Patent ID: 8891677
Filing Date: 2014-11-18
Classification: H04L,H04W

Abstract:
1. A method comprising: obtaining a precoder used to retransmit one codeword responsive to a known precoding matrix P of rank r and modulation and coding scheme MCS assignments used in an original transmission, and a desired retransmission rank r′; and scaling power in said retransmission responsive to at least three of 1) index of an uplink (UL) precoder used in a previous transmission, 2) rank r of an uplink (UL) precoder used in a previous transmission, 3) MCS assignments in a previous retransmission, 4) the desired transmission rank r′ used in a UL retransmission 5) the number of retransmit antennas x used for the codeword to be retransmitted in a previous transmission, 6) the number of retransmit antennas x′ used for the retransmission, 7) precoder used for a UL retransmission, 8) UL precoders and channel information for previous transmissions, and 9) latest channel measurements, wherein the method includes one of: a) responsive to the index and rank r of the UL precoder, MCS assignments in the previous retransmission, and the rank r′ for UL retransmission, determining a parameter β used to perform the scaling power in the retransmission and scaling a retransmission power in each antenna of the x′ antennas used for the retransmission with a factor θ=βr′/r, b) responsive to the index and rank r of the UL precoder, MCS assignments in the previous retransmission, and the rank r′ for UL retransmission, determining a parameter β used to perform the scaling power in the retransmission and scaling a retransmission power in each antenna of the x′ antennas used for the retransmission with a factor min{θ c) responsive to the index and rank r of the UL precoder, MCS assignments in the previous retransmission, and the rank r′ for UL retransmission, determining a parameter β used to perform the scaling power in the retransmission and scaling a retransmission power in each antenna of the x′ antennas used for the retransmission with a factor θ and/or min{θ d) responsive to the number of retransmit antennas x used for the codeword to be retransmitted, index of precoder and MCS assignments in the previous retransmission, the number of transmit antennas x′ to be used for retransmission, determining a parameter β used to perform the scaling power in the retransmission and scaling a retransmission power in each antenna of the x′ antennas used for the retransmission with a factor θ and/or min{θ e) responsive to the number of retransmit antennas x used for the codeword to be retransmitted, MCS assignments in the previous retransmission, the number of transmit antennas x′ to be used for retransmission, determining a parameter β used to perform the scaling power in the retransmission and scaling a retransmission power in each antenna of the x′ antennas used for the retransmission with a factor θ and/or min{θ f) responsive to index of UL precoder, MCS assignments in the previous retransmission, and precoder for UL retransmission, determining a scaling factor θ and scaling a retransmission power in each antenna of the x′ antennas used for the retransmission with a factor θ and/or min{θ g) responsive to the UL precoders and channel information for all previous transmissions, latest channel measurement, and precoder for UL retransmission, determining a scaling factor θ and resource blocks used for retransmission and scaling a retransmission of the codeword of transport blocks (TBs) in assigned resource blocks with the power in each antenna of the x′ antennas used for the retransmission with the factor θ.