• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.12
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• pp.20-25
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• 2008

Codebook-based opportunistic beamforming (COBF) technique provides a beam selection diversity to the conventional opportunistic beamforming. In this paper, we design the random matrix and codebook for the COBF technique based on a kappa-factor channel model. Applying the proposed design to the COBF, nearly optimal beams are generated. Therefore, the COBF shows an outstanding performance without regard to the channel correlation related to the kappa-factor.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.7
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• pp.1-5
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• 2009

Random beanforming exploits multiuser diversity gain in static channels. Since the gain is restricted by the user population, some extended works have been proposed. Among them, a codebook-based opportunistic beamforming technique forms multiple random beams with small pilots. The technique however has difficulty in designing beams flexibly by the channel statistics. In this paper, we propose a technique forming the multiple random beams by rotating codebooks. The proposed technique enables the flexible design of beams so that multiuser diversity and beam selection diversity are exploited simultaneously with small pilots robust to the channel statistics.