In order to perform appropriate reception quality control on each mobile
station in a multimedia broadcast/multicast service, a layered coding
section 101 encodes input data by dividing the input data into two layers
and obtains a first layer code string and a second layer code string. The
first layer code string is input to a CRC code addition section 102 and a
CRC code for an error inspection is added thereto at every predetermined
block. On the other hand, the second layer code string is input to a CRC
code addition section 103 and a CRC code for an error inspection is added
thereto at every predetermined block. The first layer code string and the
second layer code string with the CRC codes added are input to a layered
modulation section 104 and the layered modulation section 104 modulates a
plurality of code strings coded by being divided into a plurality of
layers in such away that error rates differ hierarchically among the
plurality of code strings and a radio section 105 sends the modulated
symbol.