U.S. patent application number 17/508585 was filed with the patent office on 2022-02-10 for user apparatus and transmission method.
This patent application is currently assigned to NTT DOCOMO, INC.. The applicant listed for this patent is NTT DOCOMO, INC.. Invention is credited to Satoshi Nagata, Shinpei Yasukawa, Qun Zhao.
Application Number | 20220046469 17/508585 |
Document ID | / |
Family ID | 1000005918101 |
Filed Date | 2022-02-10 |
United States Patent
Application |
20220046469 |
Kind Code |
A1 |
Yasukawa; Shinpei ; et
al. |
February 10, 2022 |
USER APPARATUS AND TRANSMISSION METHOD
Abstract
A user apparatus in a radio communication system supporting a
D2D technology, includes a message generating unit configured to
generate a message including a first segment and a second segment;
and a message transmitting unit configured to transmit, multiple
times, the message within a predetermined period, wherein
information reported by a plurality of the first segments
transmitted within the predetermined period by the message
transmitting unit, is not changed within the predetermined
period.
Inventors: |
Yasukawa; Shinpei; (Tokyo,
JP) ; Nagata; Satoshi; (Tokyo, JP) ; Zhao;
Qun; (Beijing, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NTT DOCOMO, INC. |
Tokyo |
|
JP |
|
|
Assignee: |
NTT DOCOMO, INC.
Tokyo
JP
|
Family ID: |
1000005918101 |
Appl. No.: |
17/508585 |
Filed: |
October 22, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16626691 |
Dec 26, 2019 |
11190976 |
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PCT/JP2017/024413 |
Jul 3, 2017 |
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17508585 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 28/04 20130101;
H04W 92/18 20130101; H04L 1/08 20130101 |
International
Class: |
H04W 28/04 20060101
H04W028/04; H04L 1/08 20060101 H04L001/08 |
Claims
1. A user apparatus in a radio communication system supporting a
D2D technology, the user apparatus comprising: a message generating
unit configured to generate a message including a first segment and
a second segment; and a message transmitting unit configured to
transmit, multiple times, the message within a predetermined
period, wherein information reported by a plurality of the first
segments transmitted within the predetermined period by the message
transmitting unit, is not changed within the predetermined
period.
2. The user apparatus according to claim 1, wherein the message
transmitting unit transmits control information including
scheduling information of the second segment, or control
information including scheduling information of the first segment
and the second segment, and the message.
3. The user apparatus according to claim 1, wherein the message
transmitting unit transmits the first segment by using a control
channel, and transmits the second segment using a data channel.
4. The user apparatus according to claim 1, wherein the message
transmitting unit transmits, multiple times, the message within the
predetermined period, by using a predetermined resource hopping
pattern or a resource hopping pattern set from a base station in
the radio communication system.
5. The user apparatus according to claim 1, wherein HARQ soft
combining is executed at another user apparatus, with respect to a
plurality of the first segments transmitted within the
predetermined period by the message transmitting unit.
6. A transmission method executed by a user apparatus in a radio
communication system supporting a D2D technology, the transmission
method comprising: a message generating step of generating a
message including a first segment and a second segment; and a
message transmitting step of transmitting, multiple times, the
message within a predetermined period, wherein information reported
by a plurality of the first segments transmitted within the
predetermined period at the message transmitting step, is not
changed within the predetermined period.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation application and,
thereby, claims benefit under 35 U.S.C. .sctn. 120 to U.S. patent
application Ser. No. 16/626,691 filed on Dec. 26, 2019, titled,
"USER APPARATUS AND TRANSMISSION METHOD," which is a national stage
application of PCT Application No. PCT/JP2017/024413, filed on Jul.
3, 2017. The contents of these applications are incorporated by
reference in their entirety.
TECHNICAL FIELD
[0002] The present invention relates to a user apparatus in a radio
communication system.
BACKGROUND ART
[0003] In LTE (Long Term Evolution) and successor systems of LTE
(for example, LTE-A (LTE Advanced) and NR (New Radio) (also
referred to as 5G)), a D2D (Device to Device) technology in which
user apparatuses directly communicate with each other without
involving a radio base station, is being studied.
[0004] D2D reduces the traffic between the user apparatus and the
base station, and enables communication between the user
apparatuses even when the base station becomes unable to
communicate in the event of a disaster, etc.
[0005] D2D is generally classified into D2D discovery (also
referred to as D2D detection) for finding other communicable user
apparatuses and D2D communication (also referred to as D2D direct
communication, inter-terminal direct communication, etc.) for user
apparatuses to directly communicate with each other. In the
following description, when D2D communication, D2D discovery, etc.,
are not particularly distinguished, these may be simply referred to
as D2D.
[0006] Note that in 3GPP (3rd Generation Partnership Project), D2D
is referred to as "sidelink"; however, in the present
specification, D2D, which is a more general term, is used. However,
sidelink is also used as necessary in the description of the
embodiment to be described later.
[0007] Furthermore, in 3GPP, studies are made to implement V2X
(Vehicle to Everything) by extending the above D2D function, and
the standardization is being advanced. Here, V2X is a part of ITS
(Intelligent Transport Systems), and as illustrated in FIG. 1, V2X
is a generic term of V2V (Vehicle to Vehicle) meaning a
communication mode performed between vehicles, V2I (Vehicle to
Infrastructure) meaning a communication mode performed between a
vehicle and a road-side unit (RSU) installed on the roadside, V2N
(Vehicle to Nomadic device) meaning a communication mode performed
between a vehicle and a mobile terminal of a driver, and V2P
(Vehicle to Pedestrian) meaning a communication mode between a
vehicle and a mobile terminal of a pedestrian.
