Apparatuses and methods are disclosed for block interleaving. In one embodiment, a method includes generating an interleaver sequence for a control resource set, CORESET, configuration for a physical downlink control channel, the interleaver sequence associated with an interleaving matrix; optionally, for each one of an allowed value of number of rows for the interleaving matrix, determining a number of null entries to be added to the interleaving matrix; and selecting a number of rows, R, for the interleaving matrix such that the number of null entries to be added to the interleaving matrix is: no more than a number of columns, C, of the interleaving matrix; and optionally, the smallest among the numbers of null entries determined for each of the allowed values of number of rows for the interleaving matrix. In another embodiment, a method includes decomposing the interleaver sequence.