U.S. patent application number 17/528381 was filed with the patent office on 2022-03-10 for systems and methods for reliable dynamic indication for semi-persistent csi-rs.
The applicant listed for this patent is Telefonaktiebolaget LM Ericsson (publ). Invention is credited to Mattias Frenne, Shiwei Gao, Stephen Grant, Robert Mark Harrison, Siva Muruganathan.
Application Number | 20220078658 17/528381 |
Document ID | / |
Family ID | |
Filed Date | 2022-03-10 |
United States Patent
Application |
20220078658 |
Kind Code |
A1 |
Muruganathan; Siva ; et
al. |
March 10, 2022 |
Systems and Methods for Reliable Dynamic Indication for
Semi-Persistent CSI-RS
Abstract
According to certain embodiments, a method in a wireless device
is provided that includes receiving, from a network node, dynamic
allocation signaling to commence measurement on a semi-persistent
CSI-RS resource. A first measurement is performed on the CSI-RS
resource. A first CSI report based only on the first measurement is
transmitted to the network node. A trigger message is received from
the network node that is different from the dynamic allocation
signaling. The trigger message triggers semi-persistent CSI
reporting, and the wireless device initiates semi-persistent
reporting.
Inventors: |
Muruganathan; Siva;
(Stittsville, CA) ; Frenne; Mattias; (Uppsala,
SE) ; Gao; Shiwei; (Nepean, CA) ; Grant;
Stephen; (Pleasanton, CA) ; Harrison; Robert
Mark; (Grapevine, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Telefonaktiebolaget LM Ericsson (publ) |
Stockholm |
|
SE |
|
|
Appl. No.: |
17/528381 |
Filed: |
November 17, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15765784 |
Apr 4, 2018 |
11184787 |
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PCT/SE2018/050006 |
Jan 8, 2018 |
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17528381 |
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62444241 |
Jan 9, 2017 |
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International
Class: |
H04W 24/10 20060101
H04W024/10; H04L 5/00 20060101 H04L005/00; H04L 25/02 20060101
H04L025/02; H04B 7/06 20060101 H04B007/06 |
Claims
1. A method in a wireless device for initiating semi-persistent
channel state information, CSI, measurements, the method
comprising: receiving, from a network node, dynamic allocation
signaling to commence measurement on a semi-persistent channel
state information-reference signal, CSI-RS, resource; performing a
first measurement on the semi-persistent CSI-RS resource;
transmitting, to the network node, a first CSI report based only on
the first measurement; receiving, from the network node, a trigger
message that is different than the dynamic allocation signaling,
the trigger message triggering semi-persistent CSI reporting; and
initiating semi-persistent reporting.
2. The method according to claim 1, where the dynamic allocation
signaling initiates semi-persistent CSI measurements on the CSI-RS
resource and also triggers the first CSI report.
3. The method according to claim 1, wherein the dynamic allocation
signaling comprises a MAC control element, MAC CE.
4. The method according to claim 1, wherein the trigger message
comprises downlink control information, DCI.
5. The method according to claim 1, wherein initiating
semi-persistent reporting comprises transmitting a plurality of
semi-persistent CSI reports.
6. The method according to claim 5, further comprising: ceasing
transmission of the plurality of semi-persistent CSI-RS reports
after a predetermined length of time.
7. The method according to claim 1, where the first CSI report is
an aperiodic report.
8. The method according to claim 1, where the first CSI report is a
semi-persistent report.
9. The method according to claim 1, wherein the dynamic allocation
signaling comprises at least one of the following: an indication of
semi-persistent CSI-RS measurement initiation; an indication of
semi-persistent CSI-RS resource configuration index/indices; and an
uplink resource allocation and associated modulation and coding
rate.
10. The method according to claim 1, wherein the semi-persistent
CSI-RS resource comprises a CSI-RS resource that is configured with
at least a CSI-RS transmission periodicity and for which at least
one wireless device assumption on transmission and cessation of
CSI-RS transmission applies.
11. The method according to claim 1 wherein: the semi-persistent
CSI-RS resource is configured for transmission of CSI-RS at a
configured periodicity for a limited time duration; and receipt of
the dynamic allocation is required to trigger to transmission of
the semi-persistent CSI-RS on the semi-persistent CSI-RS
resource.
12. The method according to claim 1, further comprising: receiving
dynamic deallocation signaling to terminate the measurement of on
the semi-persistent CSI-RS resource; and in response to the dynamic
deallocation signaling, ceasing the semi-persistent measurements on
the semi-persistent CSI-RS resource.
13. A wireless device for initiating semi-persistent channel state
information, CSI, measurements, the wireless device comprising: a
memory storing instructions; and processing circuitry operable to
execute the instructions to cause the wireless device to: receive,
from a network node, dynamic allocation signaling to commence
measurement on a semi-persistent channel state
information-reference signal, CSI-RS, resource; perform a first
measurement on the semi-persistent CSI-RS resource; transmit, to
the network node, a first CSI report based only on the first
measurement; receive, from the network node, a trigger message that
is different than the dynamic allocation signaling, the trigger
message triggering semi-persistent CSI reporting; and initiate
semi-persistent reporting.
14. The wireless device according to claim 13, where the dynamic
allocation signaling initiates semi-persistent CSI measurements on
the CSI-RS resource and also triggers the first CSI report.
15. The wireless device according to claim 13, wherein the dynamic
allocation signaling comprises a MAC control element. MAC CE.
16. The wireless device according to claim 13, wherein the trigger
message comprises downlink control information, DCI.
17. The wireless device according to claim 13, wherein initiating
semi-persistent reporting comprises transmitting a plurality of
semi-persistent CSI reports.
18. The wireless device according to claim 17, wherein the
processing circuitry is operable to execute the instructions to
cause the wireless device to: cease transmission of the plurality
of semi-persistent CSI-RS reports after a predetermined length of
time.
19.-24. (canceled)
25. A method in a network node for initiating semi-persistent
channel state information, CSI, measurements, the method
comprising: transmitting, to the wireless device, dynamic
allocation signaling to initiate measurement on a semi-persistent
channel state information-reference signal, CSI-RS, resource for
which the wireless device is not currently performing measurements;
determining whether a first CSI report is transmitted by the
wireless device in response to the dynamic allocation signaling;
and taking an action based on whether the first CSI report is
received in response to the dynamic allocation signaling.
26. The method according to claim 25, wherein the dynamic
allocation signaling comprises a MAC control element, MAC CE.
27. The method of claim 25, wherein: determining whether the first
CSI report is transmitted by the wireless device comprises:
receiving the first CSI report from the wireless device; and based
on receiving the first CSI report, determining that the wireless
device successfully received the dynamic allocation signaling; and
taking the action further comprises continuing transmission of
semi-persistent CSI-RS with preconfigured periodicity.
28. The method of claim 25, wherein: determining whether the first
CSI report is transmitted by the wireless device comprises:
determining that the first CSI report is not received from the
wireless device; and based on not receiving the first CSI report,
determining that the wireless device did not successfully receive
the dynamic allocation signaling; and taking the action further
comprises retransmitting the dynamic allocation signaling to the
wireless device.
29. The method according to claim 25, further comprising:
transmitting a trigger message that is different from the dynamic
allocation signaling; and in response to the trigger message,
receiving at least one semi-persistent CSI report in addition to
the first CSI report.
30. The method according to claim 29, wherein the trigger message
comprises downlink control information, DCI.
31. The method according to claim 25, wherein the dynamic
allocation signaling comprises at least one of the following: an
indication of semi-persistent CSI-RS measurement initiation; an
indication of semi-persistent CSI-RS resource configuration
index/indices; and an uplink resource allocation and associated
modulation and coding rate.
32. The method according to claim 25, wherein the semi-persistent
CSI-RS resource comprises a CSI-RS resource that is configured with
at least a CSI-RS transmission periodicity and for which at least
one wireless device assumption on transmission and cessation of
CSI-RS transmission applies.
33. The method according to claim 25 wherein: the semi-persistent
CSI-RS resource is configured for transmission of CSI-RS at a
configured periodicity for a limited time duration; and receipt of
the dynamic allocation is required to trigger to transmission of
the semi-persistent CSI-RS on the semi-persistent CSI-RS
resource.
34. The method according to claim 25, further comprising:
transmitting dynamic deallocation signaling to terminate the
measurement on the semi-persistent CSI-RS resource by the wireless
device; determine whether a second CSI report is transmitted by the
wireless device in response to the dynamic deallocation signaling;
and take an action based on whether the second CSI report is
transmitted by the wireless device in response to the dynamic
allocation signaling.
35. A network node for initiating semi-persistent channel state
information, CSI, measurements, the network node comprising: a
memory storing instructions; and processing circuitry operable to
execute the instructions to cause the network node to: transmit, to
the wireless device, dynamic allocation signaling to initiate
measurement on a semi-persistent channel state
information-reference signal, CSI-RS, resource for which the
wireless device is not currently performing measurements; determine
whether a first CSI report is transmitted by the wireless device in
response to the dynamic allocation signaling; and take an action
based on whether the first CSI report is received in response to
the dynamic allocation trigger.
36. (canceled)
37. (canceled)
38. (canceled)
39. (canceled)
40. (canceled)
41. (canceled)
42. (canceled)
43. (canceled)
44. (canceled)
Description
TECHNICAL FIELD
[0001] The present disclosure relates, in general, to wireless
communications and, more particularly, systems and methods for
reliable dynamic indication for semi-persistent channel state
information-reference signal (CSI-RS).
