U.S. patent application number 17/445373 was filed with the patent office on 2022-03-17 for multi-cell scheduling with reduced control overhead.
The applicant listed for this patent is Samsung Electronics Co., Ltd.. Invention is credited to Qiongjie Lin, Aris Papasakellariou.
Application Number | 20220086894 17/445373 |
Document ID | / |
Family ID | |
Filed Date | 2022-03-17 |
United States Patent
Application |
20220086894 |
Kind Code |
A1 |
Papasakellariou; Aris ; et
al. |
March 17, 2022 |
MULTI-CELL SCHEDULING WITH REDUCED CONTROL OVERHEAD
Abstract
Methods and apparatuses for multi-cell scheduling with reduced
control overhead. A method for receiving physical downlink control
channels (PDCCHs) includes receiving information for a first group
of N1 cells and for a second group of N2 cells, determining a total
number of PDCCH receptions in a slot on a scheduling cell based on
N1 and on a ratio of N2 over M, and receiving a number of PDCCHs in
the slot on the scheduling cell that is not larger than the total
number. A PDCCH provides a downlink control information (DCI)
format. The DCI format schedules one of: a physical downlink shared
channel (PDSCH) reception, or a physical uplink shared channel
(PUSCH) transmission, on one cell from the first group of N1 cells,
or PDSCH receptions, or PUSCH transmissions, on a number of cells
up to a maximum of M cells from the second group of N2 cells.
Inventors: |
Papasakellariou; Aris;
(Houston, TX) ; Lin; Qiongjie; (Sunnyvale,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Samsung Electronics Co., Ltd. |
Suwon-si |
|
KR |
|
|
Appl. No.: |
17/445373 |
Filed: |
August 18, 2021 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
63077960 |
Sep 14, 2020 |
|
|
|
63081595 |
Sep 22, 2020 |
|
|
|
International
Class: |
H04W 72/12 20060101
H04W072/12 |
Claims
1. A method for receiving physical downlink control channels
(PDCCHs), the method comprising: receiving information for a first
group of N1 cells and for a second group of N2 cells, wherein: a
PDCCH provides a downlink control information (DCI) format, and the
DCI format schedules one of: a physical downlink shared channel
(PDSCH) reception, or a physical uplink shared channel (PUSCH)
transmission, on one cell from the first group of N1 cells, or
PDSCH receptions, or PUSCH transmissions, on a number of cells up
to a maximum of M cells from the second group of N2 cells, wherein
M is larger than one; determining a total number of PDCCH
receptions in a slot on a scheduling cell based on N1 and on a
ratio of N2 over M; and receiving a number of PDCCHs in the slot on
the scheduling cell that is not larger than the total number.
2. The method of claim 1, wherein: the DCI format schedules the
PDSCH receptions, or the PUSCH transmissions, on the number of
cells up to the maximum of M cells from the second group of N2
cells, and the DCI format includes a field indicating the number of
cells.
3. The method of claim 1, wherein: the DCI format schedules the
PDSCH receptions, or the PUSCH transmissions, on the number of
cells up to the maximum of M cells from the second group of N2
cells, and a size of the DCI format is same for any value of the
number of cells.
4. The method of claim 1, wherein: the DCI format includes a
counter downlink assignment index (DAI) field with a first maximum
number of bits, when the DCI format schedules the PDSCH reception,
or the PUSCH transmission, on the one cell from the first group of
N1 cells, the DCI format includes the counter DAI field with a
second maximum number of bits, when the DCI format schedules the
PDSCH receptions, or the PUSCH transmissions, on the number of
cells up to the maximum of M cells from the second group of N2
cells, and the second maximum number of bits is larger than the
first maximum number of bits.
5. The method of claim 1, further comprising: receiving a second
PDCCH that provides a second DCI format, wherein: the second DCI
format schedules transmissions of first and second PUSCHs on
respective first and second cells from the second group of N2
cells, the first and second cells are in a same frequency band, and
the second DCI format includes a transmission power control (TPC)
command that provides one value; determining first and second
powers for transmission of the first and second PUSCHs,
respectively, based on the one value; and transmitting the first
and second PUSCHs using the first and second powers,
respectively.
6. The method of claim 1, further comprising: receiving a second
PDCCH that provides a second DCI format, wherein: the second DCI
format schedules transmissions of first and second PUSCHs on
respective first and second cells from the second group of N2
cells, the first cell has a smaller index that the second cell, and
the second DCI format includes a downlink assignment index (DAI)
field; determining hybrid automatic repeat request acknowledgement
(HARQ-ACK) information based on a value of the DAI field; and
transmitting the first and second PUSCHs on the first and second
cells, respectively, wherein the HARQ-ACK information is included
only in the first PUSCH.
7. The method of claim 1, further comprising: receiving a second
PDCCH that provides a second DCI format, wherein: the second DCI
format schedules receptions of first and second PDSCHs on
respective first and second cells from the second group of N2
cells, and the second DCI format includes a frequency domain
resource allocation (FDRA) field that indicates resource block
groups (RBGs), wherein an RBG includes: a first number of resource
blocks (RBs) on the first cell, and a second number of RBs on the
second cell; and receiving the first and second PDSCHs over the
indicated RBGs.
8. A user equipment (UE), comprising: a transceiver configured to
receive information for a first group of N1 cells and for a second
group of N2 cells, wherein: a physical downlink control channel
(PDCCH) provides a downlink control information (DCI) format, and
the DCI format schedules one of: a physical downlink shared channel
(PDSCH) reception, or a physical uplink shared channel (PUSCH)
transmission, on one cell from the first group of N1 cells, or
PDSCH receptions, or PUSCH transmissions, on a number of cells up
to a maximum of M cells from the second group of N2 cells, wherein
M is larger than one; and a processor operably connected to the
transceiver, the processor configured to determine a total number
of PDCCH receptions in a slot on a scheduling cell based on N1 and
on a ratio of N2 over M, wherein the transceiver is further
configured to receive a number of PDCCHs in the slot on the
scheduling cell that is not larger than the total number.
9. The UE of claim 8, wherein: the DCI format schedules the PDSCH
receptions, or the PUSCH transmissions, on the number of cells up
to the maximum of M cells from the second group of N2 cells, and
the DCI format includes a field indicating the number of cells.
10. The UE of claim 8, wherein: the DCI format schedules the PDSCH
receptions, or the PUSCH transmissions, on the number of cells up
to the maximum of M cells from the second group of N2 cells, and a
size of the DCI format is same for any value of the number of
cells.
11. The UE of claim 8, wherein: the DCI format includes a counter
downlink assignment index (DAI) field with a first maximum number
of bits, when the DCI format schedules the PDSCH reception, or the
PUSCH transmission, on the one cell from the first group of N1
cells, the DCI format includes the counter DAI field with a second
maximum number of bits, when the DCI format schedules the PDSCH
receptions, or the PUSCH transmissions, on the number of cells up
to the maximum of M cells from the second group of N2 cells, and
the second maximum number of bits is larger than the first maximum
number of bits.
12. The UE of claim 8, wherein: the transceiver is further
configured to receive a second PDCCH that provides a second DCI
format, wherein: the second DCI format schedules transmissions of
first and second PUSCHs on respective first and second cells from
the second group of N2 cells, the first and second cells are in a
same frequency band, and the second DCI format includes a
transmission power control (TPC) command that provides one value;
the processor is further configured to determine first and second
powers for transmission of the first and second PUSCHs,
respectively, based on the one value; and the transceiver is
further configured to transmit the first and second PUSCHs using
the first and second powers, respectively.
13. The UE of claim 8, wherein: the transceiver is further
configured to receive a second PDCCH that provides a second DCI
format, wherein: the second DCI format schedules transmissions of
first and second PUSCHs on respective first and second cells from
the second group of N2 cells, the first cell has a smaller index
that the second cell, and the second DCI format includes a downlink
assignment index (DAI) field; the processor is further configured
to determine hybrid automatic repeat request acknowledgement
(HARQ-ACK) information based on a value of the DAI field; and the
transceiver is further configured to transmit the first and second
PUSCHs on the first and second cells, respectively, wherein the
HARQ-ACK information is included only in the first PUSCH.
14. The UE of claim 8, wherein the transceiver is further
configured to receive: a second PDCCH that provides a second DCI
format, wherein: the second DCI format schedules receptions of
first and second PDSCHs on respective first and second cells from
the second group of N2 cells, and the second DCI format includes a
frequency domain resource allocation (FDRA) field that indicates
resource block groups (RBGs), wherein an RBG includes: a first
number of resource blocks (RBs) on the first cell, and a second
number of RBs on the second cell; and the first and second PDSCHs
over the indicated RBGs.
15. A base station, comprising: a transceiver configured to
transmit information for a first group of N1 cells and for a second
group of N2 cells, wherein: a physical downlink control channel
(PDCCH) provides a downlink control information (DCI) format, and
the DCI format schedules one of: a physical downlink shared channel
(PDSCH) transmission, or a physical uplink shared channel (PUSCH)
reception, on one cell from the first group of N1 cells, or PDSCH
transmissions, or PUSCH receptions, on a number of cells up to a
maximum of M cells from the second group of N2 cells, wherein M is
larger than one; and a processor operably connected to the
transceiver, the processor configured to determine a total number
of PDCCH transmissions in a slot on a scheduling cell based on N1
and on a ratio of N2 over M, wherein the transceiver is further
configured to transmit a number of PDCCHs in the slot on the
scheduling cell that is not larger than the total number.
16. The base station of claim 15, wherein: the DCI format schedules
the PDSCH transmissions, or the PUSCH receptions, on the number of
cells up to the maximum of M cells from the second group of N2
cells, and the DCI format includes a field indicating the number of
cells.
17. The base station of claim 15, wherein: the DCI format schedules
the PDSCH transmissions, or the PUSCH receptions, on the number of
cells up to the maximum of M cells from the second group of N2
cells, and a size of the DCI format is same for any value of the
number of cells.
18. The base station of claim 15, wherein: the DCI format includes
a counter downlink assignment index (DAI) field with a first
maximum number of bits, when the DCI format schedules the PDSCH
transmission, or the PUSCH reception, on the one cell from the
first group of N1 cells, the DCI format includes the counter DAI
field with a second maximum number of bits, when the DCI format
schedules the PDSCH transmissions, or the PUSCH receptions, on the
number of cells up to the maximum of M cells from the second group
of N2 cells, and the second maximum number of bits is larger than
the first maximum number of bits.
19. The base station of claim 15, wherein the transceiver is
further configured to: transmit a second PDCCH that provides a
second DCI format, wherein: the second DCI format schedules
receptions of first and second PUSCHs on respective first and
second cells from the second group of N2 cells, the first cell has
a smaller index that the second cell, and the second DCI format
includes a downlink assignment index (DAI) field indicating a
hybrid automatic repeat request acknowledgement (HARQ-ACK)
information report; and receive the first and second PUSCHs on the
first and second cells, respectively, wherein the HARQ-ACK
information is included only in the first PUSCH.
20. The base station of claim 15, wherein the transceiver is
further configured to transmit: a second PDCCH that provides a
second DCI format, wherein: the second DCI format schedules
transmissions of first and second PDSCHs on respective first and
second cells from the second group of N2 cells, and the second DCI
format includes a frequency domain resource allocation (FDRA) field
that indicates resource block groups (RBGs), wherein an RBG
includes: a first number of resource blocks (RBs) on the first
cell, and a second number of RBs on the second cell; and the first
and second PDSCHs over the indicated RBGs.
Description
CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIORITY
[0001] This application claims priority under 35 U.S.C. .sctn.
119(e) to U.S. Provisional Patent Application No. 63/077,960 filed
on Sep. 14, 2020 and U.S. Provisional Patent Application No.
63/081,595 filed on Sep. 22, 2020. The above-identified provisional
patent applications are hereby incorporated by reference in their
entirety.
TECHNICAL FIELD
[0002] The present disclosure relates generally to wireless
communication systems and, more specifically, the present
disclosure relates to multi-cell scheduling with reduced control
overhead.
BACKGROUND
[0003] 5th generation (5G) or new radio (NR) mobile communications
is recently gathering increased momentum with all the worldwide
technical activities on the various candidate technologies from
industry and academia. The candidate enablers for the 5G/NR mobile
communications include massive antenna technologies, from legacy
cellular frequency bands up to high frequencies, to provide
beamforming gain and support increased capacity, new waveform
(e.g., a new radio access technology (RAT)) to flexibly accommodate
various services/applications with different requirements, new
multiple access schemes to support massive connections, and so
on.
SUMMARY
[0004] This disclosure relates to multi-cell scheduling with
reduced control overhead.
[0005] In one embodiment, a method for receiving physical downlink
control channels (PDCCHs) is provided. The method includes
receiving information for a first group of N1 cells and for a
second group of N2 cells, determining a total number of PDCCH
receptions in a slot on a scheduling cell based on N1 and on a
ratio of N2 over M, and receiving a number of PDCCHs in the slot on
the scheduling cell that is not larger than the total number. A
PDCCH provides a downlink control information (DCI) format. The DCI
format schedules one of: a physical downlink shared channel (PDSCH)
reception, or a physical uplink shared channel (PUSCH)
transmission, on one cell from the first group of N1 cells, or
PDSCH receptions, or PUSCH transmissions, on a number of cells up
to a maximum of M cells from the second group of N2 cells. M is
larger than one.
[0006] In another embodiment, a user equipment (UE) is provided.
The UE includes a transceiver configured to receive information for
a first group of N1 cells and for a second group of N2 cells. A
PDCCH provides a DCI format. The DCI format schedules one of: a
physical downlink shared channel (PDSCH) reception, or a physical
uplink shared channel (PUSCH) transmission, on one cell from the
first group of N1 cells, or PDSCH receptions, or PUSCH
transmissions, on a number of cells up to a maximum of M cells from
the second group of N2 cells. M is larger than one. The UE further
includes a processor operably connected to the transceiver. The
processor is configured to determine a total number of PDCCH
receptions in a slot on a scheduling cell based on N1 and on a
ratio of N2 over M. The transceiver is further configured to
receive a number of PDCCHs in the slot on the scheduling cell that
is not larger than the total number.
[0007] In yet another embodiment, a base station is provided. The
base station includes a transceiver configured to transmit
information for a first group of N1 cells and for a second group of
N2 cells. A PDCCH provides a DCI format. The DCI format schedules
one of: a PDSCH transmission, or a PUSCH reception, on one cell
from the first group of N1 cells, or PDSCH transmissions, or PUSCH
receptions, on a number of cells up to a maximum of M cells from
the second group of N2 cells. M is larger than one. The base
station further includes a processor operably connected to the
transceiver. The processor is configured to determine a total
number of PDCCH transmissions in a slot on a scheduling cell based
on N1 and on a ratio of N2 over M. The transceiver is further
configured to transmit a number of PDCCHs in the slot on the
scheduling cell that is not larger than the total number.
[0008] Other technical features may be readily apparent to one
skilled in the art from the following figures, descriptions, and
claims.
[0009] Before undertaking the DETAILED DESCRIPTION below, it may be
advantageous to set forth definitions of certain words and phrases
used throughout this patent document. The term "couple" and its
derivatives refer to any direct or indirect communication between
two or more elements, whether or not those elements are in physical
contact with one another. The terms "transmit," "receive," and
"communicate," as well as derivatives thereof, encompass both
direct and indirect communication. The terms "include" and
"comprise," as well as derivatives thereof, mean inclusion without
limitation. The term "or" is inclusive, meaning and/or. The phrase
"associated with," as well as derivatives thereof, means to
include, be included within, interconnect with, contain, be
contained within, connect to or with, couple to or with, be
communicable with, cooperate with, interleave, juxtapose, be
proximate to, be bound to or with, have, have a property of, have a
relationship to or with, or the like. The term "controller" means
any device, system or part thereof that controls at least one
operation. Such a controller may be implemented in hardware or a
combination of hardware and software and/or firmware. The
functionality associated with any particular controller may be
centralized or distributed, whether locally or remotely. The phrase
"at least one of," when used with a list of items, means that
different combinations of one or more of the listed items may be
used, and only one item in the list may be needed. For example, "at
least one of: A, B, and C" includes any of the following
combinations: A, B, C, A and B, A and C, B and C, and A and B and
C.
[0010] Moreover, various functions described below can be
implemented or supported by one or more computer programs, each of
which is formed from computer readable program code and embodied in
a computer readable medium. The terms "application" and "program"
refer to one or more computer programs, software components, sets
of instructions, procedures, functions, objects, classes,
instances, related data, or a portion thereof adapted for
implementation in a suitable computer readable program code. The
phrase "computer readable program code" includes any type of
computer code, including source code, object code, and executable
code. The phrase "computer readable medium" includes any type of
medium capable of being accessed by a computer, such as read only
memory (ROM), random access memory (RAM), a hard disk drive, a
compact disc (CD), a digital video disc (DVD), or any other type of
memory. A "non-transitory" computer readable medium excludes wired,
wireless, optical, or other communication links that transport
transitory electrical or other signals. A non-transitory computer
readable medium includes media where data can be permanently stored
and media where data can be stored and later overwritten, such as a
rewritable optical disc or an erasable memory device.
[0011] Definitions for other certain words and phrases are provided
throughout this patent document. Those of ordinary skill in the art
should understand that in many if not most instances, such
definitions apply to prior as well as future uses of such defined
words and phrases.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For a more complete understanding of the present disclosure
and its advantages, reference is now made to the following
description taken in conjunction with the accompanying drawings, in
which like reference numerals represent like parts:
[0013] FIG. 1 illustrates an example wireless network according to
embodiments of the present disclosure;
[0014] FIG. 2 illustrates an example base station (BS) according to
embodiments of the present disclosure;
[0015] FIG. 3 illustrates an example user equipment (UE) according
to embodiments of the present disclosure;
[0016] FIGS. 4 and 5 illustrate example wireless transmit and
receive paths according to embodiments of the present
disclosure;
[0017] FIG. 6 illustrates a block diagram of an example transmitter
structure using orthogonal frequency division multiplexing (OFDM)
according to embodiments of the present disclosure;
[0018] FIG. 7 illustrates a block diagram of an example receiver
structure using OFDM according to embodiments of the present
disclosure;
[0019] FIG. 8 illustrates an example encoding process for a
downlink control information (DCI) format according to embodiments
of the present disclosure;
[0020] FIG. 9 illustrates an example decoding process for a DCI
format for use with a UE according to embodiments of the present
disclosure;
[0021] FIG. 10 illustrates an example method for a UE determining a
size of a DCI format that schedules two physical downlink shared
channel (PDSCH) receptions on respective two cells according to
embodiments of the present disclosure;
[0022] FIG. 11 illustrates an example method for a UE determining
Modulation and coding scheme (MCS) for a second PDSCH reception
scheduled by a DCI format that schedules two PDSCH receptions on
respective two cells according to embodiments of the present
disclosure;
[0023] FIG. 12 illustrates an example method for a UE determining a
frequency domain resource allocation for a PDSCH reception
depending on the DCI format that schedules the PDSCH reception
according to embodiments of the present disclosure;
[0024] FIG. 13 illustrates a diagram of a UE processing a downlink
assignment index (DAI) value in a DCI format scheduling two PDSCH
receptions on two respective cells and in another DCI format
scheduling a PDSCH reception on one cell according to embodiments
of the present disclosure;
[0025] FIG. 14 illustrates an example method for a UE determining
first and second powers for respective first and second physical
uplink shared channel (PUSCH) transmissions scheduled by a DCI
format on respective first and second cells according to
embodiments of the present disclosure;
[0026] FIG. 15 illustrates an example method for a UE multiplexing
UCI in a PUSCH transmission in response to a detection of a DCI
format scheduling two PUSCH transmissions on two respective cells
according to embodiments of the present disclosure;
[0027] FIGS. 16, 17, and 18 illustrate example methods for a UE
determining a number of physical downlink control channel (PDCCH)
candidates to monitor in a slot for scheduling on a cell for PDCCH
candidate scaling according to embodiments of the present
disclosure; and
[0028] FIG. 19 illustrates an example method for a UE switching
among groups of search space sets according to embodiments of the
present disclosure.
