Patent ID: 8625712

Claim:
A transmission method using a codebook in a multiple-input multiple output system, comprising the steps of: mapping multiple codewords to multiple layers; mapping the multiple layers to multiple antennas based on a precoding matrix selected from a rank-3 codebook; and transmitting the codewords through paths formed by mapping the layers and the antennas, wherein the rank-3 codebook is designed based on: 1 2 ⁡ [ 1 0 0 1 0 0 0 1 0 0 0 1 ] 1 2 ⁡ [ 1 0 0 - 1 0 0 0 1 0 0 0 1 ] 1 2 ⁡ [ 1 0 0 0 1 0 0 0 1 1 0 0 ] 1 2 ⁡ [ 1 0 0 0 1 0 0 0 1 - 1 0 0 ] 1 2 ⁡ [ 0 1 0 0 0 1 1 0 0 1 0 0 ] 1 2 ⁡ [ 0 1 0 0 0 1 1 0 0 - 1 0 0 ] 1 2 ⁡ [ 0 1 0 1 0 0 1 0 0 0 0 1 ] 1 2 ⁡ [ 0 1 0 1 0 0 - 1 0 0 0 0 1 ] 1 2 ⁡ [ 1 0 0 0 1 0 1 0 0 0 0 1 ] 1 2 ⁡ [ 1 0 0 0 1 0 - 1 0 0 0 0 1 ] 1 2 ⁡ [ 0 1 0 1 0 0 0 0 1 1 0 0 ] 1 2 ⁡ [ 0 1 0 1 0 0 0 0 1 - 1 0 0 ] .