Physical channels in new radio
Hybrid automatic repeat request (HARQ) processes, indicators, and similar methods may be used improve new radio performance in a number of ways. For example HARQ processes may be retransmitted, even before a response is expected, a number of times. Separate acknowledgement may be provided for various code blocks within a single transport block. Multi-bit ACK/NACK signaling may be used to efficiently express the status of individual code blocks or groups of code blocks within a transmission block. Grantless transmissions may be acknowledged implicitly, e.g., via responses comprising downlink control information or sent via a physical hybrid automatic repeat request indicator channel.
1. A first apparatus comprising a processor, a memory, and communication circuitry, the first apparatus being connected to a network via its communication circuitry, the first apparatus further comprising computer-executable instructions stored in the memory of the first apparatus which, when executed by the processor of the first apparatus, cause the first apparatus to perform operations comprising:
receiving, from a second apparatus via resources that are pre-configured for the second apparatus, a grantless transmission, the grantless transmission comprising a hybrid automatic repeat request process;
receiving, from the second apparatus via a control channel, a first redundancy version of the hybrid automatic repeat request process;
sending a response to the grantless transmission, the response to the grantless transmission comprising an acknowledgement in a downlink control information, wherein the downlink control information is specific to the second apparatus, and wherein the downlink control information comprises one or more acknowledgement bits for multiple transport blocks; and
if the first apparatus does not send a positive acknowledgement of the grantless transmission, receiving, from the second apparatus and indicated via a control channel, a second redundancy version of a retransmission.
2. The first apparatus of claim 1 , wherein the downlink control information comprises a grantless radio network temporary identifier.
3. The first apparatus of claim 1 , wherein the operations further comprise receiving multiple redundancy versions of multiple retransmissions.
4. An apparatus comprising a processor, a memory, and communication circuitry, the apparatus being connected to a network via its communication circuitry, the apparatus further comprising computer-executable instructions stored in the memory of the apparatus which, when executed by the processor of the apparatus, cause the apparatus to perform operations comprising:
sending, via resources that are pre-configured for the apparatus, a grantless transmission, the grantless transmission comprising a hybrid automatic repeat request process;
indicating, through a control channel, a first redundancy version for the hybrid automatic repeat request process;
receiving a response to the grantless transmission, the response to the grantless transmission, the response to the grantless transmission comprising an acknowledgement in a downlink control information, wherein the downlink control information is specific to the apparatus, and wherein the downlink control information comprises one or more acknowledgement bits for multiple transport blocks; and
if a positive acknowledgement is not received:
selecting a second redundancy version for a first retransmission, the first retransmission comprising the hybrid automatic repeat request process;
sending, via the resources that are pre-configured for the apparatus, the first retransmission; and
indicating, through the control channel, the second redundancy version for the hybrid automatic repeat request process.
5. The apparatus of claim 4 , wherein the downlink control information comprises a grantless radio network temporary identifier.
6. The apparatus of claim 4 , wherein the operations further comprise:
selecting multiple redundancy versions for multiple retransmissions, the second retransmission comprising the hybrid automatic repeat request process;
indicating, through the control channel, the multiple redundancy versions; and
sending, via the resources that are pre-configured for the apparatus, the multiple retransmissions.
7. The apparatus of claim 4 , wherein the operations further comprise:
transmitting a hybrid automatic repeat request process;
retransmitting the hybrid automatic repeat request process until a positive acknowledgment is received.
8. The apparatus of claim 7 , wherein the apparatus is configured to retransmit the hybrid automatic repeat request process at a specific periodicity.
9. The apparatus of claim 7 , wherein the apparatus is configured to retransmit the hybrid automatic repeat request process until a pre-determined limit for the number of retransmissions is met or a positive acknowledgment is received.
10. The apparatus of claim 9 , wherein the pre-determined limit for the number of retransmissions is two or more.
11. The apparatus of claim 9 , wherein the operations further comprise:
receiving a negative acknowledgement; and
retransmitting the hybrid automatic repeat request process a number of times after receiving the negative acknowledgement up to the pre-determined limit for the number of retransmissions.
12. The apparatus as recited in claim 7 , wherein retransmission commences prior to expected reception of an acknowledge response.
13. The apparatus of claim 4 , wherein the operations further comprise:
transmitting a first transport block comprising a first set of groups of code blocks;
receiving a multibit ACK-NACK response for the first transport block, the multibit ACK-NACK response for the first transport block comprising an ACK-NACK response for each group of code blocks in the first transport block; and
transmitting a second transport block comprising a second set of groups of code blocks, the second set of groups of code blocks comprising only those groups of code blocks of the first set of code blocks for which no ACK response was received in the multibit ACK-NACK response.
14. The apparatus of claim 13 , wherein the number of bits in the multibit ACK-NACK response is equal to the number of groups of code blocks in the first set of groups of code blocks.
15. The apparatus of claim 13 , wherein the number of bits in the multibit ACK-NACK response is equal to the number of code blocks in the first transport block.
16. The apparatus of claim 13 , wherein the second transport block further comprises link control information comprising information about the groups of code blocks that are included in the second transport block.
17. The apparatus of claim 16 , wherein the link control information is downlink control information.
18. The apparatus of claim 13 , wherein the first set of groups of code blocks comprises a first group and a second group comprising a different numbers of code blocks.