DETAILED DESCRIPTION
[0029] FIGS. 1 through 19, discussed below, and the various
embodiments used to describe the principles of the present
disclosure in this patent document are by way of illustration only
and should not be construed in any way to limit the scope of the
disclosure. Those skilled in the art will understand that the
principles of the present disclosure may be implemented in any
suitably-arranged system or device.
[0030] The following documents are hereby incorporated by reference
into the present disclosure as if fully set forth herein: 3GPP TS
38.211 v16.2.0, "NR; Physical channels and modulation;" 3GPP TS
38.212 v16.2.0, "NR; Multiplexing and Channel coding;" 3GPP TS
38.213 v16.2.0, "NR; Physical Layer Procedures for Control;" 3GPP
TS 38.214 v16.2.0, "NR; Physical Layer Procedures for Data;" 3GPP
TS 38.321 v16.1.0, "NR; Medium Access Control (MAC) protocol
specification;" and 3GPP TS 38.331 v16.1.0, "NR; Radio Resource
Control (RRC) Protocol Specification."
[0031] To meet the demand for wireless data traffic having
increased since deployment of the fourth generation (4G)
communication systems, efforts have been made to develop and deploy
an improved 5th generation (5G) or pre-5G/NR communication system.
Therefore, the 5G or pre-5G communication system is also called a
"beyond 4G network" or a "post long term evolution (LTE)
system."
[0032] The 5G communication system is considered to be implemented
in higher frequency (mmWave) bands, e.g., 28 GHz or 60 GHz bands,
so as to accomplish higher data rates or in lower frequency bands,
such as 6 GHz, to enable robust coverage and mobility support. To
decrease propagation loss of the radio waves and increase the
transmission distance, the beamforming, massive multiple-input
multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array
antenna, an analog beam forming, large scale antenna techniques are
discussed in 5G communication systems.
[0033] In addition, in 5G communication systems, development for
system network improvement is under way based on advanced small
cells, cloud Radio Access Networks (RANs), ultra-dense networks,
device-to-device (D2D) communication, wireless backhaul, moving
network, cooperative communication, coordinated multi-points
(CoMP), reception-end interference cancellation and the like.
[0034] The discussion of 5G systems and frequency bands associated
therewith is for reference as certain embodiments of the present
disclosure may be implemented in 5G systems. However, the present
disclosure is not limited to 5G systems or the frequency bands
associated therewith, and embodiments of the present disclosure may
be utilized in connection with any frequency band. For example,
aspects of the present disclosure may also be applied to deployment
of 5G communication systems, 6G or even later releases which may
use terahertz (THz) bands.
[0035] Depending on the network type, the term `base station` (BS)
can refer to any component (or collection of components) configured
to provide wireless access to a network, such as transmit point
(TP), transmit-receive point (TRP), an enhanced base station
(eNodeB or eNB), a gNB , a macrocell, a femtocell, a WiFi access
point (AP), a satellite, or other wirelessly enabled devices. Base
stations may provide wireless access in accordance with one or more
wireless communication protocols, e.g., 5G 3GPP New Radio
Interface/Access (NR), LTE, LTE advanced (LTE-A), High Speed Packet
Access (HSPA), Wi-Fi 802.11a/b/g/n/ac, etc. The terms `BS,` `gNB,`
and `TRP` can be used interchangeably in this disclosure to refer
to network infrastructure components that provide wireless access
to remote terminals. Also, depending on the network type, the term
`user equipment` (UE) can refer to any component such as mobile
station, subscriber station, remote terminal, wireless terminal,
receive point, vehicle, or user device. For example, a UE could be
a mobile telephone, a smartphone, a monitoring device, an alarm
device, a fleet management device, an asset tracking device, an
automobile, a desktop computer, an entertainment device, an
infotainment device, a vending machine, an electricity meter, a
water meter, a gas meter, a security device, a sensor device, an
appliance, and the like.
[0036] FIGS. 1-3 below describe various embodiments implemented in
wireless communications systems and with the use of orthogonal
frequency division multiplexing (OFDM) or orthogonal frequency
division multiple access (OFDMA) communication techniques. The
descriptions of FIGS. 1-3 are not meant to imply physical or
architectural limitations to the manner in which different
embodiments may be implemented. Different embodiments of the
present disclosure may be implemented in any suitably-arranged
communications system.
[0037] FIG. 1 illustrates an example wireless network 100 according
to embodiments of the present disclosure. The embodiment of the
wireless network 100 shown in FIG. 1 is for illustration only.
Other embodiments of the wireless network 100 could be used without
departing from the scope of this disclosure.
[0038] As shown in FIG. 1, the wireless network 100 includes a base
station, BS 101 (e.g., gNB), a BS 102, and a BS 103. The BS 101
communicates with the BS 102 and the BS 103. The BS 101 also
communicates with at least one network 130, such as the Internet, a
proprietary Internet Protocol (IP) network, or other data
network.
[0039] The BS 102 provides wireless broadband access to the network
130 for a first plurality of user equipment's (UEs) within a
coverage area 120 of the BS 102. The first plurality of UEs
includes a UE 111, which may be located in a small business; a UE
112, which may be located in an enterprise (E); a UE 113, which may
be located in a WiFi hotspot (HS); a UE 114, which may be located
in a first residence (R); a UE 115, which may be located in a
second residence (R); and a UE 116, which may be a mobile device
(M), such as a cell phone, a wireless laptop, a wireless PDA, or
the like. The BS 103 provides wireless broadband access to the
network 130 for a second plurality of UEs within a coverage area
125 of the BS 103. The second plurality of UEs includes the UE 115
and the UE 116. In some embodiments, one or more of the BSs 101-103
may communicate with each other and with the UEs 111-116 using
5G/NR, long term evolution (LTE), long term evolution-advanced
(LTE-A), WiMAX, WiFi, or other wireless communication
techniques.
[0040] Dotted lines show the approximate extents of the coverage
areas 120 and 125, which are shown as approximately circular for
the purposes of illustration and explanation only. It should be
clearly understood that the coverage areas associated with BSs,
such as the coverage areas 120 and 125, may have other shapes,
including irregular shapes, depending upon the configuration of the
BSs and variations in the radio environment associated with natural
and man-made obstructions.
[0041] As described in more detail below, one or more of the UEs
111-116 include circuitry, programming, or a combination thereof
for receiving multi-cell scheduling and PDCCH allocations. In
certain embodiments, and one or more of the BSs 101-103 includes
circuitry, programming, or a combination thereof for multi-cell
scheduling and allocating PDCCHs.
[0042] Although FIG. 1 illustrates one example of a wireless
network, various changes may be made to FIG. 1. For example, the
wireless network could include any number of BSs and any number of
UEs in any suitable arrangement. Also, the BS 101 could communicate
directly with any number of UEs and provide those UEs with wireless
broadband access to the network 130. Similarly, each BS 102-103
could communicate directly with the network 130 and provide UEs
with direct wireless broadband access to the network 130. Further,
the BSs 101, 102, and/or 103 could provide access to other or
additional external networks, such as external telephone networks
or other types of data networks.
[0043] FIG. 2 illustrates an example BS 102 according to
embodiments of the present disclosure. The embodiment of the BS 102
illustrated in FIG. 2 is for illustration only, and the BSs 101 and
103 of FIG. 1 could have the same or similar configuration.
However, BSs come in a wide variety of configurations, and FIG. 2
does not limit the scope of this disclosure to any particular
implementation of a BS.
[0044] As shown in FIG. 2, the BS 102 includes multiple antennas
205a-205n, multiple radio frequency (RF) transceivers 210a-210n,
transmit (TX) processing circuitry 215, and receive (RX) processing
circuitry 220. The BS 102 also includes a controller/processor 225,
a memory 230, and a backhaul or network interface 235.
[0045] The RF transceivers 210a-210n receive, from the antennas
205a-205n, incoming RF signals, such as signals transmitted by UEs
in the wireless network 100. The RF transceivers 210a-210n
down-convert the incoming RF signals to generate IF or baseband
signals. The IF or baseband signals are sent to the RX processing
circuitry 220, which generates processed baseband signals by
filtering, decoding, and/or digitizing the baseband or IF signals.
The RX processing circuitry 220 transmits the processed baseband
signals to the controller/processor 225 for further processing.
[0046] The TX processing circuitry 215 receives analog or digital
data (such as voice data, web data, e-mail, or interactive video
game data) from the controller/processor 225. The TX processing
circuitry 215 encodes, multiplexes, and/or digitizes the outgoing
baseband data to generate processed baseband or IF signals. The RF
transceivers 210a-210n receive the outgoing processed baseband or
IF signals from the TX processing circuitry 215 and up-converts the
baseband or IF signals to RF signals that are transmitted via the
antennas 205a-205n.
[0047] The controller/processor 225 can include one or more
processors or other processing devices that control the overall
operation of the BS 102. For example, the controller/processor 225
could control the reception of forward channel signals and the
transmission of reverse channel signals by the RF transceivers
210a-210n, the RX processing circuitry 220, and the TX processing
circuitry 215 in accordance with well-known principles. The
controller/processor 225 could support additional functions as
well, such as more advanced wireless communication functions. For
instance, the controller/processor 225 could support multi-cell
scheduling and allocating PDCCH. Any of a wide variety of other
functions could be supported in the BS 102 by the
controller/processor 225. In some embodiments, the
controller/processor 225 includes at least one microprocessor or
microcontroller.
[0048] The controller/processor 225 is also capable of executing
programs and other processes resident in the memory 230, such as an
OS. The controller/processor 225 can move data into or out of the
memory 230 as required by an executing process. For example, the
controller/processor 225 can move data into or out of the memory
230 according to a process that is being executed.
[0049] The controller/processor 225 is also coupled to the backhaul
or network interface 235. The backhaul or network interface 235
allows the BS 102 to communicate with other devices or systems over
a backhaul connection or over a network. The network interface 235
could support communications over any suitable wired or wireless
connection(s). For example, when the BS 102 is implemented as part
of a cellular communication system (such as one supporting 5G/NR,
LTE, or LTE-A), the network interface 235 could allow the BS 102 to
communicate with other BSs over a wired or wireless backhaul
connection. When the BS 102 is implemented as an access point, the
network interface 235 could allow the BS 102 to communicate over a
wired or wireless local area network or over a wired or wireless
connection to a larger network (such as the Internet). The network
interface 235 includes any suitable structure supporting
communications over a wired or wireless connection, such as an
Ethernet or RF transceiver.
[0050] The memory 230 is coupled to the controller/processor 225.
Part of the memory 230 could include a RAM, and another part of the
memory 230 could include a Flash memory or other ROM.
[0051] Although FIG. 2 illustrates one example of BS 102, various
changes may be made to FIG. 2. For example, the BS 102 could
include any number of each component shown in FIG. 2. As a
particular example, an access point could include a number of
network interfaces 235, and the controller/processor 225 could
support routing functions to route data between different network
addresses. As another particular example, while shown as including
a single instance of TX processing circuitry 215 and a single
instance of RX processing circuitry 220, the BS 102 could include
multiple instances of each (such as one per RF transceiver). Also,
various components in FIG. 2 could be combined, further subdivided,
or omitted and additional components could be added according to
particular needs.
[0052] FIG. 3 illustrates an example UE 116 according to
embodiments of the present disclosure. The embodiment of the UE 116
illustrated in FIG. 3 is for illustration only, and the UEs 111-115
of FIG. 1 could have the same or similar configuration. However,
UEs come in a wide variety of configurations, and FIG. 3 does not
limit the scope of this disclosure to any particular implementation
of a UE.
[0053] As shown in FIG. 3, the UE 116 includes an antenna 305, a RF
transceiver 310, TX processing circuitry 315, a microphone 320, and
receive (RX) processing circuitry 325. The UE 116 also includes a
speaker 330, a processor 340, an input/output (I/O) interface (IF)
345, an input device 350, a display 355, and a memory 360. The
memory 360 includes an operating system (OS) 361 and one or more
applications 362.
[0054] The RF transceiver 310 receives, from the antenna 305, an
incoming RF signal transmitted by a BS of the wireless network 100.
The RF transceiver 310 down-converts the incoming RF signal to
generate an intermediate frequency (IF) or baseband signal. The IF
or baseband signal is sent to the RX processing circuitry 325 that
generates a processed baseband signal by filtering, decoding,
and/or digitizing the baseband or IF signal. The RX processing
circuitry 325 transmits the processed baseband signal to the
speaker 330 (such as for voice data) or to the processor 340 for
further processing (such as for web browsing data).
[0055] The TX processing circuitry 315 receives analog or digital
voice data from the microphone 320 or other outgoing baseband data
(such as web data, e-mail, or interactive video game data) from the
processor 340. The TX processing circuitry 315 encodes,
multiplexes, and/or digitizes the outgoing baseband data to
generate a processed baseband or IF signal. The RF transceiver 310
receives the outgoing processed baseband or IF signal from the TX
processing circuitry 315 and up-converts the baseband or IF signal
to an RF signal that is transmitted via the antenna 305.
[0056] The processor 340 can include one or more processors or
other processing devices and execute the OS 361 stored in the
memory 360 in order to control the overall operation of the UE 116.
For example, the processor 340 could control the reception of
forward channel signals and the transmission of reverse channel
signals by the RF transceiver 310, the RX processing circuitry 325,
and the TX processing circuitry 315 in accordance with well-known
principles. In some embodiments, the processor 340 includes at
least one microprocessor or microcontroller.
[0057] The processor 340 is also capable of executing other
processes and programs resident in the memory 360, such as
processes for beam management. The processor 340 can move data into
or out of the memory 360 as required by an executing process. In
some embodiments, the processor 340 is configured to execute the
applications 362 based on the OS 361 or in response to signals
received from BS s or an operator. The processor 340 is also
coupled to the I/O interface 345, which provides the UE 116 with
the ability to connect to other devices, such as laptop computers
and handheld computers. The I/O interface 345 is the communication
path between these accessories and the processor 340.
[0058] The processor 340 is also coupled to the input device 350.
The operator of the UE 116 can use the input device 350 to enter
data into the UE 116. The input device 350 can be a keyboard,
touchscreen, mouse, track ball, voice input, or other device
capable of acting as a user interface to allow a user in interact
with the UE 116. For example, the input device 350 can include
voice recognition processing, thereby allowing a user to input a
voice command. In another example, the input device 350 can include
a touch panel, a (digital) pen sensor, a key, or an ultrasonic
input device. The touch panel can recognize, for example, a touch
input in at least one scheme, such as a capacitive scheme, a
pressure sensitive scheme, an infrared scheme, or an ultrasonic
scheme.
[0059] The processor 340 is also coupled to the display 355. The
display 355 may be a liquid crystal display, light emitting diode
display, or other display capable of rendering text and/or at least
limited graphics, such as from web sites.
[0060] The memory 360 is coupled to the processor 340. Part of the
memory 360 could include a random access memory (RAM), and another
part of the memory 360 could include a Flash memory or other
read-only memory (ROM).
[0061] Although FIG. 3 illustrates one example of UE 116, various
changes may be made to FIG. 3. For example, various components in
FIG. 3 could be combined, further subdivided, or omitted and
additional components could be added according to particular needs.
As a particular example, the processor 340 could be divided into
multiple processors, such as one or more central processing units
(CPUs) and one or more graphics processing units (GPUs). Also,
while FIG. 3 illustrates the UE 116 configured as a mobile
telephone or smartphone, UEs could be configured to operate as
other types of mobile or stationary devices.
[0062] FIG. 4 and FIG. 5 illustrate example wireless transmit and
receive paths according to this disclosure. In the following
description, a transmit path 400, of FIG. 4, may be described as
being implemented in a BS (such as the BS 102), while a receive
path 500, of FIG. 5, may be described as being implemented in a UE
(such as a UE 116). However, it may be understood that the receive
path 500 can be implemented in a BS and that the transmit path 400
can be implemented in a UE. In some embodiments, the receive path
500 is configured to support multi-cell scheduling and allocating
PDCCHs as described in embodiments of the present disclosure.
[0063] The transmit path 400 as illustrated in FIG. 4 includes a
channel coding and modulation block 405, a serial-to-parallel
(S-to-P) block 410, a size N inverse fast Fourier transform (IFFT)
block 415, a parallel-to-serial (P-to-S) block 420, an add cyclic
prefix block 425, and an up-converter (UC) 430. The receive path
500 as illustrated in FIG. 5 includes a down-converter (DC) 555, a
remove cyclic prefix block 560, a serial-to-parallel (S-to-P) block
565, a size N fast Fourier transform (FFT) block 570, a
parallel-to-serial (P-to-S) block 575, and a channel decoding and
demodulation block 580.
[0064] As illustrated in FIG. 4, the channel coding and modulation
block 405 receives a set of information bits, applies coding (such
as a low-density parity check (LDPC) coding), and modulates the
input bits (such as with quadrature phase shift keying (QPSK) or
quadrature amplitude modulation (QAM)) to generate a sequence of
frequency-domain modulation symbols. The serial-to-parallel block
410 converts (such as de-multiplexes) the serial modulated symbols
to parallel data in order to generate N parallel symbol streams,
where N is the IFFT/FFT size used in the BS 102 and the UE 116. The
size N IFFT block 415 performs an IFFT operation on the N parallel
symbol streams to generate time-domain output signals. The
parallel-to-serial block 420 converts (such as multiplexes) the
parallel time-domain output symbols from the size N IFFT block 415
in order to generate a serial time-domain signal. The add cyclic
prefix block 425 inserts a cyclic prefix to the time-domain signal.
The up-converter 430 modulates (such as up-converts) the output of
the add cyclic prefix block 425 to an RF frequency for transmission
via a wireless channel. The signal may also be filtered at baseband
before conversion to the RF frequency.
[0065] A transmitted RF signal from the BS 102 arrives at the UE
116 after passing through the wireless channel, and reverse
operations to those at the BS 102 are performed at the UE 116.
[0066] As illustrated in FIG. 5, the down-converter 555
down-converts the received signal to a baseband frequency, and the
remove cyclic prefix block 560 removes the cyclic prefix to
generate a serial time-domain baseband signal. The
serial-to-parallel block 565 converts the time-domain baseband
signal to parallel time domain signals. The size N FFT block 570
performs an FFT algorithm to generate N parallel frequency-domain
signals. The parallel-to-serial block 575 converts the parallel
frequency-domain signals to a sequence of modulated data symbols.
