Mobile station, base station, and communication control method

A base station configured to perform radio communication using spatial multiplexing with a mobile station, the base station comprising:

• a transmitter configured to transmit a reference signal to the mobile station;
• and
• a receiver configured to receive spatial coding information and identification information from the mobile station that received the reference signal, the spatial coding information corresponding to the number of spatial layers, and the identification information identifying a spatial layer with highest reception quality belonging to selected data unit by the mobile station, and a layer indicator to determine a precoding matrix, wherein
• the base station determines the precoding matrix by receiving not the precoding matrix itself but only the layer indicator.

A communication system comprising:

• a mobile station;
• and
• a base station configured to perform radio communication using spatial multiplexing with a mobile station, wherein
• the mobile station includes:
• a controller configured to select a data unit with highest channel quality, and to select a spatial layer with highest reception quality belonging to the selected data unit;
• and
• a transmitter configured to transmit spatial coding information and identification information to the base station, the spatial coding information corresponding to the number of spatial layers, and the identification information identifying the spatial layer selected, and a layer indicator to determine a precoding matrix,
• the base station includes:
• a receiver configured to receive the spatial coding information and the identification information, wherein
• the base station determines the precoding matrix by receiving not the precoding matrix itself but only the layer indicator.