QAM Codebooks for Low-Complexity Limited Feedback MIMO Beamforming

— This paper proposes a new QAM based codebook for beamforming in multiple-input multiple-output (MIMO) wireless systems with a limited-rate feedback channel. We show that such codebooks perform arbitrarily close to the perfect feedback case as the constellation size increases, and that full diversity order is achieved. We demonstrate a duality of the beamforming codebook search problem with that of noncoherent sequence detection. Based on this we propose a fast beamforming vector search algorithm. Monte-Carlo simulations are presented to show that the performance is comparable to the best known codebooks, and that the search complexity can be reduced by several orders of magnitude.

• Type: Conference
• Year: 2007
• Where: ICC
• Authors: Daniel J. Ryan, I. Vaughan, L. Clarkson, Iain B. Collings, Dongning Guo, Michael L. Honig
• Keywords: Beamforming, Beamforming Vector Search, Codebook, Communications, ICC 2007