A method for polar encoding performed by a device, the method comprising: receiving a message comprising information bits; encoding the message using a first polar code to obtain a first codeword; encoding the message using a second polar code to obtain a second codeword, wherein the second codeword includes two parts (221, 222), and the first part of the second polar code is same as the first polar code; transmitting the first codeword to a receiver in a first transmission; transmitting the second part of the second codeword in a second transmission without transmitting the first part of the second codeword when the receiver is unable to decode the message based on the first codeword, wherein the second part of the second codeword is transmitted as a re-transmission of the message using an incremental redundancy, IR, retransmission scheme; encoding the message using a third polar code to obtain a third codeword, wherein the third codeword includes three parts (231, 232, 233), the first part of the third polar codeword is same as the first polar code and the second part of the third polar codeword is same as the second part of the second polar code; and transmitting the third part of the third codeword without transmitting the first two parts (231, 232) of the third codeword when the receiver is unable to decode the message based on the first codeword and the second codeword, wherein the third part of the third codeword is transmitted as a re-transmission of the message using the IR retransmission scheme; characterised in that when the receiver is unable to decode the message based on the first, second and third transmissions, chase combing retransmission scheme, CC, is adopted for the subsequent retransmission of the message. receiving a message comprising information bits; encoding the message using a first polar code to obtain a first codeword; encoding the message using a second polar code to obtain a second codeword, wherein the second codeword includes two parts (221, 222), and the first part of the second polar code is same as the first polar code; transmitting the first codeword to a receiver in a first transmission; transmitting the second part of the second codeword in a second transmission without transmitting the first part of the second codeword when the receiver is unable to decode the message based on the first codeword, wherein the second part of the second codeword is transmitted as a re-transmission of the message using an incremental redundancy, IR, retransmission scheme; encoding the message using a third polar code to obtain a third codeword, wherein the third codeword includes three parts (231, 232, 233), the first part of the third polar codeword is same as the first polar code and the second part of the third polar codeword is same as the second part of the second polar code; and transmitting the third part of the third codeword without transmitting the first two parts (231, 232) of the third codeword when the receiver is unable to decode the message based on the first codeword and the second codeword, wherein the third part of the third codeword is transmitted as a re-transmission of the message using the IR retransmission scheme;