TRANSMITTING APPARATUS AND TRANSMITTING METHOD

摘要

A transmitting apparatus capable of preventing the error rate characteristic from degrading and of preventing the throughput from degrading due to repetition of retransmittals. In the apparatus, a mapping decision part (103) decides to perform a normal constellation mapping at a first transmission and decides to change the constellation mapping positions or change bit mapping of symbols in accordance with the number of times of retransmittal at a retransmittal. A data interchanging part (105) interchanges the transmitted data for each bit on a symbol-by-symbol basis such that the data are arranged in the bit mapping decided by the mapping decision part (103). A mapper part (106) maps the transmitted data, which are inputted from the data interchanging part (105), onto each symbol such that the data are arranged in the constellation mapping position decided by the mapping decision part (103).