Method and apparatus for downlink retransmission under unreliable code block group (CBG) level feedback

A method for wireless communication operable at a user equipment (UE), comprising:

• in a first slot, transmitting a first code block group (CBG) feedback corresponding to a first set of code block groups (CBGs) received from a base station (BS);
• in a second slot after the first slot, receiving downlink control information (DCI) and a first cyclic redundancy check (CRC), the first CRC generated based on the DCI and further scrambled by a first concatenation of CBG feedbacks as decoded by the BS, wherein the first concatenation of CBG feedbacks comprise CBG feedbacks respectively corresponding to a plurality of slots;
• generating a second CRC based on the DCI and further scrambled by a second concatenation of CBG feedbacks including the first CBG feedback;
• determining that the BS correctly decoded the first CBG feedback based on a comparison of the first CRC and the second CRC;
• wherein the second concatenation of CBG feedbacks comprises a first bitmap transmitted by the UE corresponding to the first set of CBGs, each bit of the first bitmap indicating an acknowledgement (ACK) or negative acknowledgement (NACK) of a corresponding CBG of the first set of CBGs;
• and
• wherein the second concatenation of CBG feedbacks further comprises a second bitmap transmitted by the UE corresponding to a second set of CBGs transmitted by the BS prior to the first set of CBGs, each bit of the second bitmap indicating the ACK or NACK of a corresponding CBG of the second set of CBGs.

A method for wireless communication operable at a user equipment (UE), comprising:

• in a first slot, transmitting a first code block group (CBG) feedback corresponding to a first set of code block groups (CBGs) received from a base station (BS);
• in a second slot after the first slot, receiving downlink control information (DCI) and a first cyclic redundancy check (CRC), the first CRC generated based on the DCI and further scrambled by a first concatenation of CBG feedbacks as decoded by the BS, wherein the first concatenation of CBG feedbacks comprise CBG feedbacks respectively corresponding to a plurality of slots;
• generating a second CRC based on the DCI and further scrambled by a second concatenation of CBG feedbacks including the first CBG feedback;
• determining that the BS correctly decoded the first CBG feedback based on a comparison of the first CRC and the second CRC;
• and
• generating the second concatenation of CBG feedbacks, excluding a bitmap comprising only bits that indicate negative acknowledgement (NACK) of a plurality of CBGs.

A method for wireless communication operable at a user equipment (UE), comprising:

• in a first slot, transmitting a first code block group (CBG) feedback corresponding to a first set of code block groups (CBGs) received from a base station (BS);
• in a second slot after the first slot, receiving downlink control information (DCI) and a first cyclic redundancy check (CRC), the first CRC generated based on the DCI and further scrambled by a first concatenation of CBG feedbacks as decoded by the BS, wherein the first concatenation of CBG feedbacks comprise CBG feedbacks respectively corresponding to a plurality of slots;
• generating a second CRC based on the DCI and further scrambled by a second concatenation of CBG feedbacks including the first CBG feedback;
• determining that the BS correctly decoded the first CBG feedback based on a comparison of the first CRC and the second CRC;
• scrambling the second CRC by a third concatenation of CBG feedbacks that is different from the second concatenation of CBG feedbacks;
• and
• if the first CRC matches the second CRC, determining that the BS correctly decoded the first CBG feedback.

A user equipment (UE) comprising:

• a communication interface configured for wireless communication;
• a memory;
• and
• a processor operatively coupled with the communication interface and the memory,
• wherein the processor and the memory are configured to:
• in a first slot, transmit a first code block group (CBG) feedback corresponding to a first set of code block groups (CBGs) received from a base station (BS);
• in a second slot after the first slot, receive downlink control information (DCI) and a first cyclic redundancy check (CRC), the first CRC generated based on the DCI and further scrambled by a first concatenation of CBG feedbacks as decoded by the BS, wherein the first concatenation of CBG feedbacks comprise CBG feedbacks respectively corresponding to a plurality of slots;
• generate a second CRC based on the DCI and further scrambled by a second concatenation of CBG feedbacks including the first CBG feedback;
• determine that the BS correctly decoded the first CBG feedback based on a comparison of the first CRC and the second CRC;
• wherein the first concatenation of CBG feedbacks comprises a first bitmap as decoded by the BS corresponding to the first set of CBGs, each bit of the first bitmap indicating an acknowledgement (ACK) or negative acknowledgement (NACK) of a corresponding CBG of the first set of CBGs, and
• wherein the first concatenation of CBG feedbacks further comprises a second bitmap as decoded by the BS corresponding to a second set of CBGs transmitted by the BS prior to the first set of CBGs, each bit of the second bitmap indicating the ACK or NACK of a corresponding CBG of the second set of CBGs.

