Methods and apparatus for sub-band-based PDCCH hopping in wireless communication
An approach for wireless communications to support reduced capability New Radio (NR) with larger available control resource sets (CORESET) bandwidths. Examples include a frequency-hopping CORESET with a predefined hopping pattern configured by higher layers, such as RRC signaling or MAC Control Element (CE) on a per CORESET per UE or purely per UE basis. Frequency hopping patterns for CORESET transmissions include the use of PRBs for CORESETs that are mirrored with respect to the central frequency of active bandwidth part (BWP), and the use of a random parameter to step through the frequency pattern. The sub-band location of the physical downlink shared channel that is scheduled by the physical downlink control channel may be indicated using the DCI format, or may be based on a last slot for PDCCH transmission.
1. A user equipment (UE) having a reduced bandwidth capability, the UE comprising:
a receiver configured to receive control resource set (CORESET) transmissions from a gNB, the CORESET transmissions following a frequency hopping pattern across a set of sub-bands, each sub-band of the set of sub-bands being a subset of a system bandwidth available from the gNB; and
processor circuitry configured to:
determine a sub-band location associated with the CORESET transmissions, the sub-band location determined from information received from a physical downlink control channel (PDCCH) transmission, and
control the receiver according to the determined sub-band location,
wherein the frequency hopping pattern is based on a randomization parameter for determination of each sub-band such that continuous PDCCH transmission blocking is avoided.
2. The UE of claim 1 , wherein the frequency hopping pattern includes a pattern mirrored with respect to a central frequency of an active bandwidth part (BWP).
3. The UE of claim 1 , wherein the sub-band location is determined by adding a random value to an index, the index being based on a number of monitoring occasions the CORESET transmissions stay at a same sub-band before hopping to another sub-band, a number of sub-bands used in the frequency hopping pattern, a sub-band offset between consecutive sub-bands, and a total number of downlink (DL) sub-bands.
4. The UE of claim 3 , wherein the random value is obtained by multiplication, by a first integer, of a previous random value, followed by a modulo operation using a second integer.
5. The UE of claim 1 , wherein the frequency hopping pattern further includes frequency hopping having a frequency hopping window that includes a number of consecutive PDCCH monitoring occasions.
6. The UE of claim 1 , wherein the receiver retunes between sub-bands, and the processor circuitry includes an allowance for retuning time in its processing.
7. The UE of claim 1 , wherein the information received from the physical downlink control channel (PDCCH) transmission is in a sub-band indicator field (SIF) in a download control information (DCI) format.
8. The UE of claim 1 , wherein the sub-band location is based on a last slot of the PDCCH transmission.
9. A method for communication by a user equipment (UE) having a reduced bandwidth capability, the method comprising:
determining a sub-band location associated with CORESET transmissions, the sub-band location being determined from information received from a physical downlink control channel (PDCCH) transmission; and
receiving the CORESET transmissions from a gNB, the CORESET transmissions following a frequency hopping pattern across a set of sub-bands, each sub-band of the set of sub-bands being a subset of a system bandwidth available from the gNB, and wherein one sub-band of the set of sub-bands is at the sub-band location,
wherein the frequency hopping pattern is based on a randomization parameter for determination of each sub-band such that continuous PDCCH transmission blocking is avoided.
10. The method of claim 9 , wherein the frequency hopping pattern includes a pattern mirrored with respect to a central frequency of an active bandwidth part (BWP).
11. The method of claim 9 , wherein the sub-band location is determined by adding a random value to an index, the index being based on a number of monitoring occasions the CORESET transmissions stay at a same sub-band before hopping to another sub-band, a number of sub-bands used in the frequency hopping pattern, a sub-band offset between consecutive sub-bands, and a total number of downlink (DL) sub-bands.
12. The method of claim 11 , wherein the random value is obtained by multiplication, by a first integer, of a previous random value, followed by a modulo operation using a second integer.
13. The method of claim 9 , further comprising:
retuning between sub-bands,
wherein the determining the sub-band location includes an allowance for retuning time in the determining.
14. The method of claim 9 , wherein the information received from the physical downlink control channel (PDCCH) transmission is in a sub-band indicator field (SIF) in a download control information (DCI) format.
15. The method of claim 9 , wherein the sub-band location is based on a last slot of the PDCCH transmission.
16. A non-transitory computer-readable media comprising instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one of more elements of a method, the method comprising:
determining a sub-band location associated with CORESET transmissions, the sub-band location being determined from information received from a physical downlink control channel (PDCCH) transmission; and
causing to receive the CORESET transmissions from a gNB, the CORESET transmissions following a frequency hopping pattern across a set of sub-bands, each sub-band of the set of sub-bands being a subset of a system bandwidth available from the gNB, and wherein one sub-band of the set of sub-bands is at the sub-band location,
wherein the frequency hopping pattern is based on a randomization parameter for determination of each sub-band such that continuous PDCCH transmission blocking is avoided.
17. The non-transitory computer-readable media of claim 16 , wherein the frequency hopping pattern includes a pattern mirrored with respect to a central frequency of an active bandwidth part (BWP).
18. The non-transitory computer-readable media of claim 16 , wherein the sub-band location is determined by adding a random value to an index, the index being based on a number of monitoring occasions the CORESET transmissions stay at a same sub-band before hopping to another sub-band, a number of sub-bands used in the frequency hopping pattern, a sub-band offset between consecutive sub-bands, and a total number of downlink (DL) sub-bands.
19. The non-transitory computer-readable media of claim 16 , wherein the information received from the physical downlink control channel (PDCCH) transmission is in a sub-band indicator field (SIF) in a download control information (DCI) format.
20. The non-transitory computer-readable media of claim 16 , wherein the sub-band location is based on a last slot of the PDCCH transmission.