Base station apparatus, terminal apparatus, wireless communication system and integrated circuit
A base station apparatus is capable of adjusting antenna gains in a horizontal direction and a vertical direction of the plurality of antennas included in the base station apparatus, by adjusting a phase and an amplitude of a signal addressed and transmitted to a terminal apparatus, stores a codebook which is shared with the terminal apparatus and describes a plurality of linear filters associated with antenna gains in the horizontal direction and antenna gains in the vertical direction, acquires control information indicating at least one out of a plurality of linear filters described in the codebook, of which notification is sent from the terminal apparatus, performs precoding on the signal addressed to the terminal apparatus, based on the control information and the first codebook, and transmits the signal subjected to the precoding.
1. A terminal apparatus that communicates with a base station apparatus including a plurality of antenna ports, the terminal apparatus comprising:
wireless reception circuitry that receives a channel state information reference signal (CSI-RS) from the base station apparatus; and
wireless transmission circuitry that transmits feedback information to the base station apparatus; wherein
the feedback information is information associated with a codebook which including a plurality of first vectors corresponding a first dimension of the plurality of antenna ports and a plurality of second vectors corresponding to a second dimension of the plurality of antenna ports,
the feedback information includes information associated with a transmission rank, and
the feedback information is generated based on a linear filter corresponding to the transmission rank.
2. The terminal apparatus according to the claim 1 , wherein
the codebook includes a first setting,
the first setting indicates that a number of the plurality of first vectors each corresponding to the first dimension of the plurality of antenna ports is equal to a number of the plurality of second vectors each corresponding to the second dimension of the plurality of antenna ports,
the first setting indicates that the plurality of first vectors corresponding to the first dimension of the plurality of antenna ports has a same norm as that of the plurality of second vectors corresponding to the second dimension of the plurality of antenna ports,
the codebook includes a second setting, and
the second setting indicates that a number of the plurality of first vectors each corresponding to the first dimension of the plurality of antenna ports is different from a number of the plurality of second vectors each corresponding to the second dimension of the plurality of antenna ports.
3. A method of operating a terminal apparatus to communicate with a base station apparatus including a plurality of antenna ports, the method comprising:
receiving a channel state information reference signal (CSI-RS) from the base station apparatus; and
transmitting feedback information to the base station apparatus; wherein
the feedback information is information associated with a codebook which includes a plurality of first vectors corresponding a first dimension of the plurality of antenna ports and a plurality of second vectors corresponding to a second dimension of the plurality of antenna ports; and
the feedback information includes information associated with a transmission rank, and
the feedback information is generated based on a linear filter corresponding to the transmission rank.