A new frequency offset estimation algorithm for orthogonal frequency division multiplexing (OFDM) systems was proposed by using a specially designed training symbol. Requiring only one training symbol, this algorithm ...
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A new frequency offset estimation algorithm for orthogonal frequency division multiplexing (OFDM) systems was proposed by using a specially designed training symbol. Requiring only one training symbol, this algorithm can efficiently estimate integer frequency offset and fraction frequency offset. The timing synchronization can also be obtained by using the proposed training symbol. Simulation results show that the proposed method not only reduces the number of the training symbols but also improves the accuracy of frequency offset estimation, while comparing with conventional algorithms.
We have performed low-temperature transport measurements on a GaAs two-dimensional electron system at low magnetic fields. Multiple temperature-independent points and accompanying oscillations are observed in the long...
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We have performed low-temperature transport measurements on a GaAs two-dimensional electron system at low magnetic fields. Multiple temperature-independent points and accompanying oscillations are observed in the longitudinal resistivity between the low-field insulator and the quantum Hall (QH) liquid. Our results support the existence of an intermediate regime, where the amplitudes of magneto-oscillations can be well described by conventional Shubnikov–de Haas theory, between the low-field insulator and QH liquid.
For multimedia applications, the routing algorithms should consider many Quality of Service (QoS) parameters. However, to find routes with two or more QoS parameters is an NP-hard problem. Therefore, recently many res...
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In this paper, a new transform‐domain based video watermarking scheme is proposed. The method embeds and detects watermarks in the DCT domain based on Singular Value Decomposition (SVD). Extensive experimental result...
In this paper, a new transform‐domain based video watermarking scheme is proposed. The method embeds and detects watermarks in the DCT domain based on Singular Value Decomposition (SVD). Extensive experimental results demonstrate that the proposed watermarking scheme is effective and robust against not only attacks such as frame dropping, frame averaging, and H.263 coding, but also attacks such as cropping, rotation, adding salt & pepper noise, sharpening and adding Gaussian noise.
In this paper, the mechanical construction, thermal regulator design and temperature measurement system of a local area were set up for large-scale linear measurement. Numerical analysis based on temperature correlate...
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In this paper, the mechanical construction, thermal regulator design and temperature measurement system of a local area were set up for large-scale linear measurement. Numerical analysis based on temperature correlated characteristic is discussed to obtain optimal observation points for the measurements. The horizontal temperature distribution of the measured area is compared with the measurement of the variation of temperature at 15℃ and 20℃ over time, and characteristic of dynamic response is also discussed. In addition, the long-time stability of measured temperature is analyzed by means of using the standard deviation. It characterizes the temperature distribution performance of a large area and how it may impact the measurement of a large-scale object.
In this paper, we consider the problem of DOA estimation using the improved polynomial rooting (IPR) method. When the IPR method is used in the cases that there are few sources with same frequency, the matrix composed...
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In this paper, we consider the problem of DOA estimation using the improved polynomial rooting (IPR) method. When the IPR method is used in the cases that there are few sources with same frequency, the matrix composed of noise eigenvectors is processed complexly. So we construct the matrix for computing the coefficient of polynomial with signal subspace. This method is effective in theory and computer simulation. It reduces the complexity of IPR method. Further more, its performance is better than MUSIC method.
annular beam tri-heterodyne confocal microscope has been proposed to improve the anti-environmental interference capability and the resolution of a eonfoeal microscope. It simultaneously detects far-, on-, and near-fo...
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annular beam tri-heterodyne confocal microscope has been proposed to improve the anti-environmental interference capability and the resolution of a eonfoeal microscope. It simultaneously detects far-, on-, and near-focus signals with given phase differences by dividing the measured light path of the eonfoeal microscope into three sub-paths （signals）. Pair-wise real-time heterodyne subtraction of the three signals is used to improve the anti-environmental interference capability, axial resolution, and linearity; and a shaped annular beam super-resolution technique is used to improve lateral resolution. Theoretical analyses and preliminary experiments indicate that an axial resolution of about 1 nm can be achieved with a shaped annular beam tri-heterodyne confoeal microscope and its lateral resolution can be better than 0.2 um for A = 632.8 nm, the numerical aperture of the lens of the microscope is NA = 0.85, and the normalized radius e = 0.5.
A method of object localization based on man height model is proposed. With the relationship between the project position of the head of object and the distance between object and camera, a man height model can be bui...
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In this research, we propose and develop a remote medical-care support system for supporting nurses, care managers and care helpers during their work. The proposed system has two functions: a multi-point communication...
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Vector controltechnology is regard as a kind of controlling manner of AC asynchronous motor, and it is already become the first method of the high-performance variable-frequency speed regulating system. Compared with...
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ISBN:
(纸本)142440813X
Vector controltechnology is regard as a kind of controlling manner of AC asynchronous motor, and it is already become the first method of the high-performance variable-frequency speed regulating system. Compared with SPWM, SVPWM (Space Vector Pulse Width Modulation) has been used widely because it has better performance. This paper introduced the basic principle of voltage SVPWM and vector control. A full-digital solution with TMS320LF2407 using simplified SVPWM control method is presented. Through the experiment of controlling to a practical motor, the resulted shows that this method is feasible, the controlling system has better dynamic and static performances and controlling effect, it would have a prospect widely used.
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