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[Keyword] handsets(3hit)

1-3hit
  • Numerical Analysis on MIMO Performance of the Modulated Scattering Antenna Array in Indoor Environment

    Lin WANG  Qiang CHEN  Qiaowei YUAN  Kunio SAWAYA  

     
    LETTER-Antennas and Propagation

      Vol:
    E94-B No:6
      Page(s):
    1752-1756

    The multiple-input multiple-output (MIMO) performance of the modulated scattering antenna array (MSAA) is analyzed numerically for the first time in indoor environment based on an approach to hybridization of the Volterra series method and method of moments (MoM) in this letter. Mutual coupling effect between the Modulated scattering element (MSE) and the normal antenna element is also considered in this analysis. It is found that MIMO performance of the MSAA is improved with reducing the array spacing of the MSAA in 4 different indoor receiving areas. At the same time, the simulated results of the MSAA are compared with those of the dipole antenna array at the same condition.

  • A Bio-Inspired Approach to Alarm Malware Attacks in Mobile Handsets

    Taejin AHN  Taejoon PARK  

     
    LETTER-Dependable Computing

      Vol:
    E92-D No:4
      Page(s):
    742-745

    With proliferation of smart handsets capable of mobile Internet, the severity of malware attacks targeting such handsets is rapidly increasing, thereby requiring effective countermeasure for them. However, existing signature-based solutions are not suitable for resource-poor handsets due to the excessive run-time overhead of matching against ever-increasing malware pattern database as well as the limitation of detecting well-known malware only. To overcome these drawbacks, we present a bio-inspired approach to discriminate malware (non-self) from normal programs (self) by replicating the processes of biological immune system. Our proposed approach achieves superior performance in terms of detecting 83.7% of new malware or their variants and scalable storage requirement that grows very slowly with inclusion of new malware, making it attractive for use with mobile handsets.

  • A Software Definable Architecture for Adaptive Space Diversity at Handsets in MC-CDMA Systems

    K. Robert LAI  Yuan-Lung CHANG  

     
    PAPER-Spread Spectrum Technologies and Applications

      Vol:
    E89-A No:5
      Page(s):
    1473-1483

    Software-Defined Radio (SDR) represents a major paradigm shift in the design of radios, allowing a large fraction of the functionality to be implemented through programmable signal processing devices, enabling the radio to change its operating parameters to accommodate new air interface, features and capabilities. However, the actual realization of innovative and software-reconfigurable receiver diversity at mobile handsets in intermediate frequency band to provide wide-ranging benefits, including more effective filtered result, less cost of the mixed channel access, improved capacity, better link reliability, and reduced power consumption, has been slowed down largely due to an absence of effective architecture reducing the complexity of adaptive combining algorithms. This paper proposes a novel reconfigurable architecture for adaptive space diversity at handsets in MC-CDMA (multicode code-division multiple-access) systems. The key to which is the development of a valid and effective alternative to the time-consuming multiplication operation and despreading acquisition. A software definable algorithm can become a multiplier-free architecture if it can restrict the weight factors to power-of-two values and repetitive gradient search procedure to contain shift operations and predicate functions. The results of numerical simulation and experimentation confirm the expectation that the constrained approach should perform comparably to, but not better than the traditional diversity algorithm. That is, the feasibility of SDR depends on its trading some performance for reduced computational complexity, improved area efficiency and less power consumption.