WIRELESS COMMUNICATION SYSTEM, BASE STATION APPARATUS, MOBILE STATION APPARATUS AND WIRELESS COMMUNICATION METHOD

摘要

A mobile station apparatus (2) uses a downlink control channel (PDCCH) to receive downlink allocation information from a base station apparatus (step S10). Then, the mobile station apparatus (2) performs the demodulation, decoding and cyclic redundancy check (CRC) of a downlink shared channel (PDSCH) in accordance with the downlink allocation information (received in step S10) (step S11). Then, the mobile station apparatus (2) generates a positive response (ACK) and a negative response (NACK) in accordance with the result of the cyclic redundancy check (CRC) (of step S11) (step S12). Then, the mobile station apparatus (2) selects the smallest and second smallest ones of the numbers of control channel elements (CCE) for which the downlink allocation information was received (step S13). Then, the mobile station apparatus (2) determines, based on the selected numbers, a physical resource block (PRB), a cyclic shift in the time domain, and a quadrature code sequence for each of a plurality of transmission antennas, and then code-spreads the positive response (ACK), the negative response (NACK) and an uplink pilot channel (step S14). Then, the mobile station apparatus (2) places the code-spread positive response (ACK), negative response (NACK) and uplink pilot channel into the physical resource block (PRB) determined for each transmission antenna and then transmits the physical resource block (PRB) to the base station apparatus (step S15). In this way, a channel structure that is as similar to LTE as possible is used with the compatibility with LTE taken into consideration, and the mobile station apparatus transmits signals from the plurality of transmission antennas, whereby a transmission diversity gain can be obtained.