Coreset enhancement for reduced bandwidth UEs initial access
Systems and methods are disclosed herein for Control Resource Set (CORESET) enhancements for initial access. In one embodiment, a method performed by a wireless communication device comprises receiving and decoding a Physical Downlink Control Channel (PDCCH) transmission in a CORESET in accordance with at least a portion of a Control Channel Element (CCE) to Resource Element Group (REG) mapping. The PDCCH transmission comprises one or more CCEs. The CCE to REG mapping comprises an interleaved portion that maps the one or more CCEs to a first set of REGs that are spread across a bandwidth of the CORESET, and a second portion that maps at least a portion of an additional CCE to at least a REG in a frequency gap between two REGs in the first set of REGs, the additional CCE corresponding to one of the CCEs mapped to the first set of REGs.
1. A method performed by a wireless communication device, the method comprising:
receiving and decoding a Physical Downlink Control Channel, PDCCH, transmission in a Control Resource Set, CORESET, in accordance with at least a portion of a Control Channel Element, CCE, to Resource Element Group, REG, mapping;
wherein:
the PDCCH transmission comprises one or more CCEs; and
the CCE to REG mapping comprises:
an interleaved portion that maps the one or more CCEs to a first set of REGs that are spread across a bandwidth of the CORESET; and
a second portion that maps at least a portion of an additional CCE to at least a REG in a frequency gap between two REGs in the first set of REGs, the additional CCE corresponding to one of the one or more CCEs mapped to the first set of REGs by the interleaved portion of the CCE to REG mapping, wherein:
the one or more CCEs comprised in the PDCCH transmission consist of a plurality of CCEs;
the interleaved portion maps the plurality of CCEs to the first set of REGs that are spread across the bandwidth of the CORESET; and
the second portion maps the additional CCE to REGs in one or more frequency gaps between REGs in the first set of REGs.
2. The method of claim 1 wherein the at least a portion of the additional CCE is also comprised in the PDCCH transmission.
3. The method of claim 1 , wherein the wireless communication device supports the bandwidth of the CORESET.
4. The method of claim 1 , wherein:
the wireless communication device supports a portion of the bandwidth of the CORESET;
the one or more CCEs comprised in the PDCCH transmission consist of a plurality of CCEs; and
receiving and decoding the PDCCH transmission comprises receiving and decoding the PDCCH transmission using:
a portion of the plurality of CCEs mapped by the interleaved portion of the CCE to REG mapping to REGs that are within the portion of the bandwidth of the CORESET supported by the wireless communication device; and
the at least a portion of the additional CCE mapped by the second portion of the CCE to REG mapping to the at least a REG in the frequency gap.
5. The method of claim 1 , wherein the interleaved portion maps each of the one or more CCEs to six REGs.
6. The method of claim 1 , wherein the CCE to REG mapping uses a REG bundle size of six.
7. The method of claim 1 , wherein:
the at least a portion of the additional CCE mapped by the second portion of the CCE to REG mapping is a copy of a corresponding at least a portion of said one of the one or more CCEs mapped to the first set of REGs by the interleaved portion of the CCE to REG mapping, wherein said corresponding at least a portion is mapped by the interleaved portion of the CCE to REG mapping to one or more REGs comprising at least one REG located outside a bandwidth supported by the wireless communication device.
8. The method of claim 1 , wherein:
the at least a portion of the additional CCE mapped by the second portion of the CCE to REG mapping is a copy of a corresponding at least a portion of said one of the one or more CCEs mapped to the first set of REGs by the interleaved portion of the CCE to REG mapping, wherein said corresponding at least a portion is mapped by the interleaved portion of the CCE to REG mapping to one or more REGs comprising at least one REG located within a bandwidth supported by the wireless communication device;
wherein the at least one REG located within the bandwidth supported by the wireless communication device is a REG adjacent to the frequency gap.
9. The method of claim 1 , wherein the CCE to REG mapping is a non-interleaved CCE to REG mapping.
10. The method of claim 1 , wherein the second portion of the CCE to REG mapping maps one or more additional CCEs to REGs in one or more frequency gaps between REGs in the first set of REGs spread across the bandwidth of the CORESET so that the CCEs of the PDCCH transmission are mapped by the CCE to REG mapping to contiguous REGs, at least up to a frequency threshold, wherein the one or more additional CCEs correspond to one or more of the CCEs mapped by the interleaved portion of the CCE to REG mapping.
