Dynamical time division duplex uplink and downlink configuration in a communications network
A technology is disclosed for an evolved Node B (eNB) operable to transmit a physical downlink control channel (PDCCH) to a user equipment (UE). The eNB can determine a set of configuration indication fields numbered 1 to N, included in a downlink control information (DCI) format Y carried on the PDCCH, where N = ⌊ L format Y M ⌋ , L format Y is equal to a payload size of the DCI format Y, and M is a number of bits of each configuration indication field. The eNB can map the DCI format Y onto the PDCCH. The eNB can transmit to the UE the PDCCH with a cyclic redundancy check (CRC) scrambled by an enhanced interference mitigation and traffic adaptation (eIMTA) Radio-Network Temporary Identifier (RNTI) for the UE.
1. An evolved Node B (eNB) operable to transmit a physical downlink control channel (PDCCH) to a user equipment (UE), the eNB comprising:
one or more processors configured to:
determine, at the eNB, a set of configuration indication fields numbered 1 to N, included in a downlink control information (DCI) format Y carried on the PDCCH, where
N
=
⌊
L
format
Y
M
⌋
,
L format Y is equal to a payload size of the DCI format Y, and M is a number of bits of each configuration indication field; and
map, at the eNB, the DCI format Y onto the PDCCH;
a transceiver configured to transmit to the UE the PDCCH with a cyclic redundancy check (CRC) scrambled by an enhanced interference mitigation and traffic adaptation (eIMTA) Radio-Network Temporary Identifier (RNTI) for the UE; and
memory configured to store the DCI format Y.
2. The eNB of claim 1 , wherein the transceiver is further configured to transmit the PDCCH to the UE for reconfiguring a time division duplex (TDD) uplink and downlink (UL/DL) configuration at the UE, wherein the PDCCH is mapped to the DCI format Y, and the DCI format Y is included in a TDD UL/DL configuration indication.
3. The eNB of claim 1 , wherein the DCI format Y is a format 1 C.
4. The eNB of claim 1 , wherein M=3.
5. The eNB of claim 1 , wherein the one or more processors are further configured to append one or more bits, with a predefined value of zero, to the set of configuration indication fields, until a total number of bits of the N configuration indication fields is equal to the payload size of the DCI format Y.
6. The eNB of claim 1 , wherein the transceiver is further configured to transmit the eIMTA-RNTI to the UE to enable the UE to decode the PDCCH.
7. The eNB of claim 1 , wherein the transceiver is further configured to transmit a time domain duplex (TDD) uplink and downlink (UL/DL) configuration index to the UE using radio resource control (RRC) signaling, wherein the TDD UL/DL configuration index is for the set of configuration indication fields numbered 1 to N.
8. The eNB of claim 1 , wherein the transceiver is further configured to receive a message from the UE that indicates that the UE supports a time division duplex (TDD) uplink and downlink (UL/DL) reconfiguration functionality.
9. The eNB of claim 1 , wherein the one or more processors are further configured to map the DCI format Y onto a common search space (CSS) of the PDCCH for transmission to the UE.
10. A user equipment (UE) operable to reconfigure a time division duplex (TDD) uplink and downlink configuration, the UE comprising:
a transceiver configured to:
receive, at the UE, an uplink and downlink (UL/DL) configuration indication from an eNB for a TDD reconfiguration, the UL/DL configuration indication comprising a set of configuration indication fields numbered 1 to N, included in a downlink control information (DCI) format Y carried on a physical downlink control channel (PDCCH), where
N
=
⌊
L
format
Y
M
⌋
,
L format Y is equal to a payload size of the DCI format Y, and M is a number of bits of each configuration indication field; and
receive, at the UE, an encoded PDCCH from the eNB, wherein the DCI format Y is mapped onto the PDCCH, wherein the PDCCH is encoded with a cyclic redundancy check (CRC) scrambled with an enhanced interference mitigation and traffic adaptation (eIMTA) Radio-Network Temporary Identifier (RNTI) for the UE; and
memory configured to store the UL/DL configuration indication.
11. The UE of claim 10 , wherein the DCI format Y is a format 1 C.
12. The UE of claim 10 , wherein M=3.
13. The UE of claim 10 , wherein one or more bits are appended, with a predefined value of zero, to the set of configuration indication fields, until a total number of bits of the N configuration indication fields is equal to the payload size of the DCI format Y.
14. The UE of claim 10 , wherein the transceiver is further configured to receive a time domain duplex (TDD) uplink and downlink (UL/DL) configuration index from the eNB using radio resource control (RRC) signaling, wherein the TDD UL/DL configuration index is for the set of configuration indication fields numbered 1 to N.
15. The UE of claim 10 , wherein the transceiver is further configured to transmit a message to the eNB that indicates that the UE supports a TDD UL-DL reconfiguration functionality.
16. A user equipment (UE) operable to modify an uplink/downlink (UL/DL) configuration, the UE comprising:
a transceiver configured to:
send, to an eNodeB, a request for a radio resource control (RRC) connection with the eNodeB;
transmit, to the eNodeB, a UE Capability information element (IE) that indicates an enhanced interference mitigation and traffic adaptation (eIMTA) capability of the UE to support an eIMTA time duplex domain (TDD) UL/DL reconfiguration functionality; and
receive, from the eNodeB, eIMTA configuration information via a radio resource control (RRC) message in response to transmitted the UE Capability IE from the UE to the eNodeB, wherein the RRC message includes an eIMTA Radio-Network Temporary Identifier (RNTI); and
memory configured to store the eIMTA configuration information.
17. The UE of claim 16 , further comprising one or more processors configured to:
attempt to decode an UL/DL reconfiguration PDCCH with a cyclic redundancy check (CRC) scrambled by the assigned eIMTA-RNTI; and
determine UL/DL configuration information from a decoded UL/DL reconfiguration PDCCH based on the assigned indicator field index.
18. The UE of claim 17 , wherein the UL/DL reconfiguration PDCCH includes N TDD UL/DL Configuration Indicator (TCI) fields, where N is determines using
N
=
⌊
L
format
Y
-
R
others
M
⌋
,
wherein L format Y is a payload size of an existing downlink control information (DCI) format Y before CRC attachment, R others ≥0 is a number of information bits used for selected functionalities, M is payload size for each UL/DL configuration indicator field within UL/DL reconfiguration PDCCH, and format Y is mapped onto a common search space.
19. The UE of claim 18 , wherein zero-padding information bits are appended to TDD UL/DL configuration indicator fields until a UL/DL reconfiguration PDCCH size is equal to a format Y size mapped onto the common search space.
20. The UE of claim 16 , further comprising one or more processors configured to monitor one common search space (CSS) on a Primary Cell (PCell) to receive the UL/DL reconfiguration PDCCH with CRC scrambled by the eIMTA-RNTI assigned for the UE.