Advanced Materials Research Vols. 765-767

Abstract: Taking the nitrogen monitoring data of two sites S1 and S2 in the period 1988-2003 in Baihe River lying Miyun reservoir stream watershed as a case, Fourier and Wavelet analysis were adopted to explore and compare the periodic patterns and temporal pattern characteristics of the two sites. The results showed that the periodic patterns of two sites were discovered using Fourier analysis. The site S1 had a period of two years, while the site S2 had no significant periodic patterns. The temporal pattern characteristics at different scales were obtained through wavelet analysis, which were at small scale for the site S1, while at moderate and small scales for the site S2. The Fourier and wavelet analysis method can both be used in the study of surface water quality temporal change pattern, the first is a coarse method and the latter is a more detailed method for analyzing surface water quality temporal pattern characteristics.

Abstract: How to improve spectral efficiency is one of the hot research topics in communication technology. UNB (Ultra Narrow Band), as a kind of modulation method that can improve spectral efficiency, has been advancing in a lot of disputation. EBPSK (Extended-BPSK) has been developed as an UNB modulation format and MEBPSK (Multi-Extended-BPSK) is also used to enhance the spectral efficiency. The details of frequency domain characteristics of MEBPSK will be investigated in this article. First, base band pulse coding is given; then, PSD expression for MEBPSK is deduced, and computer simulations are conducted with different modulation parameters, which shows that the theoretical results and simulation results are consistent. Finally, the bandwidth occupation and bandwidth efficiency of MEBPSK are analyzed according to different bandwidth definitions, a comparison is made between MEBPSK and EBPSK under the same conditions and, by analysis and experiment, it is shown that bandwidth efficiency of MEBPSK can be log₂N times that of EBPSK according to-60dB definition, N is the integer power of 2, which obviously improves the data rates greatly under the same condition.

Abstract: Orthogonal Frequency Division Multiplexing (OFDM) is considered as an important technique for future wireless communications. In addition, OFDM has a better performance at inter symbol interference (ISI). One of the major disadvantages of the multi-carrier modulation is about the sensitivity of the performance to a frequency offset. In this paper, we propose an iterative algorithm of frequency offset estimation for the OFDM system. The fundamental algorithm of our iterative algorithm is the frequency pilot aided algorithm. When we get a result with the fundamental algorithm every time, we use the result to estimate for a second time. The algorithm we proposed does not require some additional pilots or changing the data structure of the fundamental algorithm.

Abstract: The auditory filter-bank is the key component of auditory model, and its implementation involves a lot of computations. The time spent by an auditory filter-bank to finish its work has a significant effect on the real-time implementation of auditory model-based audio signal processing systems. In this paper, we give a brief introduction to the auditory filter-bank at the first, and then discuss its DSP-based implementation and optimization in details.

Abstract: Mass terrain in four fork tree index structure Xia, draws Shi needs for effective of texture map, viewpoint of moved and texture retrieved Shi scene dynamic update directly effect to displayed efficiency, used macro points block match micro-texture map of method, effective to reduced has data of frequency refresh; introduced image entropy reflect image color distribution of space features, to improve original terrain texture, to out a more meet actual of terrain draws method; experimental indicates that in mass terrain texture map process in the, Increases the level of authenticity and real-time terrain rendering

Abstract: In this paper, the concepts and related conclusions of two-direction multiresolution analysis and two-direction refinable functions are introduced; two-direction wavelet with scale 2 is researched and is extended to orthonormal symmetric and antisymmetric two-direction wavelet with scale M and relevant properties are obtained. A condition that stable solution of two-direction refinable functions can create for MRA is given; finally construction of two-direction wavelet by two-direction compactly orthonormal refinable functions is discussed.

Abstract: Multiple inputs and multiple outputs (MIMO) relay cooperative transmission, as an efficient solution for high data rate and ubiquitous coverage, is a promising key technology for next generation wireless system. The performance of MIMO relay network is dependent on the signal processing approaches adopted by relay nodes. It is more complex when multiple users are active in MIMO relay network. Considering the minimum MSE problem, two sub-optimal algorithms are proposed based on the properties of relay filters. The simulation results the sub-optimal algorithms give similar results as optimal one.

Abstract: Based on slots consumption, the performance of video transmission in Bluetooth sensor networks was analyzed. On the premise that the maximum gross user payload data rate can satisfied the output bit rate of video source coding, the slots consumption using different packet types to transmit video stream in different SNR was analyzed, and the minimum slots consumption can be obtained by selecting the appropriate packet types to transmit video packets in different SNR, thus the Bluetooth link can vacate more slots for other business.

Abstract: This paper presents a multi-sensor image registration method by combination of relaxation optimization matching and Partitioning RANSAC. Firstly, the global coarse registration is performed to establish the approximate relationship of reference and slave image. Secondly, in each pyramid level, the normalized MI and relaxation optimization technique are adopted to get the matching points, and partitioning RANSAC is used to delete the existing false matches. The coarse-to-fine strategy is integrated to refine the results, and finally the rubber sheeting method is used to realize the image registration. Two datasets have been experimented, and it can be found that satisfactory registration method can be obtained.

Abstract: Rural water conservancy construction and new rural construction are the most fundamental conditions which insure the blossoming agriculture ,and the most basic measures of environmental protection .This research aims at exploring factors influencing the development of rural water conservancy in the cognitive perspective of rural environmental protection , primarily through surveying farmers from nine counties of Hubei, by collecting valid data samples and applying them on SPSS software. Through comparative and correlation analysis, we find out that different cognitions of rural water conservancy construction exists in farmers from different regions , which provides countermeasures for future rural water conservancy construction and environmental protection.