The channel decoding and demodulation block 580 demodulates and
decodes the modulated symbols to recover the original input data
stream.
[0067] Each of the BSs 101-103 may implement a transmit path 400 as
illustrated in FIG. 4 that is analogous to transmitting in the
downlink to UEs 111-116 and may implement a receive path 500 as
illustrated in FIG. 5 that is analogous to receiving in the uplink
from UEs 111-116. Similarly, each of UEs 111-116 may implement the
transmit path 400 for transmitting in the uplink to the BSs 101-103
and may implement the receive path 500 for receiving in the
downlink from the BSs 101-103.
[0068] Each of the components in FIG. 4 and FIG. 5 can be
implemented using hardware or using a combination of hardware and
software/firmware. As a particular example, at least some of the
components in FIG. 4 and FIG. 5 may be implemented in software,
while other components may be implemented by configurable hardware
or a mixture of software and configurable hardware. For instance,
the FFT block 570 and the IFFT block 515 may be implemented as
configurable software algorithms, where the value of size N may be
modified according to the implementation.
[0069] Furthermore, although described as using FFT and IFFT, this
is by way of illustration only and may not be construed to limit
the scope of this disclosure. Other types of transforms, such as
discrete Fourier transform (DFT) and inverse discrete Fourier
transform (IDFT) functions, can be used. It may be appreciated that
the value of the variable N may be any integer number (such as 1,
2, 3, 4, or the like) for DFT and IDFT functions, while the value
of the variable N may be any integer number that is a power of two
(such as 1, 2, 4, 8, 16, or the like) for FFT and IFFT
functions.
[0070] Although FIG. 4 and FIG. 5 illustrate examples of wireless
transmit and receive paths, various changes may be made to FIG. 4
and FIG. 5. For example, various components in FIG. 4 and FIG. 5
can be combined, further subdivided, or omitted and additional
components can be added according to particular needs. Also, FIG. 4
and FIG. 5 are meant to illustrate examples of the types of
transmit and receive paths that can be used in a wireless network.
Any other suitable architectures can be used to support wireless
communications in a wireless network.
[0071] A unit for downlink (DL) signaling or for uplink (UL)
signaling on a cell is referred to as a slot and can include one or
more symbols. A bandwidth (BW) unit is referred to as a resource
block (RB). One RB includes a number of sub-carriers (SCs). For
example, a slot can have duration of one millisecond and an RB can
have a bandwidth of 180 kHz and include 12 SCs with inter-SC
spacing of 15 kHz. A sub-carrier spacing (SCS) can be determined by
a SCS configuration .mu. as 2.sup..mu.15 kHz. A unit of one
sub-carrier over one symbol is referred to as a resource element
(RE). A unit of one RB over one symbol is referred to as a physical
RB (PRB).
[0072] DL signals include data signals conveying information
content, control signals conveying DL control information (DCI),
reference signals (RS), and the like that are also known as pilot
signals. A BS (such as the BS 102) transmits data information or
DCI through respective physical DL shared channels (PDSCHs) or
physical DL control channels (PDCCHs). A PDSCH or a PDCCH can be
transmitted over a variable number of slot symbols including one
slot symbol. A BS transmits one or more of multiple types of RS
including channel state information RS (CSI-RS) and demodulation RS
(DM-RS). A CSI-RS is intended for UEs (such as the UE 116) to
perform measurements and provide channel state information (CSI) to
a BS. For channel measurement or for time tracking, non-zero power
CSI-RS (NZP CSI-RS) resources can be used. For interference
measurement reports (IMRs), CSI interference measurement (CSI-IM)
resources can be used. The CSI-IM resources can also be associated
with a zero power CSI-RS (ZP CSI-RS) configuration. A UE can
determine CSI-RS reception parameters through DL control signaling
or higher layer signaling, such as radio resource control (RRC)
signaling from a gNB. A DM-RS is typically transmitted only within
a BW of a respective PDCCH or PDSCH and a UE can use the DM-RS to
demodulate data or control information.
[0073] UL signals also include data signals conveying information
content, control signals conveying UL control information (UCI),
DM-RS associated with data or UCI demodulation, sounding RS (SRS)
enabling a gNB to perform UL channel measurement, and a random
access (RA) preamble enabling a UE (such as the UE 116) to perform
random access. A UE transmits data information or UCI through a
respective physical UL shared channel (PUSCH) or a physical UL
control channel (PUCCH). A PUSCH or a PUCCH can be transmitted over
a variable number of slot symbols including one slot symbol. When a
UE simultaneously transmits data information and UCI, the UE can
multiplex both in a PUSCH or, depending on a UE capability,
transmit both a PUSCH with data information and a PUCCH with UCI at
least when the transmissions are on different cells.
[0074] UCI includes hybrid automatic repeat request acknowledgement
(HARQ-ACK) information, indicating correct or incorrect detection
of data transport blocks (TBs) or of code block groups (CBGs) in a
PDSCH, scheduling request (SR) indicating whether a UE has data in
its buffer to transmit, and CSI reports enabling a gNB to select
appropriate parameters for PDSCH or PDCCH transmissions to a UE. A
CSI report can include a channel quality indicator (CQI) informing
a gNB of a largest modulation and coding scheme (MCS) for the UE to
detect a data TB with a predetermined block error rate (BLER), such
as a 10% BLER, of a precoding matrix indicator (PMI) informing a
gNB how to combine signals from multiple transmitter antennas in
accordance with a multiple input multiple output (MIMO)
transmission principle, of a CSI-RS resource indicator (CRI) used
to obtain the CSI report, and of a rank indicator (RI) indicating a
transmission rank for a PDSCH. In certain embodiments, UL RS
includes DM-RS and SRS. DM-RS is typically transmitted within a BW
of a respective PUSCH or PUCCH. A gNB can use a DM-RS to demodulate
information in a respective PUSCH or PUCCH. SRS is transmitted by a
UE to provide a gNB with an UL CSI and, for a TDD system, to also
provide a PMI for DL transmission. Further, as part of a random
access procedure or for other purposes, a UE can transmit a
physical random access channel (PRACH).
[0075] DL transmissions and UL transmissions can be based on an
orthogonal frequency division multiplexing (OFDM) waveform
including a variant using DFT preceding that is known as
DFT-spread-OFDM.
[0076] FIG. 6 illustrates a block diagram 600 of an example
transmitter structure using orthogonal frequency division
multiplexing (OFDM) according to embodiments of the present
disclosure. FIG. 7 illustrates a block diagram 700 of an example
receiver structure using OFDM according to embodiments of the
present disclosure.
[0077] The transmitter structure as shown in the block diagram 600
and the receiver structure as shown in the block diagram 600 can be
similar to the RF transceivers 210a-210n of FIG. 2 and the RF
transceiver 310 of FIG. 3. The example block diagram 600 of FIG. 6
and the block diagram 700 of FIG. 7 are for illustration only and
other embodiments can be used without departing from the scope of
the present disclosure.
[0078] As illustrated in the block diagram 600, information bits
610, such as DCI bits or data bits, are encoded by encoder 620,
rate matched to assigned time/frequency resources by rate matcher
630, and modulated by modulator 640. Subsequently, modulated
encoded symbols and DMRS or CSI-RS 650 are mapped to SCs by SC
mapping unit 660 with input from BW selector unit 665, an inverse
fast Fourier transform (IFFT) is performed by filter 670, a cyclic
prefix (CP) is added by CP insertion unit 680, and a resulting
signal is filtered by filter 690 and transmitted by a radio
frequency (RF) unit as transmitted bits 695.
[0079] As illustrated in the block diagram 700, a received signal
710 is filtered by filter 720, a CP removal unit 730 removes a CP,
a filter 740 applies a fast Fourier transform (FFT), SCs de-mapping
unit 750 de-maps SCs selected by BW selector unit 755, received
symbols are demodulated by a channel estimator and a demodulator
unit 760, a rate de-matcher 770 restores a rate matching, and a
decoder 780 decodes the resulting bits to provide information bits
790.
[0080] In certain embodiments, a UE monitors multiple candidate
locations for respective potential PDCCH receptions to decode
multiple DCI formats in a slot. A DCI format includes cyclic
redundancy check (CRC) bits in order for the UE to confirm a
correct detection of the DCI format. A type of a DCI format is
identified by a radio network temporary identifier (RNTI) that
scrambles the CRC bits of the DCI format.
[0081] For a DCI format scheduling a PDSCH or a PUSCH to a single
UE, the RNTI can be a cell RNTI (C-RNTI), or a configured
scheduling RNTI (CS-RNTI), or an MCS-C-RNTI and serves as a UE
identifier. In the following examples, the C-RNTI will be referred
to when needed. A UE typically receives/monitors PDCCH for
detections of DCI formats with CRC scrambled by a C-RNTI according
to a UE-specific search space (USS).
[0082] For a DCI format scheduling a PDSCH conveying system
information (SI), the RNTI can be an SI-RNTI. For a DCI format
scheduling a PDSCH providing a random access response (RAR), the
RNTI can be an RA-RNTI. For a DCI format scheduling a PDSCH
providing paging information, the RNTI can be a P-RNTI. There are
also a number of other RNTIs associated with DCI formats providing
various control information and are monitored according to a common
search space (CSS).
[0083] FIG. 8 illustrates an example encoding process 800 for a
downlink control information (DCI) format according to embodiments
of the present disclosure. FIG. 9 illustrates an example decoding
process 900 for a DCI format for use with a UE according to
embodiments of the present disclosure. The encoding process 800 of
FIG. 8 and the decoding process 900 of FIG. 9 are for illustration
only and other embodiments can be used without departing from the
scope of the present disclosure.
[0084] A BS separately encodes and transmits each DCI format in a
respective PDCCH. When applicable, a RNTI for a UE that a DCI
format is intended for masks a CRC of the DCI format codeword in
order to enable the UE to identify the DCI format. For example, the
CRC can include 16 bits or 24 bits and the RNTI can include 16 bits
or 24 bits. Otherwise, when a RNTI is not included in a DCI format,
a DCI format type indicator field can be included in the DCI
format.
[0085] As illustrated in FIG. 8, the CRC of (non-coded) DCI format
bits 810 is determined using a CRC computation unit 820, and the
CRC is masked using an exclusive OR (XOR) operation unit 830
between CRC bits and RNTI bits 840. The XOR operation is defined as
XOR(0,0)=0, XOR(0,1)=1, XOR(1,0)=1, XOR(1,1)=0. The masked CRC bits
are appended to DCI format information bits using a CRC append unit
850. An encoder 860 performs channel coding (such as tail-biting
convolutional coding or polar coding), followed by rate matching to
allocated resources by rate matcher 870. Interleaving and
modulation units 880 apply interleaving and modulation, such as
QPSK, and the output control signal 890 is transmitted.
[0086] As illustrated in FIG. 9, a received control signal 910 is
demodulated and de-interleaved by a demodulator and a
de-interleaver 920. A rate matching applied at a BS transmitter is
restored by rate matcher 930, and resulting bits are decoded by
decoder 940. After decoding, a CRC extractor 950 extracts CRC bits
and provides DCI format information bits 960. The DCI format
information bits are de-masked 970 by an XOR operation with a RNTI
980 (when applicable) and a CRC check is performed by unit 990.
When the CRC check succeeds (check-sum is zero), the DCI format
information bits are considered to be valid. When the CRC check
does not succeed, the DCI format information bits are considered to
be invalid.
[0087] Table 1, below, describes fields for a DCI format 1_2
scheduling a PDSCH reception by a UE on a single cell.
TABLE-US-00001 TABLE 1 Fields of DCI format 1_2 Information field
Number of bits Identifier for DCI formats 1 Carrier indicator 0, 1,
2, 3 Bandwidth part (BWP) indicator 0, 1, 2 PRB bundling size
indicator 0, 1 Rate matching indicator 0, 1, 2 Zero power (ZP)
CSI-RS trigger 0, 1, 2 Frequency domain resource Variable
allocation (FDRA) Time domain resource 0, 1, 2, 3, 4 allocation
(TDRA) Modulation and coding scheme (MCS) 5 New data indicator
(NDI) 1 Redundancy version (RV) 0, 1, 2 HARQ process number 0, 1,
2, 3, 4 VRB-to-PRB mapping 0 or 1 Downlink assignment index (DAI)
0, 1, 2, 4 TPC command for PUCCH 2 PUCCH resource indicator (PRI)
0, 1, 2, 3 PDSCH-to-HARQ-ACK timing 0, 1, 2, 3 Antenna port(s) 0,
4, 5, 6 SRS request 0, 1, 2, 3 DMRS sequence initialization 0, 1
Transmission configuration indication (TCI) 0, 1, 2, 3 CBG
Transmission information (CBGTI) 0, 1, 2, 3 CBG flushing out
information (CBGFI) 0, 1 CRC 24
[0088] Table 2 below describes fields for a DCI format 0_2
scheduling a PUSCH transmission from a UE on a single cell.
TABLE-US-00002 TABLE 2 Fields of DCI format 0_2 Information field
Number of bits Identifier for DCI formats 1 Carrier indicator 0, 1,
2, 3 UL/SUL indicator 0, 1 Bandwidth part (BWP) indicator 0, 1, 2
Frequency domain resource allocation (FDRA) Variable Time domain
resource allocation (TDRA) 0, 1, 2, 3, 4 Frequency hopping (FH)
flag 0, 1 Modulation and coding scheme (MCS) 5 New data indicator
(NDI)S 1 Redundancy version (RV) 0, 1, 2 HARQ process number 0, 1,
2, 3, 4 Downlink assignment index (DAI) 0, 1, 2, 4 TPC command for
PUSCH 2 SRS resource indicator (SRI) Variable Precoding information
and number of layers 0, 1, 2, 3, 4, 5, 6 Antenna port(s) 0, 2, 3,
4, 5 SRS request 0, 1, 2, 3 CSI request 0, 1, 2, 3, 4, 5, 6
PTRS-DMRS association 0, 2 beta_offset indicator 0, 1, 2 DMRS
sequence initialization 0, 1 UL-SCH indicator 1 Open-loop power
control (OLPC) parameter set 0, 1, 2 indication CRC 24
[0089] In certain embodiments, a PDCCH transmission can be within a
set of PRBs. A BS can configure a UE with one or more sets of PRB
sets, also referred to as control resource sets (CORESETs), for
PDCCH receptions. A PDCCH reception can be in control channel
elements (CCEs) that are included in a CORESET.
[0090] A UE can monitor PDCCH according to a first PDCCH monitoring
type or according to a second PDCCH monitoring type. For the first
PDCCH monitoring type that corresponds to a UE capability for PDCCH
monitoring per slot, a maximum number of PDCCH candidates
M.sub.PDCCH.sup.max,slot,.mu. and a maximum number of
non-overlapping CCEs C.sub.PDCCH.sup.max,slot,.mu. for the
reception of PDCCH candidates is defined per slot. Non-overlapping
CCEs are CCEs with different indexes or in different symbols of a
CORESET or in different CORESETs.
[0091] In certain embodiments, if a UE (such as the UE 116) can
support a first set of N.sub.cells,0.sup.DL serving cells and a
second set of N.sub.cells,1.sup.DL serving cells, then the UE
determines, for the purpose of reporting pdcch-BlindDetectionCA, a
number of serving cells as
N.sub.cells,0.sup.DL+RN.sub.cells,1.sup.DL where R is a value
reported by the UE. In this embodiment, (i) first set of
N.sub.cells,0.sup.DL serving cells where the UE is either not
provided CORESETPoolIndex or is provided CORESETPoolIndex with a
single value for all CORESETs on all DL BWPs of each serving cell
from the first set of serving cells and (ii) the second set of
N.sub.cells,1.sup.DL serving cells is associated where the UE is
provided CORESETPoolIndex with a value 0 for a first CORESET and
with a value 1 for a second CORESET on any DL BWP of each serving
cell from the second set of serving cells.
[0092] In certain embodiments, if a UE (such as the UE 116) is (i)
is configured with
N.sub.cells,0.sup.DL,.mu.+N.sub.cells,1.sup.DL,.mu. downlink cells,
(ii) associated PDCCH candidates monitored in the active DL BWPs of
the scheduling cell(s) using SCS configuration .mu., where
.SIGMA..sub..mu.=0.sup.3(N.sub.cells,0.sup.DL,.mu.+.gamma.N.sub.cells,1.s-
up.DL,.mu.)>N.sub.cells.sup.cap, and (iii) a DL BWP of an
activated cell is the active DL BWP of the activated cell, and a DL
BWP of a deactivated cell is the DL BWP with index provided by
firstActiveDownlinkBWP-Id for the deactivated cell, then the UE is
not required to monitor more than
M.sub.PDCCH.sup.total,slot,.mu.=.left
brkt-bot.N.sub.cells.sup.capM.sub.PDCCH.sup.max,slot,.mu.(N.sub.cells,0.s-
up.DL,.mu.+.gamma.N.sub.cells,1.sup.DL,.mu.)/.SIGMA..sub.j=0.sup.3(N.sub.c-
ells,0.sup.DL,j+.gamma.N.sub.cells,1.sup.DL,j).right brkt-bot.
PDCCH candidates or more than C.sub.PDCCH.sup.total,slot,.mu.=.left
brkt-bot.N.sub.cells.sup.capC.sub.PDCCH.sup.max,slot,.mu.(N.sub.cells,0.s-
up.DL,.mu.+.gamma.N.sub.cells,1.sup.DL,.mu.)/.SIGMA..sub.j=0.sup.3(N.sub.c-
ells,0.sup.DL,j+.gamma.N.sub.cells,1.sup.DL,j).right brkt-bot.
non-overlapped CCEs per slot on the active DL BWP(s) of scheduling
cell(s) from the
N.sub.cells,0.sup.DL,.mu.+N.sub.cells,1.sup.DL,.mu. downlink cells.
In this example, N.sub.cells.sup.cap is equal to 4 or is a
capability reported by the UE. Additionally, in this example,
.gamma. is a value that is provided by higher layers to the UE or
is R.
[0093] For each scheduled cell, the UE is not required to monitor
on the active DL BWP with SCS configuration .mu. of the scheduling
cell from the N.sub.cells,1.sup.DL,.mu. downlink cells more than
min(M.sub.PDCCH.sup.max,slot,.mu., M.sub.PDCCH.sup.total,slot,.mu.)
PDCCH candidates or more than min(C.sub.PDCCH.sup.max,slot,.mu.,
C.sub.PDCCH.sup.total,slot,.mu.) non-overlapped CCEs per slot.
[0094] Similar, for each scheduled cell, the UE is not required to
monitor on the active DL BWP with SCS configuration .mu. of the
scheduling cell from the N.sub.cells,1.sup.DL,.mu. downlink cells
more than min(.gamma.M.sub.PDCCH.sup.max,slot,.mu.,
M.sub.PDCCH.sup.total,slot,.mu.) PDCCH candidates or more than
min(.gamma.C.sub.PDCCH.sup.max,slot,.mu.,
C.sub.PDCCH.sup.total,slot,.mu.) non-overlapped CCEs per slot.
