Carrier aggregation configurations in wireless systems
Methods, systems, and devices for wireless communications are described. A base station may configure a secondary component carrier (CC) for a user equipment (UE) which is not aligned on a valid channel raster entry. The location of the secondary CC may be indicated based on a reference location relative to another frequency or another CC. The reference location of the secondary CC may be the center of the new CC, an edge of the secondary CC, the position of a subcarrier within the secondary CC, or the position of a resource. In some examples, the reference location of the secondary CC may be indicated relative a currently used CC, an arbitrary channel entry, or an absolute frequency location. In some examples, the relative location may be provided in resource blocks or subcarriers and the subcarrier spacing (SCS). The base station may indicate the width of the secondary CC to the UE.
1. A method for wireless communication, comprising:
configuring a first location and a set of resource blocks for a component carrier of a secondary cell for a user equipment (UE); and
transmitting control signaling to the UE, wherein the control signaling comprises an indication of a reference location of the component carrier based at least in part on an absence of a fixed location of the component carrier of the secondary cell on a channel raster entry, wherein the reference location indicates to the UE the first location of the component carrier, wherein the reference location comprises an offset from an absolute frequency corresponding to a low frequency end of the set of resource blocks for the component carrier of the secondary cell, and wherein the control signaling comprises an indication of the set of resource blocks for the component carrier.
2. The method of claim 1 , further comprising:
transmitting an indication of a relationship between the set of resource blocks and the reference location or the absolute frequency.
3. The method of claim 1 , wherein:
the indication of the set of resource blocks comprises a quantity of resource blocks for the component carrier.
4. The method of claim 1 , wherein:
the reference location indicates a center frequency associated with the component carrier, a subcarrier position associated with the component carrier, or a resource block position associated with the component carrier.
5. The method of claim 4 , wherein the reference location indicates the subcarrier position and wherein:
the subcarrier position corresponds to a center subcarrier of the component carrier, an edge subcarrier of the component carrier, or a subcarrier index of a resource block of the component carrier.
6. The method of claim 4 , wherein the reference location indicates the resource block position and wherein:
the resource block position corresponds to a center resource block of the component carrier or an edge resource block of the component carrier.
7. The method of claim 1 , wherein:
the reference location is indicated in terms of resource blocks or subcarriers and in terms of an associated subcarrier spacing.
8. The method of claim 1 , wherein the control signaling comprises a radio resource control (RRC) message comprising the indication of the reference location.
9. The method of claim 1 , wherein the control signaling comprises a radio resource control (RRC) message comprising the indication of the set of resource blocks.
10. The method of claim 1 , further comprising:
communicating, over the set of resource blocks, with the UE using the component carrier.
11. The method of claim 1 , wherein:
at least one subcarrier of the component carrier aligns with a wideband component carrier of the UE.
12. The method of claim 1 , wherein the channel raster entry comprises an absolute radio frequency channel number.
13. A method for wireless communication, comprising:
receiving, from a base station, a reference location of a component carrier of a secondary cell for a user equipment (UE) based at least in part on an absence of a fixed location of the component carrier of the secondary cell on a channel raster entry, wherein the reference location comprises an offset from an absolute frequency corresponding to a low frequency end of a set of resource blocks for the component carrier of the secondary cell;
receiving, from the base station, an indication of the set of resource blocks for the component carrier;
determining a set of parameters of the component carrier of the secondary cell based at least in part on the reference location and the set of resource blocks, wherein the set of parameters comprises a first location of the component carrier, and wherein determining the set of parameters comprises determining the first location of the component carrier based at least in part on the reference location; and
communicating with the base station using the component carrier based at least in part on the set of parameters.
14. The method of claim 13 , further comprising:
identifying a relationship between the set of resource blocks and the reference location or the absolute frequency, wherein the set of parameters is determined based at least in part on the relationship.
15. The method of claim 14 , wherein identifying the relationship comprises:
receiving, from the base station, an indication of the relationship between the set of resource blocks and the reference location or the absolute frequency.
16. The method of claim 13 , wherein:
the indication of the set of resource blocks comprises a quantity of resource blocks for the component carrier.
17. The method of claim 13 , further comprising:
receiving at least one of the reference location or the indication of the set of resource blocks via a radio resource control (RRC) message.
