Search

EP-4236178-B1 - DOWNLINK CONTROL INFORMATION (DCI) SIZE MATCHING

EP4236178B1EP 4236178 B1EP4236178 B1EP 4236178B1EP-4236178-B1

Inventors

  • LIN, Xingqin
  • PARKVALL, STEFAN
  • CHENG, JUNG-FU
  • ZHANG, JIANWEI

Dates

Publication Date
20260513
Application Date
20191028

Claims (14)

  1. A method performed by a user equipment, UE, for determining downlink control information, DCI, sizes for monitoring by the UE in a cell, the method comprising: for a frequency domain resource assignment field in each DCI format 0_0 and DCI format 1_0, using a field size that is a function of the size of a bandwidth part, BWP, wherein the size of the BWP in the function is determined according to a first rule specifying that (i) the size of the BWP is the size of an active uplink BWP for a DCI format 0_0 monitored in a UE-specific search space, USS, (ii) the size of the BWP is the size of an initial uplink BWP for a DCI format 0_0 monitored in a common search space, CSS , (iii) the size of the BWP is the size of an active downlink BWP for a DCI format 1_0 monitored in a USS, (iv) the size of the BWP is the size of an initial downlink BWP for DCI format 1_0 monitored in a CSS, if CORESET 0 is not configured in the cell, and (v) the size of the BWP is the size of CORESET 0 for DCI format 1_0 monitored in a CSS, if CORESET 0 is configured in the cell.
  2. The method of claim 1, further comprising: for each DCI format 0_0 and DCI format DCI 1_0 monitored in a CSS, applying a second rule specifying that (i) if the size of the DCI format 0_0 monitored in the CSS is less than the size of a DCI format 1_0 monitored in the CSS, zeroes are added to the DCI format 0_0 monitored in the CSS until the size of the DCI format 0_0 monitored in the CSS is equal to the size of the DCI format 1_0 monitored in the CSS, and (ii) if the size of the DCI format 1_0 monitored in the CSS is less than the size of a DCI format 0_0 monitored in the CSS, most significant bits of the frequency domain resource assignment field in the DCI format 0_0 are truncated until the size of the DCI format 0_0 monitored in the CSS is equal to the size of the DCI format 1_0 monitored in the CSS.
  3. The method of claim 2, further comprising, after applying the second rule, applying a third rule specifying that: for each DCI format 0_0 monitored in a USS, if the size of the DCI format 0_0 monitored in the USS is less than the size of a DCI format 1_0 monitored in the USS, zeroes are added to the DCI format 0_0 monitored in the USS until the size of the DCI format 0_0 monitored in the USS is equal to the size of the DCI format 1_0 monitored in the USS; and for each DCI format 1_0 monitored in a USS, if the size of the DCI format 1_0 monitored in the USS is less than the size of a DCI format 0_0 monitored in the USS, zeroes are added to the DCI format 1_0 monitored in the USS until the size of the DCI format 1_0 monitored in the USS is equal to the size of the DCI format 0_0 monitored in the USS.
  4. The method of any of claims 1-3, further comprising: monitoring one or more configured search spaces for a DCI message targeted to the UE, using the determined DCI sizes.
  5. A method performed by a base station for determining downlink control information, DCI, sizes to be monitored by a user equipment, UE, served by the base station, the method comprising: for a frequency domain resource assignment field in each DCI format 0_0 and DCI format 1_0, using a field size that is a function of the size of a bandwidth part, BWP, wherein the size of the BWP in the function is determined according to a first rule specifying that (i) the size of the BWP is the size of an active uplink BWP for a DCI format 0_0 configured to be monitored by the UE in a UE-specific search space, USS, (ii) the size of the BWP is the size of an initial uplink BWP for a DCI format 0_0 configured to be monitored by the UE in a common search space, CSS, (iii) the size of the BWP is the size of an active downlink BWP for a DCI format 1_0 configured to be monitored by the UE in a USS, (iv) the size of the BWP is the size of an initial downlink BWP for DCI format 1_0 configured to be monitored by the UE in a CSS, if CORESET 0 is not configured in the cell, and (v) the size of the BWP is the size of CORESET 0 for DCI format 1_0 configured to be monitored by the UE in a CSS, if CORESET 0 is configured in the cell.
