Methods, apparatus and systems for determining a transport block size in a wireless communication are disclosed. In one embodiment, a method performed by a wireless communication device is disclosed. The method comprises: receiving control information from a wireless communication node, wherein the control information includes a plurality of transmission parameters related to transport blocks to be transmitted between the wireless communication device and the wireless communication node; calculating an intermediate transport block size (TBS) for the transport blocks based on the plurality of transmission parameters; modifying the intermediate TBS to generate a modified TBS in response to an event that the intermediate TBS is smaller than a threshold; and determining a final. TBS for the transport blocks based on a TBS that is closest to the modified TBS, among TBSs that are in a quantized set and not smaller than the modified TBS.