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EP-3963777-B1 - DOWNLINK CONTROL INDICATOR DISTRIBUTION FOR CROSS CARRIER SCHEDULING

EP3963777B1EP 3963777 B1EP3963777 B1EP 3963777B1EP-3963777-B1

Inventors

  • XU, HUILIN
  • ANG, PETER PUI LOK
  • CHEN, WANSHI
  • GAAL, PETER
  • LUO, TAO

Dates

Publication Date
20260506
Application Date
20200302

Claims (15)

  1. A method performed by an apparatus for wireless communication, the method comprising: generating (1102) at least one slot in a control channel from a first cell, the at least one slot including a plurality of control channel segments arranged at respective times within the at least one slot, wherein: each of the plurality of control channel segments includes control information corresponding to respective slots in a traffic channel for one or more second cells, wherein the control information comprises downlink control indicators, DCIs, within a PDCCH; a predetermined maximum number of DCIs contained within each of the plurality of control channel segments is defined for each of the one or more second cells; the predetermined maximum number of DCIs is determined based on a combination of a subcarrier spacing, SCS, of the control channel of the first cell and the SCS of at least one of the one or more second cells; and transmitting (1104) the at least one slot to one or more user equipment, UE, to be used by the one or more UEs to determine the control information.
  2. The method of claim 1, wherein the first cell comprises a scheduling cell and the one or more second cells comprise scheduled cells that are scheduled by the first cell; or wherein the control channel is a physical downlink control channel, PDCCH, transmitted by the first cell to the one or more UEs in the one or more second cells.
  3. The method of claim 1, wherein the control information comprises one or more of a grant for a physical downlink shared channel, PDSCH, a grant for physical uplink shared channel, PUSCH, or a slot format indication or wherein the control channel is used for cross carrier scheduling of the one or more second cells; or wherein the control channel is configured with the subcarrier spacing, SCS, that is lower than the SCS of the traffic channel used by the at least one of the one or more second cells.
  4. The method of claim 1, wherein each of the plurality of control channel segments contain respective control channel information corresponding to the slots in the one or more second cells; or wherein each of the plurality of control channel segments contain the same control channel information corresponding to all of the slots in the one or more second cells.
  5. The method of claim 1, further comprising: setting a predetermined maximum number N of DCIs that a UE of the one or more UEs is to decode for each control channel segment.
  6. The method of claim 5, wherein the DCIs are unicast DCIs.
  7. The method of claim 1, wherein the DCI is configured to include one of a plurality of format types of DCIs that are supported by a UE of the one or more UEs, wherein the plurality of format types includes one or more of a DCI for unicast transmission, a DCI for semi-persistent scheduling, SPS, activation/deactivation, a DCI for broadcast transmission, a DCI for random access and paging, a DCI for system information transmission, or a group common DCI.
  8. The method of claim 7, wherein the DCI for unicast transmission includes one or more of a DCI for uplink, UL, and downlink, DL, unicast transmission, a DCI for DL unicast transmission; or a DCI for UL unicast transmission.
  9. An apparatus for wireless communication, comprising: at least one processor (904); a transceiver (910) communicatively coupled to the at least one processor (904); and a memory (905) communicatively coupled to the at least one processor (904), wherein the at least one processor (904) is configured to: generate a transmission including at least one slot in a control channel from a first cell, the at least one slot including a plurality of control channel segments arranged at respective times within the at least one slot, wherein: each of the plurality of control channel segments includes control information corresponding to respective slots in a traffic channel for one or more second cells, wherein the control information comprises downlink control indicators, DCIs, within a PDCCH; a predetermined maximum number of DCIs contained within each of the plurality of control channel segments is defined for each of the one or more second cells; the predetermined maximum number of DCIs is determined based on a combination of a subcarrier spacing, SCS, of the control channel of the first cell and the SCS of at least one of the one or more second cells; and transmit the at least one slot to one or more user equipment, UE, to be used by the one or more UEs to determine the control information.
  10. The apparatus of claim 9, wherein the first cell comprises a scheduling cell and the one or more second cells comprise scheduled cells that are scheduled by the first cell or wherein the control channel is a physical downlink control channel, PDCCH, transmitted by the first cell to one or more UEs in the one or more second cells; or wherein the control channel is configured with a subcarrier spacing, SCS, that is lower than an SCS of the traffic channel.
  11. A method performed by an apparatus for wireless communication, the method comprising: receiving (1202) in a user equipment, UE, from a first cell, at least one slot in a control channel, the at least one slot including a plurality of control channel segments arranged at respective times within the at least one slot, wherein: each of the plurality of control channel segments includes control information corresponding to respective slots in a traffic channel for the one or more second cells, wherein the control information comprises downlink control indicators, DCIs, within a PDCCH; a predetermined maximum number of DCIs contained within each of the plurality of control channel segments is defined for each of the one or more second cells; the predetermined maximum number of DCIs is determined based on a combination of a subcarrier spacing, SCS, of the control channel of the first cell and the SCS of at least one of the one or more second cells; and decoding (1204) the at least one slot to determine the control information.
  12. The method of claim 11, wherein the control channel is a physical downlink control channel, PDCCH, transmitted by the first cell to the UE; or wherein the control information comprises one or more of a grant for a physical downlink shared channel, PDSCH, a grant for physical uplink shared channel, PUSCH, or a slot format indication.
  13. The method of claim 11, wherein the control channel is configured with the subcarrier spacing, SCS that is lower than the SCS of the traffic channel for the one or more second cells.
  14. An apparatus for wireless communication, comprising: at least one processor (1004); a transceiver (1010) communicatively coupled to the at least one processor; and a memory (1005) communicatively coupled to the at least one processor (1004), wherein the at least one processor (1004) is configured to: receive a transmission in a user equipment, the transmission including at least one slot in a control channel from a first cell, the at least one slot further including a plurality of control channel segments arranged at respective times within the at least one slot, wherein: each of the plurality of control channel segments includes control information corresponding to respective slots in a traffic channel for one or more second cells, wherein the control information comprises downlink control indicators, DCIs, within a PDCCH; a predetermined maximum number of DCIs contained within each of the plurality of control channel segments is defined for each of the one or more second cells; the predetermined maximum number of DCIs is determined based on a combination of a subcarrier spacing, SCS, of the control channel of the first cell and the SCS of at least one of the one or more second cells; and decode the at least one slot to determine the control information.
  15. The apparatus of claim 14, wherein the at least one processor is configured to set a predetermined maximum number N of DCIs that the apparatus is to decode for each of the plurality of control channel segments.

