Apparatus and method for generating polar codes

The invention relates to an apparatus (110a) and method for generating a polar code c N of length N and dimension K, on the basis of a generator matrix G N of size N x N, wherein the generator matrix G N is based on a kernel T p of size p x p, with p ≤ N, wherein the polar code c N is given by c N = u N ⋅ G N , wherein u N = (u 0 ,..., u N-1 ) is a vector of size N, u i ,i = 0,... N - 1, corresponding to an information bit if i ∈ /, / being a set of K information bit indices, and u i = 0, if ί ∈ F, F being a set of N - K frozen bit indices. The apparatus (110a) comprises a processor (110a-1) configured to: generate a distance spectrum vector d Tp = ( d Tp (1),..., d Tp (p)) of size p of the kernel Tρ, wherein d Tp (h), h = 1,..., p, corresponds to a maximum value among all possible minimum distances of all possible polar codes of size p and dimension h generated on the basis of the kernel T p , generate a distance spectrum vector d GN of size N of the generator matrix G N on the basis of the distance spectrum vector d Tp , determine the set of K information bit indices / on the basis of the distance spectrum vector d GN , and generate the polar code c N on the basis of the set of K information bit indices /.