BACKGROUND
[0002] The fifth generation of mobile telecommunications and
wireless technology is not yet fully defined but in an advanced
draft stage within 3GPP. It includes work on 5G New Radio (NR)
Access Technology. Long-Term Evolution (LTE) terminology is used in
this disclosure in a forward looking sense, to include equivalent
5G entities or functionalities although a different term is
specified in 5G. A general description of the agreements on 5G New
Radio (NR) Access Technology so far is contained in 3GPP TR 38.802
V1.0.0 (2016-11). Final specifications may be published inter alia
in the future 3GPP TS 38.2** series.
[0003] The next generation mobile wireless communication system (5G
or NR) may support a diverse set of use cases and a diverse set of
deployment scenarios. The latter may include deployment at both low
frequencies (100s of MHz), similar to LTE today, and very high
frequencies (mm waves in the tens of GHz). At high frequencies,
propagation characteristics make achieving good coverage
challenging. One solution to the coverage issue may include
employing high-gain beamforming, typically facilitated by analog
circuitry, in order to achieve satisfactory link budget.
Beamforming will also be used at lower frequencies (typically
digital beamforming using mainly digital circuitry), and is
expected to be similar in nature to the already standardized 3GPP
LTE system (4G).
[0004] Some of the key aspects of LTE are described herein. Of
particular relevance is discussion of channel state
information-reference signal (CSI-RS). A similar signal is expected
to be designed also for NR and is the subject of the disclosure
below.
[0005] Note that terminology used here such as gNodeB (gNB) and
user equipment (UE) should be considered non-limiting and does in
particular not imply a certain hierarchical relation between the
two; in general "gNB" could be read as a reference to generic
device 1 and "UE" as device 2, wherein these two generic devices
communicate with each other over some radio channel. Alternatively,
other terminology such as "gNodeB" can be used in place of "gNB" in
different communication systems. Herein, the focus is on wireless
transmissions in the downlink, but the techniques are equally
applicable in the uplink.
[0006] LTE and NR use orthogonal frequency division multiplexing
(OFDM) in the downlink and discrete Fourier transform spread
(DFT-spread) OFDM or OFDM in the uplink. FIG. 1 illustrates the
basic LTE downlink physical resource. LTE uses OFDM in the downlink
and DFT-spread OFDM in the uplink. The basic LTE downlink physical
resource can thus be seen as a time-frequency grid, where each
resource element (or time/frequency resource element (TFRE))
corresponds to one OFDM subcarrier during one OFDM symbol interval.
Although a subcarrier spacing of .DELTA.f=15 kHz is shown in FIG.
1, different subcarrier spacing values are supported in NR. The
supported subcarrier spacing values (also reference to as different
numerologies) in NR are given by .DELTA.f=(15.times.2.sup..alpha.)
kHz where a is a non-negative integer.
[0007] FIG. 2 illustrates the LTE time-domain structure. In the
time domain, LTE downlink transmissions are organized into radio
frames of 10 ms. Each radio frame consists of ten equally-sized
subframes of length T.sub.subframe=1 ms. In NR, subframe length is
fixed at 1 ms as in LTE. A subframe in NR is further divided into a
number of slots each with 14 OFDM symbols. The slot length for a
reference numerology of (15.times.2.sup..alpha.) kHz is exactly
2.sup.-.alpha. ms.
[0008] The resource allocation in LTE is typically described in
terms of resource blocks, where a resource block corresponds to one
slot (0.5 ms) in the time domain and 12 contiguous subcarriers in
the frequency domain. Resource blocks are numbered in the frequency
domain, starting with 0 from one end of the system bandwidth. For
NR, a resource block is also 12 subcarriers in frequency
domain.
[0009] Downlink transmissions are dynamically scheduled. For
example, in each subframe or slot, the gNB may transmit control
information about to which terminals data is transmitted and upon
which resource blocks the data is transmitted, in the current
downlink subframe or slot. This control signaling is typically
transmitted in the first 1, 2, 3 or 4 OFDM symbols in each subframe
in LTE and 1 or 2 OFDM symbols of a slot in NR. A downlink system
with 3 OFDM symbols as control for LTE is illustrated in FIG.
3.
[0010] Multi-antenna techniques can significantly increase the data
rates and reliability of a wireless communication system. The
performance is in particular improved if both the transmitter and
the receiver are equipped with multiple antennas, which results in
a multiple-input multiple-output (MIMO) communication channel. Such
systems and/or related techniques are commonly referred to as
MIMO.
[0011] NR is currently evolving with MIMO support. A core component
in NR is the support of MIMO antenna deployments and MIMO related
techniques including beamforming at higher carrier frequencies.
Currently LTE and NR support an 8-layer spatial multiplexing mode
for up to 32 transmit (Tx) antennas with channel dependent
precoding. The spatial multiplexing mode is aimed for high data
rates in favorable channel conditions.
[0012] FIG. 4 illustrates an example spatial multiplexing
operation. More particularly, FIG. 4 illustrates an example
transmission structure of precoded spatial multiplexing mode in LTE
and NR. As depicted, the information carrying symbol vector s is
multiplied by an N.sub.T.times.r precoder matrix W, which serves to
distribute the transmit energy in a subspace of the N.sub.T
(corresponding to N.sub.T antenna ports) dimensional vector space.
The precoder matrix is typically selected from a codebook of
possible precoder matrices, and typically indicated by means of a
precoder matrix indicator (PMI), which specifies a unique precoder
matrix in the codebook for a given number of symbol streams. The r
symbols in s each correspond to a layer and r is referred to as the
transmission rank. In this way, spatial multiplexing is achieved
since multiple symbols can be transmitted simultaneously over the
same time/frequency resource element (TFRE). The number of symbols
r is typically adapted to suit the current channel properties.
[0013] LTE and NR use OFDM in the downlink and hence the received
N.sub.R.times.1 vector y.sub.n for a certain TFRE on subcarrier n
(or alternatively data TFRE number n) is thus modeled by
y.sub.n=H.sub.nWs.sub.n+e.sub.n
where e.sub.n is a noise/interference vector obtained as
realizations of a random process. The precoder W can be a wideband
precoder, which is constant over frequency, or frequency
selective.
[0014] The precoder matrix is often chosen to match the
characteristics of the N.sub.R.times.N.sub.T MIMO channel matrix
H.sub.n, resulting in so-called channel-dependent precoding. This
is also commonly referred to as closed-loop precoding and
essentially strives for focusing the transmit energy into a
subspace which is strong in the sense of conveying much of the
transmitted energy to the UE. In addition, the precoder matrix may
also be selected to strive for orthogonalizing the channel, meaning
that after proper linear equalization at the UE, the inter-layer
interference is reduced.
[0015] The transmission rank, and thus the number of spatially
multiplexed layers, is reflected in the number of columns of the
precoder. For efficient performance, it is important that a
transmission rank that matches the channel properties is
selected.
[0016] In LTE and NR, a reference signal is introduced for the
intent to estimate channel state information, the CSI-RS. The
CSI-RS provides several advantages over basing the channel state
information (CSI) feedback on the common reference symbols (CRS)
which were used, for that purpose, in previous releases of LTE.
Firstly, the CSI-RS is not used for demodulation of the data
signal, and thus does not require the same density as CRS (i.e.,
the overhead of the CSI-RS is substantially less). Secondly, CSI-RS
provides a much more flexible means to configure CSI feedback
measurements (e.g., which CSI-RS resource to measure on can be
configured in a UE specific manner).
[0017] By measuring on a CSI-RS, a UE can estimate the effective
channel the CSI-RS is traversing including the radio propagation
channel and antenna gains. In more mathematical rigor, this implies
that if a known CSI-RS signal, x, is transmitted, a UE can estimate
the coupling between the transmitted signal and the received signal
(i.e., the effective channel). Hence, if no virtualization is
performed in the transmission, the received signal, y, can be
expressed as
y=Hx+e,
where, again, e is noise/interference obtained as realizations of a
random process, and the UE can estimate the effective channel H. Up
to 32 CSI-RS ports can be configured for a LTE or NR UE. That is,
the UE can estimate the channel from up to thirty-two transmit
antenna ports.
[0018] An antenna port is equivalent to a reference signal resource
that the UE shall use to measure the channel. Hence, a gNB with two
antennas could define two CSI-RS ports, where each port is a set of
resource elements in the time frequency grid within a subframe or
slot. The base station transmits each of these two reference
signals from each of the two antennas so that the UE can measure
the two radio channels and report channel state information back to
the base station based on these measurements. In LTE, CSI-RS
resources with 1, 2, 4, 8, 12, 16, 20, 24, 28 and 32 ports are
supported.
[0019] In LTE, the CSI-RS utilizes an orthogonal cover code (OCC)
of length two to overlay two antenna ports on two consecutive
resource elements (REs). FIGS. 5A-5C illustrate resource element
grids. More particularly, FIGS. 5A-5C illustrate RE grids over a
resource block (RB) pair showing potential positions for LTE
Release 9/10 UE specific RS, CSI-RS (marked with a number
corresponding to the CSI-RS antenna port), and CRS. The CSI-RS
utilizes an orthogonal cover code (OCC) of length two to overlay
two antenna ports on two consecutive REs. As shown in FIGS. 5A-5C,
many different CSI-RS patterns are available. For the case of 2
CSI-RS antenna ports, we see that there are 20 different patterns
within a subframe. The corresponding number of patterns is 10 and 5
for 4 and 8 CSI-RS antenna ports, respectively. For TDD, some
additional CSI-RS patterns are available.
