A method for wireless communication, comprising: receiving a first set of encoded bits from a device, the first set of encoded bits generated based at least in part on a mapping of an information bit vector having a bit length to a first set of polarized bit channels of a first polar code having a first code length according to a first bit index set, the first bit index set being based on respective bit channel reliabilities of the first set of polarized bit channels; transmitting, to the device, an indication that decoding of the first set of encoded bits was unsuccessful; receiving a second set of encoded bits from the device, the second set of encoded bits generated based at least in part on a repetition of at least one bit (320-c) of the information bit vector to at least one of a second set of polarized bit channels of a second polar code which has a larger size than the first polar code, wherein the at least one of the second set of polarized bit channels is determined based at least in part on identifying a second bit index set comprising the first bit index set shifted by the first code length and selecting a third bit index set having the bit length of the first bit index set or the second bit index set based on respective highest bit channel reliabilities of the first bit index set and the second bit index set, and wherein the at least one bit (320-c) of the information bit vector corresponds to information bits mapped to bit channels of the first bit index set that are not in the third bit index set; and decoding the second set of encoded bits according to the second polar code to obtain the information bit vector. receiving a first set of encoded bits from a device, the first set of encoded bits generated based at least in part on a mapping of an information bit vector having a bit length to a first set of polarized bit channels of a first polar code having a first code length according to a first bit index set, the first bit index set being based on respective bit channel reliabilities of the first set of polarized bit channels; transmitting, to the device, an indication that decoding of the first set of encoded bits was unsuccessful; receiving a second set of encoded bits from the device, the second set of encoded bits generated based at least in part on a repetition of at least one bit (320-c) of the information bit vector to at least one of a second set of polarized bit channels of a second polar code which has a larger size than the first polar code, wherein the at least one of the second set of polarized bit channels is determined based at least in part on identifying a second bit index set comprising the first bit index set shifted by the first code length and selecting a third bit index set having the bit length of the first bit index set or the second bit index set based on respective highest bit channel reliabilities of the first bit index set and the second bit index set, and wherein the at least one bit (320-c) of the information bit vector corresponds to information bits mapped to bit channels of the first bit index set that are not in the third bit index set; and decoding the second set of encoded bits according to the second polar code to obtain the information bit vector.