Reconfiguration of Active Component Carrier Set in Multi-Carrier Wireless Systems
In a multi-carrier wireless system, potential problems from reconfiguring mobile station resources to accommodate changes in component-carrier configuration are mitigated by inserting a guard period each time the configuration of component carriers changes, so that transceiver reconfiguration can be carried out without interfering with ongoing transmission. A base station is configured to transmit data to a mobile station according to a first configuration of two or more component carriers, to determine that a change of configuration to a second component-carrier configuration is required, and to signal the change of configuration to the mobile station, using the first configuration of component carriers. The base station then refrains from transmitting data to the mobile station during a pre-determined guard interval of at least one transmission-time interval subsequent to the signaling of the change of configuration. After the guard interval, data is transmitted to the mobile station according to the second component-carrier configuration.
1 . A method in a base station for controlling data transmission in a wireless communications network configured for multi-carrier operation, the method comprising:
transmitting first data to a mobile station according to a first configuration of two or more component carriers;
determining that a change of configuration to a second component-carrier configuration is required;
signaling the change of configuration to the mobile station, using the first configuration;
refraining from transmitting data to the mobile station during a pre-determined guard interval of at least one transmission-time interval subsequent to the signaling of the change of configuration; and
transmitting second data to the mobile station according to the second component-carrier configuration, after the guard interval.
2 . The method of claim 1 , wherein the pre-determined guard interval consists of a single transmission-time interval.
3 . The method of claim 1 , wherein the pre-determined guard interval immediately follows the transmission-time interval in which the change of configuration is signaled.
4 . The method of claim 1 , wherein the guard interval is delayed by one or more transmission-time intervals following the transmission-time interval in which the change of configuration is signaled, and wherein the method further comprises continuing transmission of the first data according to the first configuration for at least one transmission-time interval subsequent to the signaling of the change of configuration and prior to the pre-determined guard interval.
5 . The method of claim 1 , wherein the change of configuration comprises a change in the number of component carriers to be used for data transmission.
6 . The method of claim 1 , wherein the change of configuration comprises a change to a set of active component carriers, with the number of active component carriers remaining the same.
7 . The method of claim 1 , further comprising delaying an automatic-repeat-request process corresponding to the mobile station by a number of transmission-time intervals equal to the pre-determined guard interval.
8 . A base station of a wireless communications network configured for multi-carrier operation, the base station comprising a control circuit configured to:
transmit first data to a mobile station according to a first configuration of two or more component carriers;
determine that a change of configuration to a second component-carrier configuration is required;
signal the change of configuration to the mobile station, using the first configuration;
refrain from transmitting data to the mobile station during a pre-determined guard interval of at least one transmission-time interval subsequent to the signaling of the change of configuration; and
transmit second data to the mobile station according to the second component-carrier configuration, after the guard interval.
9 . The base station of claim 8 , wherein the pre-determined guard interval consists of a single transmission-time interval.
10 . The base station of claim 8 , wherein the pre-determined guard interval immediately follows the transmission-time interval in which the change of configuration is signaled.
11 . The base station of claim 8 , wherein the guard interval is delayed by one or more transmission-time intervals following the transmission-time interval in which the change of configuration is signaled, and wherein the control circuit is configured to continue transmitting the first data according to the first configuration for at least one transmission-time interval subsequent to the signaling of the change of configuration and prior to the pre-determined guard interval.
12 . The base station of claim 8 , wherein the change of configuration comprises a change in the number of component carriers to be used for data transmission.
13 . The base station of claim 8 , wherein the change of configuration comprises a change to a set of active component carriers, with the number of active component carriers remaining the same.
14 . The base station of claim 8 , wherein the control circuit is further configured to delay an automatic-repeat-request process corresponding to the mobile station by a number of transmission-time intervals equal to the pre-determined guard interval.