Method for determining a transport block size and wireless device
A disclosure of this specification provides a method performed by a wireless device for determining a transport block size (TBS). The method may include the steps of determining a number of resource elements (REs) within a slot, calculating a value related to the TBS, based on the determined number of REs and a code rate, comparing the calculated value with a pre-determined threshold value, determining the TBS according to the comparison, wherein, if the calculated value is smaller than or equal to the pre-determined threshold value, the TBS may be determined using a predetermined table.
1. A method for determining a transport block size (TBS), the method performed by a wireless device and comprising:
determining a number of resource elements (REs) within a slot;
calculating an intermediate value related to the TBS, based on the determined number of REs and a code rate;
comparing the calculated intermediate value with a pre-determined threshold value; and
determining the TBS based on the comparison,
wherein based on that the calculated intermediate value is smaller than or equal to the pre-determined threshold value, the TBS is determined using a predetermined table,
wherein based on that the calculated intermediate value is greater than the predetermined threshold value, the TBS is determined using a mathematical function,
wherein the mathematical function includes parameters for the number of REs within the slot and the code rate, and
wherein the mathematical function includes quantizing the calculated intermediate value.
2. The method of claim 1 , wherein the mathematical function includes a ceiling function.
3. The method of claim 1 , wherein the intermediate value related to the TBS is calculated in further consideration of a modulation order and a number of layers.
4. The method of claim 1 , wherein the number of resource elements (REs) is determined except for REs for a reference signal.
5. The method of claim 1 , wherein the TBS is used to transmit a physical uplink shared channel (PUSCH) or receive a physical downlink shared channel (PDSCH).
6. The method of claim 1 , wherein the calculating of the intermediate value related to the TBS includes:
scaling the intermediate value related to the TBS with a scaling factor.
7. The method of claim 6 , wherein the scaling factor is determined based on downlink control information (DCI).
8. The method of claim 7 , wherein the DCI includes information on the scaling factor.
9. A wireless device for determining a transport block size (TBS), the wireless device comprising:
a transceiver; and
a processor configured to control the transceiver and to:
determine a number of resource elements (REs) within a slot;
calculate an intermediate value related to the TBS, based on the determined number of REs and a code rate;
compare the calculated intermediate value with a pre-determined threshold value; and
determine the TBS based on the comparison,
wherein based on that the calculated intermediate value is smaller than or equal to the predetermined threshold value, the TBS is determined using a predetermined table,
wherein based on that the calculated intermediate value is greater than the predetermined threshold value, the TBS is determined using a mathematical function,
wherein the mathematical function includes parameters for the number of REs within the slot and the code rate, and
wherein the mathematical function includes quantizing the calculated intermediate value.
10. The wireless device of claim 9 , wherein the mathematical function includes a ceiling function.
11. The wireless device of claim 9 , wherein the intermediate value related to the TBS is calculated in further consideration of a modulation order and a number of layers.
12. The wireless device of claim 9 , the number of resource elements (REs) is determined except for REs for a reference signal.