Robust Codebook Design Based on Unitary Rotation of Grassmannian Codebook

Codebook design has been investigated extensively over the past few years for quantized precoding in Multiple-Input Multiple-Output (MIMO) communication system. Grassmannian line packing (GLP) codebook is widely used in industry and literature. Traditional GLP codebook can only show good performance in spatial uncorrelated channel. But the practical channel is with varied spatial characteristic. In order to design one codebook robustly adapted to arbitrary statistic channel, a novel codebook constructed through unitary rotation of Grassmannian Line Packing (GLP) codebook is proposed in this paper. The rotation enables some codewords belong to Discrete Fourier Transform (DFT) codebook, meanwhile keeps the GLP property unchanged locally. With the virtues of DFT codebook and GLP codebook, the proposed codebook can achieve good performance in both uncorrelated channel and correlated channel.