A transmitter includes a mapping unit that maps first information data to a first layer and maps second information data a part of which is duplicative of and a part of which is different from the first information data to a second layer, a coding unit that generates transmission data by performing error detection coding and error correction coding on the first and second information data, and a transmitting unit that transmits the transmission data from the antennas corresponding to the respective layers. A receiver includes a reception processing unit that separates received data into layer data, a decoding unit that generates a soft-decision value for each of the layers, a combining unit that combines soft-decision values corresponding to information data mapped to the plurality of layers in duplicate, and a deciding unit that performs hard-decision on the layer data using a soft-decision value.