Device and method for handling a code block group-based transmission

A communication device for handling a code block group (CBG)-based transmission, comprising:

• a storage device;
• and
• a processing circuit, coupled to the storage device, wherein the storage device stores, and the processing circuit is configured to execute instructions of:
• receiving a first configuration configuring a plurality of component carriers (CCs) from a network;
• receiving a second configuration configuring a CBG-based transmission from the network;
• receiving a plurality of downlink control informations (DCIs) and a plurality of CBG sets from the network via the CBG-based transmission on the plurality of CCs, respectively, wherein each of the plurality of DCIs comprise information indicating a size of a corresponding one of the plurality of CBG sets, a corresponding one of a plurality of cumulative indices for the plurality of CBG sets and a total index for the plurality of CBG sets;
• decoding the plurality of CBG sets according to the plurality of DCIs, to generate a plurality of decoding results, respectively;
• generating a plurality of Hybrid Automatic Repeat Request (HARQ) feedback messages according to the plurality of CBG sets, the plurality of cumulative indices, the total index and the plurality of decoding results;
• and
• transmitting the plurality of HARQ feedback message to the network on at least one of the plurality of CCs;
• wherein each of the plurality of CBG sets comprises at least two CBGs;
• and
• wherein the plurality of cumulative indices indicate numbers of CBGs which have been transmitted by the network.