A method generates a frozen vector associated with a polar code codeword on the basis of a frozen matrix associated with a product code codeword, the frozen matrix being of size Nc×Nr. The method includes replicating a first matrix row of the frozen matrix Nc times to generate an expanded matrix row; replicating a first matrix column of the frozen matrix Nr times to generate an expanded matrix column; generating the frozen vector on the basis of the expanded matrix row and the expanded matrix column. The disclosure further provides a method for generating a frozen matrix associated with a product code codeword on the basis of a frozen vector associated with a polar code codeword, wherein the product code codeword comprises a matrix of size Nc×Nr, and the frozen vector comprises a vector of size N with a plurality of bits.