t bits interleaver and the channel interleaver, respectively. The value of the two types of assistant PC bits are given by NPC and npc. The length of the control information vector N and the length of the transmitted codeword E are dependent on the type, content, and number of consecutive transmissions and are reliant on the decisions taken in the higher layers [36]. The K bit output of the CRC encoder is interleaved before being fed to the polar encoder. The interleaver is activated through the I LL flag. In particular, the input bit interleaver is activated for PBCH and PDCCH payloads, while it is set to zero in the case of PUCCH and PUSCH control information. The input bit interleaver interleaves up to Kmax = 164 input bits, where the interleaving pattern is calculated based on the sequence IImax(m) given in [7]. The maximum number of input bits Kmax is set to 164 suggesting that the maximum number of control information bits without CRC is limited to 140. In more detail, (Kmax-K) is subtracted from all the entries of II(k), such that II(k) contains the integers smaller than K in permuted order. This scrambling sequence has been proposed to facilitate early termination, both during normal decoding and in DCI blind detection. This is made possible by the fact that after interleaving, every CRC remainder bit is placed after its rele- vant information bits. The interleaving function is applied to vector c to obtain the K - bit vector c' = (C II(0), CII(1), C II(K-1)) [7]. In the subchannel allocation process prior to polar encoding, the vector c' is expanded into the N-bit vector u with the addition of assistant bits and frozen bits. As a first step, NPC PC 526 Chapter 4 bits are inserted among the K information and CRC bits. Thus the polar encoder represents a (N, K + NPC) code. To create the input vector u to be encoded, the frozen set of subchan- nels needs to be identified. The number and position of frozen bits depend on N, E and the selected rate-matching scheme. To begin with, the frozen set ON and the com