Terminal, base station, and communication method

A base station, comprising:

• transmission circuitry, which in operation, transmits information indicating a plurality of ports for a reference signal for a downlink data signal;
• and
• control circuitry, which, in operation, controls transmission of the downlink data signal and the reference signal, with the number of ranks which is less than the number of the plurality of ports indicated by the information.

A communication method, comprising:

• receiving, by a terminal, information indicating a plurality of ports for a reference signal for a downlink data signal;
• and
• controlling, by the terminal, reception of the downlink data signal and the reference signal, based on the number of ranks which is less than the number of the plurality of ports indicated by the information.

A communication method, comprising:

• transmitting, by a base station, information indicating a plurality of ports for a reference signal for a downlink data signal;
• and
• controlling, by the base station, transmission of the downlink data signal and the reference signal, with the number of ranks which is less than the number of the plurality of ports indicated by the information.