Communication system, base station apparatus, and terminal apparatus

A base station apparatus that receives channel state information from a plurality of terminal apparatuses, comprising:

• a control unit that chooses a channel information norm from among a plurality of candidates as a norm of channel state information that the base station apparatus requests each of the terminal apparatuses to conform to;
• a control information generation unit that generates control information containing information that designates the chosen channel information norm;
• and
• a wireless transmitting unit that transmits the control information to the terminal apparatus,
• wherein the channel information norm includes a norm according to which the terminal apparatus calculates channel state information while taking a perturbation vector into account and a norm according to which the terminal apparatus calculates channel state information without taking a perturbation vector into account.

A terminal apparatus that notifies a base station apparatus of channel state information, comprising:

• a wireless receiving unit that receives control information containing information that designates a channel information norm that is a norm of channel state information transmitted from the base station apparatus;
• a propagation channel estimation unit that estimates a channel between the terminal apparatus and the base station apparatus;
• a channel state information generation unit that generates channel state information between the terminal apparatus and the base station apparatus on a basis of the channel information norm designated by the control information and the estimated channel between the terminal apparatus and the base station apparatus;
• and
• a wireless transmitting unit that transmits the channel state information to the base station apparatus,
• wherein the channel information norm includes a norm according to which the channel state information generation unit calculates channel state information while taking a perturbation vector into account and a norm according to which the channel state information generation unit calculates channel state information without taking a perturbation vector into account.