[0020] The CSI reference signal configurations are shown in TABLE
6.10.5.2-1 below, taken from TS 36.211 v12.5.0. For example, the
CSI RS configuration 5 for 4 antennas ports use (k', l')=(9,5) in
slot 1 (the second slot of the subframe). Using the formulas below,
it can be determined that port 15, 16, use OCC over the resource
elements (k, l)=(9,5), (9,6) and ports 17, 18 use OCC over resource
elements (3,5), (3,6), respectively (assuming physical resource
block (PRB) index m=0), where k is the subcarrier index and l is
the OFDM symbol index within each slot.
[0021] The OCC is introduced below by the factor w.sub.l''.
k = k ' + 12 .times. m + { - 0 for .times. .times. p .di-elect
cons. { 1 .times. 5 , 1 .times. 6 } , normal .times. .times. cyclic
.times. .times. prefix - 6 for .times. .times. p .di-elect cons. {
1 .times. 7 , 1 .times. 8 } , normal .times. .times. cyclic .times.
.times. prefix - 1 for .times. .times. p .di-elect cons. { 1
.times. 9 , 2 .times. 0 } , normal .times. .times. cyclic .times.
.times. prefix - 7 for .times. .times. p .di-elect cons. { 2
.times. 1 , 2 .times. 2 } , normal .times. .times. cyclic .times.
.times. prefix - 0 for .times. .times. p .di-elect cons. { 1
.times. 5 , 1 .times. 6 } , extended .times. .times. cyclic .times.
.times. prefix - 3 for .times. .times. p .di-elect cons. { 1
.times. 7 , 1 .times. 8 } , extended .times. .times. cyclic .times.
.times. prefix - 6 for .times. .times. p .di-elect cons. { 1
.times. 9 , 2 .times. 0 } , extended .times. .times. cyclic .times.
.times. prefix - 9 for .times. .times. p .di-elect cons. { 2
.times. 1 , 2 .times. 2 } , extended .times. .times. cyclic .times.
.times. prefix .times. .times. l = l ' + { l '' CSI .times. .times.
reference .times. .times. signal .times. .times. configurations
.times. .times. 0 .times. - .times. 19 , normal .times. .times.
cyclic .times. .times. prefix 2 .times. l '' CSI .times. .times.
reference .times. .times. signal .times. .times. configurations
.times. .times. 2 .times. 0 .times. - .times. 31 , normal .times.
.times. cyclic .times. .times. prefix l '' CSI .times. .times.
reference .times. .times. signal .times. .times. configurations
.times. .times. 0 .times. - .times. 27 , extended .times. .times.
cyclic .times. .times. prefix .times. .times. .times. w l '' = { 1
p .di-elect cons. { 1 .times. 5 , 1 .times. 7 , 1 .times. 9 , 2
.times. 1 } ( - 1 ) l '' p .di-elect cons. { 1 .times. 6 , 1
.times. 8 , 2 .times. 0 , 2 .times. 2 } .times. .times. .times. l
'' = 0 , 1 .times. .times. .times. m = 0 , 1 , .times. , N R
.times. B D .times. L - 1 .times. .times. .times. m ' = m + N R
.times. B max , DL - N R .times. B D .times. L 2 ##EQU00001##
TABLE-US-00001 TABLE 6.10.5.2-1 Mapping from CSI reference signal
configuration to (k', l') for normal cyclic prefix CSI reference
Number of CSI reference signals configured signal 1 or 2 4 8
configuration (k', l') n.sub.s mod 2 (k', l') n.sub.s mod 2 (k',
l') n.sub.s mod 2 Frame 0 (9, 5) 0 (9, 5) 0 (9, 5) 0 structure 1
(11, 2) 1 (11, 2) 1 (11, 2) 1 type 1 2 (9, 2) 1 (9, 2) 1 (9, 2) 1
and 2 3 (7, 2) 1 (7, 2) 1 (7, 2) 1 4 (9, 5) 1 (9, 5) 1 (9, 5) 1 5
(8, 5) 0 (8, 5) 0 6 (10, 2) 1 (10, 2) 1 7 (8, 2) 1 (8, 2) 1 8 (6,
2) 1 (6, 2) 1 9 (8, 5) 1 (8, 5) 1 10 (3, 5) 0 11 (2, 5) 0 12 (5, 2)
1 13 (4, 2) 1 14 (3, 2) 1 15 (2, 2) 1 16 (1, 2) 1 17 (0, 2) 1 18
(3, 5) 1 19 (2, 5) 1 Frame 20 (11, 1) 1 (11, 1) 1 (11, 1) 1
structure 21 (9, 1) 1 (9, 1) 1 (9, 1) 1 type 2 22 (7, 1) 1 (7, 1) 1
(7, 1) 1 only 23 (10, 1) 1 (10, 1) 1 24 (8, 1) 1 (8, 1) 1 25 (6, 1)
1 (6, 1) 1 26 (5, 1) 1 27 (4, 1) 1 28 (3, 1) 1 29 (2, 1) 1 30 (1,
1) 1 31 (0, 1) 1
[0022] In NR, the following three types of CSI-RS transmissions are
supported: [0023] Aperiodic CSI-RS Transmission: This is a one-shot
CSI-RS transmission that can happen in any subframe or slot. Here,
one-shot means that CSI-RS transmission only happens once per
trigger in one slot or subframe. The CSI-RS resources (i.e., the
resource element locations which consist of subcarrier locations
and OFDM symbol locations) for aperiodic CSI-RS are preconfigured
to UEs via higher layer signaling. The transmission of aperiodic
CSI-RS is triggered by dynamic signaling. [0024] Periodic CSI-RS
Transmission: These CSI-RS transmissions are preconfigured by
higher layer signaling and the preconfiguration includes parameters
such as periodicity and subframe or slot offset similar to LTE.
Periodic CSI-RS is controlled by higher layer signaling only and
dynamic signaling is not needed to trigger periodic CSI-RS
transmission. That is, the periodic CSI-RS transmission starts
following RRC configuration following the configured parameters.
[0025] Semi-Persistent CSI-RS Transmission: Similar to periodic
CSI-RS, resources for semi-persistent CSI-RS transmissions are
preconfigured via higher layer signaling with parameters such as
periodicity and subframe or slot offset. However, unlike periodic
CSI-RS, dynamic allocation signaling is needed to begin
transmission of semi-persistent CSI-RS on the preconfigured
resources. FIG. 6 illustrates semi-persistent CSI-RS transmitted
for a limited time duration (which is referred to as `the time
duration when semi-persistent CSI-RS` is allocated in the figure).
In some cases, dynamic deallocation signaling is needed to stop
transmission of semi-persistent CSI-RS.
[0026] In addition to multiple types of CSI-RS transmissions, NR
also supports multiple types of CSI reporting. The following types
of CSI reporting will be supported in NR: [0027] Aperiodic CSI
Reporting: This type of CSI reporting involves a single-shot (i.e.,
one time) CSI report by the UE which is dynamically triggered by
the gNB. [0028] Periodic CSI Reporting: CSI is reported
periodically by the UE. Parameters such as periodicity and subframe
or slot offset are configured by higher layer signaling. [0029]
Semi-Persistent CSI Reporting: similar to periodic CSI reporting,
semi-persistent CSI reporting has a periodicity and subframe or
slot offset. However, a dynamic trigger may be needed to begin
semi-persistent CSI reporting. In some cases, a dynamic trigger may
be needed to stop the semi-persistent CSI reporting.
[0030] With regards to relating the different CSI-RS types to the
different CSI reporting types, the following combinations will be
supported in NR: [0031] Aperiodic CSI reporting with aperiodic
CSI-RS [0032] Aperiodic CSI reporting with semi-persistent/periodic
CSI-RS [0033] Semi-persistent or periodic CSI reporting with
semi-persistent or periodic CSI-RS
[0034] LTE control signaling can be carried in a variety of ways,
including carrying control information on a physical downlink
control channel (PDCCH) or a physical uplink control channel
(PUCCH), embedded in a physical uplink shared channel (PUSCH), in
medium access control-control elements (MAC-CEs), or in RRC
signaling. Each of these mechanisms is customized to carry a
particular kind of control information.
[0035] Control information carried on PDCCH, PUCCH, or embedded in
PUSCH is physical layer related control information, such as
downlink control information (DCI), uplink control information
(UCI), as described in 3GPP TS 36.211, 36.212, and 36.213, or
corresponding specifications in the 38 series. DCI is generally
used to instruct the UE to perform some physical layer function,
providing the needed information to perform the function. UCI
generally provides the network with needed information, such as
hybrid automatic repeat request-acknowledgment (HARQ-ACK),
scheduling request (SR), channel state information (CSI), including
channel quality indicator (CQI), pre-coding matrix indicator (PMI),
rank indicator (RI), and/or contention resolution identity (CRI).
UCI and DCI can be transmitted on a subframe-by-subframe basis, and
so are designed to support rapidly varying parameters, including
those that can vary with a fast fading radio channel. Because UCI
and DCI can be transmitted in every subframe, UCI or DCI
corresponding to a given cell tend to be on the order of tens of
bits, in order to limit the amount of control overhead.
[0036] Control information carried in MAC CEs is carried in MAC
headers on the uplink and downlink shared transport channels
(UL-SCH and DL-SCH), as described in 3GPP TS 36.321. Since a MAC
header does not have a fixed size, control information in MAC CEs
can be sent when it is needed, and does not necessarily represent a
fixed overhead. Furthermore, MAC CEs can carry larger control
payloads efficiently, since they are carried in UL-SCH or DL-SCH
transport channels, which benefit from link adaptation, HARQ, and
can be turbo coded. MAC CEs are used to perform repetitive tasks
that use a fixed set of parameters, such as maintaining timing
advance or buffer status reporting, but these tasks generally do
not require transmission of a MAC CE on a subframe-by-subframe or
slot-by-slot basis. Consequently, channel state information related
to a fast fading radio channel, such as PMI, CQI, RI, and CRI are
not carried in MAC CEs in LTE up to Rel-14.
