Radio transmission apparatus and radio transmission method

摘要

Data streams stored in buffers are modulated by modulation sections. Multipliers multiply the signals output from the modulation sections by weights output from a weight control section. The signals output from the multipliers are added up by addition sections, subjected to radio transmission processing by transmission radio sections and sent through antennas. A buffer control section controls the buffers based on a retransmission count output from a retransmission count detection section. The weight control section outputs weights different from weights at the time of previous transmission to the multipliers every time data is retransmitted. This allows a diversity gain at the time of data retransmission to be increased even if a time variation of the propagation path environment for radio signals is slow.

主权项

1. A transmission apparatus comprising:
a multiplier which, in operation, multiplies a plurality of streams by a plurality of weights; a transmitter which, in operation, transmits the plurality of streams multiplied with the plurality of weights using a plurality of antennas; a receiver which, in operation, receives feedback information including acknowledgment/negative acknowledgment (ACK/NACK) information and channel quality information (CQI) which are transmitted from a reception apparatus; and a weight controller which, in operation, selects a plurality of weights for a re-transmission, in case the NACK information is received, wherein the plurality of weights to be multiplied with the plurality of streams, respectively, are rearranged between an initial transmission and the re-transmission based on the received CQI, wherein correspondence relationships between the plurality of streams and the plurality of weights for the re-transmission are derived from the feedback information for the initial transmission.