Device and method to allow cross-transmission time interval (TTI) switching and hybrid automatic repeat request (HARQ) operation in a new radio network

1. A device of a New Radio (NR) User Equipment (UE), the device comprising:

a radio frequency circuitry interface (RF circuitry interface); and

processing circuitry coupled to the RF circuitry interface, the processing circuitry configured to:

determine a maximum reference number of downlink (DL) hybrid automatic repeat request (HARQ) processes for HARQ retransmissions to a base station, the maximum reference number of DL HARQ processes being based on a duration of a Time Transmission Interval (TTI) Type for transmissions from the base station to the UE, wherein;

the DL HARQ processes are of a number of HARQ processes wherein a soft buffer including a plurality of soft buffer partitions stores a plurality of soft bits for the number of HARQ processes;

the soft buffer partitions include respective shared partitions, each of the shared partitions being shared between paired HARQ process indices including a first HARQ process index corresponding to a first HARQ process of TTI Type 1 and a second HARQ process index corresponding to a second HARQ process of TTI Type 2;

the second HARQ process index includes a set of second HARQ process indices Y i corresponding to respective ones of the second HARQ processes of TTI Type 2, where i is an integer value from 1 to a maximum number of second HARQ process indices in said each of the shared partitions; and

the first HARQ process index of the first HARQ process of TTI Type 1 and the second HARQ process indices of the second HARQ process of TTI Type 2 are based on a maximum number of HARQ processes indices for the first HARQ process of TTI Type 1 M DL_HARQ TTI type 1 and a maximum number of HARQ process indices for the second HARQ process of TTI Type 2 M DL_HARQ TTI type 1 ; and

the processing circuitry is further configured to encode the HARQ retransmissions to the base station in a cellular network based on the maximum reference number of DL HARQ processes.

2. The device of claim 1 , wherein:

the number of HARQ processes includes first HARQ processes corresponding to a first Time Transmission Interval (TTI) Type of a first duration (TTI Type 1), and second HARQ processes corresponding to a second TTI Type of a second duration (TTI Type 2) shorter than the first duration; and

the processing circuitry is further configured to effect a dynamic switching between a TTI Type 1 communication mode and a TTI Type 2 communication mode, and to selectively access the soft buffer partitions to perform, based on the switching, at least one of the first HARQ processes corresponding to TTI Type 1 and the second HARQ processes corresponding to TTI Type 2.

3. The device of claim 2 , wherein the soft buffer includes a first soft buffer portion for the first HARQ processes, and a second soft buffer portion for the second HARQ processes, the first soft buffer portion and the second soft buffer portion being non-overlapping.

4. The device of claim 3 , wherein:

the first soft buffer portion is a soft buffer portion of size NI and the second soft buffer portion is a soft buffer portion of size N2;

the soft buffer further includes a third soft buffer portion of size N3;

the processing circuitry is to dynamically share the third soft buffer portion between the first HARQ processes of TTI Type 1 and the second HARQ processes of TTI Type 2;

r1 is a weighing factor for the first soft buffer portion and r2 is a weighing factor for the second soft buffer portion; and

the processing circuitry is to:

decode a signal from the base station including information on r1 and r2;

determine N1, N2 and N3 based on r1 and r2 as follows:

N 1= N×r 1

N 2= N×r 2

N 3= N−N 1− N 2

where 0≤r1<1, 0≤r2<1 and r1+r2≤1; and

configure the first soft buffer portion, the second soft buffer portion and the third soft buffer portion based on N1, N2 and N3 respectively.

5. The device of claim 1 , wherein Y i is given by:

Y i =( i− 1)× M DL_HARQ TTI type 1 +X

where i=1, . . . , [M DL_HARQ TTI type 2 /M DL_HARQ TTI type 1 ] and M DL_HARQ TTI type 2 >M DL_HARQ TTI type 1 and X is the first HARQ process index corresponding to the first HARQ process of TTI Type 1.

6. The device of claim 1 , wherein Y i is given by:

Y i =( M DL_HARQ TTI type 1 −X+ 1)×[ M DL_HARQ TTI type 2 /M DL_HARQ TTI type 1 ]+ i

where i=0, 1, . . . , [M DL_HARQ TTI type 2 /M DL_HARQ TTI type 1 ]−1 and X is the first HARQ process index corresponding to the first HARQ process of TTI Type 1.

