Matched Filter Research Papers - Academia.edu (original) (raw)

An approach to watermarking digital signals using frequency modulation-'Chirp Coding'-is considered. The principles underlying this approach are based on the use of a matched filter to reconstruct a 'chirp stream'code... more

An approach to watermarking digital signals using frequency modulation-'Chirp Coding'-is considered. The principles underlying this approach are based on the use of a matched filter to reconstruct a 'chirp stream'code that is uniquely robust. The method is generic in the sense that it can, in principle, be used for a variety of different signal (the authentication of speech and biomedical signals, for example). Further, by generating a bit stream that is signal dependent, chirp coding provides a method of self-authentication, ...

This paper presents a unified framework, based on the generalized likelihood (GL), for the detection of targets and the estimation of their direction of arrival (DoA), when operating with modern radar systems that have general antenna... more

This paper presents a unified framework, based on the generalized likelihood (GL), for the detection of targets and the estimation of their direction of arrival (DoA), when operating with modern radar systems that have general antenna array configurations, which contain a mixture of high- and low-gain beams. Adaptive processing structures are presented to remove both side lobe and main lobe

Currently, a major difficulty for the widespread use of robots in assembly and material handling comes from the necessity of feeding accurately positioned workpieces to robots. ``Bin picking'' techniques help reduce this constraint. This... more

Currently, a major difficulty for the widespread use of robots in assembly and material handling comes from the necessity of feeding accurately positioned workpieces to robots. ``Bin picking'' techniques help reduce this constraint. This paper presents the application of matched filters for enabling robots with vision to acquire workpieces randomly stored in bins. This approach complements heuristic methods already reported. The concept of matched filter is an old one. Here, however, it is redefined to take into account robot end-effector features, in terms of geometry and mechanics. In particular, the proposed filters match local workpiece structures where the robot end-effector is likely to grasp successfully and hold workpieces. The local nature of the holdsites is very important as computation costs are shown to vary with the fifth power of structure size. In addition, the proposed filters tend to have a narrow angular bandwidth. An example, which features a parallel-jaw hand is developed in detail, using both statistical and Fourier models. Both approaches concur in requiring a very small number of filters (typically four), even if a good orientation accuracy is expected (two degrees). Success rates of about 90 percent in three or fewer attempts have been experimentally obtained on a system which includes a small minicomputer, a 128 × 128 pixel solidstate camera, a prototype Cartesian robot, and a ``universal'' parallel-jaw hand.

Nous traitons du problème de l'intégration longue pour la détection de cible mobile dans le contexte applicatif radar, à partir de données non-cohérentes et cohérentes en Doppler. Nous présentons les résultats de plusieurs techniques... more

Nous traitons du problème de l'intégration longue pour la détection de cible mobile dans le contexte applicatif radar, à partir de données non-cohérentes et cohérentes en Doppler. Nous présentons les résultats de plusieurs techniques d'intégration longue qui sont considérées comme des extensions de filtre adapté classique. Nous étendons également la transformée de Radon au cas Doppler. Nous avons mis en oeuvre et testé, en terme de performance, différentes classes d'algorithme d'intégration longue. Pour chaque méthode, nous donnons les avantages et les inconvénients de leur emploi dans le cadre applicatif radar.

PWM AC drives generate high differential mode motor voltages due to the reflected wave phenomenon. The common-mode voltage produced by a PWM inverter also has fast transitions that result in high peak currents to ground. For low power AC... more

PWM AC drives generate high differential mode motor voltages due to the reflected wave phenomenon. The common-mode voltage produced by a PWM inverter also has fast transitions that result in high peak currents to ground. For low power AC drives this can present several issues, such as pump-up of the DC bus and failure of the power module due to high instantaneous currents that are often undetected because of the typical sampling algorithm used. In this paper, existing drive output filter solutions are reviewed and a new filter design is presented, which has integrated differential-mode and common-mode impedance with damping matched to typical cable surge impedance. This eliminates reflections of both differential-mode and common-mode traveling waves, and also reduces peak cable charging currents. Experimental results are provided to demonstrate that the new filter has improved performance to reduce motor differential-mode and common-mode voltage, and drive output common-mode current, thus mitigating the issues specifically seen with low power AC drives. Complete design details for the filter and a particular implementation of the integrated differential-mode and common-mode reactor are also presented.

