Transmitter, receiver, mobile station and radio base station

Transmitter 10, the MAC layer, the MAC-PDU generator unit 11 for generating the MAC-PDU by multiplexing information elements is any of the control information and padding information with MAC-SDU received from the RLC layer is generated and and a MAC-PDU transmitter for transmitting MAC-PDU, MAC-PDU generator unit 13, to multiplex a plurality of information elements in the MAC-PDU, including the LI indicating the size of a plurality of information elements grant MAC header, the number of LI included in the MAC header is one less than the number of information elements multiplexed.