Novel Recursive Kernel Construction for Polar Codes with Practical Codeword Lengths

The basic approach introduced by Arikan in [1] to polarize equal capacity channels to unequal capacities, can be used to design only codewords of length $N=2^{n}$, which is clearly a major limitation when codewords of length $N\neq 2^{n}$ are required. In order to systematically construct polarization kernels of size 3 and higher, a recursive construction technique is developed in this paper, that...