18. The method of claim 13 , wherein:
the reference location indicates a center frequency associated with the component carrier, a subcarrier position associated with the component carrier, or a resource block position associated with the component carrier.
19. The method of claim 18 , wherein the reference location indicates the subcarrier position and wherein:
the subcarrier position corresponds to a center subcarrier of the component carrier, an edge subcarrier of the component carrier, or a subcarrier index of a resource block of the component carrier.
20. The method of claim 18 , wherein the reference location indicates the resource block position and wherein:
the resource block position corresponds to a center resource block of the component carrier or an edge resource block of the component carrier.
21. The method of claim 13 , wherein:
the reference location is indicated in terms of resource blocks or subcarriers and in terms of an associated subcarrier spacing.
22. The method of claim 13 , wherein:
at least one subcarrier of the component carrier aligns with a wideband component carrier of the UE.
23. The method of claim 13 , wherein the channel raster entry comprises an absolute radio frequency channel number.
24. An apparatus for wireless communication, comprising:
a processor;
memory coupled with the processor; and
instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to:
configure a first location and a set of resource blocks for a component carrier of a secondary cell for a user equipment (UE); and
transmit control signaling to the UE, wherein the control signaling comprises an indication of a reference location of the component carrier based at least in part on an absence of a fixed location of the component carrier of the secondary cell on a channel raster entry, wherein the reference location indicates to the UE the first location of the component carrier, wherein the reference location comprises an offset from an absolute frequency corresponding to a low frequency end of the set of resource blocks for the component carrier of the secondary cell, and wherein the control signaling comprises an indication of the set of resource blocks for the component carrier.
25. The apparatus of claim 24 , wherein the instructions are further executable by the processor to:
transmit an indication of a relationship between the set of resource blocks and the reference location or the absolute frequency.
26. The apparatus of claim 24 , wherein:
the indication of the set of resource blocks comprises a quantity of resource blocks for the component carrier.
27. The apparatus of claim 24 , wherein:
the reference location indicates a center frequency associated with the component carrier, a subcarrier position associated with the component carrier, or a resource block position associated with the component carrier.
28. The apparatus of claim 27 , wherein the reference location indicates the subcarrier position and wherein:
the subcarrier position corresponds to a center subcarrier of the component carrier, an edge subcarrier of the component carrier, or a subcarrier index of a resource block of the component carrier.
29. The apparatus of claim 27 , wherein the reference location indicates the resource block position and wherein:
the resource block position corresponds to a center resource block of the component carrier or an edge resource block of the component carrier.
30. The apparatus of claim 24 , wherein:
the reference location is indicated in terms of resource blocks or subcarriers and in terms of an associated subcarrier spacing.
31. The apparatus of claim 24 , wherein the control signaling comprises a radio resource control (RRC) message comprising the indication of the reference location.
32. The apparatus of claim 24 , wherein the control signaling comprises a radio resource control (RRC) message comprising the indication of the set of resource blocks.
33. The apparatus of claim 24 , wherein the instructions are further executable by the processor to:
communicate, over the set of resource blocks, with the UE using the component carrier.
34. The apparatus of claim 24 , wherein:
at least one subcarrier of the component carrier aligns with a wideband component carrier of the UE.
35. The apparatus of claim 24 , wherein the channel raster entry comprises an absolute radio frequency channel number.
36. An apparatus for wireless communication, comprising:
a processor;
memory coupled with the processor; and
instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to:
receive, from a base station, a reference location of a component carrier of a secondary cell for a user equipment (UE) based at least in part on an absence of a fixed location of the component carrier of the secondary cell on a channel raster entry, wherein the reference location comprises an offset from an absolute frequency corresponding to a low frequency end of a set of resource blocks for the component carrier of the secondary cell;
receive, from the base station, an indication of the set of resource blocks for the component carrier;
determine a set of parameters of the component carrier of the secondary cell based at least in part on the reference location and the set of resource blocks, wherein the set of parameters comprises a first location of the component carrier, and wherein determining the set of parameters comprises determining the first location of the component carrier based at least in part on the reference location; and
communicate with the base station using the component carrier based at least in part on the set of parameters.
37. The apparatus of claim 36 , wherein the instructions are further executable by the processor to:
identify a relationship between the set of resource blocks and the reference location or the absolute frequency, wherein the set of parameters is determined based at least in part on the relationship.
