According to an embodiment of the present disclosure, a method for performing SL communication by a first device is provided. The method comprises the steps of: determining a plurality of first bits on which interleaving is to be performed from among a plurality of bits of a first encoded code block and a plurality of second bits except for the plurality of first bits from among the plurality of bits of the first encoded code block; performing interleaving on the plurality of first bits; transmitting, to a second device, the plurality of first bits on which the interleaving has been performed, on a plurality of first REs related to the plurality of first bits; and transmitting, to the second device, the plurality of second bits on a plurality of second REs related to the plurality of second bits.