Abstract: The disclosure relates to a method performed in a wireless device for establishing a feedback metric. The wireless device is configured with a grouping of available precoding matrix indicators, PMIs, of a codebook, the grouping comprising two or more groups each of which comprises an exclusive subset of the available precoding matrix indicators, PMIs. The method comprises: identifying for one or more rank indicator, RI, hypotheses a respective parent PMI providing the highest link quality metric, LQM; establishing for one or more of the identified parent PMIs, a respective set of child PMIs; determining a link quality metric, LQM for each child PMIs of the established one or more sets of child PMIs; and establishing the feedback metric to be the child PMI having the highest link quality metric, LQM. The disclosure also relates to a wireless device, method in a network node, network node, computer programs and computer program products.

Abstract: The disclosure relates to a method performed in a wireless device for establishing a feedback metric. The wireless device is configured with a grouping of available precoding matrix indicators, PMIs, of a codebook, the grouping comprising two or more groups each of which comprises an exclusive subset of the available precoding matrix indicators, PMIs. The method comprises: identifying for one or more rank indicator, RI, hypotheses a respective parent PMI providing the highest link quality metric, LQM; establishing for one or more of the identified parent PMIs, a respective set of child PMIs; determining a link quality metric, LQM for each child PMIs of the established one or more sets of child PMIs; and establishing the feedback metric to be the child PMI having the highest link quality metric, LQM. The disclosure also relates to a wireless device, method in a network node, network node, computer programs and computer program products.