An Efficient Bit Loading for OFDM with Diversity Scheme over Mobile Channel

  • Tae Jin Hwang
  • Sang Soon Park
  • Ho Seon Hwang
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4217)


This paper discusses an adaptive modulation technique combined with space-frequency block coded OFDM(SFBC OFDM) over frequency selective channels and evaluates the performance in terms of the outdated channel state information(CSI) in mobile environments. This paper employs the Alamouti’s diversity scheme in multiple input multiple output OFDM (MIMO OFDM) and an adaptive modulation with enhanced performance. Adaptive modulation scheme shows very attractive performance when the CSI is perfect. The CSI for bit loading in MIMO OFDM can be obtained from the singular value decomposition(SVD) of MIMO channel. But, SFBC OFDM system based on Alamouti’s diversity scheme does not require the SVD process. Through various simulations, the performance of SFBC OFDM employing adaptive modulation is compared with that of fixed modulation. Also, in adaptive modulation scheme, the effects of the outdated CSI under mobile environments are shown


Orthogonal Frequency Division Multiplex Singular Value Decomposition Channel State Information Orthogonal Frequency Division Multiplex System MIMO Channel 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • Tae Jin Hwang
    • 1
  • Sang Soon Park
    • 1
  • Ho Seon Hwang
    • 1
  1. 1.Department of Electronic EngineeringChonbuk National UniversityJeonjuKorea

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