Long acoustic multipath limits the applicability of MIMO OFDM channel estimation methods that require matrix inversion of size M T L, where M T is the number of transmit elements and L is the multipath spread measure...
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ISBN:
(纸本)9781424436767
Long acoustic multipath limits the applicability of MIMO OFDM channel estimation methods that require matrix inversion of size M T L, where M T is the number of transmit elements and L is the multipath spread measured in 1/B, the bandwidth inverse. To overcome this problem, sparse nature of the channel is exploited in an algorithm based on a compact signal representation that leads to two forms of adaptive implementation: one that requires matrix inversion but of a reduced size, and another that completely eliminates it. Channel estimation is coupled with phase tracking and prediction to enable decision-directed operation in the presence of non-uniform Doppler distortion, which in turn provides improved performance and reduced overhead. Performance is demonstrated on real data, recorded during a recent experiment in the coastal North Atlantic.
Over time DSP education has tracked the evolution and growth of its theoretical foundations, hardware and implementation resources, and engineering education context. First year DSP courses have often had dual objecti...
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ISBN:
(纸本)9781424436767
Over time DSP education has tracked the evolution and growth of its theoretical foundations, hardware and implementation resources, and engineering education context. First year DSP courses have often had dual objectives of both motivating students to consider EE through an interesting first course and laboratory experience and also satisfying some part of the major curriculum requirements. Recent trends in engineering education and curriculum reform may offer opportunities to include DSP content in the early curriculum in a more distributed manner rather than as a single course. Reformed EE programs may focus on multidisciplinary and integrated freshman experiences in terms of design projects or specific context themes. This paper explores how DSP course content might be integrated into first year experiences in this context and explores implications with respect to concept continuity and assessment.
A new approach to piecewise-polynomial approximation and recursive implementation structures for linear-phase Finite Impulse Response (FIR) filters have been recently proposed. In this paper, we describe hardware prot...
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In this paper we present a new design of a psychoacoustic model for audio coding following the model used in the standard MPEG-1 audio layer 3. This architecture is based on appropriate wavelet packet decomposition in...
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In this paper we present a new design of a psychoacoustic model for audio coding following the model used in the standard MPEG-1 audio layer 3. This architecture is based on appropriate wavelet packet decomposition instead of a short term Fourier transformation. Its important characteristic is to propose an analysis of the frequency bands that come closer to the critical bands of the ear. This study shows the best performance of the Gammachirp coder.
By solving a linear inverse problem under a sparsity constraint, one can successfully recover the coefficients, if there exists such a sparse approximation for the proposed class of signals. In this framework the dict...
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By solving a linear inverse problem under a sparsity constraint, one can successfully recover the coefficients, if there exists such a sparse approximation for the proposed class of signals. In this framework the dictionary can be adapted to a given set of signals using dictionary learning methods. The learned dictionary often does not have useful structures for a fast implementation, i.e. fast matrix-vector multiplication. This prevents such a dictionary being used for the real applications or large scale problems. The structure can be induced on the dictionary throughout the learning progress. Examples of such structures are shift-invariance and being multi-scale. These dictionaries can be efficiently implemented using a filter bank. In this paper a well-known structure, called compressibility, is adapted to be used in the dictionary learning problem. As a result, the complexity of the implementation of a compressible dictionary can be reduced by wisely choosing a generative model. By some simulations, it has been shown that the learned dictionary provides sparser approximations, while it does not increase the computational complexity of the algorithms, with respect to the pre-designed fast structured dictionaries.
This paper introduces an improved BCI system based on alpha rhythm, the main composition units of the system are electrodes, acquisition circuit, online detecting algorithm and outer devices. For improving the perform...
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The presented work develops a high-dynamic quaternion attitude estimation unscented Kalman filter suitable for the implementation in low cost sensor systems, comprising accelerometers, gyroscopes and magnetic field se...
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The presented work develops a high-dynamic quaternion attitude estimation unscented Kalman filter suitable for the implementation in low cost sensor systems, comprising accelerometers, gyroscopes and magnetic field sensors. The adoption of a spherical sigma-point selection strategy and the implementation of the square-root version reduces the requirements for computational resources. A special handling of angular rate, gyroscope bias, and translational accelerations within the process model is implemented and evaluated. Issues regarding the quaternion mean calculations, noise representation as well as control noise scaling are discussed. The performance of the designed filter is assessed using real hand motion reference data and correspondingly generated noisy sensor measurements.
The examples of periodic signals with variable period are provided, as one of the models of such signals the definition of periodic function with variable period is given. The system of orthogonal trigonometric functi...
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The examples of periodic signals with variable period are provided, as one of the models of such signals the definition of periodic function with variable period is given. The system of orthogonal trigonometric functions with variable period is constructed. It is believed that in the future the theory of periodic functions with variable period will be properly developed and the functions will be applied in the research tasks of transient modes of technical systems, in the problems of the patient's functional state assessment, in the evaluation of rehabilitation processes, in sport and space medicine.
signal space diversity (SSD) has been lately adopted into the second generation of the terrestrial digital video broadcasting standard DVB-T2. While spectrally efficient, SSD improves the performance of QAM constellat...
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signal space diversity (SSD) has been lately adopted into the second generation of the terrestrial digital video broadcasting standard DVB-T2. While spectrally efficient, SSD improves the performance of QAM constellations over fading channels thanks to an increased diversity. In this paper, flexible mapper and demapper architectures for DVB-T2 standard are detailed. A detection based on the decomposition of the constellation into two-dimensional sub-regions in signal space associated to an algorithmic simplification constitute the main novelty of this work. They enable to strongly decrease the complexity of the demapper. The design and the FPGA prototyping of the resultant architecture are then described. Low architecture complexity and measured performance demonstrate the efficiency of the detection method.
Image/video spatial resolution upconversion aims to obtain a high resolution output from the original low resolution input. Fast resolution upconversion is desired in many applications. In this paper, we develop a GPU...
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Image/video spatial resolution upconversion aims to obtain a high resolution output from the original low resolution input. Fast resolution upconversion is desired in many applications. In this paper, we develop a GPU-friendly two-pass directional image/video resolution upconversion algorithm and present a GPU implementation of the method, using the NVIDIA CUDA (Compute Unified Device Architecture) technology. design considerations to speed up the execution are discussed, by taking full advantage of the properties of the CUDA framework and the upconversion scheme. Experimental results show that using a mid-range GPU card, the GPU-optimized resolution upconversion implementation can be more than five times as fast as the original method.
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