11. The method of claim 1 , further comprising receiving information that configures the CORESET.
12. The method of claim 1 , wherein the CORESET is:
employed for scheduling system information; and/or
employed for initial access; and/or
is a CORESET #0;
one or more transmitters;
one or more receivers; and
processing circuitry associated with the one or more transmitters and the one or more receivers, the processing circuitry configured to cause the wireless communication device to.
13. The method of claim 1 , wherein:
the first set of REGs to which the interleaved portion of the CCE to REG mapping maps the one or more CCEs comprises REGs in one or more symbols; and
the second portion of the CCE to REG mapping maps at least a portion of a second additional CCE to one or more REGs comprising at least one REG in a symbol other than the one or more symbols, the second additional CCE corresponding to another one of the one or more CCEs.
14. The method of claim 1 , wherein the interleaved portion of the CCE to REG mapping is used in a legacy system.
15. The method of claim 1 , wherein the wireless communication device is a reduced bandwidth device.
16. A wireless communication device comprising:
receive and decode a Physical Downlink Control Channel, PDCCH, transmission in a Control Resource Set, CORESET, in accordance with at least a portion of a Control Channel Element, CCE, to Resource Element Group, REG, mapping;
wherein:
the PDCCH transmission comprises one or more CCEs; and
the CCE to REG mapping comprises:
an interleaved portion that maps the one or more CCEs to a first set of REGs that are spread across a bandwidth of the CORESET; and
a second portion that maps at least a portion of an additional CCE to at least a REG in a frequency gap between two REGs in the first set of REGs, the additional CCE corresponding to one of the one or more CCEs mapped to the first set of REGs by the interleaved portion of the CCE to REG mapping, wherein:
the one or more CCEs comprised in the PDCCH transmission consist of a plurality of CCEs;
the interleaved portion maps the plurality of CCEs to the first set of REGs that are spread across the bandwidth of the CORESET; and
the second portion maps the additional CCE to REGs in one or more frequency gaps between REGs in the first set of REGs.
17. A method performed by a network node, the method comprising:
transmitting a Physical Downlink Control Channel, PDCCH, transmission in a Control Resource Set, CORESET, in accordance with a Control Channel Element, CCE, to Resource Element Group, REG, mapping;
wherein:
the PDCCH transmission comprises one or more CCEs; and
the CCE to REG mapping comprises:
an interleaved portion that maps the one or more CCEs to a first set of REGs that are spread across a bandwidth of the CORESET; and
a second portion that maps at least a portion of an additional CCE to at least a REG in a frequency gap between two REGs in the first set of REGs, the additional CCE corresponding to one of the one or more CCEs mapped to the first set of REGs by the interleaved portion of the CCE to REG mapping, wherein:
the one or more CCEs comprised in the PDCCH transmission consist of a plurality of CCEs;
the interleaved portion maps the plurality of CCEs to the first set of REGs that are spread across the bandwidth of the CORESET; and
the second portion maps the additional CCE to REGs in one or more frequency gaps between REGs in the first set of REGs.
18. The method of claim 17 wherein the at least a portion of the additional CCE is also comprised in the PDCCH transmission.
19. A network node comprising processing circuitry configured to cause the network node to:
transmit a Physical Downlink Control Channel, PDCCH, transmission in a Control Resource Set, CORESET, in accordance with a Control Channel Element, CCE, to Resource Element Group, REG, mapping;
wherein:
the PDCCH transmission comprises one or more CCEs; and
the CCE to REG mapping comprises:
an interleaved portion that maps the one or more CCEs to a first set of REGs that are spread across a bandwidth of the CORESET; and
a second portion that maps at least a portion of an additional CCE to at least a REG in a frequency gap between two REGs in the first set of REGs, the additional CCE corresponding to one of the one or more CCEs mapped to the first set of REGs by the interleaved portion of the CCE to REG mapping, wherein:
the one or more CCEs comprised in the PDCCH transmission consist of a plurality of CCEs;
the interleaved portion maps the plurality of CCEs to the first set of REGs that are spread across the bandwidth of the CORESET; and
the second portion maps the additional CCE to REGs in one or more frequency gaps between REGs in the first set of REGs.