Method and apparatus for transport block retransmission in mobile communications

1 . A method, comprising:

transmitting, by a processor of an apparatus, a first set of encoded bits corresponding to a first transport block (TB) via a first physical downlink share channel (PDSCH) to a user equipment (UE);

generating, by the processor, a second set of encoded bits corresponding to the first TB and a third set of encoded bits corresponding to a second TB; and

transmitting, by the processor, the second set of encoded bits and the third set of encoded bits via a second PDSCH to the UE.

2 . The method of claim 1 , wherein the second set of encoded bits is generated based on the first TB without cyclic redundancy check (CRC) code, and the third set of encoded bits is generated based on the second TB with CRC code derived from the second TB.

3 . The method of claim 1 , further comprising:

transmitting, by the processor, control information to the UE, wherein the control information indicates to the UE that the first TB and the second TB are carried by the second PDSCH.

4 . The method of claim 3 , wherein the control information further indicates to the UE that the first TB and the second TB are multiplexed in a time-frequency domain within time-frequency resources allocated to the second PDSCH.

5 . The method of claim 3 , wherein the control information further indicates to the UE a plurality of first physical resource blocks (PRBs) associated with the first TB and a plurality of second PRBs associated with the second TB.

6 . The method of claim 3 , wherein the control information further includes a value denoting a number of PRBs allocated to the second TB.

7 . The method of claim 3 , wherein the control information further indicates a first redundancy version associated with the first TB and a second redundancy version associated with the second TB to generate the first set of encoded bits and the second set of encoded bits.

8 . The method of claim 3 , wherein the control information further indicates to the UE that the first TB and the second TB are multiplexed in a spatial domain within time-frequency resources allocated to the second PDSCH.

9 . The method of claim 3 , wherein the control information further indicates to the UE at least one first spatial layer associated with the first TB and at least one second spatial layer associated with the second TB.

10 . The method of claim 3 , wherein the control information is included in a downlink control information (DCI) or a radio resource control (RRC) message.

11 . A method, comprising:

receiving, by a processor of an apparatus, a first set of encoded bits corresponding to a first transport block (TB) via a first physical downlink share channel (PDSCH) from a network node;

transmitting, by the processor, a negative acknowledgment (NACK) corresponding to the first TB to the network node; and

receiving, by the processor, a second set of encoded bits corresponding to the first TB and a third set of encoded bits corresponding to the second TB via a second PDSCH from the network node.

12 . The method of claim 11 , further comprising:

transmitting, by the processor, an indicator indicating a quality gap between a reference quality and a quality of receiving the first PDSCH to the network node.

13 . The method of claim 11 , further comprising:

receiving, by the processor, control information from the network node, wherein the control information indicates to the apparatus that the first TB and the second TB are multiplexed in a time-frequency domain or in a spatial domain, within time-frequency resources allocated to the second PDSCH.

14 . The method of claim 13 , wherein the control information further indicates to the apparatus a plurality of first physical resource blocks (PRBs) associated with the first TB and a plurality of second PRBs associated with the second TB.

15 . The method of claim 13 , wherein the control information further includes a value denoting a number of PRBs allocated to the second TB.

16 . The method of claim 13 , wherein the control information further indicates to the apparatus a first redundancy version associated with the first TB and a second redundancy version associated with the second TB.

17 . The method of claim 13 , wherein the control information further indicates to the apparatus at least one first spatial layer associated with the first TB and at least one second spatial layer associated with the second TB.

18 . The method of claim 11 , wherein the third set of encoded bits are generated according to the second TB transmitted with cyclic redundancy check (CRC) code and the second set of encoded bits are generated according to the first TB transmitted without CRC code.

19 . An apparatus, comprising:

a transceiver which, during operation, wirelessly communicates with a user equipment (UE); and

a processor communicatively coupled to the transceiver such that, during operation, the processor performs operations comprising:

transmitting, by the transceiver, a first set of encoded bits corresponding to a first transport block (TB) via a first physical downlink share channel (PDSCH) to the UE;

generating a second set of encoded bits corresponding to the first TB and a third set of encoded bits corresponding to a second TB; and

transmitting, by the transceiver, the second set of encoded bits and the third set of encoded bits via a second PDSCH to the UE.

20 . An apparatus, comprising:

a transceiver which, during operation, wirelessly communicates with a network node; and

a processor communicatively coupled to the transceiver such that, during operation, the processor performs operations comprising:

receiving, by the transceiver, a first set of encoded bits corresponding to a first transport block (TB) via a first physical downlink share channel (PDSCH) from the network node;

transmitting, by the transceiver, a negative acknowledgment (NACK) corresponding to the first TB to the network node; and

receiving, by the transceiver, a second set of encoded bits corresponding to the first TB and a third set of encoded bits corresponding to the second TB via a second PDSCH from the network node.