CPC H04B 7/0478 (2013.01) [H04B 7/024 (2013.01); H04B 7/0456 (2013.01); H04B 7/0634 (2013.01); H04B 7/0639 (2013.01); H04B 7/0641 (2013.01); H04B 7/0663 (2013.01); H04L 25/03904 (2013.01); H04L 25/03917 (2013.01); H04B 7/0469 (2013.01); H04B 2001/3855 (2013.01); H04B 2001/3861 (2013.01); H04W 88/02 (2013.01); H04W 88/08 (2013.01)] | 20 Claims |
1. A base station comprising:
an antenna system having a plurality of dual-polarized antennas, the plurality of dual-polarized antennas to include a first antenna array with a first polarization and a second antenna array with a second polarization;
a feedback information reception unit to receive feedback information from one or more wireless terminals;
a codebook conservation unit to store an extended codebook that defines a plurality of extended precoding matrices;
a sender unit communicatively coupled with the feedback information reception unit and the codebook conservation unit, the sender unit to:
select an extended precoding matrix from the extended codebook based at least in part on the feedback information, wherein: the extended precoding matrix is a combination of a first precoding matrix and a second precoding matrix; a difference of direction between a first element and a second element of the first precoding matrix is equal to m times 11.25°, where m is an integer; and the second precoding matrix corresponds to the first precoding matrix with a phase offset; and
perform a downlink data transmission via the antenna system based at least in part on the extended precoding matrix.
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