7. The device of claim 1 , wherein the processing circuitry is further configured to decode a Downlink Control Information signal (DCI) comprising an information element (IE) including information on a which of the second HARQ process indices are to be used in a retransmission that is according to the first HARQ process of TTI Type 1.

8. The device of claim 7 , wherein the IE has a number of bits N provided by N=[log 2 (i)], wherein a first value of the number of bits N in the IE being equal to 0 or 1 is to indicate that a first one of the second HARQ process indices is to be used for retransmission, and wherein a second value of the number of bits N in the IE being equal to 1 or 0 is to indicate that a second one of the second HARQ process indices is to be used for retransmission, the second value of the bits being different from the first value of the bits.

9. The device of claim 1 , wherein the processing circuitry is further configured to decode a Downlink Control Information signal (DCI) from the base station, the DCI including a field including a number of bits based on the reference maximum number of HARQ processes, the reference maximum number of HARQ processes being based on a first maximum number of HARQ processes corresponding to first HARQ processes of a TTI Type 1 and a second maximum number of HARQ processes corresponding to second HARQ processes of TTI Type 2.

10. The device of claim 9 , wherein the reference maximum number of HARQ processes is equal to the first maximum number, the second maximum number, or a number in between the first maximum number and the second maximum number, and wherein the first maximum number and the second maximum number are different from one another.

11. The device of claim 1 , wherein the processing circuitry is further configured to:

encode a signal including information, for each component carrier, on an indication of a maximum number of the first HARQ processes with a first soft buffer processing capability, of a maximum number of the second HARQ processes with a second soft buffer processing capability, and of a number of third HARQ processes with simultaneous support for the first and second soft buffer processing capabilities, the information to allow the base station to configure the number of HARQ processes;

cause transmission of the signal including the information on the indication to the base station; and

decode a Downlink Control Information signal (DCI) from the base station including a field having a bitwidth, the bitwidth indicating, for each component carrier, the reference maximum number of HARQ processes.

12. The device of claim 1 , further including a radio frequency (RF) circuitry coupled to the processing circuitry, and a front end module coupled to the RF circuitry.

13. The device of claim 12 , further including one or more antennas coupled to the front end module, the device to transmit and receive signals by way of the one or more antennas.

14. A product comprising one or more tangible computer-readable non-transitory storage media comprising computer-executable instructions operable to, when executed by a device of a New Radio (NR) User Equipment (UE), enable the device to implement operations at the UE, the operations comprising:

determining a maximum reference number of downlink (DL) hybrid automatic repeat request (HARQ) processes for HARQ retransmissions to a base station, the maximum reference number of DL HARQ processes being based on a duration of a Time Transmission Interval (TTI) Type for transmissions from the base station to the UE, wherein

the DL HARQ processes are of a number of HARQ processes wherein a soft buffer including a plurality of soft buffer partitions stores a plurality of soft bits for the number of HARQ processes;

the soft buffer partitions include respective shared partitions, each of the shared partitions being shared between paired HARQ process indices including a first HARQ process index corresponding to a first HARQ process of TTI Type 1 and a second HARQ process index corresponding to a second HARQ process of TTI Type 2;

the second HARQ process index includes a set of second HARQ process indices Y i corresponding to respective ones of the second HARQ processes of TTI Type 2, where i is an integer value from 1 to a maximum number of second HARQ process indices in said each of the shared partitions;

the first HARQ process index of the first HARQ process of TTI Type 1 and the second HARQ process indices of the second HARQ process of TTI Type 2 are based on a maximum number of HARQ processes indices for the first HARQ process of TTI Type 1 M DL_HARQ TTI type 1 and a maximum number of HARQ process indices for the second HARQ process of TTI Type 2 M DL_HARQ TTI type 1 ; and

encoding the HARQ retransmissions to the base station in a cellular network based on the maximum reference number of DL HARQ processes.

15. The product of claim 14 , wherein:

the number of HARQ processes includes first HARQ processes corresponding to a first Time Transmission Interval (TTI) Type of a first duration (TTI Type 1), and second HARQ processes corresponding to a second TTI Type of a second duration (TTI Type 2) shorter than the first duration; and

the operations further comprise effecting a dynamic switching between a TTI Type 1 communication mode and a TTI Type 2 communication mode, and to selectively access the soft buffer partitions to perform, based on the switching, at least one of the first HARQ processes corresponding to TTI Type 1 and the second HARQ processes corresponding to TTI Type 2.

