3,180 research outputs found
Cdma blind channel equalization: a weighted subsface a proach
This paper considers the problem of blind demodulation of multiuser information symbols in a direct-sequence code-division multiple access (DS-CDMA) environment. Channel estimation and symbol detection in the presence of both multiple access interference (MAI) and intersymbol interference (ISI) is carried out with second order statistics methods from the received data. This problem is similar to direction of arrival (DOA) estimation, where many solutions like the MUSIC algorithm orPeer ReviewedPostprint (published version
Blind channel equalization using weighted subspace methods
This paper addresses the problems of blind channel estimation and symbol detection with second order statistics methods from the received data. It can be shown that this problem is similar to direction of arrival (DOA) estimation, where many solutions like the MUSIC algorithm orPeer ReviewedPostprint (published version
Symbol decoding based on signal subspace decomposition in msk
The availability of fast processors with architectures tailored to meet the computational demand of digital signal processing algorithms is widely applied to demodulation and decodification of CPM signals in some scenes: Mobiles, AWGN channels,… In this application the number of floating point operations executed by each processed symbol is a critical parameter to be designed, this is to be minimized. In this paper a method that reduces significantly the number of operations (until 80%) by symbol for CPM signals is presented. The decodification stage is performed from the rank reduced signal subspace obtained by means of an orthogonal decomposition of the signal [1].Peer ReviewedPostprint (published version
Kinect as an access device for people with cerebral palsy: A preliminary study
Cerebral palsy (CP) describes a group of disorders affecting the development of movement and posture, causingactivity limitation. Access to technology can alleviate some of these limitations. Many studies have used vision- based movement capture systems to overcome problems related to discomfort and fear of wearing devices. Incontrast, there has been no research assessing the behavior of vision-based movement capture systems in peoplewith involuntary movements. In this paper, we look at the potential of the Kinect sensor as an assistive technologyfor people with cerebral palsy. We developed a serious game, called KiSens NĂşmeros, to study the behavior ofKinect in this context and eighteen subjects with cerebral palsy used it to complete a set of sessions. The resultsof the experiments show that Kinect filters some of peoples involuntary movements, confirming the potential ofKinect as an assistive technology for people with motor disabilities
PWM Control of a Buck Converter with an Amorphous Core Coil
Pulse-width modulation is widely used to control electronic converters. One of the most topologies used for high DC voltage/low DC voltage conversion is the Buck converter. It is obtained as a second order system with a LC filter between the switching subsystem and the load. The use of a coil with an amorphous magnetic material core instead of air core lets design converters with smaller size. If high switching frequencies are used for obtaining high quality voltage output, the value of the auto inductance L is reduced throughout the time. Then, robust controllers are needed if the accuracy of the converter response must not be affected by auto inductance and load variations. This paper presents a robust controller for a Buck converter based on a state space feedback control system combined with an additional virtual space variable which minimizes the effects of the inductance and load variations when a not-toohigh switching frequency is applied. The system exhibits a null steady-state average error response for the entire range of parameter variations. Simulation results are presented
Emotions Detection based on a Single-electrode EEG Device
The study of emotions using multiple channels of EEG represents a widespread practice in the field of research
related to brain computer interfaces (Brain Computer Interfaces). To date, few studies have been reported in
the literature with a reduced number of channels, which when used in the detection of emotions present results
that are less accurate than the rest. To detect emotions using an EEG channel and the data obtained is useful
for classifying emotions with an accuracy comparable to studies in which there is a high number of channels,
is of particular interest in this research framework. This article uses the Neurosky Maindwave device; which
has a single electrode to acquire the EEG signal, Matlab software and IBM SPSS Modeler; which process
and classify the signals respectively. The accuracy obtained in the detection of emotions in relation to the
economic resources of the hardware dedicated to the acquisition of EEG signal is remarkable
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