  6. The method of claim 5, further comprising: for each DCI format 0_0 and DCI format DCI 1_0 configured to be monitored by the UE in a CSS, applying a second rule specifying that (i) if the size of the DCI format 0_0 configured to be monitored by the UE in the CSS is less than the size of a DCI format 1_0 configured to be monitored by the UE in the CSS, zeroes are added to the DCI format 0_0 configured to be monitored by the UE in the CSS until the size of the DCI format 0_0 configured to be monitored by the UE in the CSS is equal to the size of the DCI format 1_0 configured to be monitored by the UE in the CSS, and (ii) if the size of the DCI format 1_0 configured to be monitored by the UE in the CSS is less than the size of a DCI format 0_0 configured to be monitored by the UE in the CSS, most significant bits of the frequency domain resource assignment field in the DCI format 0_0 are truncated until the size of the DCI format 0_0 configured to be monitored by the UE in the CSS is equal to the size of the DCI format 1_0 configured to be monitored by the UE in the CSS.
  7. The method of claim 6, further comprising, after applying the second rule, applying a third rule specifying that: for each DCI format 0_0 configured to be monitored by the UE in a USS, if the size of the DCI format 0_0 configured to be monitored by the UE in the USS is less than the size of a DCI format 1_0 configured to be monitored by the UE in the USS, zeroes are added to the DCI format 0_0 configured to be monitored by the UE in the USS until the size of the DCI format 0_0 configured to be monitored in the USS is equal to the size of the DCI format 1_0 configured to be monitored by the UE in the USS; and for each DCI format 1_0 configured to be monitored by the UE in a USS, if the size of the DCI format 1_0 configured to be monitored by the UE in the USS is less than the size of a DCI format 0_0 configured to be monitored by the UE in the USS, zeroes are added to the DCI format 1_0 configured to be monitored by the UE in the USS until the size of the DCI format 1_0 configured to be monitored by the UE in the USS is equal to the size of the DCI format 0_0 configured to be monitored by the UE in the USS.
  8. A user equipment, UE, for use in a wireless communications system, for determining downlink control information, DCI, sizes for monitoring by the UE in a cell, the UE being adapted to: for a frequency domain resource assignment field in each DCI format 0_0 and DCI format 1_0, use a field size that is a function of the size of a bandwidth part, BWP, wherein the size of the BWP in the function is determined according to a first rule specifying that (i) the size of the BWP is the size of an active uplink BWP for a DCI format 0_0 monitored in a UE-specific search space, USS, (ii) the size of the BWP is the size of an initial uplink BWP for a DCI format 0_0 monitored in a common search space, CSS , (iii) the size of the BWP is the size of an active downlink BWP for a DCI format 1_0 monitored in a USS, (iv) the size of the BWP is the size of an initial downlink BWP for DCI format 1_0 monitored in a CSS, if CORESET 0 is not configured in the cell, and (v) the size of the BWP is the size of CORESET 0 for DCI format 1_0 monitored in a CSS, if CORESET 0 is configured in the cell.
  9. The UE of claim 8, further adapted to: for each DCI format 0_0 and DCI format DCI 1_0 monitored in a CSS, apply a second rule specifying that (i) if the size of the DCI format 0_0 monitored in the CSS is less than the size of a DCI format 1_0 monitored in the CSS, zeroes are added to the DCI format 0_0 monitored in the CSS until the size of the DCI format 0_0 monitored in the CSS is equal to the size of the DCI format 1_0 monitored in the CSS, and (ii) if the size of the DCI format 1_0 monitored in the CSS is less than the size of a DCI format 0_0 monitored in the CSS, most significant bits of the frequency domain resource assignment field in the DCI format 0_0 are truncated until the size of the DCI format 0_0 monitored in the CSS is equal to the size of the DCI format 1_0 monitored in the CSS.