[0037] With regards to dynamic allocation signaling to begin
transmission of semi-persistent CSI-RS, one solution is to use a
MAC CE based indication. FIG. 7 illustrates an example of MAC CE
based dynamic allocation signaling for beginning semi-persistent
CSI-RS transmission. With this MAC CE based solution, generally
there is a delay, denoted as X, between the dynamic allocation
signaling and the beginning of semi-persistent CSI-RS measurement.
This delay includes the following: [0038] MAC CE decoding delay at
the UE [0039] The time delay due to HARQ ACK/NACK feedback on the
dynamic allocation signal which is sent from the UE to the gNB
Thus, a major problem with the MAC CE based dynamic allocation to
begin semi-persistent CSI-RS measurement is that it involves long
allocation latencies. The gNB does not have much control over the
time gap between dynamic allocation and the beginning of
semi-persistent CSI-RS measurement as this time gap X is determined
by MAC CE decoding delay and HARQ ACK/NACK feedback delay, etc.
[0040] With regards to dynamic deallocation signaling to stop
transmission of semi-persistent CSI-RS, one solution is to use a
MAC CE based indication. FIG. 8 illustrates an example of MAC CE
based dynamic deallocation signaling for stopping semi-persistent
CSI-RS transmission. In FIG. 8, the delay between the dynamic
deallocation signal and the ending of the semi-persistent CSI-RS
measurement is denoted as Y. Due to reasons stated above, a major
problem with the MAC CE based dynamic deallocation to stop
semi-persistent CSI-RS transmission is that it involves long
deallocation delays. The gNB does not have much control over the
time gap between dynamic deallocation and the stopping of
semi-persistent CSI-RS measurement as this time gap Y is determined
by MAC CE decoding delay and HARQ ACK/NACK feedback delay, etc.
[0041] Another solution to dynamically indicate the starting or
stopping of semi-persistent CSI-RS measurements is to use DCI. FIG.
9 illustrates the problems for the combination of semi-persistent
CSI-RS measurement with semi-persistent CSI reporting, the above
problems are also present when semi-persistent CSI-RS is combined
with aperiodic (single-shot) CSI reporting DCI based dynamic
indication for semi-persistent CSI-RS measurement provides better
control of the time gaps X and Y abovementioned. However, since
there is no HARQ acknowledgement associated with the reception of
the DCI, the gNB does not know whether or not the UE has
successfully received the DCI indication. Thus, reliability is a
problem associated with DCI based dynamic indication to start/stop
semi-persistent CSI-RS measurements.
[0042] Although FIGS. 7-9 illustrate the problems for the
combination of semi-persistent CSI-RS measurement with
semi-persistent CSI reporting, the above problems are also present
when semi-persistent CSI-RS is combined with aperiodic
(single-shot) CSI reporting.
SUMMARY
[0043] To address the foregoing problems with existing solutions,
disclosed is systems and methods for reliable dynamic indication
for semi-persistent CSI-RS. According to certain embodiments, a
method in a wireless device is provided that includes receiving,
from a network node, dynamic allocation signaling to commence
measurement on a semi-persistent CSI-RS resource. A first
measurement is performed on the CSI-RS resource. A first CSI report
based only on the first measurement is transmitted to the network
node. A trigger message is received from the network node that is
different from the dynamic allocation signaling. The trigger
message triggers semi-persistent CSI reporting, and the wireless
device initiates semi-persistent reporting.
[0044] According to certain embodiments, a wireless device is
provided that includes a memory storing instructions and processing
circuitry operable to execute the instructions to cause the
wireless device to receive, from a network node, dynamic allocation
signaling to commence measurement of a semi-persistent CSI-RS
resource. A first measurement of the CSI-RS resource is performed,
and a first CSI report based only on the first measurement is
transmitted to the network node. A trigger message is received from
the network node that is different from the dynamic allocation
signaling. The trigger message triggers semi-persistent CSI
reporting, and the wireless device initiates semi-persistent
reporting.
[0045] According to certain embodiments, a method in a network node
includes transmitting, to a wireless device, dynamic allocation
signaling to initiate measurement of a semi-persistent CSI-RS
resource. It is determined whether a first CSI report is
transmitted by the wireless device in response to the dynamic
allocation signaling and an action is taken based on whether the
first CSI report is received in response to the dynamic allocation
trigger.
[0046] According to certain embodiments, a network node includes a
memory storing instructions and processing circuitry operable to
execute the instructions to cause the network node to transmit, to
a wireless device, dynamic allocation signaling to initiate
measurement of a semi-persistent CSI-RS resource. It is determined
whether a first CSI report is transmitted by the wireless device in
response to the dynamic allocation signaling and an action is taken
based on whether the first CSI report is received in response to
the dynamic allocation trigger.
[0047] Certain embodiments of the present disclosure may provide
one or more technical advantages. For example, certain embodiments
may avoid the long allocation/deallocation latencies associated
with schemes such as MAC CE based allocation/deallocation.
According to certain embodiments, a technical advantage may be that
the semi-persistent CSI-RS measurement can occur in the same
subframe or slot as the activation/allocation trigger. Still
another technical advantage may be the high reliability of the DCI
based allocation or deallocation to start or stop semi-persistent
CSI-RS measurements (and thus gNB transmissions of CSI-RS), which
has similar reliability as MAC CE based approaches.
[0048] Other advantages may be readily apparent to one having skill
in the art. Certain embodiments may have none, some, or all of the
recited advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] For a more complete understanding of the disclosed
embodiments and their features and advantages, reference is now
made to the following description, taken in conjunction with the
accompanying drawings, in which:
[0050] FIG. 1 illustrates the basic Long Term Evolution (LTE)
downlink physical resource;
[0051] FIG. 2 illustrates the LTE time-domain structure;
[0052] FIG. 3 illustrates a downlink system with 3 orthogonal
frequency division multiplexing (OFDM) symbols as control for
LTE;
[0053] FIG. 4 illustrates an example spatial multiplexing
operation;
[0054] FIGS. 5A-5C illustrate resource element grids;
[0055] FIG. 6 illustrates semi-persistent channel state information
reference signal (CSI-RS) transmitted for a limited time
duration;
[0056] FIG. 7 illustrates an example of medium access control
control element (MAC CE) based dynamic allocation signaling for
beginning semi-persistent CSI-RS transmission;
[0057] FIG. 8 illustrates an example of MAC CE based dynamic
deallocation signaling for stopping semi-persistent CSI-RS
transmission;
[0058] FIG. 9 illustrates the problems for the combination of
semi-persistent CSI-RS measurement with semi-persistent channel
state information (CSI) reporting;
[0059] FIG. 10 illustrates example reliable downlink control
information (DCI) based dynamic allocation for semi-persistent
CSI-RS with aperiodic CSI reporting, according to certain
embodiments;
[0060] FIG. 11 illustrates example reliable DCI based dynamic
allocation for semi-persistent CSI-RS with semi-persistent CSI
reporting, according to certain embodiments;
[0061] FIG. 12 illustrates example reliable DCI based dynamic
deallocation for semi-persistent CSI-RS with semi-persistent CSI
reporting, according to certain embodiments;
[0062] FIG. 13 illustrates an example network for reliable dynamic
indication for semi-persistent CSI-RS, according to certain
embodiments;
[0063] FIG. 14 illustrates an example wireless device for
facilitating reliable dynamic indication for semi-persistent
CSI-RS, according to certain embodiments;
[0064] FIG. 15 illustrates an example method for initiating
semi-persistent CSI measurements on a CSI-RS resource configured by
higher layers, according to certain embodiments;
[0065] FIG. 16 illustrates an example method for terminating
semi-persistent CSI measurements on a CSI-RS resource configured by
higher layers, according to certain embodiments;
[0066] FIG. 17 illustrates an example method by a wireless device
for facilitating reliable dynamic indication for semi-persistent
CSI-RS, according to certain embodiments;
[0067] FIG. 18 illustrate an example network node for reliable
dynamic indication for semi-persistent CSI-RS, according to certain
embodiments;
[0068] FIG. 19 illustrates an example method by a network node for
initiating semi-persistent CSI measurements on a CSI-RS resource
configured by higher layers, according to certain embodiments;
[0069] FIG. 20 illustrates an example method by a network node for
terminating semi-persistent CSI measurements on a CSI-RS resource
configured by higher layers, according to certain embodiments;
and
[0070] FIG. 21 illustrates an exemplary radio network controller or
core network node reliable dynamic indication for semi-persistent
CSI-RS, according to certain embodiments.
DETAILED DESCRIPTION
[0071] Particular embodiments of the present disclosure may provide
solutions reliable dynamic indication for semi-persistent channel
state information reference signal (CSI-RS). Specifically, certain
embodiments may provide reliable downlink control information (DCI)
based dynamic allocation/deallocation for semi-persistent CSI-RS
measurements. In some such embodiments, semi-persistent CSI-RS
measurements in the wireless device is initiated with dynamic DCI
based allocation signaling. To ensure reliability, in one
embodiment, after a wireless device receives the DCI based dynamic
allocation of semi-persistent CSI-RS from the gNodeB (gNB), the
wireless device measures the first instance of the semi-persistent
CSI-RS and the wireless device sends a first aperiodic channel
state information (CSI) report based on the first measurement to
the gNB. By contrast, according to previous reporting systems, a
wireless device configured to have Aperiodic CSI reporting would
begin measurements in response to successfully receiving a
semi-persistent allocation but not transmit the CSI report until it
receives an Aperiodic CSI trigger. According to embodiments
described herein, however, the first aperiodic CSI report is
triggered by the semi-persistent CSI-RS allocation trigger. The gNB
can use this first aperiodic CSI report to verify that the UE
received the dynamic allocation DCI indication successfully.