Additionally, for each scheduled cell, the UE is not required to
monitor on the active DL BWP with SCS configuration .mu. of the
scheduling cell from the N.sub.cells,1.sup.DL,.mu. downlink cells
more than min(M.sub.PDCCH.sup.max,slot,.mu.,
M.sub.PDCCH.sup.total,slot,.mu.) PDCCH candidates or more than
min(C.sub.PDCCH.sup.max,slot,.mu., C.sub.PDCCH.sup.total,slot,.mu.)
non-overlapped CCEs per slot for CORESETs with same
CORESETPoolIndex value. If a CORESETPoolIndex is not provided for a
cell or if a single CORESETPoolIndex is provided for a cell, then
.gamma.=0.
[0095] In certain embodiments, a UE determines CCEs for decoding a
PDCCH candidate based on a search space. For some RNTIs, such as a
C-RNTI, a set of PDCCH candidates for respective DCI formats define
corresponding UE-specific search space sets. For other RNTIs, such
as a SI-RNTI, a set of PDCCH candidates for respective DCI formats
define corresponding common search space sets (CSS sets). A search
space set is associated with a CORESET where the UE monitors PDCCH
candidates for the search space set. A UE expects to monitor PDCCH
candidates for up to 4 sizes of DCI formats that include up to 3
sizes of DCI formats with CRC scrambled by C-RNTI or MCS-C-RNTI per
serving cell. The UE can count a number of sizes for DCI formats
per serving cell based on a number of configured PDCCH candidates
in respective search space sets for the corresponding active DL
BWP.
[0096] In certain embodiments, for cross-carrier scheduling, the
number of PDCCH candidates for monitoring and the number of
non-overlapped CCEs per span or per slot are separately counted for
each scheduled cell.
[0097] For a search space set s associated with CORESET p, the CCE
indexes for aggregation level L corresponding to PDCCH candidate
m.sub.s,n.sub.CI of the search space set in slot n.sub.s,f.sup..mu.
for an active DL BWP of a serving cell corresponding to carrier
indicator field value n.sub.CI are given by Equation (1), below. As
described in Equation (1), for any CSS,
Y.sub.p,n.sub.s,f.sub..mu.=0. Similar, for a USS,
Y.sub.p,n.sub.s,f.sub..mu.=(A.sub.pY.sub.p,n.sub.s,f.sub..mu..sub.-1)
modD, Y.sub.p,-1=n.sub.RNTI.noteq.0, A.sub.p=39827 for pmod3=0,
A.sub.p=39829 for pmod3=1, A.sub.p=39839 for pmod3=2, and D=65537.
Additionally, as described in Equation (1), i=0, . . . , L-1, and
N.sub.CCE,p is a number of CCEs, numbered from 0 to N.sub.CCE,p-1,
in CORESET p. Similar, n.sub.CI is a carrier indicator field value
if the UE is configured with a carrier indicator field for the
serving cell on which PDCCH is monitored; otherwise, including for
any CSS, n.sub.CI=0. The expression m.sub.s,n.sub.CI as described
in Equation (1), illustrates that m.sub.s,n.sub.CI=0, . . . ,
M.sub.s,n.sub.CI.sup.(L)-1, where M.sub.s,n.sub.CI.sup.(L) is the
number of PDCCH candidates the UE is configured to monitor for
aggregation level L of a search space set s for a serving cell
corresponding to n.sub.CI. For a USS, M.sub.s,max.sup.(L) is the
maximum of M.sub.s,n.sub.CI.sup.(L) over all configured n.sub.CI
values for a CCE aggregation level L of search space set s.
Further, the RNTI value used for n.sub.RNTI is the C-RNTI.
L { ( Y p , n s , f .mu. + m s , n CI N CCE , p L M s , max ( L ) +
n CI ) .times. mod .times. N CCE , p .times. / .times. L } + i ( 1
) ##EQU00001##
[0098] In certain embodiments, a UE (such as the UE 116) monitors
PDCCH according to a CSS for scheduling a PDSCH providing system
information, random access response, or paging only on one cell
that is referred to as primary cell. The UE transmits PUCCH only on
the primary cell. In certain embodiments, the UE is configured as a
primary secondary cell (PSCell) for PUCCH transmissions. When the
UE is configured as a PSCell, the UE transmits PUCCH on the primary
cell for a master/primary cell group and transmits PUCCH on the
PSCell for a secondary cell group. For brevity, the embodiments
descriptions of this disclosure considers the primary cell, but the
embodiments can be directly extended to a PSCell.
[0099] In certain embodiments, an ability of a gNB (such as the BS
102) to schedule a UE (such as the UE 116) on a cell depends on a
maximum PDCCH monitoring capability of the UE for scheduling on the
cell as defined by min(M.sub.PDCCH.sup.max,slot,.mu.,
M.sub.PDCCH.sup.total,slot,.mu.) PDCCH candidates and
min(C.sub.PDCCH.sup.max,slot,.mu., C.sub.PDCCH.sup.total,slot,.mu.)
non-overlapped CCEs per slot for a scheduling cell from the
N.sub.cells,0.sup.DL,.mu. downlink cells or by
min(.gamma.M.sub.PDCCH.sup.max,slot,.mu.,
M.sub.PDCCH.sup.total,slot,.mu.) PDCCH candidates and
min(.gamma.C.sub.PDCCH.sup.max,slot,.mu.,
C.sub.PDCCH.sup.total,slot,.mu.) for a scheduling cell from the
N.sub.cells,1.sup.DL,.mu. downlink cells. While
M.sub.PDCCH.sup.max,slot,.mu. and C.sub.PDCCH.sup.max,slot,.mu. are
predetermined numbers for a SCS configuration .mu.,
M.sub.PDCCH.sup.total,slot,.mu. and C.sub.PDCCH.sup.total,slot,.mu.
are variable and depend on a total number of cells for SCS
configuration .mu.,
N.sub.cells,0.sup.DL,.mu.+.gamma.N.sub.cells,1.sup.DL,.mu., and on
a total number of cells across all SCS configurations
.SIGMA..sub.j=0.sup.3(N.sub.cells,0.sup.DL,j+.gamma.N.sub.cells,1.sup.DL,-
j). Determining M.sub.PDCCH.sup.total,slot,.mu. and
C.sub.PDCCH.sup.total,slot,.mu. based on a number of configured
cells results to an under-dimensioning of the PDCCH monitoring
capability of the UE as, at a given time, the UE can
deterministically know that it cannot be scheduled in certain cells
and therefore a corresponding PDCCH monitoring capability can be
reallocated to other cells where scheduling can occur.
[0100] At least for initial deployments, UEs using new radio (NR)
radio access technology (NR UEs) coexist with legacy UEs using
long-term evolution (LTE) radio access technology (LTE UEs) in a
same network. To enable such coexistence in a same spectrum,
dynamic spectrum sharing (DSS) is used where NR UEs and LTE UEs
share a same channel and a network can dynamically allocate
resources among LTE UEs and NR UEs. During certain time instances
(slots for NR or subframes for LTE), a network may allocate most of
the DL resources to LTE UEs while typically UL spectrum is not
fully utilized and can be used for transmission from either NR UEs
or LTE UEs. It is also possible that some DL spectrum can be
available for PDSCH receptions by NR UEs. To enable such operation
for NR UEs capable of carrier aggregation (CA) operation, the PDCCH
receptions scheduling the PDSCH receptions on the first cell where
LTE UEs and NR UEs coexist can be offloaded to a second cell where
only NR UEs exist. As the first cell is typically a macro-cell
providing synchronization signals and broadcast system information,
it is a primary cell and the second cell is a secondary cell.
However, DSS operation can also be applicable among secondary
cells. In general, with DSS, an NR UE can be scheduled either from
a first cell, such as a primary cell, or from a second cell such as
an SCell. In the remaining of this disclosure, unless otherwise
explicitly mentioned, the term UE refers to an NR UE.
[0101] Scheduling a UE on a first cell, such as a primary cell,
from either the first cell or from a second cell, such as a
secondary cell, creates additional conditions for PDCCH monitoring
on both the primary cell and on the secondary cell. One such
condition is to maintain up to 3 sizes of DCI formats with CRC
scrambled by C-RNTI per serving cell for the first cell. Another
condition, when the UE is configured by UE-specific RRC signaling
to monitor PDCCH for detection of DCI formats according to a CSS,
referred to as Type3-PDCCH CSS, on the secondary cell relates to
treating the secondary cell as the primary cell with respect to
overbooking the PDCCH capability of the UE on the secondary cell
and then having to perform search space set dropping by
prioritizing search space sets corresponding to PDCCH monitoring
according to CSS.
[0102] To reduce PDCCH overhead for scheduling PDSCH receptions or
PUSCH transmissions in CA operation, a single DCI format that
schedules multiple PDSCH receptions by a UE or multiple PUSCH
transmissions from a UE in respective multiple cells can be used.
For brevity, the DCI format is referred to as DCI format 0_3 for
scheduling of PUSCH transmissions or as DCI format 1_3 for
scheduling of PDSCH receptions.
[0103] Compared to using multiple respective DCI formats, a DCI
format 1_3 allows for having a single CRC and can also potentially
allow a single value for other fields such as a PUCCH resource
indicator for a PUCCH transmission with HARQ-ACK information
corresponding to multiple PDSCH receptions, a PDSCH-to-HARQ-ACK
timing field indicating a slot for the PUCCH transmission, a
transmission power control (TPC) command field, and a downlink
assignment index (DAI) field for determining a HARQ-ACK codebook.
As DCI format 1_3 can be more reliably detected by a UE than a DCI
format scheduling a single PDSCH reception, because a missed
detection for the former results to multiple PDSCH missed
receptions by the UE, it is important to maintain a small size for
DCI format 1_3 in order to obtain meaningful resource savings over
using multiple DCI formats for scheduling respective PDSCH
receptions.
[0104] Therefore, embodiments of the present disclosure take into
consideration there is a need to design a DCI format that schedules
PDSCH receptions by a UE on multiple cells and provide a size for
the DCI format that is substantially smaller than a proportional
multiple of a size of a DCI format that schedules a PDSCH reception
by the UE on a single cell.
[0105] Embodiments of the present disclosure also take into
consideration that there is a need to design a DCI format that
schedules PUSCH transmissions from a UE on multiple cells and
provide a size for the DCI format that is substantially smaller
than a proportional multiple of a size of a DCI format that
schedules a PUSCH transmission from the UE on a single cell.
[0106] Additionally, embodiments of the present disclosure take
into consideration that there is a need to determine a total number
of PDCCH candidates and a total number of non-overlapped CCEs when
a UE is configured to monitor PDCCH for detection of only DCI
formats that schedule PDSCH receptions or PUSCH transmissions on
multiple cells.
[0107] Accordingly, embodiments of the present disclosure relate to
designing a DCI format that schedules PDSCH receptions by a UE on
multiple cells and provide a size for the DCI format that is
substantially smaller than a proportional multiple of a size of a
DCI format that schedules a PDSCH reception by the UE on a single
cell. The present disclosure also relates to designing a DCI format
that schedules PUSCH transmissions from a UE on multiple cells and
provide a size for the DCI format that is substantially smaller
than a proportional multiple of a size of a DCI format that
schedules a PUSCH transmission from the UE on a single cell. The
present disclosure further relates to determining a total number of
PDCCH candidates and a total number of non-overlapped CCEs when a
UE is configured to monitor PDCCH for detection of only DCI formats
that schedule PDSCH receptions or PUSCH transmissions on multiple
cells.
[0108] Embodiments of the present disclosure describe a DCI format
scheduling multiple PDSCH receptions by a UE on respective multiple
cells. The following examples and embodiments describe designing a
DCI format scheduling multiple PDSCH receptions by a UE on
respective multiple cells.
[0109] An embodiment of this disclosure considers a design for a
DCI format that schedules multiple PDSCH receptions by a UE on
respective multiple cells. For brevity, such DCI format is referred
to as DCI format 1_3. The exemplary embodiments consider scheduling
of two PDSCH receptions on two respective DL cells but are directly
applicable to any number of M.sub.cells.sup.max_sched>2
scheduled cells.
[0110] As different cells can have different operating
characteristics, such as different operating bandwidth or different
duplexing method (such as frequency division duplex (FDD) or time
division duplex (TDD)) and as a UE can experience different channel
conditions, such as different signal-to-interference and noise
ratios (SINRs), the size of each field in DCI format 1_3 needs to
be separately figured for each cell.
[0111] A DCI format 1_3 can include same or similar fields as a DCI
format 1_2. A possibility of additional field is separately
considered. A configuration for a number of bits for each field can
be independent per scheduled cell. A limitation of such an approach
is that a total number of sizes for DCI format 1_3 can be large
when a DCI format 1_3 can schedule PDSCH receptions on any
combination of cells.
[0112] For example, if (i) DCI format 1_3 is restricted to schedule
PDSCH receptions on two cells, (ii) a UE is configured four
scheduled cells, indexed as {c.sub.0, c.sub.1, c.sub.2, c.sub.3},
for a scheduling cell, and (iii) a total size for fields in DCI
format 1_3 corresponding to scheduling PDSCH receptions on each of
the {c.sub.0, c.sub.1, c.sub.2, c.sub.3} cells is {s.sub.0,
s.sub.1, s.sub.2, s.sub.3} respectively, then DCI format 1_3 can
have a size that is any of the combinations that includes the sum
of two values from {s.sub.0, s.sub.1, s.sub.2, s.sub.3} (excluding
CRC bits). For the present example of four scheduled cells having
four separate respective total sizes for fields in DCI format 1_3,
a maximum number of different sizes for DCI format 1_3 is six.
[0113] To minimize an increase in a number of sizes of DCI formats
with CRC scrambled by C-RNTI that a UE is configured to decode, a
size for DCI format 1_3 can be same regardless of the cells that
DCI format 1_3 schedules PDSCH receptions. For example, a number of
scheduled cells where DCI format 1_3 can schedule PDSCH receptions
can be predetermined, such as two cells, a size of DCI format 1_3
can be configured by higher layers, and a sum of sizes for first
fields and second fields associated with scheduling PDSCH
receptions on first and second cells, respectively, can be assumed
to be equal to the size of DCI format 1_3 (with padding bits used
in case the sum is smaller than the total size).
[0114] Instead of configuring a size of DCI format 1_3 by explicit
RRC signaling, a UE can determine a size of DCI format 1_3 based on
a sum of sizes for first and second fields corresponding to
scheduling two PDSCH receptions on respective two reference cells.
For example, the two reference cells can be the scheduling cell and
another scheduled cell with the smallest index among remaining
scheduled cells, or the cells resulting to a largest value for the
sum of the sizes of the corresponding first and second fields in
DCI format 1_3. Alternatively, the UE can expect a total size of
DCI format 1_3 to be same for scheduling two PDSCH receptions on
any combination of two scheduled cells from the set of scheduled
cells.
[0115] For instance, when a UE is configured four scheduled cells
and a corresponding scheduling cell, wherein the indexes of the
scheduled cells are 0, 1, 2, and 3, and wherein the scheduling cell
has index 1, the UE determines the size of DCI format 1_3 based on
the sum of the field sizes for scheduling PDSCH receptions on the
cell with index 1 and of the field sizes for scheduling PDSCH
receptions on the cell with index 0. For example, the UE can expect
a sum of sizes for first and second fields used for scheduling
respective first and second PDSCH receptions on two cells to be
same for any two cells from the set of four scheduled cells.
[0116] FIG. 10 illustrates an example method for a UE determining a
size of a DCI format 1_3 that schedules two PDSCH receptions on
respective two cells according to embodiments of the present
disclosure. For example, the steps of the method 1000 can be
performed by any of the UEs 111-116 of FIG. 1, such as the UE 116
of FIG. 3. The method 1000 of FIG. 10 is for illustration only and
other embodiments can be used without departing from the scope of
the present disclosure.
[0117] As illustrated in FIG. 10, the method 1000 describes a UE
(such as the UE 116) receiving a configuration for a scheduling
cell and for a set of scheduled cells (step 1010). In step 1020,
the UE receives a configuration for a search space set to monitor
PDCCH wherein the search space set configuration includes a DCI
format 1_3 and wherein DCI format 1_3 schedules two PDSCH
receptions on two respective cells from the set of scheduled
cells
[0118] In step 1030, for each cell from the set of scheduled cells,
the UE receives a configuration for a size of each field from a
first subset of fields, wherein the first subset of fields is from
a predetermined set of fields in DCI format 1_3 that are associated
with scheduling a PDSCH reception on the cell from the set of
scheduled cells. A field from the first subset of fields is
included twice in DCI format 1_3, wherein a first occasion is
associated with scheduling a first PDSCH reception on a first cell
from the set of scheduled cells and a second occasion is associated
with scheduling a second PDSCH reception on a second cell from the
set of scheduled cells.
[0119] In step 1040, the UE also receives a configuration for a
size of each field from a second subset of fields from the
predetermined set of fields, wherein the second subset of fields is
commonly used for scheduling first and second PDSCH receptions on
respective first and second cells from the set of scheduled
cells.
[0120] In certain embodiments, the fields in DCI format 1_3 can be
arranged in ascending order of an index of a scheduled cell where
the DCI format scheduled a corresponding PDSCH reception. For
example, if DCI format includes fields {f.sub.0, f.sub.1, . . . ,
f.sub.M}, then DCI format 1_3 can include two blocks of such
fields. In this example, a first block for a scheduled cell with a
smaller index followed by a second block for a scheduled cell with
a larger cell index. Alternatively, fields can be interleaved
between scheduled cells in an ascending order of the cell index and
DCI format 1_3 can first include two fields f.sub.0, followed by
two fields f.sub.1, and so on up to two fields f.sub.M. A same
arrangement can apply for the fields of DCI format 0_3.
[0121] In certain embodiments, if the scheduled cells where DCI
format 1_3 can schedule PDSCH receptions are not predetermined,
such as for example a scheduling cell and a predetermined scheduled
cell, DCI format 1_3 needs to include a field that indicates a pair
scheduled cells. When a UE can be scheduled PDSCH receptions on any
pair from N.sub.cells.sup.DL,2 scheduled cells, a number of .left
brkt-top.log.sub.2(N.sub.cells.sup.DL,2(N.sub.cells.sup.DL,2-1)/2).right
brkt-bot. bits in DCI format 1_3 can indicate the pair of scheduled
cells. Therefore, instead of a per-cell carrier indicator field,
DCI format 1_3 can include a dual-carrier indicator field of .left
brkt-top.log.sub.2(N.sub.cells.sup.DL,2(N.sub.cells.sup.DL,2-1)/2).right
brkt-bot. bits. The dual-carrier indicator field can be located
first in DCI format 1_3 (possibly only after an "identifier for DCI
formats" field of predetermined size) in order for a UE to
unambiguously determine the location of the field in DCI format
1_3. It is also possible for DCI format 1_3 to include a bitmap to
indicate two scheduled cells from the N.sub.cells.sup.DL,2 cells.
The above can be directly generalized to a maximum of
M.sub.cells.sup.max_sched>2 scheduled cells.