16. The product of claim 15 , wherein the soft buffer includes a first soft buffer portion for the first HARQ processes, and a second soft buffer portion for the second HARQ processes, the first soft buffer portion and the second soft buffer portion being non-overlapping.

17. The product of claim 16 , wherein:

the first soft buffer portion is a soft buffer portion of size N1 and the second soft buffer portion is a soft buffer portion of size N2;

the soft buffer further includes a third soft buffer portion of size N3;

wherein the third soft buffer portion is dynamically shared between the first HARQ processes of TTI Type 1 and the second HARQ processes of TTI Type 2;

r1 is a weighing factor for the first soft buffer portion and r2 is a weighing factor for the second soft buffer portion; and

the operations further include:

decoding a signal from the base station including information on r1 and r2;

determining N1, N2 and N3 based on r1 and r2 as follows:

N 1= N×r 1

N 2= N×r 2

N 3= N−N 1− N 2

where 0≤r1<1, 0≤r2<1 and r1+r2≤1; and

configuring the first soft buffer portion, the second soft buffer portion and the third soft buffer portion based on N1, N2 and N3 respectively.

18. The product of claim 14 , the operations further comprising decoding a Downlink Control Information signal (DCI) from the base station, the DCI including a field including a number of bits based on the reference maximum number of HARQ processes, the reference maximum number of HARQ processes being based on a first maximum number of HARQ processes corresponding to first HARQ processes of a TTI Type 1 and a second maximum number of HARQ processes corresponding to second HARQ processes of TTI Type 2.

19. The product of claim 18 , wherein the reference maximum number of HARQ processes is equal to the first maximum number, the second maximum number, or a number in between the first maximum number and the second maximum number, and wherein the first maximum number and the second maximum number are different from one another.

20. The product of claim 14 , the operations further comprising:

encoding a signal including information, for each component carrier, on an indication of a maximum number of the first HARQ processes with a first soft buffer processing capability, of a maximum number of the second HARQ processes with a second soft buffer processing capability, and of a number of third HARQ processes with simultaneous support for the first and second soft buffer processing capabilities, the information to allow the base station to configure the number of HARQ processes; causing transmission of the signal including the information on the indication to the base station; and

decoding a Downlink Control Information signal (DCI) from the base station including a field having a bitwidth, the bitwidth indicating, for each component carrier, the reference maximum number of HARQ processes.

21. A device of a New Radio (NR) User Equipment (UE), the device including:

means for determining a maximum reference number of downlink (DL) hybrid automatic repeat request (HARQ) processes for HARQ retransmissions to a base station, the maximum reference number of DL HARQ processes being based on a duration of a Time Transmission Interval (TTI) Type for transmissions from the base station to the UE, wherein;

the DL HARQ processes are of a number of HARQ processes wherein a soft buffer including a plurality of soft buffer partitions stores a plurality of soft bits for the number of HARQ processes;

the soft buffer partitions include respective shared partitions, each of the shared partitions being shared between paired HARQ process indices including a first HARQ process index corresponding to a first HARQ process of TTI Type 1 and a second HARQ process index corresponding to a second HARQ process of TTI Type 2;

the second HARQ process index includes a set of second HARQ process indices Y i corresponding to respective ones of the second HARQ processes of TTI Type 2, where i is an integer value from 1 to a maximum number of second HARQ process indices in said each of the shared partitions;

the first HARQ process index of the first HARQ process of TTI Type 1 and the second HARQ process indices of the second HARQ process of TTI Type 2 are based on a maximum number of HARQ processes indices for the first HARQ process of TTI Type 1 M DL_HARQ TTI type 1 and a maximum number of HARQ process indices for the second HARQ process of TTI Type 2 M DL_HARQ TTI type 1 ; and

means for encoding the HARQ retransmissions to the base station in a cellular network based on the maximum reference number of DL HARQ processes.

22. The device of claim 21 , wherein:

the number of HARQ processes includes first HARQ processes corresponding to a first Time Transmission Interval (TTI) Type of a first duration (TTI Type 1), and second HARQ processes corresponding to a second TTI Type of a second duration (TTI Type 2) shorter than the first duration; and

the device further including means to effect a dynamic switching between a TTI Type 1 communication mode and a TTI Type 2 communication mode, and to selectively access the soft buffer partitions to perform, based on the switching, at least one of the first HARQ processes corresponding to TTI Type 1 and the second HARQ processes corresponding to TTI Type 2.