[0072] According to certain other embodiments, a separate aperiodic
CSI measurement report trigger may be sent from gNB to the wireless
device after the semi-persistent CSI-RS measurement trigger so that
the gNB can use the CSI report to verify the successful reception
of the semi-persistent CSI-RS trigger by the wireless device.
[0073] According to still another embodiment, semi-persistent CSI
reporting may be triggered in the wireless device by the gNB
simultaneously with the same DCI as the semi-persistent CSI-RS
measurement, then the gNB can use the semi-persistent CSI reports
to verify whether the UE has received the trigger correctly.
[0074] Accordingly, in an example embodiment, to ensure reliability
of DCI based dynamic deallocation to stop semi-persistent CSI-RS
measurements, a mechanism is used where after receiving the DCI
based dynamic deallocation of semi-persistent CSI-RS from the gNB,
the wireless device stops measuring semi-persistent CSI-RS. If the
wireless device received the DCI based dynamic deallocation
indication successfully, the wireless device may not send further
semi-persistent CSI reports after DCI based dynamic deallocation
indication (i.e., since semi-persistent CSI-RS measurements have
been stopped by the DCI based dynamic deallocation indication).
Thus, not receiving further semi-persistent CSI reports can be used
by the gNB to verify that the wireless device received the dynamic
deallocation DCI indication successfully. Alternatively stated,
from the gNB perspective, receiving further semi-persistent CSI
reports after DCI based dynamic deallocation indication is a
negative acknowledgement that the dynamic deallocation DCI
indication was received successfully. The gNB may then react by
initiating a retransmission of the deallocation indication.
[0075] Particular embodiments are described in FIGS. 10-21 of the
drawings, like numerals being used for like and corresponding parts
of the various drawings. FIG. 10 illustrates example reliable DCI
based dynamic allocation for semi-persistent CSI-RS with aperiodic
CSI reporting, according to certain embodiments. Specifically, to
ensure reliability of DCI based dynamic allocation to start
measurement in the wireless device on semi-persistent CSI-RS, and
possibly also to start CSI-RS transmissions from gNB, a mechanism
is used. Note that triggering a measurement in the wireless device
does not necessarily imply that a CSI-RS transmission is initiated,
the CSI-RS may be present in earlier slots as well, used for
measurements by other served wireless device. Thus, when describing
triggering of a measurement in the wireless device, it could mean
that gNB starts transmitting the corresponding CSI-RS or it could
mean that gNB simply continues to transmit that CSI-RS if that
CSI-RS has been initiated earlier. In this mechanism, gNB sends a
DCI (possibly over physical downlink control channel (PDCCH)) with
an indication of starting a semi-persistent CSI-RS measurement. The
indication may be included in an uplink data grant. In some cases,
the first CSI-RS measurement (and thus a CSI-RS transmission) may
occur in the same subframe or slot as the PDCCH. After receiving
the DCI based dynamic allocation of semi-persistent CSI-RS from the
gNB, the wireless device measures the first instance of the
semi-persistent CSI-RS transmission and sends a first aperiodic CSI
report based on the first measurement to the gNB over the uplink
resources allocated in the uplink data grant. The gNB may use this
first aperiodic CSI report to verify that the wireless device
received the dynamic allocation DCI indication successfully. If the
gNB does not receive the aperiodic CSI report nor has a CSI
decoding error after sending the dynamic allocation via DCI, then
the gNB assumes that the wireless device has not received the
dynamic DCI allocation successfully and retransmits the dynamic DCI
allocation to the wireless device.
[0076] If the first aperiodic CSI report is received correctly and
the DCI based dynamic allocation signal is deemed successfully
received by the wireless device, then the gNB transmission and
wireless device measurements of semi-persistent CSI-RS continues
with preconfigured periodicity as shown in FIG. 10. Thus, as shown
in FIG. 10, only the first aperiodic CSI report is triggered by the
DCI based dynamic allocation signal, and separate aperiodic CSI
triggers will trigger subsequent aperiodic CSI reports. That is,
the DCI based dynamic allocation signals both the start of the
semi-persistent CSI-RS measurement and also a request for the first
aperiodic CSI report.
[0077] The DCI used for the dynamic allocation includes as least
some of the following fields: [0078] Indication of semi-persistent
CSI-RS measurement initiation [0079] Indication of semi-persistent
CSI-RS configuration index/indices [0080] Uplink resource
allocation and associated modulation and coding rate
[0081] In certain other embodiments, the semi-persistent CSI-RS
measurement (and possible initiation of the transmission from gNB
if the CSI-RS not already being transmitted) is combined with
semi-persistent CSI reporting. FIG. 11 illustrates reliable DCI
based dynamic allocation where semi-persistent CSI-RS measurement
and the semi-persistent CSI report are triggered by different DCI
indications. In this case, to ensure reliability of DCI based
dynamic allocation to start semi-persistent CSI-RS measurement, a
single-shot CSI report that follows immediately after the first
instance of the semi-persistent CSI-RS measurement can be used by
the gNB to verify that the wireless device received the dynamic
allocation DCI successfully. This single-shot CSI report captures
the wireless device's measurement of the first instance of the
semi-persistent CSI-RS transmission. If the gNB does not receive
the single-shot CSI report after sending the dynamic allocation via
DCI, then the gNB assumes that the wireless device has not received
the dynamic DCI allocation successfully and retransmits the dynamic
DCI allocation to the wireless device. As shown in FIG. 11, only
the single-shot CSI report is triggered by the DCI based dynamic
allocation signal, and a separate semi-persistent CSI trigger
initiates the semi-persistent CSI reports. That is, the DCI based
dynamic allocation signal both starts the semi-persistent CSI-RS
measurements (and possibly initiate the gNB transmission of CSI-RS)
and also triggers the single-shot CSI report.
[0082] In still another embodiment, semi-persistent CSI-RS
measurement and semi-persistent CSI reporting may be triggered or
activated using a single DCI. In this case, semi-persistent CSI-RS
measurement is triggered by the DCI in the same way as in
embodiments 2 and 3. However, semi-persistent CSI reporting is also
activated by the same DCI. For example, when a wireless device
receives the DCI, it assumes that a semi-persistent CSI-RS
transmission starts in the same subframe or slot as the one over
which the DCI is received and the UE starts measuring CSI based on
the configured CSI-RS and reports CSI periodically according the
configured reporting periodicity and subframe or slot offsets. If
the gNB receives CSI at the configured subframes or slots
successfully from the wireless device, then the semi-persistent
CSI-RS measurement is initiated successfully, otherwise if the gNB
did not detect the expected CSI reports successfully, then the
initiation is not successful and another DCI would be sent to the
UE to initiate semi-persistent CSI-RS measurements.
[0083] Mechanisms may also be used to ensure reliability of DCI
based dynamic deallocation to stop semi-persistent CSI-RS
measurements (and possibly also to stop CSI-RS transmissions from
the gNB in case no other wireless device is measuring on this
CSI-RS). FIG. 12 illustrates reliable DCI based dynamic
deallocation for semi-persistent CSI-RS with semi-persistent CSI
reporting. According to the depicted embodiment, after receiving
the DCI based dynamic deallocation of semi-persistent CSI-RS from
the gNB, the wireless device assumes that the semi-persistent
CSI-RS transmission has been stopped after the subframe or slot
over which the DCI is received and, thus, stops measuring
semi-persistent CSI-RS. If the wireless device received the DCI
based dynamic deallocation indication successfully, the wireless
device will not send further semi-persistent CSI reports after DCI
based dynamic deallocation indication (i.e., since semi-persistent
CSI-RS transmissions have been stopped by the DCI based dynamic
deallocation indication). As such, not receiving further
semi-persistent CSI reports can be used by the gNB to verify that
the wireless device received the dynamic deallocation DCI
indication successfully. Alternatively stated, from the gNB
perspective, receiving further semi-persistent CSI reports after
DCI based dynamic deallocation indication is a negative
acknowledgement that the dynamic deallocation DCI indication was
received successfully. If the gNB does receive further
semi-persistent CSI reports after sending the dynamic deallocation
via DCI, then the gNB assumes that the wireless device has not
received the dynamic DCI deallocation successfully and retransmits
the dynamic DCI deallocation to the wireless device. Both "not
receiving further semi-persistent CSI reports" and "receive further
semi-persistent CSI reports" can be indicated by whether CSI
reports are decoded correctly or incorrectly. Multiple report
instances may be monitored to ensure detection reliability.
[0084] FIG. 13 is a block diagram illustrating an embodiment of a
wireless network 100 for reliable dynamic indication for
semi-persistent CSI-RS, in accordance with certain embodiments.
Network 100 includes one or more wireless devices 110A-C, which may
be interchangeably referred to as wireless devices 110 or UEs 110,
and network nodes 115A-C, which may be interchangeably referred to
as network nodes 115 or eNodeBs 115. A wireless device 110 may
communicate with network nodes 115 over a wireless interface. For
example, wireless device 110A may transmit wireless signals to one
or more of network nodes 115, and/or receive wireless signals from
one or more of network nodes 115. The wireless signals may contain
voice traffic, data traffic, control signals, and/or any other
suitable information. In some embodiments, an area of wireless
signal coverage associated with a network node 115 may be referred
to as a cell. In some embodiments, wireless devices 110 may have
device to device (D2D) capability. Thus, wireless devices 110 may
be able to receive signals from and/or transmit signals directly to
another wireless device 110. For example, wireless device 110A may
be able to receive signals from and/or transmit signals to wireless
device 110B.