[0122] In the following example, reference is made to fields of a
DCI format 1_2 as described in Table 1, above. A size of a DL BWP
indicator field can be separately configured for each scheduled
cell from the N.sub.cells.sup.DL,2 cells. For example, a DL BWP
indicator field can have a size of 2 bits for a first scheduled
cell and can have a size of 0 bits for a second scheduled cell.
Alternatively, when both scheduled cells have a non-zero size for
the DL BWP indicator field, DCI format 1_3 can include a single
field with a value that applies to both scheduled cells. For
example, if a first scheduled cell has 4 configured DL BWP, a
second scheduled cell has 2 configured BWPs, and a DL BWP indicator
field includes 2 bits, the value of the DL BWP indicator field
indicates one of the four DL BWPs for the first scheduled cell and
the value of the DL BWP indicator field modulo 2 indicates one of
the two DL BWPs for the second scheduled cell. For example, linking
DL BWPs for PDSCH receptions on scheduled cells can applicable
because either large or small amounts TB s are typically scheduled
on both cells. Therefore, when a BWP change is needed,
corresponding reasons do not depend on a particular cell and are
applicable for all cells.
[0123] A size of a time-domain resource allocation (TDRA) field, a
PRB bundling size indicator field, a rate matching indicator field,
a ZP CSI-RS trigger field, a VRB-to-PRB mapping field, an antenna
ports field, an SRS request field, a DMRS sequence initialization
field, a transmission configuration indication field, a CBGTI
field, or a CBGFI field, can be separately configured for each
scheduled cell from the N.sub.cells.sup.DL,2 cells.
[0124] A size of a counter DAI field, a total DAI field, a TPC
command field, a PUCCH resource indicator field, or a
PDSCH-to-HARQ-ACK timing field can be separately configured each
scheduled cell from the N.sub.cells.sup.DL,2 cells or can be same
for at least some cells from the N.sub.cells.sup.DL,2 cells. In the
latter case, the corresponding fields can be common for the
scheduled cells and a corresponding configuration can be common for
all scheduled cells.
[0125] A size of a modulation and coding scheme (MCS) field can be
either separately configured for each scheduled cell or set to 5
bits. When the MCS field is separately configured for each
scheduled cell, in order to reduce an increase in a payload of DCI
format 1_3 relative to a payload of a DCI format scheduling a PDSCH
reception on a single cell, the MCS field value for the second
scheduled cell can indicate a differential value of the MCS field
value for the first scheduled cell. For example, when a first MCS
field for a first scheduled cell has 5 bits indicating one of 32
entries from an MCS table, a second MCS field for a second
scheduled cell can be configured to have B<5 bits, wherein first
2.sup.B-1 values indicate an offset to a lower MCS value (negative
offset) than the MCS value indicated by the first MCS field, a
2.sup.B-1+1 value indicates a same MCS value as indicated by the
first MCS field (zero offset), and last 2.sup.B-1-1 values indicate
an offset to a larger MCS value (positive offset) than the MCS
value indicated by the first MCS field. Therefore, when B=0 for a
scheduled cell, a MCS for PDSCH reception on the scheduled is
determined from the MCS field value for the first scheduled cell
and, when B=0 for all scheduled cells, the MCS field value is
common for all scheduled cells.
[0126] A size of a RV field or of a HARQ process number field can
be separately configured for each scheduled cell from the
N.sub.cells.sup.DL,2 cells. A size of NDI field can be either
separately configured for each scheduled cell or set to 1 bit. If a
PDSCH transmission on a scheduled cell is configured to be with 2
TBs, the RV field, the HARQ process number field, and the NDI field
are repeated for the second TB with a same number of bits as for
the first TB.
[0127] In certain embodiments, it is possible that DCI format 1_3
is used to schedule only initial TB transmissions (a DCI format
scheduling a single PDSCH reception can be used for TB
retransmissions) and then the NDI and RV fields can have 0 bits
(that is, be absent) in DCI format 1_3. To further reduce an
increase in a DCI format 1_3 payload, compared to a payload of a
DCI format scheduling a PDSCH reception on a single cell, a use of
DCI format 1_3 can be restricted for scheduling PDSCH receptions
for a same HARQ process on both cells and then DCI format 1_3 can
include only one HARQ process number field.
[0128] A size of a FDRA field can be separately configured for each
scheduled cell from the N.sub.cells.sup.DL,2 cells since an active
DL BWP size can be different among scheduled cells. CA operation
targets large data rates and therefore a bandwidth for a
corresponding PDSCH reception on a scheduled cell is typically
large. As the FDRA field usually requires the largest number of
bits among all fields in a DCI format scheduling a PDSCH reception,
it is beneficial to determine a number of bits for the FDRA field
in DCI format 1_3 using a larger RB group (RBG) size than for
determining a number of bits for the FDRA field in a DCI format
scheduling a single PDSCH reception on one scheduled cell. For
example, for an active DL BWP of 96 RBs, an RBG size can be 8 RBs
for a DCI format scheduling a single PDSCH reception on a
corresponding cell and therefore an FDRA field for a bitmap of RBGs
includes 12 bits, while for a DCI format 1_3 an RBG size can be 16
RBs and therefore an FDRA field for a bitmap of RBGs includes 6
bits.
[0129] In certain embodiments, the RBG size is be predetermined per
range of DL BWP sizes. For example, the RBG size can be 8 RBs for a
DL BWP size between 50 RB and 100 RBs, or the RBG size for an
active DL BWP can be provided to a UE by UE-specific RRC signaling
either separately per DCI format (at least for DCI formats
scheduling on PDSCH reception or two PDSCH receptions) or jointly
for all DCI formats. In the latter case, an RBG size for
interpreting the FDRA field can be derived separately for DCI
format 1_3 by scaling an indicated RBG size either by a
predetermined factor, such as 2, or be a factor provided to the UE
by UE-specific RRC signaling. The size (number of RBs) of RBGs
indicated by the FDRA field in the DCI format can be for a
reference cell such as the cell of the PDSCH reception that
provides the DCI format.
[0130] FIG. 11 illustrates an example method 1100 for a UE
determining MCS for a second PDSCH reception scheduled by a DCI
format 1_3 that schedules two PDSCH receptions on respective two
cells according to embodiments of the present disclosure. For
example, the steps of the method 1100 can be performed by any of
the UEs 111-116 of FIG. 1, such as the UE 116 of FIG. 3. The method
1100 of FIG. 11 is for illustration only and other embodiments can
be used without departing from the scope of the present
disclosure.
[0131] As illustrated in FIG. 11, step 1110, describes a UE
receiving a configuration for a scheduling cell and for a set of
scheduled cells. In step 1120, the UE receives a configuration for
a search space set to monitor PDCCH. The search space set
configuration includes a DCI format 1_3 that schedules two PDSCH
receptions on two respective cells from the set of scheduled
cells.
[0132] In step 1130, the UE receives a configuration for a size of
a second MCS field in DCI format 1_3 wherein a value of the second
MCS field is an offset to a value of a first MCS field in DCI
format 1_3. In step 1140, the UE determines an MCS for the second
PDSCH reception from an index in an MCS table wherein the index is
determined from the sum of the value of the first MCS field and the
offset.
[0133] FIG. 12 illustrates an example method 1200 for a UE
determining a frequency domain resource allocation for a PDSCH
reception depending on the DCI format that schedules the PDSCH
reception according to embodiments of the present disclosure. For
example, the steps of the method 1200 can be performed by any of
the UEs 111-116 of FIG. 1, such as the UE 116 of FIG. 3. The method
1200 of FIG. 12 is for illustration only and other embodiments can
be used without departing from the scope of the present
disclosure.
[0134] As illustrated in FIG. 12, step 1210, describes a UE
receiving (or determining) a configuration for a first RBG size and
for a second RBG size. In step 1220, the UE detects a DCI format
scheduling a PDSCH reception.
[0135] In step 1230, the UE determines whether the DCI format is a
first DCI format (or a whether the DCI format is a second DCI
format). In response to determining that the DCI format is a second
DCI format, the UE, in step 1240 determines a FDRA field size in
the DCI format based on the second RBG size. Alternatively, in
response to determining that the DCI format is a first DCI format,
the UE, in step 1250 determines a FDRA field size in the DCI format
based on the first RBG size.
[0136] For determining a location in a HARQ-ACK codebook of
HARQ-ACK information bits in response to decoding of TBs provided
in two PDSCH receptions scheduled on two respective cells by a DCI
format 1_3 that a UE detects in a PDCCH monitoring occasion m, a
value of a counter DAI (C-DAI) field, V.sub.C-DAI,c,m.sup.DL, in
the DCI format 1_3 is incremented by 2, instead of being
incremented by 1 as in case of a DCI format scheduling a single
PDSCH reception. Then, for the PDSCH reception on cells with
indexes c and with c.sub.1 with c<c.sub.1, a location in the
HARQ-ACK codebook of corresponding HARQ-ACK information bits for
PDSCH reception on cell c can be based on a C-DAI value of
V.sub.C-DAI,c,m.sup.DL-1 and cell indexes {c+1, . . . c.sub.1} can
be cyclically shifted in order to place HARQ-ACK information for
the cell with index c.sub.1 after HARQ-ACK information for the cell
with index c. This is described in Syntax (1) below. In syntax (1),
T.sub.D=2.sup.N.sup.C_DAI.sup.DL and N.sub.C-DAI.sup.DL is a number
of bits for the C-DAI field.
.times. Syntax .times. .times. if .times. .times. the .times.
.times. PDSCH .times. .times. on .times. .times. cell .times.
.times. c .times. .times. is .times. .times. scheduled .times.
.times. by .times. .times. a .times. .times. DCI .times. .times.
format .times. .times. that .times. .times. also .times. .times.
schedules .times. .times. a .times. .times. PDSCH .times. .times.
.times. reception .times. .times. on .times. .times. cell .times.
.times. c 1 .times. .times. with .times. .times. c 1 > c .times.
.times. .times. if .times. .times. V c - DAI , c , m DL = 1 .times.
.times. .times. V C - DAI , c , m DL = 2 T D ; .times. .times.
.times. else .times. .times. .times. V C - DAI , c , m DL = 2 T D ;
.times. .times. .times. else .times. .times. .times. V C - DAI , c
, m DL = V C - DAI , c , m DL - 1 ; .times. .times. .times. end
.times. .times. if .times. .times. .times. temp = c 1 ; .times.
.times. .times. k = 1 ; .times. .times. .times. while .times.
.times. k < c 1 - c .times. .times. .times. serving .times.
.times. cell .times. .times. index .times. .times. c + k + 1 = c +
k ; .times. .times. .times. k = k + 1 ; .times. .times. .times. end
.times. .times. while .times. .times. .times. serving .times.
.times. cell .times. .times. index .times. .times. c + 1 = temp ;
.times. .times. .times. end .times. .times. if ( 1 )
##EQU00002##
[0137] In certain embodiments, a size of a counter DAI field (or of
a total DAI field) in DCI format 1_3 can be larger, for example by
1 bit in case of two scheduled cells, than a size of a counter DAI
field in a DCI format scheduling a single PDSCH reception. A reason
is to provide a same level of protection against missed detections
for DCI format 1_3 since a counter DAI value in DCI format 1_3 is
incremented by 2, instead of 1, in case of two scheduled cells. In
general, for a configurable number of bits for a counter DCI field
in a DCI format that can schedule PDSCH receptions on more than one
cells, a maximum number of bits can be larger than a maximum number
of bits for the counter DAI field in a DCI format that schedules a
PDSCH reception on only one cell. A same approach can apply for a
total DAI field.
[0138] FIG. 13 illustrates a diagram 1300 of a UE processing a DAI
value in a DCI format scheduling two PDSCH receptions on two
respective cells and in another DCI format 1_3 scheduling a PDSCH
reception on one cell according to embodiments of the present
disclosure.
[0139] As described in the diagram 1300, in a PDCCH monitoring
occasion, a UE (such as the UE 116) detects a first DCI format that
schedules a PDSCH reception on cell 0 and includes a counter DAI
field with value 1 1310. The UE also detects a DCI format 1_3 that
schedules a PDSCH reception on cell 1 1320 and a PDSCH reception on
cell 3 1330 and includes a counter DAI field with value 3. The UE
also detects a DCI format that schedules a PDSCH reception on cell
3 1340. For reporting HARQ-ACK information in a HARQ-ACK codebook,
the UE places first HARQ-ACK information in response to PDSCH
reception on cell 0 1350, following by HARQ-ACK information in
response to PDSCH reception on cell 1 1360, HARQ-ACK information in
response to PDSCH reception on cell 3 1370, and HARQ-ACK
information in response to PDSCH reception on cell 2 1380. Serving
cell indexes are rearranged for placing corresponding HARQ-ACK
information in a HARQ-ACK codebook.
[0140] In certain embodiments, DCI format 1_3 is also be used for
scheduling a single PDSCH. This can be achieved by including a
1-bit field in DCI format 1_3 indicating scheduling of one PDSCH
reception, for example with a value of `0`, or scheduling of two
PDSCH receptions, for example with a value of `1`. In case of one
PDSCH reception, a UE can ignore the fields associated with the
second PDSCH reception. Alternatively, the UE can reinterpret the
bits of the fields associated with the second PDSCH reception, at
least the ones that are separate from the fields associated with
the first PDSCH reception, to be part of the bits of the
corresponding fields associated with the first PDSCH reception in
order to increase the size of some or all of such fields up to a
maximum predetermined size and therefore increase a scheduling
configurability/flexibility for the first PDSCH reception.
[0141] Although FIGS. 10, 11, and 12 illustrate the methods 1000,
1100, and 1200, various changes may be made to FIGS. 10, 11, and
12. For example, while the method 1000 of FIG. 10, the method 1100
of FIG. 11, and the method 1200 of FIG. 12 are shown as a series of
steps, various steps could overlap, occur in parallel, occur in a
different order, or occur multiple times. In another example, steps
may be omitted or replaced by other steps. For example, steps of
the method 1000 can be executed in a different order.
[0142] Embodiments of the present disclosure describe a DCI format
scheduling multiple PUSCH transmissions from a UE on respective
multiple cells. The following examples and embodiments describe
designing a DCI format scheduling multiple PUSCH transmissions from
a UE on respective multiple cells.
[0143] An embodiment of this disclosure also considers a design for
a DCI format that schedules multiple PUSCH transmissions from a UE
on respective multiple cells. For brevity, such DCI format is
referred to as DCI format 0_3 and the exemplary embodiment
considers scheduling of two PUSCH transmissions on two respective
DL cells.
[0144] Since different cells can have different operating
characteristics, such as different operating bandwidth or different
duplexing method (such as FDD or TDD) and as a UE can experience
different channel conditions, such as different
signal-to-interference and noise ratios (SINRs), the size of each
field in DCI format 0_3 are separately configured for each
cell.
[0145] For a DCI format 0_3 scheduling PUSCH transmissions on
multiple cells, same design principles can apply for all fields
that also exist in DCI format 1_3. For example, an MCS field in a
DCI format scheduling multiple PUSCH transmissions on respective
multiple scheduled cells can be applicable to all the multiple
PUSCH transmissions or can be applicable to a PUSCH transmission on
a first scheduled cell and additional MCS fields of B bits can be
applicable to remaining scheduled cells from the multiple cells.
Corresponding descriptions are omitted for brevity and the
remaining for the description are for fields that exist in DCI
format 0_3 but do not exist in DCI format 1_3.
[0146] With reference to fields of DCI format 0_2 in Table 2,
above, a size of a SUL indicator field, of a FH flag field, of a
TPC command field, of an SRI field, of a precoding information and
number of layers field, of antenna port(s) field, of a PTRS-DMRS
association field, of a DMRS sequence initialization field, or of
an OLPC parameter set indication field, can be separately
configured for each scheduled cell from the N.sub.cells.sup.UL,2
cells. In case a TPC command field size associated with scheduling
a second PUSCH transmission is not provided, for example for
intra-band CA where similar channel fading conditions apply to
PUSCH transmissions on both cells, the UE applies a same TPC
command provided by the single TPC command field in DCI format 0_3
to determine a power for both the first and second PUSCH
transmissions on corresponding first and second cells.
[0147] In certain embodiments, a DAI field, a CSI request field, a
beta_offset indicator field, or an UL-SCH indicator field can be
separately configured for each scheduled cell from the
N.sub.cells.sup.UL,2 cells or can be same for at least some cells
from the N.sub.cells.sup.UL,2 cells. In the latter case, a UE the
fields can be common for the scheduled cells and are not configured
per scheduled cell, or can be configured only for a first cell. The
applicability of the DAI, CSI request, beta_offset indicator, or
UL-SCH indicator field can be for only for one PUSCH of the two
PUSCHs and the one PUSCH can be same for all those fields. The one
PUSCH can be the PUSCH transmitted on a cell with a smallest index
or a largest index between the two cells, or the PUSCH transmitted
on the scheduling cell, if any, or otherwise on the cell determined
either explicitly, based on an additional 1-bit field in DCI format
0_3, or implicitly such as for example based on a number of
available resources for UCI multiplexing or a MCS of a PUSCH
transmission and then the UE selects the PUSCH providing a larger
corresponding value.
[0148] A UE can expect that a size of DCI format 0_3 is same as a
size of DCI format 1_3 if, otherwise, a number of sizes of DCI
formats with CRC scrambled by a C-RNTI that a UE is configured to
monitor would be larger than 3.
[0149] FIG. 14 illustrates an example method 1400 for a UE
determining first and second powers for respective first and second
PUSCH transmissions scheduled by a DCI format on respective first
and second cells according to embodiments of the present
disclosure. FIG. 15 illustrates an example method 1500 for a UE
multiplexing UCI in a PUSCH transmission in response to a detection
of a DCI format scheduling two PUSCH transmissions on two
respective cells according to embodiments of the present
disclosure. For example, the steps of the method 1400 and the
method 1500 can be performed by any of the UEs 111-116 of FIG. 1,
such as the UE 116 of FIG. 3. The method 1400 of FIG. 14 and the
method 1500 of FIG. 15 are for illustration only and other
embodiments can be used without departing from the scope of the
present disclosure.
[0150] As illustrated in FIG. 14, step 1410, describes a UE
receiving a configuration for a scheduling cell and for a set of
scheduled cells. In step 1420, the UE receives a configuration for
a search space set to monitor PDCCH wherein the search space set
configuration includes a DCI format 0_3. The DCI format 0_3
schedules two PUSCH transmissions on two respective cells from the
set of scheduled cells. In step 1430, the UE receives a value for a
TPC command through a TPC command field in DCI format 0_3. In step
1440, the UE determines both a first power for a first PUSCH
transmission on a first cell and a second power for a second PUSCH
transmission on a second cell based on the value of the TPC
command.
[0151] As illustrated in FIG. 15, step 1510, describes a UE
receiving a configuration for a scheduling cell and for a set of
scheduled cells. In step 1520, the UE receives a configuration for
a search space set to monitor PDCCH wherein the search space set
configuration includes a DCI format 0_3 and wherein DCI format 0_3
schedules two PUSCH transmissions on two respective cells from the
set of scheduled cells.
