Radio transmission device and radio transmission method
View Patent ↗Data streams stored in buffers ( 101 ) are modulated by modulation sections ( 102 ). Multipliers ( 103 ) multiply the signals output from the modulation sections ( 102 ) by weights output from a weight control section ( 112 ). The signals output from the multipliers ( 103 ) are added up by addition sections ( 104 ), subjected to radio transmission processing by transmission radio sections ( 105 ) and sent through antennas ( 106 ). A buffer control section ( 111 ) controls the buffers ( 101 ) based on a retransmission count output from a retransmission count detection section ( 110 ). The weight control section ( 112 ) outputs weights different from weights at the time of previous transmission to the multipliers ( 103 ) 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.
1. A radio transmission apparatus comprising:
a plurality of antennas;
a weighting section operable to weight a plurality of data streams with a first set of weight vectors in a first transmission and to weight the plurality of data streams with a second set of weight vectors in a second transmission, the second set being different from the first set; and
a transmission section operable to transmit the plurality of data streams weighted with the first set of weight vectors from the plurality of antennas in the first transmission and to transmit the plurality of data streams weighted with the second set of weight vectors from the plurality of antennas in the second transmission;
wherein the weight vectors of the second set of weight vectors comprise the weight vectors of the first set of weight vectors, and wherein, in the second set of weight vectors, each of the weight vectors of the first set of weight vectors is switched in position relative to its position in the first set of weight vectors.
2. A radio transmission method comprising:
weighting a plurality of data streams with a first set of weight vectors;
transmitting in a first transmission the plurality of data streams weighted with the first set of weight vectors from a plurality of antennas;
switching each of the weight vectors of the first set of weight vectors with respect to its position in the first set of weight vectors to produce a second set of weight vectors which is different from the first set of weight vectors;
weighting the plurality of data streams with the second set of weight vectors; and
transmitting in a second transmission the plurality of data streams weighted with the second set of weight vectors from the plurality of antennas.
3. A base station apparatus equipped with said radio transmission apparatus according to claim 1 .
4. A mobile station apparatus equipped with said radio transmission apparatus according to claim 1 .