| abstract |
A method for transmitting a data stream from a User Equipment (201), the User Equipment comprising four antennas, by means of which one or two pairs of antennas are selected for transmission, the method comprising the steps of: - receiving ( S1), from a radio base station (101), a precoding codebook or information identifying the precoding codebook; - receiving (S1), from the radio base station (101), information identifying an entry of the precoding codebook to control transmissions from said four antennas, said codebook comprising a plurality of entries, said entries comprising different combinations of pairs of antennas of said four antennas, wherein a plurality of entries of said codebook is arranged to use only one pair of said antennas; - storing (S2) the information received; - precoding (S3) said data stream according to said input; and - transmitting (S3) the data stream precoded by said one or two pairs of antennas. |