[0152] In step 1530, the UE determines to multiplex UCI (such as
HARQ-ACK information or a CSI report) and associated parameters for
UCI multiplexing in one of the two PUSCH transmissions based on
information provided by values for one or more single fields of a
DAI, a CSI request, a beta_offset indicator, or an UL-SCH indicator
in the DCI format 0_3.
[0153] In step 1540, the UE multiplexes the UCI in the PUSCH
transmission on a cell with a smaller index or in the PUSCH
transmission indicated by an additional binary field in DCI format
0_3.
[0154] Although FIGS. 14, and 15 illustrate the methods 1400, and
1500, various changes may be made to FIGS. 14, and 15. For example,
while the method 1400 of FIG. 14 and the method 1500 of FIG. 15 are
shown as a series of steps, various steps could overlap, occur in
parallel, occur in a different order, or occur multiple times. In
another example, steps may be omitted or replaced by other steps.
For example, steps of the method 1400 can be executed in a
different order.
[0155] Embodiments of the present disclosure describe PDCCH
monitoring capability for cells. The following examples and
embodiments describe where a UE is scheduled by a DCI format 0_3 or
by a DCI format 1_3.
[0156] An embodiment of this disclosure also considers a
determination for a total number of PDCCH candidates and a total
number of non-overlapped CCEs when a UE is configured to monitor
PDCCH for detection only DCI format 0_3 or only DCI format 1_3 for
scheduling on a subset of scheduled cells from a set of scheduled
cells.
[0157] In certain embodiments, a partitioning of a PDCCH monitoring
capability for a UE between cells where the UE is configured at
least one search space set for monitoring PDCCH to detect a DCI
format scheduling a single PDSCH reception or a single PUSCH
transmission and cells where the UE is configured only search space
sets for monitoring PDCCH to detect a DCI format 0_3 or a DCI
format 1_3 is subsequently considered. The exemplary embodiment
considers two cells but a same determination applies when a DCI
format 0_3 or a DCI format 1_3 can schedule a maximum of
M.sub.cells.sup.max_sched scheduled cells.
[0158] For example, a UE (such as the UE 116) can configure a first
set of N.sub.cells,0.sup.DL,1,.mu. serving cells. In this example,
the UE (i) is either not provided CORESETPoolIndex or is provided
CORESETPoolIndex with a single value for all CORESETs on all DL
BWPs of each cell from the first set of cells
N.sub.cells.sup.DL,1,.mu., and (ii) at least one search space set
is for monitoring PDCCH to detect a DCI format scheduling a single
PDSCH reception or a single PUSCH transmission for each cell from
the first set of N.sub.cells,0.sup.DL,1,.mu.. The UE can also
configure a second set of N.sub.cells,0.sup.DL,2,.mu. serving
cells. Here, the UE (i) is either not provided CORESETPoolIndex or
is provided CORESETPoolIndex with a single value for all CORESETs
on all DL BWPs of each cell from the first set of cells
N.sub.cells,0.sup.DL,2,.mu., and (ii) all search space sets are for
monitoring PDCCH to detect only DCI formats scheduling two PDSCH
receptions or two PUSCH transmissions on two respective cells from
the second set of N.sub.cells,0.sup.DL,2,.mu.. The UE can also
configure a third set of N.sub.cells,1.sup.DL,1,.mu. serving cells.
Here, the UE (i) is provided CORESETPoolIndex with a value 0 for a
first CORESET and with a value 1 for a second CORESET on any DL BWP
of each cell from the second set of N.sub.cells,1.sup.DL,1,.mu.
cells, and (ii) at least one search space set is for monitoring
PDCCH to detect a DCI format scheduling a single PDSCH reception or
a single PUSCH transmission for each cell from the first set of
N.sub.cells,1.sup.DL,1,.mu.. The UE can also configure another set
of N.sub.cells,0.sup.DL,2,.mu. serving cells. Here, the UE (i) is
provided CORESETPoolIndex with a value 0 for a first CORESET and
with a value 1 for a second CORESET on any DL BWP of each cell from
the second set of N.sub.cells,1.sup.DL,1,.mu. cells, and (ii) all
search space sets are for monitoring PDCCH to detect only DCI
formats scheduling two PDSCH receptions or two PUSCH transmissions
on two respective cells from the second set of
N.sub.cells,1.sup.DL,2,.mu.. In these examples
N.sub.cells,0.sup.DL,1,.mu.+N.sub.cells,0.sup.DL,2,.mu.=N.sub.cells,0.sup-
.DL,.mu. and
N.sub.cells,1.sup.DL,1,.mu.+N.sub.cells,1.sup.DL,2,.mu.=N.sub.cells,1.sup-
.DL,.mu., the UE is not required to monitor more than the
expressions described in Equation (2) or Equation (3). In
particular, Equation (2) is for PDCCH candidates while Equation (3)
is for non-overlapped CCEs per slot on the active DL BWP(s) of
scheduling cell(s) from the
N.sub.cells,0.sup.DL,.mu.+N.sub.cells,1.sup.DL,.mu. downlink
cells.
M PDCCH total , slot , .mu. = N cells cap M PDCCH max , slot , .mu.
( N cells , 0 DL , 1 , .mu. + N cells , 0 DL , 2 , .mu. .times. /
.times. 2 + .gamma. ( N cells , 1 DL , 1 , .mu. + N cells , 1 DL ,
2 , .mu. .times. / .times. 2 ) ) .times. / .times. j = 0 3 .times.
.times. ( N cells , 0 DL , 1 , j + N cells , 0 DL , 2 , j .times. /
.times. 2 + .gamma. ( N cells , 1 DL , 1 , j + N cells , 1 DL , 2 ,
j .times. / .times. 2 ) ) ( 2 ) C PDCCH total , slot , .mu. = N
cells cap C PDCCH max , slot , .mu. ( N cells , 0 DL , 1 , .mu. + N
cells , 0 DL , 2 , .mu. .times. / .times. 2 + .gamma. ( N cells , 1
DL , 1 , .mu. + N cells , 1 DL , 2 , .mu. .times. / .times. 2 ) )
.times. / .times. j = 0 3 .times. .times. ( N cells , 0 DL , 1 , j
+ N cells , 0 DL , 2 , j .times. / .times. 2 + .gamma. ( N cells ,
1 DL , 1 , j + N cells , 1 DL , 2 , j .times. / .times. 2 ) ) ( 3 )
##EQU00003##
[0159] In the above expressions of Equations (2) and (3) for
M.sub.PDCCH.sup.total,slot,.mu. and
C.sub.PDCCH.sup.total,slot,.mu., it is also possible to consider a
possibly slightly larger value for M.sub.PDCCH.sup.total,slot,.mu.
and C.sub.PDCCH.sup.total,slot,.mu. from having
N.sub.cells,0.sup.DL,2,.mu. cells and the
N.sub.cells,1.sup.DL,2,.mu. cells and determine Equation (4) or
Equation (5). In particular, Equation (4) is for PDCCH candidates
while Equation (5) is for non-overlapped CCEs per slot on the
active DL BWP(s) of scheduling cell(s) from the
N.sub.cells,0.sup.DL,.mu.+N.sub.cells,1.sup.DL,.mu. downlink
cells.
M PDCCH total , slot , .mu. = N cells cap M PDCCH max , slot , .mu.
( N cells , 0 DL , 1 , .mu. + N cells , 0 DL , 2 , .mu. .times. /
.times. 2 + .gamma. ( N cells , 1 DL , 1 , .mu. + N cells , 1 DL ,
2 , .mu. .times. / .times. 2 ) ) .times. / .times. j = 0 3 .times.
.times. ( N cells , 0 DL , 1 , j + N cells , 0 DL , 2 , j .times. /
.times. 2 + .gamma. ( N cells , 1 DL , 1 , j + N cells , 1 DL , 2 ,
j .times. / .times. 2 ) ) ( 4 ) C PDCCH total , slot , .mu. = N
cells cap C PDCCH max , slot , .mu. ( N cells , 0 DL , 1 , .mu. + N
cells , 0 DL , 2 , .mu. .times. / .times. 2 + .gamma. ( N cells , 1
DL , 1 , .mu. + N cells , 1 DL , 2 , .mu. .times. / .times. 2 ) )
.times. / .times. j = 0 3 .times. .times. ( N cells , 0 DL , 1 , j
+ N cells , 0 DL , 2 , j .times. / .times. 2 + .gamma. ( N cells ,
1 DL , 1 , j + N cells , 1 DL , 2 , j .times. / .times. 2 ) ) ( 5 )
##EQU00004##
[0160] In certain embodiments, a UE evaluates, per slot, whether a
number of configured PDCCH candidates, according to corresponding
configured search space sets, exceeds a limit for non-overlapping
CCE or a limit for a number of PDCCH candidates, also referred to
as blind decoding (BD) limit, that the UE is expected to be able to
monitor in a slot. When the UE is configured to monitor PDCCH
according to a combination (X, Y), where X is a number of symbols
between first symbols in successive PDCCH monitoring occasions that
are separated by more than Y symbols defining a span, the UE can
perform the previous evaluation only for the first span of each
slot. As described in Syntax (2), below, the UE drops PDCCH
monitoring for all search space sets with indexes larger than or
equal to the index of a search space set where the UE reaches the
limit for the number of non-overlapped CCEs or the limit for the
number of PDCCH candidates that the UE can monitor in a slot (or
the first span of a slot).
[0161] Syntax (2) [0162] Denote by V.sub.CCE(S.sub.uss(j)) the set
of non-overlapping CCEs for search space set s.sub.uss(j) and by
C(V.sub.CCE(S.sub.uss(j))) the cardinality of
V.sub.CCE(S.sub.uss(j)) where the non-overlapping CCEs for search
space set s.sub.uss(j) are determined considering the allocated
PDCCH candidates for monitoring for the CSS sets and the allocated
PDCCH candidates for monitoring for all search space sets
s.sub.uss(k), 0.ltoreq.k.ltoreq.j.
[0162] .times. Set .times. .times. M PDCCH uss = min .function. ( M
PDCCH max , slot , .mu. , M PDCCH total , slot , .mu. ) - M PDCCH
css ##EQU00005## .times. Set .times. .times. C PDCCH uss = min
.function. ( C PDCCH max , slot , .mu. , C PDCCH total , slot ,
.mu. ) - C PDCCH css ##EQU00005.2## .times. Set .times. .times. j =
0 ##EQU00005.3## .times. while .times. .times. L .times. M S uss
.function. ( j ) ( L ) .ltoreq. M PDCCH uss .times. .times. AND
.times. .times. .function. ( V CCE .function. ( S uss .function. (
j ) ) ) .ltoreq. C PDCCH uss ##EQU00005.4## .times. allocate
.times. .times. L .times. M S uss .function. ( j ) ( L ) .times.
.times. PDCCH .times. .times. candidates .times. .times. for
.times. .times. monitoring .times. .times. to .times. .times. USS
.times. .times. set .times. .times. S uss .function. ( j )
##EQU00005.5## .times. M PDCCH uss = M PDCCH uss - L .times. M S
uss .function. ( j ) ( L ) ; ##EQU00005.6## .times. C PDCCH uss = C
PDCCH uss - .function. ( V CCE .function. ( S uss .function. ( j )
) ) ; ##EQU00005.7## .times. j = j + 1 ; ##EQU00005.8## .times. end
.times. .times. while ##EQU00005.9##
[0163] Accordingly, embodiments of the present disclosure relate to
PDCCH allocation or dropping by scaling of PDCCH candidates to
monitor for PDCCH blind decoding in a slot or a span. The
disclosure additionally relates to search space set switching for
PDCCH monitoring requested by UE. This disclosure also relates to
PDCCH allocation or dropping based on predetermined CCE AL order
for PDCCH blind decoding in a slot or a span.
[0164] In certain embodiments, when a UE (such as the UE 116) is
configured to monitor in a slot more non-overlapped CCEs or more
PDCCH candidates for scheduling on a cell than a corresponding UE
PDCCH monitoring capability in the slot for the cell as was
previously described, the UE skips PDCCH monitoring for all search
space (SS) set(s) with larger than or equal search space set ID
than the search space ID where a corresponding limit is reached. As
such, PDCCH candidate dropping at a granularity of search spaceset
level is coarse and can result to more dropped PDCCH candidates
than necessary. For example, when after an allocation of PDCCH
candidates and non-overlapping CCEs to search space sets with first
indexes, a remaining number of PDCCH candidates is 5 and a number
of configured for a search space set with a next index is 6, a UE
drops PDCCH monitoring for all remaining PDCCH candidates even
though a corresponding capability would be exceeded by only one
PDCCH candidate. The inefficient PDCCH dropping rule could cause
unnecessary PDCCH blocking due to an unnecessary reduction in PDCCH
candidates. The problem can be more severe for mid-tier UEs that
typically require reduced cost and consequently have reduced
capabilities (RedCap UEs) as the percentage of unnecessarily
dropped PDCCH candidates, relative to the total number of PDCCH
candidates, can be larger than for UEs with a larger PDCCH
monitoring capability.
[0165] In addition to unnecessary PDCCH candidate dropping, PDCCH
dropping per search space set can degrade a reliability of PDCCH
reception when multiple beams are used and PDCCHs can be configured
to be received in control resource sets (CORESETs) having a
different transmission configuration indicator (TCI) state that
corresponding to a different PDCCH transmission beam through
corresponding different quasi collocation (QCL) properties. For
example, a search space set is associated with a CORESET that has a
QCL assumption indicating a directional beam for reception. When
PDCCH dropping is per whole search space set, search space sets
corresponding to CORESETs with different beam directions or QCL
assumptions may be dropped for some beam directions.
[0166] When dropping PDCCH candidates to satisfy a UE monitoring
capability per slot and per scheduled cell for a corresponding
sub-carrier spacing (SCS) configuration for a scheduling cell, it
can be beneficial for a UE to drop candidates that are less likely
to be used for scheduling PDSCH receptions by or PUSCH
transmissions from the UE. For example, as a serving gNB (such as
the BS 102) configures a UE (such as the UE 116) with search space
sets based on RRC signaling, and RRC re-configurations are
infrequent in order to avoid corresponding signaling overhead, a
search space set is likely to include PDCCH candidates for channel
control element (CCE) aggregation levels ranging from a smallest
one, such as 1 CCE, to a largest one such as 16 CCEs to enable
scheduling when the UE experiences corresponding favorable or
unfavorable channel conditions such as a larger
signal-to-interference and noise ratio (SINR) or a low SINR.
However, the gNB may use for a PDCCH transmission a corresponding
CCE aggregation level reflecting a last reference signal received
power (RSRP) report or a last channel state information (CSI)
report from the UE for a scheduling cell and then a UE would
unnecessarily monitor a number of PDCCH candidates that
corresponding to CCE aggregation levels that are unlikely to be
used by a serving gNB on the scheduling cell. Accordingly, it would
then be beneficial for a UE to monitor PDCCH according to search
space sets reflecting channel conditions that the UE is
experiencing, such as a SINR, or to avoid monitoring PDCCH
candidates for CCE aggregation levels that are unlikely to be used
by a serving gNB for PDCCH transmissions to the UE on a scheduling
cell to schedule unicast PDSCH receptions by the UE or PUSCH
transmissions from the UE.
[0167] Therefore, embodiments of the present disclosure take into
consideration that there is a need to support a scaling of PDCCH
candidates for PDCCH dropping. Embodiments of the present
disclosure also take into consideration that there is a need to
support UE requested search space set switching. Additionally,
embodiments of the present disclosure take into consideration that
there is need to support PDCCH dropping based on predetermined CCE
AL order.
[0168] Accordingly, when the UE is configured to monitor PDCCH
according to a combination (X, Y), where X is a number of symbols
between first symbols in successive PDCCH monitoring occasions that
are separated by more than Y symbols defining a span, where Y is
larger than a slot, the UE can evaluate per span only whether a
number of configured PDCCH candidates, according to any of
approaches defined in this disclosure, exceeds a limit for
non-overlapping CCE or a limit for a number of PDCCH candidates
only for the span.
[0169] Embodiments of the present disclosure describe scaling PDCCH
candidates for PDCCH dropping. The following examples and
embodiments describe scaling PDCCH candidates for PDCCH
dropping.
[0170] An embodiment of this disclosure considers a PDCCH candidate
allocation procedure, or a PDCCH candidate dropping procedure, by
scaling a number of PDCCH candidates that a UE monitors in a slot
or in a span.
[0171] Let M.sub.PDCCH.sup.USS and C.sub.PDCCH.sup.USS be the
remaining PDCCH candidates and remaining non-overlapping CCEs for
search space sets where a UE (such as the UE 116) monitors PDCCH
according to USS, respectively, after the UE performs a
corresponding allocation to search space sets where the UE monitors
PDCCH according to CSS. The UE determines the initial value as
described in Equations (6) and (7), below.
M.sub.PDCCH.sup.USS=min(M.sub.PDCCH.sup.max,slot,.mu.,
M.sub.PDCCH.sup.total,slot,.mu.)-M.sub.PDCCH.sup.CSS (6)
C.sub.PDCCH.sup.USS=min(C.sub.PDCCH.sup.max,slot,.mu.,
C.sub.PDCCH.sup.total,slot,.mu.)-C.sub.PDCCH.sup.CSS (7)
[0172] Denote by V.sub.CCE(S.sub.USS(j)) the set of non-overlapping
CCEs for search space set S.sub.USS(j) and by
C(V.sub.CCE(S.sub.USS(j))) the cardinality of
V.sub.CCE(S.sub.USS(j)). M.sub.S.sub.USS.sub.(j).sup.(L) denotes
the number of configured PDCCH candidates for search space set
S.sub.USS(j) at CCE aggregation level (AL) of L CCEs.
[0173] In a first approach, a procedure for scaling a number of
PDCCH candidates is used. A UE applies a scaling for the number of
PDCCH candidates across all configured USS sets. The UE determines
the allocated PDCCH candidates for K configured USS set(s) in an
accumulate manner based on a PDCCH candidate allocation or dropping
rule, as described in Syntax (3), below.
.times. Syntax .times. .times. .times. set .times. .times. X = X
step , j = 0. .times. .times. while .times. .times. X .ltoreq. X
step M S USS .function. ( j ) ( L ) .ltoreq. M PDCCH USS .times.
.times. AND .times. .times. X step .function. ( V CCE .function. (
S USS .function. ( j ) ) ) .ltoreq. C PDCCH USS .times. .times.
allocate .times. .times. ( additional ) .times. .times. .SIGMA. L
.times. X step M S USS .function. ( j ) ( L ) .times. .times. PDCCH
.times. .times. candidates .times. .times. for .times. .times.
.times. monitoring .times. .times. to .times. .times. USS .times.
.times. set .times. .times. S UUS .function. ( j ) .times. .times.
.times. M PDCCH USS = M PDCCH USS - .SIGMA. L .times. X step M S
USS .function. ( j ) ( L ) ; .times. .times. .times. C PDCCH USS =
C PDCCH USS - X step .function. ( V CCE .function. ( S USS
.function. ( j ) ) ) ; .times. .times. .times. j = mod .function. (
j + 1 , K ) .times. .times. .times. If .times. .times. j = 0 ,
.times. .times. set .times. .times. X = X + X step .times. .times.
