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[Author] Xin CHENG(5hit)

1-5hit
  • Pipelining Gauss Seidel Method for Analysis of Discrete Time Cellular Neural Networks

    Naohiko SHIMIZU  Gui-Xin CHENG  Munemitsu IKEGAMI  Yoshinori NAKAMURA  Mamoru TANAKA  

     
    PAPER-Neural Networks

      Vol:
    E77-A No:8
      Page(s):
    1396-1403

    This paper describes a pipelining universal system of discrete time cellular neural networks (DTCNNs). The new relaxation-based algorithm which is called a Pipelining Gauss Seidel (PGS) method is used to solve the CNN state equations in pipelining. In the systolic system of N processor elements {PEi}, each PEi performs the convolusional computation (CC) of all cells and the preceding PEi-1 performs the CC of all cells taking precedence over it by the precedence interval number p. The expected maximum number of PE's for the speeding up is given by n/p where n means the number of cells. For its application, the encoding and decoding process of moving images is simulated.

  • Algorithm-Hardware Co-Design of Real-Time Edge Detection for Deep-Space Autonomous Optical Navigation

    Hao XIAO  Yanming FAN  Fen GE  Zhang ZHANG  Xin CHENG  

     
    PAPER

      Pubricized:
    2020/06/15
      Vol:
    E103-D No:10
      Page(s):
    2047-2058

    Optical navigation (OPNAV) is the use of the on-board imaging data to provide a direct measurement of the image coordinates of the target as navigation information. Among the optical observables in deep-space, the edge of the celestial body is an important feature that can be utilized for locating the planet centroid. However, traditional edge detection algorithms like Canny algorithm cannot be applied directly for OPNAV due to the noise edges caused by surface markings. Moreover, due to the constrained computation and energy capacity on-board, light-weight image-processing algorithms with less computational complexity are desirable for real-time processing. Thus, to fast and accurately extract the edge of the celestial body from high-resolution satellite imageries, this paper presents an algorithm-hardware co-design of real-time edge detection for OPNAV. First, a light-weight edge detection algorithm is proposed to efficiently detect the edge of the celestial body while suppressing the noise edges caused by surface markings. Then, we further present an FPGA implementation of the proposed algorithm with an optimized real-time performance and resource efficiency. Experimental results show that, compared with the traditional edge detection algorithms, our proposed one enables more accurate celestial body edge detection, while simplifying the hardware implementation.

  • Optimum ISI and ICI Cancellation Filter for OFDM Systems without CP

    Lan YANG  Shixin CHENG  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E90-B No:2
      Page(s):
    364-367

    In this letter, we consider an Orthogonal Frequency Division Multiplexing (OFDM) system without cyclic prefix (CP), i.e. with full spectral efficiency and present an optimum frequency-domain filtering scheme for mitigating inter-symbol interference (ISI) and inter-carrier interference (ICI). Simulation results show the signal to interference and noise ratio (SINR) improvement.

  • Interference Cancellation with DFE in Frequency Domain for OFDM Systems with Insufficient CP

    Lan YANG  Shixin CHENG  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E88-B No:12
      Page(s):
    4616-4624

    In OFDM systems, employing a cyclic prefix (CP) as the guard interval is a simple way to combat the inter-symbol interference (ISI) and the inter-carrier interference (ICI), however it reduces the transmission efficiency of the system, especially for some channels with a very long delay spread. In this paper, we consider the OFDM system with insufficient CP, much more efficient than conventional OFDM systems. First, we present the system mathematical model and give the ISI and ICI analysis. Then the signal-to-interference power ratio (SIR) performance is presented. To reduce the ISI and ICI due to the insufficient CP, we develop a minimum-mean-square-error decision feedback equalizer (MMSE_DFE). Based on the MMSE criterion, the optimum feedforward and feedback filter coefficients are derived. For time-varying channel, to avoid brute force matrix inversion in conventional schemes, we propose an adaptive LMS based solution to update the filtering coefficients by tracing the channel variation. Since the high complexity of MMSE_DFE, a reduced complexity scheme, ordered successive partial interference cancellation DFE (OSPIC_DFE), is developed. From the performance comparison between the MMSE_DFE and the OSPIC_DFE, we see that the latter is very near to the former. Finally the simulation shows these proposed methods are highly effective in combating ISI and ICI with low complexity.

  • Method of 3 D Model Reconstruction from Multi-Views Line Drawings

    Xingxin CHENG  Shinji OZAWA  

     
    PAPER-Image Processing, Computer Graphics and Pattern Recognition

      Vol:
    E73-E No:6
      Page(s):
    995-1003

    In order to reconstruct the 3 D geometric model of a real object from multi-view line drawings some restrictions in a symmetric space of the original 3 D space have been set up. Based on these restriction a new algorithm of 3 D geometric model reconstruction is proposed. This method can work effectively under the more natural condition than other methods, and it is suitable for the situation of auxiliary views as well as the situation of perspective projection. Some practical computational results have been made which show that this algorithm is effective.