Applied Mechanics and Materials Vols. 543-547

Abstract: In order to solve the problems in the traditional remote sensing image based on spectral information, such as low classification accuracy, different object with the same spectral features or the same object with the different spectral features, and limited sample quantity and so on, a remote sensing image classification method based on the support vector machine (SVM) including with textural features is proposed. Using Langqi Island of Fuzhou as experimental area, preprocessing and principal component analysis were made to initialize TM images, and the spectral features and GLCM-based textural features of ground objects were extracted and analyzed respectively. Then, the extraction, training and testing of samples based on the two types of features were finished for training various SVM classifiers, which were used for classifying land use in the experimental area. Through the maximum likelihood method, the BP neural network and the support vector machine (SVM), a crossed classification and contrast experiment was made to two different types of samples based on the simple spectral features and the features combined with texture respectively. The experimental results showed that the SVM classification method including textural features can effectively improve the accuracy of land use classification, and therefore it can be promoted better.

Abstract: The Physical Control Format Indicator Channel (PCFICH) is one among the downlink physical control channel and it carries the number of OFDM symbols used by the PDCCH channel, denoted as Control Format Indicator (CFI).These control channels play a key role in the correct decoding of the payload information. The CFI is the first information received by the User and so is important for the system performance. In this paper, Research on the PCFICH in eNodeB, a simple implementation approach is proposed in the TMS320C64xDSP, The program has been applied to the development of LTE-TDD wireless integrated test instrument. The running results verify that the program is feasible and effective.

Abstract: To remove the noise and interference signals in the blind detection of FH signals from HF channel, this paper gives a FH signals extraction method based on the improved symmetric GLCM, by combining the time-frequency analysis with the threshold method of GLCM. Firstly, the paper defines the calculation of improved symmetric GLCM on the direction of frequency and time. Then, the noise threshold is estimated based on the noise probability in the improved GLCM of frequency and the FH signals from the improved GLCM of time can be extracted by using the noise threshold. Simulation results show that the method can extract integrated FH signals under low SNR without any prior information, and that the estimation of noise threshold is more accurate and stable. Furthermore the method is simple with a small amount of computation, which is easy to be applied in the engineering.

Abstract: In this paper, we consider a system where a secondary base station (SBS) with K antennas utilizes the licensed spectrum of a single primary user (PU) to send information to N secondary users (SUs). Each SU and PU is equipped with one antenna, respectively. The SBS selects only one antenna out of the K antennas by using maximum signal power to leak interference power ratio strategy (SLIR). Using asymptotic analysis, we first derive the average capacity of the best user scheme, with perfect channel state information from the SBS to the PU (interference CSI) available at the SBS. Due to limited cooperation between the SBS and the PU, perfect interference CSI is not always available at the SBS. Then, we characterize their capacity loss in the case that perfect interference CSI is not always available at the SBS.

Abstract: The MIMO technology, namely through many antenna clear signal transmission and the receive, in does not increase the extra band width under the premise, enhanced the channel capacity greatly. Understood the MIMO channel the characteristic, studies the channel modelling method, unified the FPGA parallel characteristic, the design has manufactured one kind based on XILINX FPGA the platform MIMO channel analog meter, through the massive test confirmation, and did with the theoretically simulation performance compares, has confirmed the accuracy.

Abstract: Virtual Private LAN Service (VPLS), as a new layer-2 Virtual Private Network (VPN) technology has attracted enormous interest in the filed during the last few years. Unlike traditional layer 2 VPN, which provides only point-to-point connectivity, VPLS is built for multi-point connectivity and has a broadcast capability like a common LAN.A series of RFCs and drafts related to VPLS have been proposed by IETF. To enable VPLS in a real network, signaling setup is the first step. In this paper, we first conduct some research on LDP-based signaling protocol and demonstrate how to set up control-plane communication in VPLS network. Then, based on the research, we implement the signaling protocol in an embedded router system. In combination with existing data plane software, VPLS is deployed in a real network and some experiments are conducted to test the validity of signaling protocol. All the test results show that the implementation of signaling protocol works quite well. With VPLS deploying more widely in the world, service providers and customers will benefit greatly from this technology.

Abstract: Vector hydrophone is composed of acoustic pressure sensor and particle velocity sensor, which can simultaneously measure acoustic pressure and orthogonal components of particle velocity. MUSIC (Multiple Signal Classification) algorithm is a high resolution spatial spectrum analysis method based on subspace decomposition. This paper introduces the operation principles of this algorithm in detail and investigates the application of MUSIC algorithm to the DOA estimation of acoustic sources by a vector-hydrophone ULA (Uniform Linear Array) output model. Simulation results indicate that the resolution capability of MUSIC algorithm under larger SNRs is excellent.

Abstract: With the development of stream processing technology, achieving load balance of resource accessing becomes one of key problems. However, the existing technologies are difficult to balance the system and maintain the data integrity requirements when large data stream arrive. In this paper, combined with the dynamic load balancing algorithm, we propose a load balancing algorithm of stream data based on correlation analysis (SDCA-LBA). The algorithm analyses correlation of stream data through the window feature statistics. On the basis of ensuring the load balancing of the stream data system, we consider the data correlation. The experiment results show that this method can effectively solve the problem of stream data load balancing, maintain the data integrity, and improve the system data processing capabilities.

Abstract: Various tone reproduction operators have been proposed to display high dynamic range images on low dynamic range (LDR) devices. Many recent computational photography techniques decompose an image into a piecewise smooth base layer, containing large scale variations in intensity, and a residual detail layer capturing the smaller scale details in the image. In these techniques, its important to control the scale of the extracted details and it is often needed to manipulate details in order to avoid the appearance of visual artifacts. In this paper, a new method is proposed to preserve details for high dynamic range images tone reproduction using multi-level image decomposition. We show that current base-detail decomposition techniques, based on the bilateral filter, are limited in their ability to extract detail at arbitrary scales. Thus, we achieve detail enhancement by applying the bilateral filter iteratively, and this process is called multi-level decomposition. By minimizing the proposed energy function, we can choose the proper decomposition level. Simulation results demonstrate that the proposed method can acquire better visual quality in detail enhancement while make the base smoothness.

Abstract: the performance of UAV (Unmanned Aircraft Vehicle) data link is restrained by wireless channel, in this paper, we analyzed theoretically the characteristics of wireless channels of UAV data link, studied the simulation channel models of flat fading and selective fading which are suitable for low-speed command and remote measuring information and high-speed sensor information respectively, which will be used for designing the system of UAV data link and enhance the performance of UAV data link system.