Advanced Materials Research Vols. 605-607

Abstract: In order to meet the demand for higher capacity transmission over optical fiber communication, we propose a new LDPC coded modulation scheme. Using spectrally-efficient modulation format and LDPC codes, the proposed scheme offers an advanced forward error correction (FEC) solution. From the simulation results, we can get the SNR at the bit error rate (BER) of 10-7 as 3.8dB, 5.5dB, and6.9dB when 16-, 32-, and 64-points constellations are used, respectively.

Abstract: Radio beacon is required for dynamic self-test of vessel carrier's radio measuring and controlling equipment. Also it is required to process angle-adjusting of the equipment. The paper proposes a kind of method to design beacon based on quadrature frequency-conversion technology. The parameters of the beacon can been set flexibly through MCU control. Sidebands and local oscillator’s leakage are suppressed in circuit implementation. The beacon works reliable and its performance meets requirements. Real application shows fair result. The beacon supports technically naval adjustment of vessel carrier's radio measuring and controlling equipments.

Abstract: Due to the characteristics of the large amount of data and the high rate of transmission in the system of remote image acquisition, introduces a remote image storage memory based on the LVDS. The FPGA design as the core, and adopting the LVDS interface solution string and the drive chip combined, ensure the effective of receiving remote data. Meanwhile the system adopted the flash programming technology of alternative two-plane to storage the image data. It realized the speed of 28.95 MB/s high-speed real-time image data storage requirements in system. The application shows that the data memory stable and reliable, meets the practical requirements

Abstract: The spectral degree of polarization is studied based on the cross-spectral density matrix of an elliptically polarized laser beam propagating in the slant path through turbulent atmosphere. In addition, the effects of the turbulence on the spectral degree of polarization of an elliptically polarized Gaussian Schell-model beam and a partially polarized laser beam are contrasted and analyzed. And the different elliptically polarized laser beams are investigated.

Abstract: This paper deals with suitable frequency range for wireless communication between sensor in the sewer and the ground receiver. Soil（Relatively dry soils, partially saturated cohesionless soils and saturated cohesionless soils）, the materials (HDPE and cement)of sewer and the roughness of the wall of sewer are analyzed to obtain the appropriate frequency range is 400-500MHz. Taking into account these above factors, the conclusions as follows (1) In soil, the higher the frequency, the greater the attenuation of the signal. (2)In sewer: in the near region, the higher the frequency, the greater the attenuation of the signal.However, in the far region, the lower the frequency, the greater the attenuation of the signal. Furthermore, the greater the roughness of the wall of sewer, the greater influence on 150MHz and 1800MHz, and the less compared to 450MHz and 900MHz. With the increase of the of sewer size, the influence of roughness decreases markedly.

Abstract: The design of the solar LED street lamps based on MCU , which combines the MPPT of solar cells with PWM improves the reliability of the operating system of solar LED street lamps and extend the lifespan of the lead-acid battery , It adopt a controlling method for battery discharging process according to SOC of battery and the signal output of different PWM at different stages only to make the intelligent development of the solar LED street lamps uniquely advantageous and enjoy the better prospects of wider application.

Abstract: For the problem of automobile exhaust emission pollution is more and more serious, according to the basic principle of non-dispersive infrared method(NDIR), we design a new kind of automobile exhaust wireless monitoring system with the existing GPRS/GSM/GPS technology. This system uses the three-layer structure of car-terminal, wireless network and PC monitoring center. We introduce and research the key technologies and methods of realizing the system. This system has the advantages of convenience and quick, good real-time, easy to manage and etc.

Abstract: Azimuth-sign is a benchmark facility for the TT&C ship’s equipment during the dock calibration. Because the current way of measuring is tedious, the azimuth-sign does not suit for the changing environment. To ensure the accuracy of the measurement, we must increase efficiency and improve automation calibration level. The paper introduces a system of wireless autonomous positioning system. Through analyzing the principle, we give the design scheme of the system. The paper introduces briefly the hardware and software of the system. The test of the system shows that the design is reasonable and the precision of positioning meets the requirement.

Abstract: A light emitting diode (LED) light guide bar based on concave V-grooves is investigated by using optical simulation software to control the distribution of illumination angle. The structure parameters of V-groove and the distribution of micro-prism are considered. It is found that the illumination angle of LED light guide bar is most concentrated within ±35 degrees.

Abstract: In this paper, a method of correction for the trapezoid distortion of the single fingerprint acquisition system is proposed, which combines nearly telecentric optical path and the inclined plane compensation. According to the method presented, an actual fingerprint acquisition system is designed. There is a prism and two lenses in the system. The resolution of fingerprint acquisition can reach 500dpi. Its optical length is in 45mm, the maximum grid distortion is 0.43%. These meet the standard of the FBI fingerprint scanning system.