  10. The UE of claim 9, further adapted to, after applying the second rule, apply a third rule specifying that: for each DCI format 0_0 monitored in a USS, if the size of the DCI format 0_0 monitored in the USS is less than the size of a DCI format 1_0 monitored in the USS, zeroes are added to the DCI format 0_0 monitored in the USS until the size of the DCI format 0_0 monitored in the USS is equal to the size of the DCI format 1_0 monitored in the USS; and for each DCI format 1_0 monitored in a USS, if the size of the DCI format 1_0 monitored in the USS is less than the size of a DCI format 0_0 monitored in the USS, zeroes are added to the DCI format 1_0 monitored in the USS until the size of the DCI format 1_0 monitored in the USS is equal to the size of the DCI format 0_0 monitored in the USS.
  11. The UE of any of claims 8-10, further adapted to: monitor one or more configured search spaces for a DCI message targeted to the UE, using the determined DCI sizes.
  12. A base station, for use in a wireless communications system, for determining downlink control information, DCI, sizes to be monitored by a user equipment, UE, served by the base station, the base station being adapted to: for a frequency domain resource assignment field in each DCI format 0_0 and DCI format 1_0, use a field size that is a function of the size of a bandwidth part, BWP, wherein the size of the BWP in the function is determined according to a first rule specifying that (i) the size of the BWP is the size of an active uplink BWP for a DCI format 0_0 configured to be monitored by the UE in a UE-specific search space, USS, (ii) the size of the BWP is the size of an initial uplink BWP for a DCI format 0_0 configured to be monitored by the UE in a common search space, CSS, (iii) the size of the BWP is the size of an active downlink BWP for a DCI format 1_0 configured to be monitored by the UE in a USS, (iv) the size of the BWP is the size of an initial downlink BWP for DCI format 1_0 configured to be monitored by the UE in a CSS, if CORESET 0 is not configured in the cell, and (v) the size of the BWP is the size of CORESET 0 for DCI format 1_0 configured to be monitored by the UE in a CSS, if CORESET 0 is configured in the cell.
  13. The base station of claim 12, further adapted to: for each DCI format 0_0 and DCI format DCI 1_0 configured to be monitored by the UE in a CSS, apply a second rule specifying that (i) if the size of the DCI format 0_0 configured to be monitored by the UE in the CSS is less than the size of a DCI format 1_0 configured to be monitored by the UE in the CSS, zeroes are added to the DCI format 0_0 configured to be monitored by the UE in the CSS until the size of the DCI format 0_0 configured to be monitored by the UE in the CSS is equal to the size of the DCI format 1_0 configured to be monitored by the UE in the CSS, and (ii) if the size of the DCI format 1_0 configured to be monitored by the UE in the CSS is less than the size of a DCI format 0_0 configured to be monitored by the UE in the CSS, most significant bits of the frequency domain resource assignment field in the DCI format 0_0 are truncated until the size of the DCI format 0_0 configured to be monitored by the UE in the CSS is equal to the size of the DCI format 1_0 configured to be monitored by the UE in the CSS.
  14. The base station of claim 13, further adapted to, after applying the second rule, apply a third rule specifying that: for each DCI format 0_0 configured to be monitored by the UE in a USS, if the size of the DCI format 0_0 configured to be monitored by the UE in the USS is less than the size of a DCI format 1_0 configured to be monitored by the UE in the USS, zeroes are added to the DCI format 0_0 configured to be monitored by the UE in the USS until the size of the DCI format 0_0 configured to be monitored in the USS is equal to the size of the DCI format 1_0 configured to be monitored by the UE in the USS; and for each DCI format 1_0 configured to be monitored by the UE in a USS, if the size of the DCI format 1_0 configured to be monitored by the UE in the USS is less than the size of a DCI format 0_0 configured to be monitored by the UE in the USS, zeroes are added to the DCI format 1_0 configured to be monitored by the UE in the USS until the size of the DCI format 1_0 configured to be monitored by the UE in the USS is equal to the size of the DCI format 0_0 configured to be monitored by the UE in the USS.