[0085] In certain embodiments, network nodes 115 may interface with
a radio network controller (not depicted in FIG. 13). The radio
network controller may control network nodes 115 and may provide
certain radio resource management functions, mobility management
functions, and/or other suitable functions. In certain embodiments,
the functions of the radio network controller may be included in
network node 115. The radio network controller may interface with a
core network node. In certain embodiments, the radio network
controller may interface with the core network node via an
interconnecting network. The interconnecting network may refer to
any interconnecting system capable of transmitting audio, video,
signals, data, messages, or any combination of the preceding. The
interconnecting network may include all or a portion of a public
switched telephone network (PSTN), a public or private data
network, a local area network (LAN), a metropolitan area network
(MAN), a wide area network (WAN), a local, regional, or global
communication or computer network such as the Internet, a wireline
or wireless network, an enterprise intranet, or any other suitable
communication link, including combinations thereof.
[0086] In some embodiments, the core network node may manage the
establishment of communication sessions and various other
functionalities for wireless devices 110. Wireless devices 110 may
exchange certain signals with the core network node using the
non-access stratum layer. In non-access stratum signaling, signals
between wireless devices 110 and the core network node may be
transparently passed through the radio access network. In certain
embodiments, network nodes 115 may interface with one or more
network nodes over an internode interface. For example, network
nodes 115A and 115B may interface over an X2 interface.
[0087] As described above, example embodiments of network 100 may
include one or more wireless devices 110, and one or more different
types of network nodes capable of communicating (directly or
indirectly) with wireless devices 110. Wireless device 110 may
refer to any type of wireless device communicating with a node
and/or with another wireless device in a cellular or mobile
communication system. Examples of wireless device 110 include a
mobile phone, a smart phone, a PDA (Personal Digital Assistant), a
portable computer (e.g., laptop, tablet), a sensor, a modem, a
machine-type-communication (MTC) device/machine-to-machine (M2M)
device, laptop embedded equipment (LEE), laptop mounted equipment
(LME), USB dongles, a D2D capable device, or another device that
can provide wireless communication. A wireless device 110 may also
be referred to as UE, a station (STA), a device, or a terminal in
some embodiments. Also, in some embodiments, generic terminology,
"radio network node" (or simply "network node") is used. It can be
any kind of network node, which may comprise a Node B, base station
(BS), multi-standard radio (MSR) radio node such as MSR BS, eNode
B, network controller, radio network controller (RNC), base station
controller (BSC), relay donor node controlling relay, base
transceiver station (BTS), access point (AP), transmission points,
transmission nodes, RRU, RRH, nodes in distributed antenna system
(DAS), core network node (e.g. MSC, MME etc.), O&M, OSS, SON,
positioning node (e.g. E-SMLC), MDT, or any suitable network node.
Example embodiments of wireless devices 110, network nodes 115, and
other network nodes (such as radio network controller or core
network node) are described in more detail with respect to FIGS.
14, 18, and 21, respectively.
[0088] Although FIG. 13 illustrates a particular arrangement of
network 100, the present disclosure contemplates that the various
embodiments described herein may be applied to a variety of
networks having any suitable configuration. For example, network
100 may include any suitable number of wireless devices 110 and
network nodes 115, as well as any additional elements suitable to
support communication between wireless devices or between a
wireless device and another communication device (such as a
landline telephone). Furthermore, although certain embodiments may
be described as implemented in a LTE network, the embodiments may
be implemented in any appropriate type of telecommunication system
supporting any suitable communication standards and using any
suitable components, and are applicable to any radio access
technology (RAT) or multi-RAT systems in which the wireless device
receives and/or transmits signals (e.g., data). For example, the
various embodiments described herein may be applicable to LTE,
LTE-Advanced, LTE-U Universal Mobile Telecommunications System
(UMTS), High Speed Packet Access (HSPA), Global System for Mobile
Communications (GSM), cdma2000, WiMax, WiFi, another suitable radio
access technology, or any suitable combination of one or more radio
access technologies. Although certain embodiments may be described
in the context of wireless transmissions in the downlink, the
present disclosure contemplates that the various embodiments are
equally applicable in the uplink and vice versa.
[0089] The techniques described herein are applicable to both
Licensed Assisted Access (LAA) LTE and standalone LTE operation in
license-exempt channels. The described techniques are generally
applicable for transmissions from both network nodes 115 and
wireless devices 110.
[0090] FIG. 14 illustrates an example wireless device 110 reliable
dynamic indication for semi-persistent CSI-RS, in accordance with
certain embodiments. As depicted, wireless device 210 includes
transceiver 210, processing circuitry 220, and memory 230. In some
embodiments, transceiver 210 facilitates transmitting wireless
signals to and receiving wireless signals from network node 115
(e.g., via an antenna 240), processing circuitry 220 executes
instructions to provide some or all of the functionality described
above as being provided by wireless device 110, and memory 230
stores the instructions executed by processing circuitry 220.
Examples of a wireless device 110 are provided above.
[0091] Processing circuitry 220 may include any suitable
combination of hardware and software implemented in one or more
modules to execute instructions and manipulate data to perform some
or all of the described functions of wireless device 110. In some
embodiments, processing circuitry 220 may include, for example, one
or more computers, one or more central processing units (CPUs), one
or more processors, one or more microprocessors, one or more
applications, and/or other logic.
[0092] Memory 230 is generally operable to store instructions, such
as a computer program, software, an application including one or
more of logic, rules, algorithms, code, tables, etc. and/or other
instructions capable of being executed by processing circuitry.
Examples of memory 230 include computer memory (for example, Random
Access Memory (RAM) or Read Only Memory (ROM)), mass storage media
(for example, a hard disk), removable storage media (for example, a
Compact Disk (CD) or a Digital Video Disk (DVD)), and/or or any
other volatile or non-volatile, non-transitory computer-readable
and/or computer-executable memory devices that store
information.
[0093] Other embodiments of wireless device 110 may include
additional components beyond those shown in FIG. 14 that may be
responsible for providing certain aspects of the wireless device's
functionality, including any of the functionality described above
and/or any additional functionality (including any functionality
necessary to support the solution described above).
[0094] FIG. 15 illustrates an example method by a wireless device
110 for initiating semi-persistent CSI measurements on a CSI-RS
resource configured by higher layers, according to certain
embodiments. The method begins at step 304 when wireless device 110
receives, from network node 115, a dynamic allocation trigger to
commence measurement of a semi-persistent CSI-RS resource. At step
306, a first measurement of the CSI-RS resource is performed. At
step 308, a first CSI report based only on the first measurement is
transmitted to the network node 115.
[0095] FIG. 16 illustrates an example method a wireless device 110
for terminating semi-persistent CSI measurements on a CSI-RS
resource configured by higher layers, according to certain
embodiments. The method begins at step 404 when wireless device 110
receives, from a network node, a dynamic deallocation trigger to
terminate semi-persistent measurements on a CSI-RS resource. At
step 406, wireless device 110 terminates the semi-persistent
measurements on the CSI-RS resource.
[0096] FIG. 17 illustrates an example method by a wireless device
110, according to certain embodiments. The method begins at step
502 when wireless device 110 receives, from a network node 115,
dynamic allocation signaling to commence measurement on a
semi-persistent CSI-RS resource. According to certain embodiments,
the semi-persistent CSI-RS resource includes a CSI-RS resource that
is configured with at least a CSI-RS transmission periodicity and
for which at least one UE assumption on transmission and cessation
of CSI-RS transmission applies. As another example, the
semi-persistent CSI-RS resource may be configured for transmission
of CSI-RS at a configured periodicity for a limited time duration
and receipt of the dynamic allocation may be required to trigger to
transmission of the semi-persistent CSI-RS on the semi-persistent
CSI-RS resource.
[0097] According to certain embodiments, the dynamic allocation
signaling initiates semi-persistent CSI measurements on the CSI-RS
resource and also trigger the first CSI report. In a particular
embodiment, the dynamic allocation signaling includes at least one
of an indication of semi-persistent CSI-RS measurement initiation,
an indication of semi-persistent CSI-RS resource configuration
index/indices, and an uplink resource allocation and associated
modulation and coding rate. In a particular embodiment, the dynamic
allocation signaling comprises a MAC CE.
[0098] At step 504, wireless device 110 performs a first
measurement on the semi-persistent CSI-RS resource. Wireless device
110 transmits, to the network node 115, a first CSI report based
only on the first measurement at step 506. In a particular
embodiment, the first CSI report is an aperiodic report. In another
embodiment, the first CSI report is a semi-persistent report.
[0099] At step 508, wireless device 110 receives, from the network
node 115, a trigger message that is different than the dynamic
allocation signaling of step 502. According to certain embodiments,
the trigger message triggers semi-persistent CSI reporting.
According to a particular embodiment, for example, the trigger
message includes DCI.
[0100] At step 510, wireless device 110 initiates semi-persistent
reporting in response to the trigger message. According to a
particular embodiment, wireless device 110 may transmit a plurality
of semi-persistent CSI reports.
[0101] According to a particular embodiment, wireless device 110
may cease transmission of the semi-persistent CSI-RS reports after
a predetermined length of time. In other embodiments, wireless
device 110 may receive dynamic deallocation signaling to terminate
the measurement of on the semi-persistent CSI-RS resource and cease
the semi-persistent measurements on the semi-persistent CSI-RS
resource in response to the dynamic deallocation trigger.
[0102] FIG. 18 illustrate an example network node 115 for reliable
dynamic indication for semi-persistent CSI-RS, according to certain
embodiments. As described above, network node 115 may be any type
of radio network node or any network node that communicates with a
wireless device and/or with another network node. Examples of a
network node 115 are provided above.
