Apparatus and method for codebook search for multiple-input multiple-output (MIMO) system
AssigneeSamsung Electronics Co., Ltd.
InventorsFederico Penna, Hongbing Cheng, Jungwon Lee
Life of this patent
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Abstract
A method for selecting a precoder from a codebook for a channel matrix H and an apparatus. The method includes determining, by a processor, a reference precoder V for the channel H and a phase rotation for V; for all codewords W from a codebook, determining, by the processor, phase rotations for W and phase distances based on differences between phases of elements of V and W; and selecting, by the processor, the codeword W with a minimum phase distance, wherein H has a size of NR×NT, NR is a number of receive antennas, NT is a number of transmit antennas, V has a size of NT×L, and L is a number of data layers transmitted simultaneously.
Claims20
A method for selecting a precoder from a codebook to adapt a transmitted signal to a wireless channel, given a channel matrix H, comprising:
- determining, by a processor, a reference precoder V for the channel matrix H;
- determining, by a processor, a phase rotation for V;
- for each codeword W from a plurality of codewords in the codebook, determining, by the processor, phase rotations for W and phase distances between phases of each element of V and the corresponding element of W, and determining a sum of the phase distances for each W;
- and
- selecting, by the processor, the precoder as the codeword W with a minimum phase distance being the smallest sum of phase distances from among all of the determined sums of phase distances, wherein H has a size of NR×NT, NR is a number of receive antennas, NT is a number of transmit antennas, V has a size of NT×L, and L is a number of data layers transmitted simultaneously.
An apparatus, in a Multiple-In Multiple-Out (MIMO) system, to select a precoder from a codebook to adapt a transmitted signal to a wireless channel, comprising:
- a precoder processor configured to determine a precoder V for a channel matrix H;
- a first phase rotation processor configured to determine a phase rotation for V;
- a codeword reading processor configured to select codewords W from a codebook;
- a second phase rotation processor configured to determine phase rotations for W;
- a phase distance processor configured to determine, for each codeword of the codewords W, phase distances between phases of each element of V and the corresponding element of W, and to determine a sum of the phase distances for each W;
- and
- a codeword selector configured to select the precoder as a codeword from the codewords W, with a minimum phase distance being the smallest sum of phase distances from among all of the determined sums of phase distances.
Dependencies are inferred from the claim text.