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[Author] Kotoku OMURA(2hit)

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  • Performance Improvement of Error-Resilient 3D DWT Video Transmission Using Invertible Codes

    Kotoku OMURA  Shoichiro YAMASAKI  Tomoko K. MATSUSHIMA  Hirokazu TANAKA  Miki HASEYAMA  

     
    PAPER-Video Coding

      Vol:
    E99-A No:12
      Page(s):
    2256-2265

    Many studies have applied the three-dimensional discrete wavelet transform (3D DWT) to video coding. It is known that corruptions of the lowest frequency sub-band (LL) coefficients of 3D DWT severely affect the visual quality of video. Recently, we proposed an error resilient 3D DWT video coding method (the conventional method) that employs dispersive grouping and an error concealment (EC). The EC scheme of our conventional method adopts a replacement technique of the lost LL coefficients. In this paper, we propose a new 3D DWT video transmission method in order to enhance error resilience. The proposed method adopts an error correction scheme using invertible codes to protect LL coefficients. We use half-rate Reed-Solomon (RS) codes as invertible codes. Additionally, to improve performance by using the effect of interleave, we adopt a new configuration scheme at the RS encoding stage. The evaluation by computer simulation compares the performance of the proposed method with that of other EC methods, and indicates the advantage of the proposed method.

  • Wireless Packet Communications Protected by Secret Sharing and Vector Coding

    Shoichiro YAMASAKI  Tomoko K. MATSUSHIMA  Shinichiro MIYAZAKI  Kotoku OMURA  Hirokazu TANAKA  

     
    PAPER-Communication Theory and Systems

      Vol:
    E100-A No:12
      Page(s):
    2680-2690

    Secret sharing is a method to protect information for security. The information is divided into n shares, and the information is reconstructed from any k shares but no knowledge of it is revealed from k-1 shares. Physical layer security is a method to yield a favorable receive condition to an authorized destination terminal in wireless communications based on multi-antenna transmission. In this study, we propose wireless packet communications protected by the secret sharing based on Reed Solomon coding and the physical layer security based on vector coding, which implements a single-antenna system and a multi-antenna system. Evaluation results show the validity of the proposed scheme.