Flexible grant-free resource configuration signaling
An embodiment method for grant-free resource configuration comprises configuring a first type of grant-free resource, wherein the first type of grant-free resource is cell-specific and is configured using broadcast signaling, and wherein the first type of grant-free resource is accessible to a UE without further configuration; and configuring a second type of grant-free resource, wherein the second type of grant-free resource is UE-specific and is configured using a combination of broadcast signaling and unicast/multicast signaling, and wherein the second type of grant-free resource is accessible to a UE only after the unicast/multicast configuration.
1. A method for grant-free (GF) transmissions, the method comprising:
receiving, by a user equipment (UE), a Radio Resource Control (RRC) signal specifying at least a UE-specific GF radio network temporary identifier (GF-RNTI), wherein the UE-specific GF-RNTI is different from a cell-RNTI (C-RNTI) for a grant-based initial transmission or retransmission of the grant-based initial transmission;
performing, by the UE, a GF uplink (UL) transmission in a transmission resource without receiving a downlink control information (DCI) signal for allocation of the transmission resource;
receiving, by the UE, a UL grant; and
Performing, by the UE, a grant-based UL retransmission of the GF UL transmission using the UL grant and the UE-specific GF-RNTI.
2. The method of claim 1 , the receiving the UL grant comprising;
detecting, by the UE, the DCI signal in a search space of a physical downlink control channel (PDCCH) using the UE-specific GF-RNTI, the DCI signal comprising information about the grant based UL retransmission.
3. The method of claim 2 , wherein the DCI signal comprises GF specific configuration parameters.
4. The method of claim 2 , further comprising:
performing, by the UE, the GF UL transmission in response to the receiving the RRC signal and before the detecting the DCI signal.
5. The method of claim 2 , wherein the detecting the DCI signal in the search space of the PDCCH using the UE-specific GF-RNTI comprises:
descrambling, by the UE, a cyclic redundancy check (CRC) of the DCI signal in accordance with the UE-specific GF-RNTI; and
performing, by the UE, a CRC check of the DCI signal using the descrambled CRC.
6. The method of claim 1 , further comprising:
prior to the receiving, performing, by the UE, initial access by sending a preamble through a random access (RA) channel (RACH).
7. The method of claim 1 , wherein the performing comprises:
performing, by the UE, the GF UL transmission using a contention transmission unit (CTU) selected based on the UE-specific GF-RNTI.
8. A user equipment (UE) for grant-free (GF) transmissions, the UE comprising:
a non-transitory memory; and
a hardware processor configured to:
receive a Radio Resource Control (RRC) signal specifying at least a UE-specific GF radio network temporary identifier (GF-RNTI), wherein the UE-specific GF-RNTI is different from a cell-RNTI (C-RNTI) for a grant-based initial transmission or retransmission of the grant-based initial transmission;
perform a GF uplink (UL) transmission in a transmission resource without receiving a downlink control information (DCI) signal for allocation of the transmission resource;
receive a UL grant; and
perform a grant-based UL retransmission of the GF UL transmission using the UL grant and the UE-specific GF-RNTI.
9. The UE of claim 8 , the hardware processor further configured to receive the UL grant by:
detecting the DCI signal in a search space of a physical downlink control channel (PDCCH) using the UE-specific GF-RNTI, the DCI signal comprising information about the grant-based UL retransmission.
10. The UE of claim 9 , wherein the DCI signal comprises GF specific configuration parameters.
11. The UE of claim 9 , the hardware processor further configured to:
perform the GF UL transmission in response to receipt of the RRC signal and before detection of the DCI signal.
12. The UE of claim 9 , wherein the hardware processor is configured to detect the DCI signal in the search space of the PDCCH using the UE-specific GF-RNTI by:
descrambling a cyclic redundancy check (CRC) of the DCI signal in accordance with the UE-specific GF-RNTI; and
performing a CRC check of the DCI signal using the descrambled CRC.
13. The UE of claim 8 , the hardware processor further configured to:
prior to receiving the RRC signal, perform initial access by sending a preamble through a random access (RA) channel (RACH).
14. A method for grant-free (GF) transmissions, the method comprising:
transmitting, by a base station to a user equipment (UE), a Radio Resource Control (RRC) signal specifying at least a UE-specific GF radio network temporary identifier (GF-RNTI), wherein the UE-specific GF-RNTI is different from a cell-RNTI (C-RNTI) for a grant-based initial transmission or retransmission of the grant-based initial transmission;
receiving, by the base station, a GF uplink (UL) transmission in a transmission resource without transmitting a downlink control information (DCI) signal to the UE for allocating the transmission resource;
transmitting, by the base station, a UL grant; and
receiving, by the base station, a grant-based UL retransmission of the GF UL transmission using the UL grant and the UE-specific GF-RNTI.
15. The method of claim 14 , the transmitting the UL grant comprising:
transmitting, by the base station, the DCI signal comprising information about the grant-based UL retransmission, wherein the UE detect the DCI signal in a search space of a physical downlink control channel (PDCCH) using the UE-specific GF-RNTI.
16. The method of claim 15 , wherein the DCI signal comprises GF specific configuration parameters.
17. The method of claim 15 , further comprising:
receiving, by the base station, the GF UL transmission in response to the transmitting the RRC signal and before the transmitting the DCI signal.
18. The method of claim 14 , further comprising:
prior to the transmitting the RRC signal, receiving, by the base station, initial access by receiving a preamble through a random access (RA) channel (RACH).
19. An apparatus for grant-free (GF) transmissions, the apparatus comprising:
a non-transitory memory; and
a hardware processor configured to:
transmit, to a user equipment (UE), a Radio Resource Control (RRC) signal specifying at least a UE-specific GF radio network temporary identifier (GF-RNTI), wherein the UE-specific GF-RNTI is different from a cell-RNTI (C-RNTI) for a grant-based initial transmission or retransmission of the grant-based initial transmission;
receive a GF uplink (UL) transmission in a transmission resource without transmitting a downlink control information (DCI) signal to the UE for allocating the transmission resource;
transmit a UL grant; and
receive a grant-based UL retransmission of the GF UL transmission using the UL grant and the UE-specific GF-RNTI.
20. The apparatus of claim 19 , the hardware processor further configured to transmit the UL grant by:
transmitting the DCI signal comprising information about the grant-based UL retransmission, wherein the UE detect the DCI signal in a search space of a physical downlink control channel (PDCCH) using the UE-specific GF-RNTI.
21. The apparatus of claim 20 , wherein the DCI signal comprises GF specific configuration parameters.
22. The apparatus of claim 20 , the hardware processor further configured to:
receive the GF UL transmission in response to the transmitting the RRC signal and before transmitting the DCI signal.
23. The apparatus of claim 19 , the hardware processor further configured to:
prior to transmitting the RRC signal, receive initial access by receiving a preamble through a random access (RA) channel (RACH).