Applications of digital signal processing in telecommunications are considered, taking into account the characteristics of telecommunications systems, aspects of digital transmission, digital switching, digital signal processing in... more

Applications of digital signal processing in telecommunications are considered, taking into account the characteristics of telecommunications systems, aspects of digital transmission, digital switching, digital signal processing in pulse-code modulated transmission terminals, ...

In the modern age, High-resolution radar images can be achieved by employing SAR technique. It is well known that SAR can provide several times better image resolution than conventional radars. The exploration for efficient image... more

In the modern age, High-resolution radar images can be achieved by employing SAR technique. It is well known that SAR can provide several times better image resolution than conventional radars. The exploration for efficient image denoising methods still remains a valid challenge for researchers. Despite the difficulty of the recently proposed methods, mostly of the algorithms have not yet attained a pleasing level of applicability; each algorithm has its assumptions, advantages, and limitations. This paper presents a review of synthetic aperture radar. Behind a brief introduction in our work we are especially targeting the noise called backscattered noise in SAR terminology which causes the appearance of speckle Potential future work in the area of air flight navigation, mapping Weather Monitoring & during natural disaster like earth quake. The SAR having the capability, to make human visibility beyond optical vision, is also discussed.

—Matched and mismatched filters are considered important parts of a radar signal processing unit. In this paper, we present an approach to optimize the matched filters and mismatched filters in short range pulse radars. For radar, the... more

—Matched and mismatched filters are considered important parts of a radar signal processing unit. In this paper, we present an approach to optimize the matched filters and mismatched filters in short range pulse radars. For radar, the matched filter coefficients are the complex conjugates of transmitted code. We used binary phase codes as transmitted pulse. The disadvantage of binary phase codes is having high sidelobe levels in the output of correlation function. Thus, we decided to use optimization algorithms for finding binary phase codes with minimum peak sidelobe levels (MPS). After that, we succeeded in producing mismatched filter coefficients (Mis-co) for each code using floating point genetic algorithm (FGA) and we could generate and test the filter coefficients with maximum peak to sidelobe level ratio (PSR). For testing the filter, we plotted ambiguity function for each set of coefficients and tested the filter with Doppler shift.

In this paper, a system analysis of needs and possible application of DIRLS mismatched filter in portable surveillance radar PR-15 is presented. Transmitting pulses are binary phase intra-pulse modulated. Because of limited peak power,... more

In this paper, a system analysis of needs and possible application of DIRLS mismatched filter in portable surveillance radar PR-15 is presented. Transmitting pulses are binary phase intra-pulse modulated. Because of limited peak power, the usage of longer radar pulses is necessary in long distance mode of operation. Applied binary M sequences have insufficient good autocorrelation properties so a method of side-lobs suppression became needed. We designed and verified the signal processing unit for this kind of compressors on a digital radar signal synthesis and processing platform based on DDS and FPGA technology.

In radar signal detection, the problem is to automatically detect a target in a nonstationary noise and clutter background while maintaining a constant probability of false alarm. Classical detection using a matched filter receiver and a... more

In radar signal detection, the problem is to automatically detect a target in a nonstationary noise and clutter background while maintaining a constant probability of false alarm. Classical detection using a matched filter receiver and a fixed threshold is not applicable due to the nonstationary nature of the background noise. Therefore, adaptive threshold techniques are needed to maintain a constant false-alarm rate (CFAR). One approach to adaptive detection in nonstationary noise and clutter background is to compare the processed target signal to an adaptive threshold. In the cell-averaging CFAR processing, an estimate of the background noise from the leading and the lagging reference windows is used to set the adaptive threshold. A threshold multiplier (or scaling factor) is used to scale the threshold to achieve the desired probability of false alarm. In the first part of this report, we have proposed two modified cell-averaging detectors for multiple target situations. The firs...