Mobile station and reception method

A communication method comprising:

• mapping first reference signals on a plural resource elements in a resource block;
• mapping second reference signals on a same one resource element in the resource block, the second reference signals having a polarity opposite to each other, and the first reference signals being associated with mobile stations of a first type and the second reference signals being associated with mobile stations of a second type;
• and
• transmitting the mapped first reference signals, and transmits the mapped second reference signals via a pair of antenna ports.

A communication method comprising:

• mapping first reference signals on a plural resource elements in a resource block;
• mapping second reference signals on a same one resource element in the resource block, one of the second reference signals being multiplied by −1, the first reference signals being associated with mobile stations of a first type and the second reference signals being associated with mobile stations of a second type;
• and
• transmitting the mapped first reference signals, and transmits the mapped second reference signals via a pair of antenna ports.