Downlink control channel in wireless systems
Systems, methods, and instrumentalities may be disclosed for implementing a flexible radio access communication system. A flexible radio access communication system may be supported using spectrum of varying size, including aggregation of non-adjacent carriers in the same and/or in different frequency bands. A wireless transmit/receive unit (WTRU) may receive a first transmission via a common downlink control channel. The first transmission may include first control information. The first control information may include information regarding the configuration of a first dedicated downlink control channel of one or more dedicated control channels. The WTRU may receive a second transmission via the first dedicated downlink control channel of the dedicated control channels. The second transmission may include second control information. The second control information may be associated with a transmission of a first transmission type. The dedicated downlink control channels may be used for providing control information associated with different types of transmissions.
1. A wireless transmit/receive unit (WTRU), comprising:
a processor; and
a receiver operatively coupled to the processor;
the processor and receiver configured to:
determine a first bandwidth region associated with a first subcarrier spacing and a first cyclic prefix, wherein the first bandwidth region is a subset of a system bandwidth and is used by the WTRU when initially accessing a cell;
receive a first downlink control channel transmission within the first bandwidth region;
receive configuration information related to: 1) a second downlink control channel transmission associated with a second bandwidth region of the system bandwidth and 2) a set of search spaces associated with the second bandwidth region, wherein the second bandwidth region is associated with a second subcarrier spacing and a second cyclic prefix; and
monitor for the second downlink control channel transmission in at least the set of search spaces associated with the second bandwidth region.
2. The WTRU of claim 1 , wherein the configuration information related to the second downlink control channel transmission is associated with any of: a waveform, a numerology, a resource element type, a resource block type, or a control channel type.
3. The WTRU of claim 2 , wherein the numerology comprises any of: the second subcarrier spacing, a time symbol length, or the second cyclic prefix.
4. The WTRU of claim 1 , wherein the processor and the receiver are further configured to monitor for the second downlink control channel transmission in at least the set of search spaces based on an indication received via the first downlink control channel transmission.
5. The WTRU of claim 1 , wherein each of the first and second bandwidth regions is associated with a respective set of contiguous physical resource blocks.
6. The WTRU of claim 1 , wherein the first downlink control channel transmission is a common control channel transmission, and the second downlink control channel transmission is a dedicated control channel transmission.
7. The WTRU of claim 1 , wherein the configuration information indicates a time and frequency location of the second downlink control channel transmission associated with the second bandwidth region.
8. The WTRU of claim 1 , wherein the first and second bandwidth regions are each associated with a different numerology.
9. The WTRU of claim 1 , wherein the configuration information is received using Radio Resource Control (RRC) signaling.
10. The WTRU of claim 1 , wherein the receiver is further configured to receive the second downlink control channel transmission within the second bandwidth region.
11. The WTRU of claim 1 , wherein the configuration information indicates the set of search spaces associated with the second bandwidth region is different from a set of search spaces associated with the first bandwidth region.
12. The WTRU of claim 1 , wherein the configuration information indicates any of: the second subcarrier spacing associated with the second bandwidth region is different from the first subcarrier spacing associated with the first bandwidth region, or the second cyclic prefix associated with the second bandwidth region is different from the first cyclic prefix associated with the first bandwidth region.
13. The WTRU of claim 1 , wherein the processor and receiver are configured to: when monitoring for the second downlink control channel transmission in at least the set of search spaces, attempt to decode or receive the second downlink control channel transmission within the second bandwidth region.
14. A method implemented in a wireless transmit/receive unit (WTRU) for wireless communications, the method comprising:
determining a first bandwidth region associated with a first subcarrier spacing and a first cyclic prefix, wherein the first bandwidth region is a subset of a system bandwidth and is used by the WTRU when initially accessing a cell;
receiving a first downlink control channel transmission within the first bandwidth region;
receiving configuration information related to: 1) a second downlink control channel transmission associated with a second bandwidth region of the system bandwidth and 2) a set of search spaces associated with the second bandwidth region, wherein the second bandwidth region is associated with a second subcarrier spacing and a second cyclic prefix; and
monitoring for the second downlink control channel transmission in at least the set of search spaces associated with the second bandwidth region.
15. The method of claim 14 , wherein the configuration information related to the second downlink control channel transmission is associated with any of: a waveform, a numerology, a resource element type, a resource block type, or a control channel type.
16. The method of claim 15 , wherein the numerology comprises any of: the second subcarrier spacing, a time symbol length, or the second cyclic prefix.
17. The method of claim 14 , wherein the first and second bandwidth regions are each associated with a different numerology.
18. The method of claim 14 , wherein the configuration information is received using Radio Resource Control (RRC) signaling.
19. The method of claim 14 , further comprising:
receiving the second downlink control channel transmission within the second bandwidth region.
20. The method of claim 14 , wherein the monitoring for the second downlink control channel transmission in at least the set of search spaces comprises attempting to decode or receive the second downlink control channel transmission within the second bandwidth region.