[0103] Network nodes 115 may be deployed throughout network 100 as
a homogenous deployment, heterogeneous deployment, or mixed
deployment. A homogeneous deployment may generally describe a
deployment made up of the same (or similar) type of network nodes
115 and/or similar coverage and cell sizes and inter-site
distances. A heterogeneous deployment may generally describe
deployments using a variety of types of network nodes 115 having
different cell sizes, transmit powers, capacities, and inter-site
distances. For example, a heterogeneous deployment may include a
plurality of low-power nodes placed throughout a macro-cell layout.
Mixed deployments may include a mix of homogenous portions and
heterogeneous portions.
[0104] Network node 115 may include one or more of transceiver 610,
processing circuitry 620, memory 630, and network interface 640. In
some embodiments, transceiver 610 facilitates transmitting wireless
signals to and receiving wireless signals from wireless device 110
(e.g., via an antenna 650), processing circuitry 620 executes
instructions to provide some or all of the functionality described
above as being provided by a network node 115, memory 630 stores
the instructions executed by processing circuitry 620, and network
interface 640 communicates signals to backend network components,
such as a gateway, switch, router, Internet, Public Switched
Telephone Network (PSTN), core network nodes or radio network
controllers, etc.
[0105] In certain embodiments, network node 115 may be capable of
using multi-antenna techniques, and may be equipped with multiple
antennas and capable of supporting MIMO techniques. The one or more
antennas may have controllable polarization. In other words, each
element may have two co-located sub elements with different
polarizations (e.g., 90 degree separation as in
cross-polarization), so that different sets of beamforming weights
will give the emitted wave different polarization.
[0106] Processing circuitry 620 may include any suitable
combination of hardware and software implemented in one or more
modules to execute instructions and manipulate data to perform some
or all of the described functions of network node 115. In some
embodiments, processing circuitry 620 may include, for example, one
or more computers, one or more central processing units (CPUs), one
or more microprocessors, one or more applications, and/or other
logic.
[0107] Memory 630 is generally operable to store instructions, such
as a computer program, software, an application including one or
more of logic, rules, algorithms, code, tables, etc. and/or other
instructions capable of being executed by a processor. Examples of
memory 630 include computer memory (for example, Random Access
Memory (RAM) or Read Only Memory (ROM)), mass storage media (for
example, a hard disk), removable storage media (for example, a
Compact Disk (CD) or a Digital Video Disk (DVD)), and/or or any
other volatile or non-volatile, non-transitory computer-readable
and/or computer-executable memory devices that store
information.
[0108] In some embodiments, network interface 640 is
communicatively coupled to processing circuitry 620 and may refer
to any suitable device operable to receive input for network node
115, send output from network node 115, perform suitable processing
of the input or output or both, communicate to other devices, or
any combination of the preceding. Network interface 640 may include
appropriate hardware (e.g., port, modem, network interface card,
etc.) and software, including protocol conversion and data
processing capabilities, to communicate through a network.
[0109] Other embodiments of network node 115 may include additional
components beyond those shown in FIG. 18 that may be responsible
for providing certain aspects of the radio network node's
functionality, including any of the functionality described above
and/or any additional functionality (including any functionality
necessary to support the solutions described above). The various
different types of network nodes may include components having the
same physical hardware but configured (e.g., via programming) to
support different radio access technologies, or may represent
partly or entirely different physical components. Additionally, the
terms first and second are provided for example purposes only and
may be interchanged.
[0110] FIG. 19 illustrates an example method for initiating
semi-persistent CSI measurements on a CSI-RS resource configured by
higher layers, according to certain embodiments. The method begins
at step 702 when network node 115 transmits, to the wireless device
110, dynamic allocation signaling to initiate measurement on a
semi-persistent CSI-RS resource. According to certain embodiments,
the semi-persistent CSI-RS resource includes a CSI-RS resource that
is configured with at least a CSI-RS transmission periodicity and
for which at least one UE assumption on transmission and cessation
of CSI-RS transmission applies. As another example, the
semi-persistent CSI-RS resource may be configured for transmission
of CSI-RS at a configured periodicity for a limited time duration
and receipt of the dynamic allocation may be required to trigger to
transmission of the semi-persistent CSI-RS on the semi-persistent
CSI-RS resource.
[0111] In a particular embodiment, the dynamic allocation signaling
includes at least one of an indication of semi-persistent CSI-RS
measurement initiation, an indication of semi-persistent CSI-RS
resource configuration index/indices, and an uplink resource
allocation and associated modulation and coding rate. In a
particular embodiment, the dynamic allocation signaling comprises a
MAC CE.
[0112] At step 704, it is determined whether a first CSI report is
transmitted by wireless device 110 in response to the dynamic
allocation signaling.
[0113] At step 706, network node 115 takes an action based on
whether the first CSI report is transmitted by wireless device 110
in response to the dynamic allocation signaling.
[0114] In certain embodiments, determining whether a first CSI
report is transmitted by wireless device 110 may include
determining that the first CSI report was received by network node
115. The first CSI report may indicate to network node 115 that
wireless device 110 successfully received the dynamic allocation
signaling. Thus, network node may continue transmission of
semi-persistent CSI-RS with preconfigured periodicity.
[0115] In certain other embodiments determining whether a first CSI
report is transmitted by wireless device 110 may include
determining that the first CSI report was not received by network
node 115. Not receiving the first CSI report may indicate to
network node 115 that wireless device 110 did not successfully
receive the dynamic allocation signaling. Thus, network node 115
may retransmit the dynamic allocation signaling to wireless device
110.
[0116] According to a particular embodiment, wireless device 110
may cease transmission of the semi-persistent CSI-RS reports after
a predetermined length of time. In other embodiments, network node
115 may transmit dynamic deallocation signaling to terminate the
measurement of on the semi-persistent CSI-RS resource by the
wireless device 110. Additionally, network node 115 may determine
whether a second CSI report is transmitted by the wireless device
in response to the dynamic deallocation signaling and take an
action based on whether the second CSI report is transmitted by the
wireless device in response to the dynamic allocation
signaling.
[0117] FIG. 20 illustrates an example method by network node 115
for terminating semi-persistent CSI measurements on a CSI-RS
resource configured by higher layers, according to certain
embodiments. The method begins at step 802 when network node 115
transmits to wireless device 110 dynamic deallocation signaling to
terminate measurement on a semi-persistent CSI-RS resource. In a
particular embodiment, the dynamic deallocation signaling may
include DCI.
[0118] At step 806, network node 115 determines whether a second
CSI report is transmitted by wireless device 110 in response to the
dynamic deallocation signaling. At step 808, network node 115 takes
an action based on whether the second CSI report is received in
response to the dynamic deallocation signaling.
[0119] In certain embodiments, it may be determined that the second
CSI report was received. Receipt of the second CSI report may
indicate to network node 115 that wireless device 110 did not
receive the dynamic deallocation signaling. Thus, network node 115
may take further action to retransmit the dynamic deallocation
signaling.
[0120] In certain embodiments, it may be determined that the second
CSI report was not received. Failure to receive a second CSI report
may indicate to network node 115 that wireless device 110
successfully received the dynamic deallocation signaling. Thus,
network node 115 may take further action by terminating periodic
transmission of CSI-RS.
[0121] FIG. 21 illustrates an exemplary radio network controller or
core network node 900, in accordance with certain embodiments.
Examples of network nodes can include a mobile switching center
(MSC), a serving GPRS support node (SGSN), a mobility management
entity (MME), a radio network controller (RNC), a base station
controller (BSC), and so on. The radio network controller or core
network node 900 include processor or processing circuitry 920,
memory 930, and network interface 940. In some embodiments,
processor 920 executes instructions to provide some or all of the
functionality described above as being provided by the network
node, memory 930 stores the instructions executed by processor 920,
and network interface 940 communicates signals to any suitable
node, such as a gateway, switch, router, Internet, Public Switched
Telephone Network (PSTN), network nodes 115, radio network
controllers or core network nodes 900, etc.
[0122] Processor 920 may include any suitable combination of
hardware and software implemented in one or more modules to execute
instructions and manipulate data to perform some or all of the
described functions of the radio network controller or core network
node 900. In some embodiments, processor 920 may include, for
example, one or more computers, one or more central processing
units (CPUs), one or more microprocessors, one or more
applications, and/or other logic.
[0123] Memory 930 is generally operable to store instructions, such
as a computer program, software, an application including one or
more of logic, rules, algorithms, code, tables, etc. and/or other
instructions capable of being executed by a processor. Examples of
memory 930 include computer memory (for example, Random Access
Memory (RAM) or Read Only Memory (ROM)), mass storage media (for
example, a hard disk), removable storage media (for example, a
Compact Disk (CD) or a Digital Video Disk (DVD)), and/or or any
other volatile or non-volatile, non-transitory computer-readable
and/or computer-executable memory devices that store
information.
[0124] In some embodiments, network interface 940 is
communicatively coupled to processor 920 and may refer to any
suitable device operable to receive input for the network node,
send output from the network node, perform suitable processing of
the input or output or both, communicate to other devices, or any
combination of the preceding. Network interface 940 may include
appropriate hardware (e.g., port, modem, network interface card,
etc.) and software, including protocol conversion and data
processing capabilities, to communicate through a network.
[0125] Other embodiments of the network node may include additional
components beyond those shown in FIG. 21 that may be responsible
for providing certain aspects of the network node's functionality,
including any of the functionality described above and/or any
additional functionality (including any functionality necessary to
support the solution described above).