Description

TECHNICAL FIELD The technology discussed herein relates generally to wireless communication systems, and more particularly to the provision and use of downlink control indicator (DCI) distribution for cross carrier scheduling in a wireless communication system. INTRODUCTION In wireless communication systems that utilize carrier aggregation (CA) with cross carrier scheduling, a cell known as a scheduling cell may schedule a number of other cells, known as scheduled cells. Typically, up to eight (8) cells may be scheduled by a scheduling cell. In these systems, the subcarrier spacing (SCS) (i.e., frequency spacing between subcarrier frequencies in a symbol) of the scheduling cell transmissions may be different from the SCS of the scheduled cell transmissions. For example, the scheduling cell might have an SCS of 15kHz, whereas all of the scheduled cells might have an SCS of 120 kHz. Downlink control indicators (DCIs) within the physical downlink control channel (PDCCH), which are used for downlink (DL) reception and uplink (UL) transmission by the scheduled cells, are decoded from the PDCCH transmissions from the scheduling cell in cross carrier scheduling systems. In cases of SCS disparity, however, the subcarrier spacing difference may decrease the ability of a user equipment (UE) to timely decode the PDCCH and the subsequent user data traffic in a physical downlink shared channel (PDSCH) before having to transmit a requisite acknowledgement/negative-acknowledgment (ACK/NACK) report at a specified time on the uplink channels. The document "HUAWEI ET AL: Discussion on NR CA for cross-carrier scheduling with different numerologies", 3GPP Draft, R1-1901580 discusses issues about cross-carrier scheduling with different numerologies. The document "Intel Corporation: Cross-carrier scheduling with different Numerologies", 3GPP Draft, R1-1904326 discusses Scheduling timing for PDSCH and Support of contiguous data transmission. The document "Qualcomm Incorporated: Ll Enhancements for eURLLC", 3GPP Draft, R1-1809457 discusses URLLC use cases and design schemes. The document "OPPO: On Cross-carrier Scheduling with Different Numerologies", 3GPP Draft, R1-1902709 discusses Cross-carrier Scheduling with Different Numerologies. BRIEF SUMMARY OF SOME EXAMPLES The method and apparatuses for wireless communication are disclosed by the present disclosure as claimed in claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of a wireless communication system.FIG. 2 is a conceptual illustration of an example of a radio access network.FIG. 3 illustrates an organization of wireless resources in an air interface utilizing orthogonal frequency divisional multiplexing (OFDM).FIG. 4 illustrates an example of slot structures in a CA system using cross carrier scheduling with different SCS for the scheduling entities and scheduled entities.FIG. 5 illustrates an example of utilizing multiple spans of a control channel in a slot of a scheduling cell or entity according to aspects of the present disclosure.FIG. 6 illustrates another example of utilizing multiple spans of a control channel in a slot of a scheduling cell or entity according to aspects of the present disclosure.FIG. 7 illustrates an example of utilizing multiple spans and frequencies for a control channel in a slot of a scheduling cell or entity according to aspects of the present disclosure.FIG. 8 illustrates another example of utilizing multiple spans and frequencies for a control channel in a slot of a scheduling cell or entity according to aspects of the present disclosure.FIG. 9 is a block diagram illustrating an example of a hardware implementation for a scheduling entity apparatus employing a processing system.FIG. 10 is a block diagram illustrating an example of a hardware implementation for a scheduled entity apparatus employing a processing system.FIG. 11 is a flow diagram of an exemplary method for configuring transmissions in a wireless system according to exemplary aspects of the present disclosure.FIG. 12 is another flow diagram of an exemplary method for receiving transmissions in a wireless system according to exemplary aspects of the present disclosure. DETAILED DESCRIPTION The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts. While aspects and embodiments are described in this application by illustration to some examples, those skilled in the art will understand that