.times. end .times. .times. if ; .times. .times. .times. end
.times. .times. while ( 3 ) ##EQU00006##
[0174] As described in Syntax (3), X and X.sub.step are accumulated
scaling factor and scaling for each step, respectively. X.sub.step
can be provided to UE either by higher layer signaling or
predefined in the specification of system operation. For example,
X.sub.step=0.25.
[0175] In certain embodiments instead of starting from X0 and
increasing the PDCCH candidate allocation fraction by X.sub.step,
the procedure first checks whether any scaling is needed. If the
scaling factor is needed the procedure decreases/scales the number
of PDCCH candidates across the search space sets for USS by a
factor of X.sub.step, determines whether the decreased/scaled PDCCH
candidates can be allocated, and either stops the procedure is the
scaled/decreased PDCCH candidates can be allocated or repeats the
procedure from the step of scaling (again) the number of PDCCH
candidates across the search space sets for USS by a factor of
X.sub.step. The corresponding Syntax (4), below, for the PDCCH
allocation as described in Syntax (4) below.
.times. Syntax .times. .times. .times. set .times. .times. X = 1 ,
j = 0 .times. .times. .times. while .times. .times. j .noteq. K
.times. .times. AND .times. .times. X > 0 .times. .times.
.times. set .times. .times. j = 0 , M PDCCH ( X ) = M PDCCH USS , C
PDCCH ( X ) = C PDCCH USS ; .times. .times. while .times. .times.
.SIGMA. L .times. X M S USS .function. ( j ) ( L ) .ltoreq. M PDCCH
( X ) .times. .times. AND .times. .times. X .function. ( V CCE
.function. ( S USS .function. ( j ) ) ) .ltoreq. C PDCCH ( X )
.times. ( re ) .times. allocate .times. .times. .SIGMA. L .times. X
M S USS .function. ( j ) ( L ) .times. .times. PDCCH .times.
.times. candidates .times. .times. for .times. .times. monitoring
.times. .times. to .times. .times. .times. USS .times. .times. set
.times. .times. S USS .function. ( j ) .times. .times. .times. M
PDCCH ( X ) = M PDCCH ( X ) - .SIGMA. L .times. X M S USS
.function. ( j ) ( L ) ; .times. .times. .times. C PDCCH ( X ) = C
PDCCH ( X ) - X .function. ( V CCE .function. ( S USS .function. (
j ) ) ) ; .times. .times. .times. j = j + 1 .times. .times. .times.
end .times. .times. while .times. .times. .times. set .times.
.times. X = X - X step .times. .times. .times. end .times. .times.
while ( 4 ) ##EQU00007##
[0176] As described in Syntax (4), X.sub.step is the updating step
for the scaling factor 0<X.ltoreq.1. X.sub.step can be provided
to UE either by higher layer signaling or can be predefined in the
specification of system operation. For example,
X.sub.step=0.25.
[0177] FIGS. 16, 17, and 18 illustrate example methods 1600, 1700
and 1800, respectively, for a UE determining a number of PDCCH
candidates to monitor in a slot for scheduling on a cell for PDCCH
candidate scaling according to embodiments of the present
disclosure. For example, the steps of the method 1500 can be
performed by any of the UEs 111-116 of FIG. 1, such as the UE 116
of FIG. 3. The methods 1600, 1700 and 1800, are for illustration
only and other embodiments can be used without departing from the
scope of the present disclosure.
[0178] As illustrated in FIG. 16, step 1602, describes a UE being
provided with configuration of K USS sets and scaling factor for an
updating step, X.sub.step. In step 1604, for a slot or a span, the
UE sets a value of scaling factor X to Xstep, j=0. In step 1606,
the UE determines whether (i) X.ltoreq.1, (ii) .SIGMA..sub.L.left
brkt-top.XstepM.sub.S.sub.USS.sub.(j).sup.(L).right
brkt-bot..ltoreq.M.sub.PDCCH.sup.USS, and (iii) .left
brkt-top.XstepC(V.sub.CCE(S.sub.USS(j))).right
brkt-bot..ltoreq.C.sub.PDCCH.sup.USS.
[0179] Upon determining that any of the three conditions are not
satisfied, The UE in step 409 considers PDCCH allocation process
ends, and UE decodes allocated PDCCH candidates in the slot or
span.
[0180] Upon determining that all three conditions are satisfied,
the UE in step 1608 allocates (additional) .SIGMA..sub.L.left
brkt-top.XstepM.sub.S.sub.USS.sub.(j).sup.(L).right brkt-bot. PDCCH
candidates for monitoring to USS set S.sub.USS(j). Thereafter, in
step 1610, the UE updates remaining PDCCH candidates and
non-overlapping CCEs, as described in Equation (8) and Equation
(9), below. In step 1612, the UE updates USS set index, as
described in Equation (10), below. In step 407, the UE determines
whether j is equal to zero. When the UE determines that J does not
equal to zero, the UE returns to step 403. Alternately, when the UE
determines that j is equal to zero, then in step 408, the UE
updates the scaling factor, as described in Equation (11). After
updated the scaling factor the UE returns to step 403.
M.sub.PDCCH.sup.USS=M.sub.PDCCH.sup.USS-.SIGMA..sub.L.left
brkt-top.XstepM.sub.S.sub.USS.sub.(j).sup.(L).right brkt-bot.
(8)
C.sub.PDCCH.sup.USS=C.sub.PDCCH.sup.USS-.left
brkt-top.XstepC(V.sub.CCE(S.sub.USS(j))).right brkt-bot. (9)
j=mod(j+1, K) (10)
X=X+X.sub.step (11)
[0181] Upon determining that any of the three conditions of step
403 are not satisfied, The UE in step 409 considers PDCCH
allocation process ends, and UE decodes allocated PDCCH candidates
in the slot or span.
[0182] For example, when a UE determines that an initial number of
PDCCH candidates for USS is
M.sub.PDCCH.sup.USS=min(M.sub.PDCCH.sup.max,slot,.mu.,
M.sub.PDCCH.sup.total,slot,.mu.)-M.sub.PDCCH.sup.CSS=36, after
allocation to CSS, and the UE has 4 USS sets with {8, 16}, {8, 16},
and {8, 16} PDCCH candidates associated with two CCE ALs, for
example CCE AL of 1 and 2 then, for accumulated scaling factor
X=Xstep=0.25, the UE allocates PDCCH candidates {8, 16}*0.25={2, 4}
to USS set 0 with remaining PDCCH candidates
M.sub.PDCCH.sup.USS=36-6=30, {2, 4} to USS set 1 with remaining
PDCCH candidates M.sub.PDCCH.sup.USS=30-6=24, {2, 4} to USS set 2
with remaining PDCCH candidates M.sub.PDCCH.sup.USS=24-6=18, {2, 4}
to USS set 3 with remaining PDCCH candidates
M.sub.PDCCH.sup.USS=18-6=12. For accumulated scaling factor X=0.5,
UE allocates additional PDCCH candidates {2, 4} to USS set 0 with
remaining PDCCH candidates M.sub.PDCCH.sup.USS=12-6=6, additional
{2, 4} to USS set 1 with remaining PDCCH candidates
M.sub.PDCCH.sup.USS=6-6=0. As .SIGMA..sub.L.left
brkt-top.X.sub.stepM.sub.S.sub.USS.sub.(j).sup.(L).right
brkt-bot.=6>0, the UE finishes the PDCCH candidate allocation to
USS sets. The resulting PDCCH candidate allocation is {4, 8}, {4,
8}, {2, 4}, {2, 4} for USS set 0, USS set 1, USS set 2, USS set 3,
respectively.
[0183] As illustrated in FIG. 17, step 1702, describes a UE is
provided with configuration of K USS sets and scaling factor update
step, X.sub.step. In step 1704, for a slot or a span, the UE sets a
value of scaling factor X to 1 and j=0. In step 1706, the UE
determines whether condition (1) j.noteq.K and condition (2) X>0
are satisfied.
[0184] Upon determining that at least one condition of step 1706 is
not satisfied, (such as if X.ltoreq.0 or j=K) then in step 1718,
the UE considers that the PDCCH candidates allocation process to
USS sets ends and the UE monitors PDCCH according to the allocated
PDCCH candidates in the slot or span.
[0185] Alternatively, upon determining that both conditions of 1706
are satisfied the UE starts or continues the allocation process for
PDCCH candidates for the K USS sets by applying the scaling factor
X (step 1708). That is, in step 1708, the UE first sets the
remaining PDCCH candidates and non-overlapping CCEs associated with
scaling factor X as M.sub.PDCCH.sup.(X)=M.sub.PDCCH.sup.USS and
C.sub.PDCCH.sup.(X)=C.sub.PDCCH.sup.USS, respectively, and j=0,
where M.sub.PDCCH.sup.USS and C.sub.PDCCH.sup.USS are determined
based on UE PDCCH monitoring capability and configured PDCCH
candidates in CSS sets.
[0186] In step 1710, the UE determines whether for a current USS
set S.sub.USS(j) it is .SIGMA..sub.L.left
brkt-top.XM.sub.S.sub.SS.sub.(j).sup.(L).right
brkt-bot..ltoreq.M.sub.PDCCH.sup.(X) and .left
brkt-top.X(V.sub.CCE(S.sub.USS(j))).right
brkt-bot..ltoreq.C.sub.PDCCH.sup.(X). When the conditions of step
1710 are satisfied, in 1712 the UE in step 1712 (re)allocate
.SIGMA..sub.L.left brkt-top.XM.sub.S.sub.USS.sub.(j).sup.(L).right
brkt-bot. PDCCH candidates for monitoring to USS set S.sub.USS(j).
In step 1714 the UE updates remaining PDCCH candidates and
non-overlapping CCEs, such that
M.sub.PDCCH.sup.(X)=M.sub.PDCCH.sup.(X)-.SIGMA..sub.L.left
brkt-top.XM.sub.S.sub.USS.sub.(j).sup.(L).right brkt-bot., and
C.sub.PDCCH.sup.(X)=C.sub.PDCCH.sup.(X)-.left
brkt-top.X(V.sub.CCE(S.sub.USS(j))).right brkt-bot.. Thereafter, in
step 1716, the UE updates the USS set index, such that j=j+1.
[0187] When any of the conditions of step 1710 are not satisfied,
then in step 1720, the UE ends the PDCCH candidate allocation
process for the current scaling factor X and decreases the scaling
factor such that X=X-X.sub.step. After decreasing the scaling
factor in step 1720, the method 1700 returns to step 1706 for the
UE to check whether the two conditions (j.noteq.K AND X>0) are
satisfied.
[0188] For example, when a UE determines that an initial number of
PDCCH candidates for USS is
M.sub.PDCCH.sup.USS=min(M.sub.PDCCH.sup.max,slot,.mu.,
M.sub.PDCCH.sup.total,slot,.mu.)-M.sub.PDCCH.sup.CSS=36, after
allocation to CSS, and the UE has 4 USS sets with {8, 16}, {8, 16},
and {8, 16} PDCCH candidates associated with CCE ALs of {1, 2}. For
scaling factor X=1, the UE can only allocate PDCCH candidates {8,
16} for USS set 0 with remaining PDCCH candidates
M.sub.PDCCH.sup.(1)=36-24=12, the UE decreases X to 0.75. For
scaling factor X=0.75, the UE can reallocate PDCCH candidates {6,
12} for USS set 0 with remaining PDCCH candidates
M.sub.PDCCH.sup.(0.75)=36-18=18, and PDCCH candidates {6, 12} for
USS set 1 with remaining PDCCH candidates
M.sub.PDCCH.sup.(0.75)=18-18=0. The UE decreases X to 0.5. For
scaling factor X=0.5, the UE reallocates PDCCH candidates {4, 8}
for USS set 0 with remaining PDCCH candidates
M.sub.PDCCH.sup.(0.5)=36-12=24, PDCCH candidates {4, 8} for USS set
1 with remaining PDCCH candidates M.sub.PDCCH.sup.(0.5)=24-12=12,
and PDCCH candidates {4, 8} for USS set 2 with remaining PDCCH
candidates M.sub.PDCCH.sup.(0.5)=12-12=0. The UE decreases X to
0.25. For scaling factor X=0.25, the UE reallocates PDCCH
candidates {2, 4} for USS set 0 with remaining PDCCH candidates
M.sub.PDCCH.sup.(0.25)=36-6=30, PDCCH candidates {2, 4} for USS set
1 with remaining PDCCH candidates M.sub.PDCCH.sup.(0.25)=30-6=24,
PDCCH candidates {2, 4} for USS set 2 with remaining PDCCH
candidates M.sub.PDCCH.sup.(0.25)=24-6=18, and PDCCH candidates {2,
4} for USS set 3 with remaining PDCCH candidates
M.sub.PDCCH.sup.(0.25)=18-6=12. Eventually, UE allocates PDCCH
candidates {2, 4}, {2, 4}, {2, 4}, and {2, 4} for USS set 0, USS
set 1, USS set 2, and USS set 3, respectively.
[0189] Another approach for dropping PDCCH candidates by scaling a
number of PDCCH candidates across all search space sets where a UE
is configured to monitor PDCCH according to USS, the UE applies
PDCCH scaling for a USS set when the UE determines that a total
number of configured PDCCH candidates for the search space set is
larger than a remaining number of PDCCH candidates. Instead of
dropping the entire search space set, the UE allocates partial
PDCCH candidates, relative to the configured number of PDCCH
candidates, for the search space set. The UE determines the
allocated PDCCH candidates for K configured USS set(s) based on a
predetermined PDCCH allocation or dropping syntax (5) below.
.times. Syntax .times. .times. .times. set .times. .times. j = 0
.times. .times. while .times. .times. .SIGMA. L .times. M S USS
.function. ( j ) ( L ) .ltoreq. M PDCCH USS .times. .times. AND
.times. .times. .function. ( V CCE * ( S USS .function. ( j ) ) )
.ltoreq. C PDCCH USS .times. .times. allocate .times. .times.
.SIGMA. L .times. M S USS .function. ( j ) ( L ) .times. .times.
PDCCH .times. .times. candiates .times. .times. for .times. .times.
monitoring .times. .times. to .times. .times. USS .times. .times.
set .times. .times. S USS .function. ( j ) .times. .times. .times.
M PDCCH USS = M PDCCH USS - .SIGMA. L .times. M S USS .function. (
j ) ( L ) ; .times. .times. .times. C PDDCH USS = C PDCCH USS -
.function. ( V CCE .function. ( S USS .function. ( j ) ) ) ;
.times. .times. .times. j = j + 1 ; .times. .times. .times. end
.times. .times. while .times. .times. .times. set .times. .times. X
= 1 - X step .times. .times. while .times. .times. .SIGMA. L
.times. X M S USS .function. ( j ) ( L ) > M PDCCH USS .times.
.times. OR .times. .times. X .function. ( V CCE .function. ( S USS
.function. ( j ) ) ) > C PDCCH USS .times. .times. .times. X = X
- X step ; .times. .times. .times. end ( 5 ) ##EQU00008##
[0190] As described in Syntax (5), a UE allocates
.SIGMA..sub.L.left brkt-top.XM.sub.S.sub.USS.sub.(j).sup.(L).right
brkt-bot. PDCCH candidates for monitoring to USS set S.sub.USS(j).
Additionally, X.sub.step is the updating step for the scaling
factor 0<X.ltoreq.1. X.sub.step can be provided to UE either by
higher layer signaling or can be predefined in the specification of
system operation. For example, X.sub.step=0.25.
[0191] As illustrated in FIG. 18, step 1802, describes a UE being
provided with a configuration of USS sets and an initial scaling
factor updating step, X.sub.step. In step 1804, for a slot or a
span, the UE sets a value of USS index to 0, i.e. j=0. In step
1806, the UE determines for a current USS set, S.sub.USS(j),
whether a first condition
.SIGMA..sub.LM.sub.S.sub.USS.sub.(j).sup.(L).ltoreq.M.sub.PDCCH.sup.USS
and whether a second condition
C(V.sub.CCE(S.sub.USS(j))).ltoreq.C.sub.PDCCH.sup.USS are
satisfied. Upon determining that both conditions are satisfied, the
UE in step 1808 allocates
.SIGMA..sub.LM.sub.S.sub.USS.sub.(j).sup.(L) PDCCH candidates for
PDCCH monitoring to USS set S.sub.USS(j). In step 1810, the UE then
updates a number of remaining PDCCH candidates and a number of
remaining non-overlapping CCEs, such that Equation (12) and
Equation (13) are satisfied. Then in step 1812, the UE increases a
USS set index by 1, as described in Equation (14).
M.sub.PDCCH.sup.USS=M.sub.PDCCH.sup.USS-.SIGMA..sub.LM.sub.S.sub.USS.sub-
.(j).sup.(L) (12)
C.sub.PDCCH.sup.USS=C.sub.PDCCH.sup.USS-(V.sub.CCE(S.sub.USS(j)))
(13)
j=j+1 (14)
[0192] When either of the conditions of step 1806 are not
satisfied, the UE scales the number of configured PDCCH candidates
for the current USS set, S.sub.USS(j), that do not yet have an
allocation of PDCCH candidates. In step 1814, the UE sets
X=1-X.sub.step, M.sub.PDCCH.sup.(X)=M.sub.PDCCH.sup.USS,
C.sub.PDCCH.sup.(X)=C.sub.PDCCH.sup.USS. In step 1816, the UE
determines whether the conditions of Equations (15) and (16) are
satisfied.
.SIGMA..sub.L.left brkt-top.XM.sub.S.sub.USS.sub.(j).sup.(L).right
brkt-bot.M.sub.PDCCH.sup.(X) (15)
.left brkt-top.X(V.sub.CCE(S.sub.USS(j))).right
brkt-bot.C.sub.PDCCH.sup.(X) (16)
[0193] In response to determining that at least one of the
conditions of step 1816 is not satisfied, the UE in step 1818,
updates the scaling factor as described in Equation (17).
Thereafter the method 1700 retunes to step 1816.
X=X-X.sub.step (17)
[0194] In response to determining that both conditions of step 1816
are satisfied, the UE in step 1820, allocates .SIGMA..sub.L.left
brkt-top.XM.sub.S.sub.USS.sub.(j).sup.(L).right brkt-bot. PDCCH
candidates for monitoring to USS set S.sub.USS(j). In step 1822,
the UE considers that the PDCCH allocation process ends and
monitors PDCCH according to the allocated PDCCH candidates in the
slot or span.
[0195] For example, when a UE determines that an initial number of
PDCCH candidates for USS is
M.sub.PDCCH.sup.USS=min(M.sub.PDCCH.sup.max,slot,.mu.,
M.sub.PDCCH.sup.total,slot,.mu.)-M.sub.PDCCH.sup.CSS=36, after
allocation to CSS, and the UE has 4 USS sets with {8, 16}, {8, 16},
and {8, 16} PDCCH candidates associated with CCE ALs of {1, 2}, the
UE allocates {8, 16} to USS set 0 with remaining PDCCH candidates
M.sub.PDCCH.sup.USS=36-24=12. As the UE cannot allocate X=100%
configured PDCCH candidates for USS set 1, the UE then starts
scaling the number of PDCCH candidates for USS set 1. When X=0.5,
.SIGMA..sub.L.left brkt-top.XM.sub.S.sub.USS.sub.(j).sup.(L).right
brkt-bot.=12, which is no larger than M.sub.PDCCH.sup.USS=12. The
UE further allocates {4, 8} PDCCH candidates to USS set 1. The UE
drops USS set 2 and USS set 3 for PDCCH monitoring for the
corresponding slot or span.