[0126] According to certain embodiments, a method in a wireless
device may be provided for initiating semi-persistent CSI
measurements on a CSI-RS resource configured by higher layers,
wherein the resource is used for CSI reporting, for which resource
the wireless device is not currently performing measurements. The
method may include: [0127] receiving, from a network node, a
dynamic allocation trigger to commence measurement of a
semi-persistent CSI-RS resource; [0128] performing a first
measurement of the CSI-RS resource; [0129] transmitting, to the
network, a first CSI report based only on the first measurement;
[0130] optionally, the dynamic allocation trigger initiates
semi-persistent CSI measurements on the CSI-RS resource and also
triggers the first CSI report; [0131] optionally, the CSI reporting
except for the first CSI report is triggered by a trigger message
different than the dynamic allocation trigger message; [0132]
optionally, the CSI report is an aperiodic report; [0133]
optionally, the CSI report is a semi-persistent report; [0134]
optionally, semi-persistent CSI-RS are transmitted for a
predetermined length of time, and semi-persistent CSI-RS
transmissions cease after the predetermined length of time, and the
UE stops providing CSI reports corresponding to the semi-persistent
CSI-RS; [0135] optionally, the dynamic allocation trigger comprises
at least one of the following: an indication of semi-persistent
CSI-RS measurement initiation, an indication of semi-persistent
CSI-RS configuration index/indices, and an uplink resource
allocation and associated modulation and coding rate; [0136]
optionally, the method further includes receiving a dynamic
deallocation trigger for the semi-persistent CSI-RS and ceasing
transmission of CSI reports corresponding to the semi-persistent
CSI-RS after receiving the dynamic deallocation trigger.
[0137] According to certain embodiments, a wireless device is
provided for initiating semi-persistent CSI measurements on a
CSI-RS resource configured by higher layers, wherein the resource
is used for CSI reporting, for which resource the wireless device
is not currently performing measurements. The wireless device may
include: [0138] a memory storing instructions; and [0139]
processing circuitry operable to execute the instructions to cause
the processing circuitry to: [0140] receive, from a network node, a
dynamic allocation trigger to commence measurement of a
semi-persistent CSI-RS resource; [0141] perform a first measurement
of the CSI-RS resource; and [0142] transmit, to the network, a
first CSI report based only on the first measurement; [0143]
optionally, the dynamic allocation trigger initiates
semi-persistent CSI measurements on the CSI-RS resource and also
triggers the first CSI report; [0144] optionally, the CSI reporting
except for the first CSI report is triggered by a trigger message
different than the dynamic allocation trigger message; [0145]
optionally, the CSI report is an aperiodic report; [0146]
optionally, the CSI report is a semi-persistent report; [0147]
optionally, semi-persistent CSI-RS are transmitted for a
predetermined length of time, and semi-persistent CSI-RS
transmissions cease after the predetermined length of time, and the
processing circuitry is operable to stop providing CSI reports
corresponding to the semi-persistent CSI-RS; [0148] optionally, the
dynamic allocation trigger comprises at least one of the following:
an indication of semi-persistent CSI-RS measurement initiation, an
indication of semi-persistent CSI-RS configuration index/indices,
and an uplink resource allocation and associated modulation and
coding rate;
[0149] According to certain embodiments, method in a wireless
device for terminating semi-persistent CSI measurements on a CSI-RS
resource configured by higher layers, wherein the resource is used
for CSI reporting, for which resource the wireless device is
currently performing measurements. The method may include [0150]
receiving a dynamic deallocation trigger to terminate
semi-persistent measurements on a CSI-RS resource; and [0151]
terminating the semi-persistent measurements on the CSI-RS
resource.
[0152] According to certain embodiments, a wireless device for
terminating semi-persistent CSI measurements on a CSI-RS resource
configured by higher layers, wherein the resource is used for CSI
reporting, for which resource the wireless device is currently
performing measurements, the wireless device comprising: [0153] a
memory storing instructions; and [0154] processing circuitry
operable to execute the instructions to cause the processing
circuitry to: [0155] receive, from a network node, a dynamic
deallocation trigger to terminate semi-persistent measurements on a
CSI-RS resource; [0156] terminate, the semi-persistent measurements
on the CSI-RS resource.
[0157] According to certain embodiments, a method in a network node
for initiating semi-persistent CSI measurements on a CSI-RS
resource by a wireless device configured by higher layers, wherein
the resource is used for CSI reporting, for which resource the
wireless device is not currently performing measurements. The
method may include [0158] transmitting, to the wireless device, a
dynamic allocation trigger to initiate measurement of a
semi-persistent CSI-RS resource; [0159] determining whether a first
CSI report is received in response to the dynamic allocation
trigger; and [0160] taking an action based on whether the first CSI
report is received in response to the dynamic allocation trigger;
[0161] optionally, it may be determined the first CSI report was
received, indicating that the wireless device successfully received
the dynamic allocation trigger, and taking the action further
comprises continue transmission of semi-persistent CSI-RS with
preconfigured periodicity; [0162] optionally, it may be determined
that the first CSI report was not received, indicating that the
wireless device did not receive the dynamic allocation trigger; and
taking the action further comprises retransmitting the dynamic
allocation trigger to the wireless device.
[0163] According to certain embodiments, a network node for
initiating semi-persistent CSI measurements on a CSI-RS resource by
a wireless device configured by higher layers, wherein the resource
is used for CSI reporting, for which resource the wireless device
is not currently performing measurements. The network node may
include: [0164] a memory storing instructions; and [0165]
processing circuitry operable to execute the instructions to cause
the processing circuitry to: [0166] transmit, to the wireless
device, a dynamic allocation trigger to initiate measurement of a
semi-persistent CSI-RS resource; [0167] determine whether a first
CSI report is received in response to the dynamic allocation
trigger; and [0168] take an action based on whether the first CSI
report is received in response to the dynamic allocation trigger.
[0169] optionally, it may be determined the first CSI report was
received, indicating that the wireless device successfully received
the dynamic allocation trigger, and taking the action further
comprises continue transmission of semi-persistent CSI-RS with
preconfigured periodicity; [0170] optionally, it may be determined
that the first CSI report was not received, indicating that the
wireless device did not receive the dynamic allocation trigger; and
taking the action further comprises retransmitting the dynamic
allocation trigger to the wireless device.
[0171] According to certain embodiments, a method in a network node
for terminating semi-persistent CSI measurements on a CSI-RS
resource by a wireless device configured by higher layers, wherein
the resource is used for CSI reporting, for which resource the
wireless device is currently performing measurements. The method
may include: [0172] transmitting, to the wireless device, a dynamic
deallocation trigger to terminate measurement of a semi-persistent
CSI-RS resource; and [0173] determining whether a first CSI report
is received in response to the dynamic deallocation trigger; and
[0174] taking an action based on whether the first CSI report is
received in response to the dynamic deallocation trigger; [0175]
optionally, it may be determined the first CSI report was received,
indicating that the wireless device did not receive the dynamic
deallocation trigger, and taking the action may include
retransmitting the dynamic deallocation trigger; [0176] optionally,
it may be determined that the first CSI report was not received,
indicating that the wireless device received the dynamic allocation
trigger; and [0177] taking the action may include terminating
periodic transmission of CSI-RS.
[0178] According to certain embodiments, a network node for
terminating semi-persistent CSI measurements on a CSI-RS resource
by a wireless device configured by higher layers, wherein the
resource is used for CSI reporting, for which resource the wireless
device is currently performing measurements. The network node
[0179] a memory storing instructions; and [0180] processing
circuitry operable to execute the instructions to cause the
processing circuitry to: [0181] transmit, to the wireless device, a
dynamic deallocation trigger to terminate measurement of a
semi-persistent CSI-RS resource; [0182] determine whether a first
CSI report is received in response to the dynamic deallocation
trigger; and [0183] take an action based on whether the first CSI
report is received in response to the dynamic deallocation trigger;
[0184] optionally, it may be determined the first CSI report was
received, indicating that the wireless device did not receive the
dynamic deallocation trigger, and taking the action may include
retransmitting the dynamic deallocation trigger; [0185] optionally,
it may be determined that the first CSI report was not received,
indicating that the wireless device received the dynamic allocation
trigger; and taking the action may include terminating periodic
transmission of CSI-RS.
[0186] Modifications, additions, or omissions may be made to the
systems and apparatuses described herein without departing from the
scope of the disclosure. The components of the systems and
apparatuses may be integrated or separated. Moreover, the
operations of the systems and apparatuses may be performed by more,
fewer, or other components. Additionally, operations of the systems
and apparatuses may be performed using any suitable logic
comprising software, hardware, and/or other logic. As used in this
document, "each" refers to each member of a set or each member of a
subset of a set.
[0187] Modifications, additions, or omissions may be made to the
methods described herein without departing from the scope of the
disclosure. The methods may include more, fewer, or other steps.
Additionally, steps may be performed in any suitable order.
[0188] Although this disclosure has been described in terms of
certain embodiments, alterations and permutations of the
embodiments will be apparent to those skilled in the art.
Accordingly, the above description of the embodiments does not
constrain this disclosure. Other changes, substitutions, and
alterations are possible without departing from the spirit and
scope of this disclosure, as defined by the following claims.
[0189] Abbreviations used in the preceding description include:
[0190] CRS--Cell-specific Reference Signal
[0191] CSI-RS--Channel State Information Reference Signal
[0192] gNB--NR base station node
[0193] HARQ--Hybrid Automatic Repeat-reQuest
[0194] NW--Network
[0195] PDCCH--Physical Downlink Control Channel
[0196] PRB--Physical Resource Block
[0197] RRC--Radio Resource Control
[0198] UE--User Equipment
* * * * *