a bandpass or a bandstop filter. The resulting coefficient values, due to such transformations, become quite low compared with conventional structures. When the coefficient values are expressed in minimum signed powers...
Subspace-based robust blind channel identification algorithm[1] using sign covariance matrix has recently been proposed to mitigate the adverse effect of impulsive noise. Since batch eigen-decomposition, which is computationally very expensive, needs to be implemented to estimate subspace of the sign covariance matrix for channel vector estimation, a subspace-tracking-based channel identification...
Three major aspects in the protection of digital documents have been pointed out, each of them with different requirements: first copyright protection, protecting ownership and usage rights; secondly tamper-proofing, aiming at checking document integrity; and thirdly authentication, the purpose of which is to check the authenticity of a document. While robust watermarks are typically used for copyright...
This paper studies lifting schemes that are adaptive with respect to the gradient vector of the input signal and require no overhead information for perfect reconstruction. The choice of the update filter is triggered by a binary decision criterion based on a weighted ℓ1-type seminorm of the gradient. Such an adaptive scheme has great potential for preserving the discontinuities in signals and images...
Wiener filtering is used to reduce the quantization error of the DCT transform coefficients. The process is applied in the transform domain with a sub-band decomposition structure. That is, the corresponding coefficients from each block are grouped together. To model the spectrum of the transform coefficients, two approaches are taken. The first one is to directly estimate the spectrum of the whole...
This paper presents a new version of the exact discrete Radon [1] transform denoted as Mojette transform. Whereas the Mojette transform backprojects a single bin into a grey value pixel at each iteration, the proposed version backprojects a bin onto an entire segment of binary pixels. Implementation of this discrete exact backprojector is presented and used for specific binary images of incomplete...
This paper proposes a new acoustic echo cancellation (AEC) system which combines a conventional AEC algorithm with the pitch analysis technique. Departing from the use of pitch prediction in speech coding, we use two signals, i.e. the estimated echo and the residual echo, to fulfill the pitch extraction in the AEC system. This system is suitable for the applications of digital networks where the nonlinearities...
This paper presents a novel technique for modeling and quantization of the phase information in low-rate harmonic+noise coding. In the proposed phase model, each frequency track is adjusted by a frequency deviation (FD) that reduces the error between measured and predicted phases. By exploiting the intraframe relationship of the FD's, the phase information is represented more efficiently when compared...
This paper investigates the performance of Maximum A Posteriori (MAP) Space-Time receivers for GSM (Global System for Mobile communications) radio interfaces in subway tunnel environments Results obtained with channel responses measured at the subway of Paris show that these receivers exhibit a much better performance than conventional Maximum Likelihood (ML) receivers.
The utilization of multiple DSP systems for parallel processing in computationally demanding applications is growing fast. The field of 2-D imaging and multidimensional signal processing is a good candidate for parallel processing due to the large amount of low level computations required. In this paper we present a 2-D parallel algorithm for the overlap-add digital block filter and a multiprocessor...
The normalized least mean square (NLMS) algorithm is known to result in a faster convergence than the least mean square (LMS) algorithm but at the expense of a larger steady-state error. A time-varying normalized mixed-norm LMS-least mean fourth (LMF) algorithm is presented in this work to preserve the fast convergence of the NLMS algorithm while resulting in a lower steady-state error. The simulation...
A hybrid equalizer using a linear combiner and a recurrent neural network is presented. It characterizes itself for being adaptive and presenting: 1) a worst case performance very close to the best of the substructures that composes it, being better that each one of them in critical situations; 2) a computational complexity that makes its implementation feasible; and, 3) a good performance in difficult...
Boolean regression models are useful tools for various applications in nonlinear filtering, nonlinear prediction, classification and clustering. We discuss here the socalled normalized maximum likelihood (NML) models for these classes of models. Examples of discrimination of cancer types by using the universal NML model for the Boolean regression models indicate its ability to select sets of feature...
In this paper, a new method for the estimation of the direction-of-arrival (DOA) and relative propagation delay in the context of multipath rays is described. The proposed algorithm processes the received signals at a uniform circular array and uses ESPRIT-like approach for the estimation of the relevant parameters. We show, in particular that in the context of circular arrays, this algorithm increases...
Exploiting experiences accumulated during MPEG-4 Structured Audio [1] [5] process of standardization and OCCAMM [2] European project related to multimedia content protection, this paper proposes a new approach to Intellectual Property Management and Protection (IPMP) of multimedia content streams.
In this paper we consider turbo-coded multi-user DS-CDMA communications. We first present a new scheme for Soft-Input Soft-Output multi-user detection. Our method provides the Maximum A Posteriori estimate for each user bit together with its fiability in the form of an extrinsic information. It is based on the stack algorithm over the tree diagram of the CDMA channel. The Soft-Input Soft-Output multi-user...
The present paper proposes a hybrid content-based image search and retrieval technique based on the use of the DC coefficient information and the Encoding Cost Map (ECM), extracted from compressed JPEG data. The proposed scheme combines color-based indexing of the DC DCT coefficient data with shape-based indexing of the ECM. The use of ECM along with the information carried in the DC DCT coefficients...
We address the problem of mitigating a dominant alien near-end crosstalker such as HDSL, SDSL or HPNA in DMT-based ADSL and VDSL receivers. Due to the different symbol rates of crosstalker and signal of interest, linear time-invariant filtering is not appropriate. Recently, Zeng et al. presented a method to tackle this problem [4]. In this paper, we present an alternative procedure, which, unlike...
Most of the current Second Order (SO) and Higher Order (HO) blind source separation (BSS) methods aim at blindly separating statistically independent sources, assumed zero-mean, stationary and ergodic. However in practical situations, such as in radiocommunications contexts, the sources are non stationary and very often cyclostationary. In a previous paper [4] the cumulant-based BSS problem for cyclostationary...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.