Complex-field coding for OFDM over fading wireless channels

  • Authors:
  • Zhengdao Wang;G. B. Giannakis

  • Affiliations:
  • Dept. of Electr. & Comput. Eng., Iowa State Univ., Ames, IA, USA;-

  • Venue:
  • IEEE Transactions on Information Theory
  • Year:
  • 2006

Quantified Score

Hi-index 754.84

Visualization

Abstract

Orthogonal frequency-division multiplexing (OFDM) converts a time-dispersive channel into parallel subchannels, and thus facilitates equalization and (de)coding. But when the channel has s close to or on the fast Fourier transform (FFT) grid, uncoded OFDM faces serious symbol recovery problems. As an alternative to various error-control coding techniques that have been proposed to ameliorate the problem, we perform complex-field coding (CFC) before the symbols are multiplexed. We quantify the maximum achievable diversity order for independent and identically distributed (i.i.d.) or correlated Rayleigh-fading channels, and also provide design rules for achieving the maximum diversity order. The maximum coding gain is given, and the encoder enabling the maximum coding gain is also found. Simulated performance comparisons of CFC-OFDM with existing block and convolutionally coded OFDM alternatives favor CFC-OFDM for the code rates used in a HiperLAN2 experiment.