38. The apparatus of claim 37 , wherein the instructions are further executable by the processor to:
receive, from the base station, an indication of the relationship between the set of resource blocks and the reference location or the absolute frequency.
39. The apparatus of claim 37 , wherein:
the indication of the set of resource blocks comprises a quantity of resource blocks for the component carrier.
40. The apparatus of claim 36 , wherein the instructions are further executable by the processor to:
receive at least one of the reference location or the indication of the set of resource blocks via a radio resource control (RRC) message.
41. The apparatus of claim 36 , wherein:
the reference location indicates a center frequency associated with the component carrier, a subcarrier position associated with the component carrier, or a resource block position associated with the component carrier.
42. The apparatus of claim 41 , wherein the reference location indicates the subcarrier position and wherein:
the subcarrier position corresponds to a center subcarrier of the component carrier, an edge subcarrier of the component carrier, or a subcarrier index of a resource block of the component carrier.
43. The apparatus of claim 41 , wherein the reference location indicates the resource block position and wherein:
the resource block position corresponds to a center resource block of the component carrier or an edge resource block of the component carrier.
44. The apparatus of claim 36 , wherein:
the reference location is indicated in terms of resource blocks or subcarriers and in terms of an associated subcarrier spacing.
45. The apparatus of claim 36 , wherein:
at least one subcarrier of the component carrier aligns with a wideband component carrier of the UE.
46. The apparatus of claim 36 , wherein the channel raster entry comprises an absolute radio frequency channel number.
47. An apparatus for wireless communication, comprising:
means for configuring a first location and a set of resource blocks for a component carrier of a secondary cell for a user equipment (UE); and
means for transmitting control signaling to the UE, wherein the control signaling comprises an indication of a reference location of the component carrier based at least in part on an absence of a fixed location of the component carrier of the secondary cell on a channel raster entry, wherein the reference location indicates to the UE the first location of the component carrier, wherein the reference location comprises an offset from an absolute frequency corresponding to a low frequency end of the set of resource blocks for the component carrier of the secondary cell, and wherein the control signaling comprises an indication of the set of resource blocks for the component carrier.
48. An apparatus for wireless communication, comprising:
means for receiving, from a base station, a reference location of a component carrier of a secondary cell for a user equipment (UE) based at least in part on an absence of a fixed location of the component carrier of the secondary cell on a channel raster entry, wherein the reference location comprises an offset from an absolute frequency corresponding to a low frequency end of a set of resource blocks for the component carrier of the secondary cell;
means for receiving, from the base station, an indication of the set of resource blocks for the component carrier;
means for determining a set of parameters of the component carrier of the secondary cell based at least in part on the reference location and the set of resource blocks, wherein the set of parameters comprises a first location of the component carrier, and wherein determining the set of parameters comprises determining the first location of the component carrier based at least in part on the reference location; and
means for communicating with the base station using the component carrier based at least in part on the set of parameters.
49. A non-transitory computer readable medium storing code for wireless communication, the code comprising instructions executable by a processor to:
configure a first location and a set of resource blocks for a component carrier of a secondary cell for a user equipment (UE);
transmit control signaling to the UE, wherein the control signaling comprises an indication of a reference location of the component carrier indicates to the UE the first location of the component carrier based at least in part on an absence of a fixed location of the component carrier of the secondary cell on a channel raster entry, wherein the reference location comprises an offset from an absolute frequency corresponding to a low frequency end of the set of resource blocks for the component carrier of the secondary cell; and
transmit, to the UE, an indication of the set of resource blocks for the component carrier.
50. A non-transitory computer readable medium storing code for wireless communication, the code comprising instructions executable by a processor to:
receive, from a base station, a reference location of a component carrier of a secondary cell for a user equipment (UE) based at least in part on an absence of a fixed location of the component carrier of the secondary cell on a channel raster entry, wherein the reference location comprises an offset from an absolute frequency corresponding to a low frequency end of a set of resource blocks for the component carrier of the secondary cell;
receive, from the base station, an indication of the set of resource blocks for the component carrier;
determine a set of parameters of the component carrier of the secondary cell based at least in part on the reference location and the set of resource blocks, wherein the set of parameters comprises a first location of the component carrier, and wherein determining the set of parameters comprises determining the first location of the component carrier based at least in part on the reference location; and
communicate with the base station using the component carrier based at least in part on the set of parameters.