[0196] Although FIGS. 16, 17, and 18 illustrate the methods 1600,
1700, and 1800, various changes may be made to FIGS. 16, 17, and
18. For example, while the method 1600 of FIG. 16 is shown as a
series of steps, various steps could overlap, occur in parallel,
occur in a different order, or occur multiple times. In another
example, steps may be omitted or replaced by other steps. For
example, steps of the method 1600 can be executed in a different
order.
[0197] Embodiments of the present disclosure also describe a UE
requested search space set switching. The following examples and
embodiments describe UE requested search space set switching.
[0198] An embodiment of this disclosure considers switching between
groups of search space sets based on a request by a UE. Based on
the request, the UE can be triggered by a serving gNB to switch
from current active search space sets to new active search space
sets for PDCCH monitoring. The UE allocates PDCCH candidates to
monitor for the active search space sets instead of all configured
search space sets for the groups of search space sets.
[0199] For example, for group search space set switching,
applicable groups of search space sets include only search space
sets where a UE monitors PDCCH according to a USS. For another
example, the applicable groups of search space sets include both
search space sets where a UE monitors PDCCH according to a USS and
search space sets where a UE monitors PDCCH according to a CSS. For
yet another example, the applicable groups of search space sets are
configured by higher layers. In the configuration of an applicable
group of search space sets, a UE can be provided an associated
group index for the search space sets.
[0200] A UE request for switching from a first group of search
space sets to a second group of search space sets can be based on a
signal-to-interference and noise ratio (SINR) measured by the UE in
CORESETs of PDCCH receptions for the search space sets, or on block
error rate (BLER) statistics for detection of DCI formats provided
by PDCCH receptions, and so on. The different groups of search
space sets can include a different number of PDCCH candidates per
CCE aggregation level so that the UE can indicate a group of search
space sets that includes more PDCCH candidates for CCE aggregation
levels that the UE considers as appropriate to be used for PDCCH
receptions. A serving gNB receiving the request from the UE can
respond with an indication of a group of search space sets for the
UE to monitor PDCCH by providing a corresponding group index,
wherein the group index can be same as or different than an index
for a current group of search space sets that the UE uses to
monitor PDCCH.
[0201] FIG. 19 illustrates an example method 1900 for a UE
switching among groups of search space sets based on a request by
the UE according to embodiments of the present disclosure. For
example, the steps of the method 1900 can be performed by any of
the UEs 111-116 of FIG. 1, such as the UE 116 of FIG. 3. The method
1900 is for illustration only and other embodiments can be used
without departing from the scope of the present disclosure.
[0202] As illustrated in FIG. 19, step 1910, describes a UE
reporting information to indicate a preferred group of search space
sets for PDCCH monitoring. In step 1920, the UE receives an index
for a group of search space sets for PDCCH monitoring. The UE is
configured the groups of search space sets in advance through
higher layer signaling such as RRC signaling. In step 1930, the UE
determines whether current active search space set(s) are same as
indicated search space sets by determining whether the indicated
index of a group of search space sets is same as (or different)
than a current index of a group of search space sets for PDCCH
monitoring. If current active search space set(s) are different
from the indicated search space set(s), the UE, in step 1940, stops
monitoring current active search space set(s) and starts monitoring
PDCCH according to the search space set(s) corresponding to the
indicated group index. For example, the PDCCH monitoring can start
Y symbols/slots after the last symbol/slot when UE receives the
PDCCH associated with the indication of a group index.
Alternatively, if current active search space set(s) are the same
as the indicated search space set(s), the UE, in step 1950,
continues to monitor PDCCH according to the current active search
space set(s).
[0203] In certain embodiments, a UE provides a request for a group
of search space sets, from a configured set of groups of search
space sets, by providing a corresponding index for the group. The
group index can be indicated by log.sub.2(N) bits where N is the
number of groups of search space sets the UE is configured by
higher layers. In a first example, the UE can provide the index
through a MAC control element in a PUSCH transmission. In another
example, the UE can provide the index through a PUCCH transmission
where the UE can be configured a PUCCH resource, a periodicity, and
a time offset relative to a first slot of a system frame number for
the PUCCH transmission. In another example, the PUCCH resource can
be same as a PUCCH resource for periodic or semi-persistent
HARQ-ACK, or scheduling request, or CSI reporting and the group
index indication can be multiplexed in the PUCCH transmission
together with the other UCI information. A periodicity for
multiplexing the group index can be same as or different than a
periodicity for multiplexing the other UCI report in the PUCCH
transmission.
[0204] Instead of providing an explicit indication for an index of
a group of search space sets, the UE can be configured a mapping
among indexes of groups of search space sets and RSRP values. After
reporting an RSRP value, the UE can apply the corresponding group
of search space sets for PDCCH monitoring after the UE detects a
DCI format scheduling a transmission of a new transport block for a
same HARQ process as for the transport block of the PUSCH
transmission with the RSRP report. For example, for two groups of
search space sets, the UE can be configured to associate the first
group with an RSRP value that is smaller than or equal to a
configured RSRP threshold (and to associate the second group with
an RSRP value that is larger than the threshold).
[0205] A serving gNB (such as the BS 102) can provide to a UE (such
as the UE 116) an index for a group of search space sets for the UE
to monitor PDCCH either by a MAC control element in a PDSCH
reception or by a field in a DCI format in a PDCCH reception. In
this example, the UE can monitor PDCCH for detection of the DCI
format either according to CSS or according to USS. The group index
can be indicated by log.sub.2(N) bits where N is the number of
groups of search space sets the UE is configured by higher
layers.
[0206] When a group index is provided to a UE through a MAC CE in a
PDSCH reception, the UE can determine an application delay of Y
symbols/slots for monitoring PDCCH according to an indicated group
of search space sets to be after a last slot/symbol of PUCCH where
UE transmits HARQ-ACK information in response to the reception of
the PDSCH. When a group index is provided to a UE through a DCI
format in a PDCCH reception, the UE can determine an application
delay of Y symbols/slots for monitoring PDCCH according to an
indicated group of search space sets to be Y slots/symbols after
the last slot/symbol where the UE receives the PDCCH. The value of
Y can be predetermined. In one example, the value of Y is provided
to the UE through higher layer signaling. In another example, the
value of Y can be reported by the UE as UE capability. In yet
another example, the value of Y is defined in the specification of
system operation. For example, Y=1 slot.
[0207] Although FIG. 19 illustrate the method 1900 various changes
may be made to FIG. 19. For example, while the method 1900 of FIG.
19 is shown as a series of steps, various steps could overlap,
occur in parallel, occur in a different order, or occur multiple
times. In another example, steps may be omitted or replaced by
other steps. For example, steps of the method 1900 can be executed
in a different order.
[0208] Embodiments of the present disclosure describe PDCCH
dropping per CCE AL. The following examples and embodiments
describe PDCCH dropping per CCE AL.
[0209] An embodiment of this disclosure considers scaling or
dropping of PDCCH candidates based on predetermined CCE AL order in
a slot or a span. A UE (such as the UE 116) can be provided with a
predetermined order of CCE ALs for allocating PDCCH candidates to
monitor PDCCH for corresponding search space sets. The UE
determines PDCCH candidates to allocated for search space sets in a
slot/span based on the predetermined order of CCE ALs and PDCCH
monitoring capability per slot/span. The UE can be provided with a
list of CCE ALs, denoted as L.sub.BD, and the predetermined order
of CCE ALs is indicated by the index i of the list, L.sub.BD. For
example, the list can include the CCE ALs in the order of {2, 4, 8,
1, 16}.
[0210] For example, let M.sub.PDCCH.sup.USS and C.sub.PDCCH.sup.USS
be the remaining PDCCH candidates and remaining non-overlapping
CCEs for USS, respectively, after the UE allocates PDCCH candidates
and non-overlapping CCEs to search space sets associated with PDCCH
monitoring according to CSS. The UE determines the initial value of
M.sub.PDCCH.sup.USS=min(M.sub.PDCCH.sup.max,slot,.mu.,
M.sub.PDCCH.sup.total,slot,.mu.)-M.sub.PDCCH.sup.CSS and
C.sub.PDCCH.sup.USS=min(C.sub.PDCCH.sup.max,slot,.mu.,
C.sub.PDCCH.sup.total,slot,.mu.)-C.sub.PDCCH.sup.CSS.
[0211] Denote by V.sub.CCE(S.sub.USS(j)) the set of non-overlapping
CCEs for search space set S.sub.USS(j) and by
C(V.sub.CCE(S.sub.USS(j))) the cardinality of
V.sub.CCE(S.sub.USS(j)). M.sub.S.sub.USS.sub.(j).sup.(L) denotes
the number of configured PDCCH candidate for search space set
S.sub.USS(j) at CCE AL of L.
[0212] Denote by V.sub.CCE(S.sub.USS.sup.L.sup.BD.sup.(i)(j)) the
set of non-overlapping CCEs for search space set S.sub.USS(j) at
CCE AL L.sub.BD(i) and by
C(V.sub.CCE(S.sub.USS.sup.L.sup.BD.sup.(i)(j))) the cardinality of
V.sub.CCE(S.sub.USS.sup.L.sup.BD.sup.(i)(j)). Denote by
M.sub.S.sub.USS.sub.(j).sup.L.sup.BD.sup.(i) the PDCCH candidates
for search space set S.sub.USS(j) at CCE AL L.sub.BD(i).
[0213] In a first approach for PDCCH allocation based on
predetermined CCE AL order, a UE (such as the UE 116) applies the
predetermined CCE AL order to all available USS sets where the
non-overlapping CCEs for search space set S.sub.USS(j) at CCE
aggregation level, L.sub.BD(i), are determined considering the
allocated PDCCH candidates for monitoring for the CSS sets and the
allocated PDCCH candidates for monitoring for all L.sub.BD(k),
0.ltoreq.k.ltoreq.i. The UE determines the allocated PDCCH
candidates for K configured USS set(s) based on predetermined PDCCH
allocation or dropping as described in Syntax (6), below.
.times. Syntax .times. .times. .times. Set .times. .times. i = 0 ,
j = 0 .times. .times. while .times. .times. M S USS .function. ( j
) L BD .function. ( j ) .ltoreq. M PDCCH USS .times. .times. AND
.times. .times. .function. ( V CCE .function. ( S USS L BD
.function. ( i ) .function. ( j ) ) ) .ltoreq. C PDCCH USS .times.
.times. allocate .times. .times. M S USS .function. ( j ) L BD
.function. ( i ) .times. .times. PDCCH .times. .times. candidates
.times. .times. for .times. .times. monitoring .times. .times. to
.times. .times. CCE .times. .times. AL .times. .times. L BD
.function. ( i ) .times. .times. of .times. .times. .times. USS
.times. .times. set .times. .times. S USS .function. ( j ) ;
.times. .times. .times. M PDCCH USS = M PDCCH USS - M S USS
.function. ( j ) L BD .function. ( i ) ; .times. .times. .times. C
PDCCH USS = C PDCCH USS - .function. ( V CCE .function. ( S USS L
BD .function. ( i ) .function. ( j ) ) ) ; .times. .times. .times.
j = mod .function. ( j + 1 , K ) ; .times. .times. .times. if
.times. .times. j = 0 .times. .times. .times. set .times. .times. i
= 1 ; .times. .times. .times. end .times. .times. if .times.
.times. .times. end .times. .times. while ( 6 ) ##EQU00009##
[0214] In another approach for PDCCH allocation based on
predetermined CCE aggregation level order, a UE applies the
predetermined CCE aggregation level order to remaining search space
sets without PDCCH allocation when the UE is not able to allocate
all configured PDCCH candidates to the search space sets. The UE
determines the allocated PDCCH candidates for K USS set(s) based on
a predetermined PDCCH allocation or dropping as described in Syntax
(7), below.
.times. Syntax .times. .times. .times. set .times. .times. j = 0
.times. .times. while .times. .times. .SIGMA. L .times. M S USS
.function. ( j ) ( L ) .ltoreq. M PDCCH USS .times. .times. AND
.times. .times. .function. ( V CCE .function. ( S USS .function. (
j ) ) ) .ltoreq. C PDCCH USS .times. .times. .times. allocate
.times. .times. .SIGMA. L .times. M S USS .function. ( j ) ( L )
.times. .times. PDCCH .times. .times. candidates .times. .times. to
.times. .times. USS .times. .times. set .times. .times. S USS
.function. ( j ) .times. .times. .times. M PDCCH USS = M PDCCH USS
- .SIGMA. L .times. M S USS .function. ( j ) ( L ) ; .times.
.times. .times. C PDCCH USS = C PDCCH USS - .function. ( V CCE
.function. ( S USS .function. ( j ) ) ) ; .times. .times. .times. j
= j + 1 ; .times. .times. .times. end .times. .times. while .times.
.times. .times. set .times. .times. i = 0 , j .times. .times. 0 = j
; .times. .times. while .times. .times. M S USS .function. ( j ) (
L ) .ltoreq. M PDCCH USS .times. .times. AND .times. .times.
.function. ( V CCE .function. ( S USS L BD .function. ( i )
.function. ( j ) ) ) .ltoreq. C PDCCH USS .times. .times. allocate
.times. .times. M S USS .function. ( j ) L BD .function. ( i )
.times. .times. PDCCH .times. .times. candidates .times. .times. to
.times. .times. CCE .times. .times. AL .times. .times. L BD
.function. ( i ) .times. .times. of .times. .times. USS .times.
.times. set .times. .times. .times. S USS .function. ( j ) .times.
.times. .times. M PDCCH USS = M PDCCH USS - M S USS .function. ( j
) L BD .function. ( i ) ; .times. .times. .times. C PDCCH USS = C
PDCCH USS - .function. ( V CCE .function. ( S USS L BD .function. (
i ) .function. ( j ) ) ) ; .times. .times. .times. j = mod
.function. ( j + 1 , K - j .times. .times. 0 ) + j .times. .times.
0 ; .times. .times. .times. if .times. .times. j = j .times.
.times. 0 .times. .times. .times. set .times. .times. i = i + 1 ;
.times. .times. .times. end .times. .times. if .times. .times.
.times. end .times. .times. while ( 7 ) ##EQU00010##
[0215] In yet another approach for PDCCH allocation based on a
predetermined CCE AL order, a UE applies the predetermined CCE AL
order only to a search space set with index j to remaining PDCCH
candidates and non-overlapping CCEs after the UE allocates all
configured PDCCH candidates and non-overlapping CCEs to search
space sets with index smaller than j. The UE determines the
allocated PDCCH candidates for USS set(s) based on predetermined
PDCCH allocation or dropping described in Syntax (8), below.
.times. Syntax .times. .times. .times. set .times. .times. j = 0
.times. .times. while .times. .times. .SIGMA. L .times. M S USS
.function. ( j ) ( L ) .ltoreq. M PDCCH US .times. .times. AND
.times. .times. .function. ( V CCE .function. ( S USSS .function. (
j ) ) ) .ltoreq. C PDCCH USS .times. .times. allocate .times.
.times. .SIGMA. L .times. M S USS .function. ( j ) ( L ) .times.
.times. PDCCH .times. .times. candidates .times. .times. for
.times. .times. monitoring .times. .times. to .times. .times. USS
.times. .times. set .times. .times. S USS .function. ( j ) .times.
.times. .times. M PDCCH USS = M PDCCH USS - .SIGMA. L M S USS
.function. ( j ) ( L ) ; .times. .times. .times. C PDCCH USS = C
PDCCH USS - .function. ( V CCE .function. ( S USS .function. ( j )
) ) ; .times. .times. .times. j = j + 1 ; .times. .times. .times.
end .times. .times. while .times. .times. .times. set .times.
.times. i = 0 .times. .times. while .times. .times. M S USS
.function. ( j ) L BD .function. ( i ) .ltoreq. M PDCCH USS .times.
.times. AND .times. .times. .function. ( V CCE .function. ( S USS L
BD .function. ( i ) .function. ( j ) ) ) .ltoreq. C PDCCH USS
.times. .times. allocate .times. .times. M S USS .function. ( j ) L
BD .function. ( i ) .times. .times. PDCCH .times. .times.
candidates .times. .times. for .times. .times. monitoring .times.
.times. to .times. .times. CCE .times. .times. AL .times. .times. L
BD .function. ( i ) .times. .times. of .times. .times. .times. USS
.times. .times. set .times. .times. S USS .function. ( j ) .times.
.times. .times. M PDCCH USS = M PDCCH USS - M S USS .function. ( j
) L BD .function. ( i ) ; .times. .times. .times. C PDCCH USS = C
PDCCH USS - .function. ( V CCE .function. ( S USS L BD .function. (
i ) .function. ( j ) ) ) ; .times. .times. .times. i = i + 1 ;
.times. .times. .times. end .times. .times. while ( 8 )
##EQU00011##
[0216] According to Syntax (6), Syntax (7), and Syntax (8), the UE
initially allocates all configured PDCCH candidates and
non-overlapping CCEs to USS sets based on legacy PDCCH allocation
rule (after the UE has allocated PDCCH candidates and
non-overlapping CCEs to CSS sets). Then, the UE allocates remaining
PDCCH candidates and non-overlapping CCEs according to a set
L.sub.BD of CCE ALs across USS sets to USS set S.sub.USS(j).
[0217] For determining the set L.sub.BD of CCE ALs, in one example
L.sub.BD can be provided to UE through higher layer signaling. In
another example, L.sub.BD can be predefined in the specification of
system operation, such as L.sub.BD=[1, 2, 4, 8, 16]. In yet another
example, L.sub.BD can be reported from UE to gNB as assistance
information by higher layer signaling. In yet another example,
L.sub.BD can be preferred CCE ALs or PDCCH CSI reported by UE via a
PUCCH or PUSCH.
[0218] The above flowcharts illustrate example methods that can be
implemented in accordance with the principles of the present
disclosure and various changes could be made to the methods
illustrated in the flowcharts herein. For example, while shown as a
series of steps, various steps in each figure could overlap, occur
in parallel, occur in a different order, or occur multiple times.
In another example, steps may be omitted or replaced by other
steps.
[0219] Although the figures illustrate different examples of user
equipment, various changes may be made to the figures. For example,
the user equipment can include any number of each component in any
suitable arrangement. In general, the figures do not limit the
scope of this disclosure to any particular configuration(s).
Moreover, while figures illustrate operational environments in
which various user equipment features disclosed in this patent
document can be used, these features can be used in any other
suitable system.
[0220] Although the present disclosure has been described with
exemplary embodiments, various changes and modifications may be
suggested to one skilled in the art. It is intended that the
present disclosure encompass such changes and modifications as fall
within the scope of the appended claims. None of the description in
this application should be read as implying that any particular
element, step, or function is an essential element that must be
included in the claims scope. The scope of patented subject matter
is defined by the claims.
* * * * *