Applied Mechanics and Materials Vols. 556-562

Abstract: Multi-phase Interpolation Filters are used widely in wireless communication. Based on the requirements of a high data rate satellite modem, this paper analyses the basic design principle of a multi-phase interpolation filter. A new design scheme of multi-phase interpolation filter is presented and implemented with VHDL TOP-DOWN method on FPGA. Finally, part simulation and application test results are given.

Abstract: Spectrum sensing is a fundamental problem for cognitive radio system as it allows secondary user (SU) to find spectrum holes for opportunistic reuse. This paper presents a new spectrum sensing method based on the data stacking technique (temporal smoothing technique) and power method. The “maximum eigenvector” is used to detect the spectrum holes. Compared with the previous works, the proposed approach can provide better performance, such as higher detection probability in the lower signal-to-noise-ratio (SNR) scenario, etc.

Abstract: The principles and methods of their combined mode SINS/celestial navigation, and applying the theory of error state Kalman filter integrated navigation systems were analyzed. Derivation of a new measurement equation, written Kalman filtering process filter analysis was carried out to prove that the model has a good combination of inertial devices drift suppression effect.

Abstract: In this paper, we investigate the outage performance of a multiuser two-way relaying system over Nakagami-m fading channels. In particular, we consider the amplify-and-forward (AF) relay system with beamforming at the base station. Furthermore, the base station and mobile users have asymmetric traffic requirements. We fist derive a tight lower bound for the outage probability (OP). Moreover, the asymptotic outage probability expression is derived to shed light on the system's diversity order. Finally, Monte Carlo simulations are conducted to verify the analytical results.

Abstract: Due to the rapid development of wireless communication technology and the increasing demand for wireless communication, spectrum resources are increasingly scarce. Cooperative spectrum sensing technology has effectively improve the spectrum efficiency, in order to avoid secondary users (cognitive user) causing interference to the primary user (authorized user), this paper proposes a new cooperative spectrum sensing algorithm, When an primary user occurs, the algorithm for different secondary users assign different contribution value, authorized users can quickly detected. The end of each round, the node number of low contribution value, the fusion center will not use its test results. Simulation results show that the false alarm probability and detection probability are better than generally cooperative spectrum sensing algorithms to verify the feasibility of the proposed algorithm.

Abstract: In the three-dimensional (3-D) Laguerre-based finite-difference time-domain method, each electric field variable has the relationship with the adjacent twelve electric fields. This results in the tedious modification of field components adjacent to the total-field/scatter-field boundary in analyzing scattering problems. In addition, the plane wave excitation requires much time in evaluating the expansion coefficient of incident field which involves integral of the weighted Laguerre polynomials with respect to time. In this letter, the plane wave is introduced by defining a set of equivalent currents on a closed Huygen's surface and a computationally efficient one-dimensional auxiliary propagator is presented to speed up the plane wave excitation. Numerical results indicated that the proposed method is valid.

Abstract: The paper carries research on the accurate modeling issue for the disabled athletes’ three-dimensional visual gaits. The three-dimensional visual gaits are important gait features when the disabled athletes are walking which have some regularity. However the features present in a mess. The traditional three-dimensional visual gaits model based on visual images don’t consider the messy problems in the gait feature resulting in lower dimensional simulation fidelity. This paper proposes a three-dimensional visual gait modeling method using the human dynamics which can obtain the body features of the three-dimensional visual gaits by analyzing the periodic features of the gaits. The experimental results show that the model can quickly and accurately emulate the three-dimensional visual gaits for the disabled athletes with higher fidelity and lower errors.

Abstract: In this paper, a synchronization code based on hadamard matrix has been designed for MIMO-OFDM systems. A new timing synchronization scheme is introduced. Based on orthogonal properties of the new synchronization code, the transmitted signals by each transmit antenna can cancel most of the inter-channel interference. The synchronization estimator is designed to have matching filter function, the time offset of each different transmit antenna can be directly estimated without ICI which is an advantage over existing algorithms. In addition, the proposed synchronization code can be widely generated from other code, it can be generally applicable in MIMO-OFDM system. The performance of the proposed approach verify the effectiveness of combating ICI, and is analyzed with other methods to confirm that it has a considerable timing detection probability for MIMO systems.

Abstract: In order to obtain the reliable results on time series, the application of subsampling the distribution of diveriging statistics on it was analyzed in depth. First, the relating theories were summarized. Second, the theory model of subsampling for diverging statistics was disscussed. Finally, a case study on econometric application was carried out, and the statistics results showed that this method can be applied in the finance statistics effectively.

Abstract: The fluctuations observed in tokamaks, stellarators and linear machines were similar with turbulent plasma in fusion devices, which were stochastic system, and the application of statistics method on them is studied in depth. First, the relating theories were summarized; Second, the mathematical model of the multifractal process is analyzed; Finally, the simulation on multifractal analysis of plasma turbulence and financial time series is carried out, results show that this method can be applied in time series effectively.