A user equipment (UE) comprising:

• a communication interface configured for wireless communication;
• a memory;
• and
• a processor operatively coupled with the communication interface and the memory,
• wherein the processor and the memory are configured to:
• in a first slot, transmit a first code block group (CBG) feedback corresponding to a first set of code block groups (CBGs) received from a base station (BS);
• in a second slot after the first slot, receive downlink control information (DCI) and a first cyclic redundancy check (CRC), the first CRC generated based on the DCI and further scrambled by a first concatenation of CBG feedbacks as decoded by the BS, wherein the first concatenation of CBG feedbacks comprise CBG feedbacks respectively corresponding to a plurality of slots;
• generate a second CRC based on the DCI and further scrambled by a second concatenation of CBG feedbacks including the first CBG feedback;
• determine that the BS correctly decoded the first CBG feedback based on a comparison of the first CRC and the second CRC;
• wherein the second concatenation of CBG feedbacks comprises a first bitmap transmitted by the UE corresponding to the first set of CBGs, each bit of the first bitmap indicating an acknowledgement (ACK) or negative acknowledgement (NACK) of a corresponding CBG of the first set of CBGs, and
• wherein the second concatenation of CBG feedbacks further comprises a second bitmap transmitted by the UE corresponding to a second set of CBGs transmitted by the BS prior to the first set of CBGs, each bit of the second bitmap indicating the ACK or NACK of a corresponding CBG of the second set of CBGs.

A user equipment (UE) comprising:

• a communication interface configured for wireless communication;
• a memory;
• and
• a processor operatively coupled with the communication interface and the memory,
• wherein the processor and the memory are configured to:
• in a first slot, transmit a first code block group (CBG) feedback corresponding to a first set of code block groups (CBGs) received from a base station (BS);
• in a second slot after the first slot, receive downlink control information (DCI) and a first cyclic redundancy check (CRC), the first CRC generated based on the DCI and further scrambled by a first concatenation of CBG feedbacks as decoded by the BS, wherein the first concatenation of CBG feedbacks comprise CBG feedbacks respectively corresponding to a plurality of slots;
• generate a second CRC based on the DCI and further scrambled by a second concatenation of CBG feedbacks including the first CBG feedback;
• determine that the BS correctly decoded the first CBG feedback based on a comparison of the first CRC and the second CRC;
• and
• generate the second concatenation of CBG feedbacks, excluding a bitmap comprising only bits that indicate negative acknowledgement (NACK) of a plurality of CBGs.

A user equipment (UE) comprising:

• a communication interface configured for wireless communication;
• a memory;
• and
• a processor operatively coupled with the communication interface and the memory,
• wherein the processor and the memory are configured to:
• in a first slot, transmit a first code block group (CBG) feedback corresponding to a first set of code block groups (CBGs) received from a base station (BS);
• in a second slot after the first slot, receive downlink control information (DCI) and a first cyclic redundancy check (CRC), the first CRC generated based on the DCI and further scrambled by a first concatenation of CBG feedbacks as decoded by the BS, wherein the first concatenation of CBG feedbacks comprise CBG feedbacks respectively corresponding to a plurality of slots;
• generate a second CRC based on the DCI and further scrambled by a second concatenation of CBG feedbacks including the first CBG feedback;
• determine that the BS correctly decoded the first CBG feedback based on a comparison of the first CRC and the second CRC;
• scramble the second CRC by a third concatenation of CBG feedbacks that is different from the second concatenation of CBG feedbacks;
• and
• if the first CRC matches the second CRC, determining that the BS correctly decoded the first CBG feedback.