Patent ID: 8159981

Claim:
A method of determining a TBS (Transport Block Size) comprising: setting a CQI (Channel Quality Indicator) value which is transmitted from a UE (User Equipment) which communicates based on a packet transmission standard HSDPA (High Speed Downlink Packet Access); acquiring the TBS by referring to a CQI mapping table based on the set CQI value; setting a BLER (BLock Error Rate) before, simultaneously, or after said setting a CQI value, and before, simultaneously, or after said acquiring the TBS; and changing said TBS based on the BLER, wherein said changing comprises: calculating a MAC-d PDU (Medium Access Control-dedicated Protocol Data Unit) count indicating a number of MAC-d PDUs contained in said TBS; increasing/decreasing the MAC-d PDU count based on the BLER; and making the TBS large/small in correspondence to the increase/decrease of the MAC-d PDU count, wherein said increasing/decreasing comprises: determining whether or not the BLER is lower than a minimum reference value; and increasing the MAC-d PDU count when the BLER is determined to be lower than the minimum reference value, said making the TBS large/small comprises: making the TBS large in correspondence to the increase of the MAC-d PDU count, wherein said increasing the MAC-d PDU count comprises: acquiring an upper TBS by referring to said CQI mapping table based on an upper CQI value obtained by incrementing the set CQI value; setting an upper MAC-d PDU count for the upper TBS; and increasing the MAC-d PDU count in a range which does not exceed the upper MAC-d PDU count, wherein said increasing the MAC-d PDU count in a range comprises: calculating a difference between the upper MAC-d PDU count and the MAC-d PDU count; repeating increasing the MAC-d PDU count based on the BLER; and setting an increasing amount of the MAC-d PDU count as a new difference when the increasing amount exceeds the difference.