Description

BACKGROUND The 5th generation (5G) wireless access technology currently under development by members of the 3rd-Generation Partnership Project (3GPP), known as new radio (NR), will address a variety of usage scenarios from enhanced mobile broadband (eMBB) to ultra-reliable low-latency communications (URLLC) to massive machine-type communications (mMTC). Key NR features include ultra-lean transmission, support for low latency, advanced antenna technologies, and spectrum flexibility including operation in high frequency bands, interworking between high and low frequency bands, and dynamic time division multiplexing (TDD). Downlink control information (DCI) is used in NR to, among other things, transmit scheduling decisions from the gNB (3GPP terminology for an NR base station) to the UE (3GPP terminology for an access terminal, such as a mobile telephone or a machine-type communications (MTC) device. Different DCI formats are defined for different purposes, differing in, for example, the information carried in the DCI. According to the NR specifications, a UE blindly detects the DCI format based on (among other things) payload size and the RNTI used. DCI size budget is a major constraint in NR specification to respect UE processing capability. This constraint is captured in 3GPP TS 38.212 as follows: the total number of different DCI sizes [that a UE is] configured to monitor is no more than 4 for the cell, andthe total number of different DCI sizes with C-RNTI [that a UE is] configured to monitor is no more than 3 for the cell. The DCI formats supported in NR include: DCI format 0_0: Scheduling of PUSCH in one cellDCI format 0_1: Scheduling of PUSCH in one cellDCI format 1_0: Scheduling of PDSCH in one cellDCI format 1_1: Scheduling of PDSCH in one cellDCI format 2_0: Notifying a group of UEs of the slot formatDCI format 2_1: Notifying a group of UEs of the PRB(s) and OFDM symbol(s) where UE may assume no transmission is intended for the UEDCI format 2_2: Transmission of TPC commands for PUCCH and PUSCHDCI format 2_3: Transmission of a group of TPC commands for SRS transmissions by one or more UEs The DCI formats 0_0 and 1_0 are usually referred to as fallback DCI. The DCI formats 0_1 and 1_1 are usually referred to as non-fallback DCI. The UE blindly attempts to decode DCI messages using the RNTIs the UE is supposed to monitor. If the CRC checks, the DCI is correctly received and intended for this UE, and the UE thus follows the content of the DCI. If the CRC does not check, either the DCI was received in error or it was intended for another UE - in either case, the UE ignores it. Blindly detecting the DCI is done according to search spaces that can be configured in the UE. Search spaces can be either common search spaces (CSS) or UE-specific search spaces (USS). Not all RNTIs or DCI formats are allowed in all search spaces: A common search space (CSS) can only be configured with fallback DCI formats 0_0 and 1_0A given UE specific search space (USS) can be configured with either fallback DCI formats 0_0 and 1_0, or non-fallback DCI formats 0_1 and 1_1, but not both. Hence, to support both fallback DCI formats 0_0 and 1_0, or non-fallback DCI formats 0_1 and 1_1 in USS, two USSs need to be configured: one USS for fallback DCI formats 0_0 and 1_0, and the other USS for non-fallback DCI formats 0_1 and 1_1 To indicate the UE addressed (and sometimes the purpose of the DCI), an identity, referred to as a Radio Network Temporary Identifier (RNTI) is included in the Cyclic Redundancy Check (CRC) of the DCI as transmitted. The RNTIs used to scramble the DCI CRC for each of the various formats are summarized in the below table. DCI formatRNTI0_0• C-RNTI or CS-RNTI or MCS-C-RNTI• TC-RNTI0_1• C-RNTI or CS-RNTI or SP-CSI-RNTI or MCS-C-RNTI1_0• C-RNTI or CS-RNTI or MCS-C-RNTIo DCI scrambled by C-RNTI for PDCCH ordered random access has a different field description, compared to a corresponding DCI scrambled by C-RNTI for regular PDSCH transmission• P-RNTI• SI-RNTI• RA-RNTI• TC-RNTI1_1• C-RNTI or CS-RNTI or MCS-C-RNTI2_0• SFI-RNTI2_1• INT-RNTI2_2• TPC-PUSCH-RNTI or TPC-PUCCH-RNTI2_3• TPC-SRS-RNTI A more detailed description of NR DCI can be found in Section 7.3.1 of 3GPP TS 38.212, v15.3.0. To reduce device power consumption, a UE may be active on a wide bandwidth for a short time, e.g., in the event of bursty traffic, while being active on a narrow bandwidth for the remaining time. This is commonly referred to as bandwidth adaptation and is addressed in NR by a new concept known as bandwidth part (BWP). A BWP is a subset of contiguous RBs on the carrier. Up to four bandwidth parts can be configured in the UE for each of the UL and DL, but at a given time only one bandwidth part is active per transmission direction. Thus, the UE can receive on a narrow BWP and, when needed, the network can dynamically inform the UE to switch to a wider BWP for reception. The 3GPP document R1-1807738 by Ericsson entitled "Outcome of offl