| 摘要 |
When transmission of a downlink signal is to be performed in sub-frame 5, at this point, no feedback of reception quality information and transmit signal pre-coding information in mode 2, which would be covered by transmit signal pre-coder confirmation, has been performed. Therefore, information on the pre-coding that has been applied to all assigned resources is transmitted by being added to a downlink control signal (353). In sub-frame 9, a downlink signal is transmitted, and transmit signal pre-coder confirmation is added thereto. With respect to this case, the mobile station apparatus determines that the downlink signal has been pre-coded using the transmit signal pre-coding information transmitted in sub-frame 8, and demodulates the received signal with it. Sub-frame 12 represents a case where downlink data is transmitted by assigning sub-band 7. In so doing, it is preferable that the base station apparatus use the reception quality information and transmit signal pre-coding information for sub-band 7 reported in sub-frame 10. Accordingly, the base station apparatus transmits to the mobile station apparatus the transmit signal pre-coding information obtained in sub-frame 10 by explicitly including it in downlink control information (358). Thus, in cases where there exist a plurality of modes for transmitting transmit signal pre-coding information, it is possible to solve the problem where information whose priority should be high is readily overwritten by information of low priority. |
