Abstract: The method includes calculating by user equipment an SINR of each of precoding vectors in a precoding matrix; whether there is an SINR greater than a first threshold in the SINRs of the precoding vectors; selecting by the user equipment a precoding vector to which the SINR greater than the first predetermined threshold corresponds according to a predefined policy; and feeding back by the user equipment to a base station a PMI of the selected precoding vector and a quantified value of the corresponding SINR, or feeding back by the user equipment to a base station a PMI of the selected precoding vector, a quantified value of the corresponding SINR and a number of times of transformation to which the SINR corresponds, or feeding back by the user equipment to a base station only a number of times of transformation.

Abstract: This invention relates to a method, device, computer program and computer program product for determining a mapping for a sequence of information-carrying values, including determining K representations of a sequence of information-carrying values in K successive stages, respectively, wherein in a first stage, a first representation of said K representations is determined to be equal to said sequence of information-carrying values, wherein in subsequent stages, each representation is determined by performing a mapping operation on the representation determined in the preceding stage, and wherein said mapping operation is the same for each stage; calculating, in each stage, a parameter from a transformation of the representation determined in said stage; and determining for which stage of said K stages an extreme value of said parameter is calculated.