A method for wireless communications, comprising: determining a target coding rate, R T , for transmitting a group of K information bits, based on a first coding rate, Ri, corresponding to a first target block error rate, BLER, for a first transmission of a first redundancy version, RV of the group and a second coding rate, R 2 , corresponding to a second target BLER for a last transmission of a last RV of the group, wherein R T = (R 1 ∗ a + R 2 ∗ b) ∗ β, wherein a, b, and β are constants ; determining a circular buffer size, N, of a circular buffer for use in transmitting the first RV and the last RV of the group, wherein determining the circular buffer size, N, comprises: obtaining a minimum supported coding rate, R min ; calculating a first buffer size, N R , as the minimum integral power of two which is not less than K/R min ; calculating a second buffer size, N T , as the minimum integral power of two which is not less than K/R T ; obtaining a maximum coded block size, N max ; and calculating N as the minimum of N R , N T , and N max ; generating encoded information bits from the K information bits using a polar code having a mother code size of N; writing the encoded information bits to the circular buffer; determining a maximum number of retransmissions, based on a latency requirement for the group; generating different RVs from the encoded information bits in the circular buffer, each of the different RVs based on a corresponding target BLER; and transmitting the first RV via a wireless medium. determining a target coding rate, R T , for transmitting a group of K information bits, based on a first coding rate, Ri, corresponding to a first target block error rate, BLER, for a first transmission of a first redundancy version, RV of the group and a second coding rate, R 2 , corresponding to a second target BLER for a last transmission of a last RV of the group, wherein R T = (R 1 ∗ a + R 2 ∗ b) ∗ β, wherein a, b, and β are constants ; determining a circular buffer size, N, of a circular buffer for use in transmitting the first RV and the last RV of the group, wherein determining the circular buffer size, N, comprises: obtaining a minimum supported coding rate, R min ; calculating a first buffer size, N R , as the minimum integral power of two which is not less than K/R min ; calculating a second buffer size, N T , as the minimum integral power of two which is not less than K/R T ; obtaining a maximum coded block size, N max ; and calculating N as the minimum of N R , N T , and N max ; obtaining a minimum supported coding rate, R min ; calculating a first buffer size, N R , as the minimum integral power of two which is not less than K/R min ; calculating a second buffer size, N T , as the minimum integral power of two which is not less than K/R T ; obtaining a maximum coded block size, N max ; and calculating N as the minimum of N R , N T , and N max ; generating encoded information bits from the K information bits using a polar code having a mother code size of N; writing the encoded information bits to the circular buffer; determining a maximum number of retransmissions, based on a latency requirement for the group; generating different RVs from the encoded information bits in the circular buffer, each of the different RVs based on a corresponding target BLER; and transmitting the first RV via a wireless medium. <EOS>