System and method for supporting inter-band carrier aggregation with different UL/DL TDD configurations
In some implementations, a method of wireless communications between a wireless communications network and wireless user equipment includes receiving, using a primary Time Division Duplex (TDD) configuration, data on a primary component carrier in a first frequency band. Using a secondary TDD configuration, data on a secondary component carrier is received in a second frequency band different from the first frequency band. A Hybrid Automatic Repeat Request (HARQ) for data received on the secondary component carrier is transmitted using a supplemental TDD configuration. A transmission or retransmission on the secondary component carrier uses a supplemental TDD configuration as well. The supplemental TDD configuration is different from the secondary TDD configuration. Furthermore, an uplink supplemental configuration may be different from a downlink supplemental configuration.
1. A method, comprising:
determining a first transmission direction in a same subframe in a primary component carrier using a primary Time Division Duplex (TDD) configuration, wherein the primary component carrier is in a first frequency band;
determining a second transmission direction at the same subframe in a secondary component carrier using a secondary TDD configuration, wherein the second component carrier is in a second frequency band different from the first frequency band;
if the first transmission direction is different from the second transmission direction, selecting a muted component carrier from the primary component carrier and the secondary component carrier; and
muting transmission and reception on the muted component carrier at the same subframe.
2. The method of claim 1 , further comprising:
transmitting an uplink Hybrid Automatic Repeat Request (HARQ) for uplink data transmitted on the secondary component carrier at transmission times defined in the primary TDD configuration; and
receiving a downlink HARQ for downlink data received on the secondary component carrier at transmission times defined in the primary TDD configuration.
3. The method of claim 2 , further comprising transmitting an uplink grant granting resources for uplink data transmissions on the secondary component carrier at transmission times defined in the primary TDD configuration.
4. The method of claim 2 , further comprising retransmitting an uplink data packet on the secondary component carrier at a modified uplink retransmission subframe different from an uplink retransmission subframe specified by supplemental TDD configuration.
5. The method of claim 4 , wherein the modified uplink transmission or retransmission subframe is one subframe prior to an uplink transmission subframe specified by the primary TDD configuration.
6. The method of claim 4 , wherein the modified uplink transmission or retransmission subframe is at a next available uplink subframe after an uplink transmission subframe specified by the primary TDD configuration.
7. The method of claim 1 , wherein selecting the muted component carrier is periodically executed, and the selection is based, at least in part, on an evaluation of at least one interference condition or traffic condition.
8. A user equipment (UE), comprising:
at least one processor; and
one or more memories coupled to the at least one processor and storing programming instructions for execution by the at least one processor to cause the UE to:
receive, using a primary time division duplex (TDD) configuration, data on a primary component carrier in a first frequency band;
receive, using a secondary TDD configuration, data on a secondary component carrier in a secondary frequency band different from the first frequency band; and
transmit a Hybrid Automatic Repeat Request (HARQ) for data received on the second component carrier using a supplemental TDD configuration, wherein the supplemental TDD configuration is different from the secondary TDD configuration.
9. The user equipment of claim 8 , wherein the primary TDD configuration comprises a primary downlink TDD configuration including downlink subframes, the secondary TDD configuration comprises a secondary downlink TDD configuration including downlink subframes, and a supplemental downlink TDD configuration specifies a set of downlink subframes including downlink subframes specified in the primary TDD configuration and the secondary TDD configuration.
10. The user equipment of claim 8 , wherein the one or more memories store programming instructions for execution by the at least one processor to cause the UE to: transmit an uplink HARQ for uplink data received on the secondary component carrier by using a supplemental uplink TDD configuration, wherein the supplemental uplink TDD configuration specifies a set of uplink subframes including uplink subframes in the primary TDD configuration and the secondary TDD configuration.
11. The user equipment of claim 10 , wherein the one or more memories store programming instructions for execution by the at least one processor to cause the UE to transmit, using the supplemental uplink TDD configuration, an uplink grant granting resources for uplink data transmissions on the secondary component carrier.
12. The user equipment of claim 11 , wherein the one or more memories store programming instructions for execution by the at least one processor to cause the UE to retransmit an uplink data packet on the secondary component carrier at a modified uplink retransmission subframe different from an uplink retransmission subframe specified by the supplemental TDD configuration.
13. The user equipment of claim 12 , wherein the modified uplink retransmission subframe is a subframe preceding the uplink retransmission subframe.
14. The user equipment of claim 12 , wherein the modified uplink retransmission subframe is a next available uplink subframe not previously scheduled after the uplink retransmission subframe.
15. The user equipment of claim 8 , wherein the supplemental TDD configuration comprises a supplemental downlink TDD configuration or a supplemental uplink TDD configuration.
16. The user equipment of claim 8 , wherein the one or more memories store programming instructions for execution by the at least one processor to cause the UE to receive data on tertiary component carrier using a third TDD configuration in a third frequency band different from the first frequency band and the second frequency band, wherein the supplemental TDD configuration comprises an aggregation of the primary TDD configuration and third TDD configuration.
17. The user equipment of claim 8 , wherein the one or more memories store programming instructions for execution by the at least one processor to cause the UE to, in response to not receiving a DL PDCCH to schedule grants, execute at least one of Cross Transmission Time Interval (TTI) scheduling, bundle scheduling, or temporarily disable cross-carrier scheduling.
18. A user equipment (UE), comprising:
at least one processor; and
one or more memories coupled to the at least one processor and storing programming instructions for execution by the at least one processor to cause the UE to:
determine a first transmission direction at a subframe in a primary component carrier using a primary Time Division Duplex (TDD) configuration, wherein the primary component carrier is in a first frequency band;
determine a second transmission direction at the subframe in a secondary component carrier using a secondary TDD configuration, wherein the second component carrier is in a second frequency band different from the first frequency band;
receive an indication on a muted component carrier if the first transmission direction is different from the second transmission direction; and
mute transmission and reception on the muted component carrier at the subframe.
19. The user equipment of claim 18 , wherein the one or more memories store programming instructions for execution by the at least one processor to cause the UE to:
receive an uplink Hybrid Automatic Repeat Request (HARQ) for uplink data transmitted on the secondary component carrier at transmission times defined in the primary TDD configuration; and
transmit a downlink HARQ for downlink data received on the secondary component carrier at transmission times defined in the primary TDD configuration.
20. The user equipment of claim 19 , wherein the one or more memories store programming instructions for execution by the at least one processor to cause the UE to receive an uplink grant granting resources for uplink data transmissions on the secondary component carrier at transmission times defined in the primary TDD configuration.