[0008] In Rel-14 of LTE, standardization relating to several
functions of V2X has been made (for example, Non-Patent Literature
1). In this specification, Mode 3 and Mode 4 are defined with
respect to resource allocation for V2X communication to the user
apparatus. In Mode 3, transmission resources are dynamically
allocated by DCI (Downlink Control Information) sent from the base
station to the user apparatus. Furthermore, in Mode 3, SPS (Semi
Persistent Scheduling) is also possible. In Mode 4, the user
apparatus autonomously selects a transmission resource from the
resource pool.
CITATION LIST
Non-Patent Literature
[NPTL 1]
[0009] 3GPP TS 36.213 V14.2.0 (2017 March)
[NPTL 2]
[0009] [0010] 3GPP TS 36.300 V14.3.0 (2017 June)
SUMMARY OF INVENTION
Technical Problem
[0011] By the above-described D2D discovery, for example, a user
apparatus B, which receives a D2D discovery message transmitted
from a certain user apparatus A, can discover the user apparatus A
and determine a destination ID of the user apparatus A.
[0012] Furthermore, it is considered that the user apparatus B
measures the radio quality (for example, path loss) by receiving
the D2D discovery message, and performs link adaptation. For
example, the user apparatus B can select appropriate transmission
parameters (for example, transmission power, MCS, transmission
beam) for performing D2D communication with the user apparatus A,
by link adaptation.
[0013] It is also considered to apply the link adaptation by D2D
discovery to V2X. However, in V2X, it is assumed that each user
apparatus moves at a high speed, and therefore it is necessary to
measure the radio quality by receiving D2D discovery messages in
short periods. For this purpose, the user apparatus needs to
transmit D2D discovery messages in short periods. Furthermore, for
example, in order to measure the path loss on the receiving side,
it is necessary to include information on the transmission power of
the transmission source, etc., in the D2D discovery message.
[0014] However, if the D2D discovery messages including information
are transmitted in short periods, there is a first problem that the
overhead of radio resources increases. Although it is conceivable
to measure the radio quality by using the D2D communication, in
this case also, there is the first problem that the overhead of
radio resources increases, similar to the case of using the D2D
discovery message. The first problem is not limited to V2X; this
problem may arise in D2D in general.
[0015] Furthermore, in V2X, a use case of transmitting a message
such as CAM/BSM (CAM: Cooperative Awareness Message/Basic Safety
Message) including the position information of the transmission
source user apparatus, is being studied. This use case can be
considered as discovery at the application layer. In such a use
case, it is assumed that the information to be transmitted in
messages is frequently changed (for example, every time a message
is transmitted).
[0016] However, the conventional D2D discovery message does not
assume a use case in which the information to be transmitted may be
changed frequently as in the above use case; for example, the
resource size is fixed in the conventional D2D discovery message.
Therefore, the conventional D2D discovery is not suitable for use
cases assumed in V2X. That is, there is a second problem that a
message transmission technology suitable for a use case in which
information to be transmitted may be frequently changed, is
required.
[0017] The present invention has been made particularly in view of
the second problem, and it is an object of the present invention to
provide a technology for enabling messages to be appropriately
transmitted and received, even when information, which is
transmitted in a message by a user apparatus on the transmitting
side, may be frequently changed, in D2D.
Solution to Problem
[0018] According to the disclosed technology, a user apparatus in a
radio communication system supporting a D2D technology is provided,
the user apparatus including
[0019] a message generating unit configured to generate a message
including a first segment and a second segment; and
[0020] a message transmitting unit configured to transmit, multiple
times, the message within a predetermined period, wherein
[0021] information reported by a plurality of the first segments
transmitted within the predetermined period by the message
transmitting unit, is not changed within the predetermined
period.
Advantageous Effects of Invention
[0022] According to the disclosed technology, a technology is
provided for enabling messages to be appropriately transmitted and
received, even when information, which is transmitted in a message
by a user apparatus on the transmitting side, may be frequently
changed, in D2D.
BRIEF DESCRIPTION OF DRAWINGS
[0023] FIG. 1 is a diagram for describing V2X.
[0024] FIG. 2A is a diagram for describing D2D.
[0025] FIG. 2B is a diagram for describing D2D.
[0026] FIG. 3 is a diagram for describing MAC PDU used for D2D
communication.
[0027] FIG. 4 is a diagram for describing a format of an SL-SCH
subheader.
[0028] FIG. 5 is a diagram for describing an example of a channel
structure used in D2D.
[0029] FIG. 6A is a diagram illustrating an example of a structure
of PSDCH.
[0030] FIG. 6B is a diagram illustrating an example of the
structure of PSDCH.
[0031] FIG. 7A is a diagram illustrating an example of the
structure of PSCCH and PSSCH.
[0032] FIG. 7B is a diagram illustrating an example of the
structure of PSCCH and PSSCH.
[0033] FIG. 8A is a diagram illustrating a resource pool
configuration.
[0034] FIG. 8B is a diagram illustrating a resource pool
configuration.
[0035] FIG. 9 is a diagram illustrating a configuration example of
a radio communication system according to an embodiment.
[0036] FIG. 10 is a diagram for describing a basic operation
according to the embodiment.
[0037] FIG. 11A is a diagram illustrating an example of mapping
between message type discovery and signal type discovery.
[0038] FIG. 11B is a diagram illustrating an example of mapping
between message type discovery and signal type discovery.
[0039] FIG. 12 is a diagram illustrating an example (option 1) of a
method of multiplexing a discovery message and a discovery
signal.
[0040] FIG. 13 is a diagram illustrating an example (option 2-1) of
a method of multiplexing a discovery message and a discovery
signal.
[0041] FIG. 14 is a diagram illustrating an example (option 2-2) of
a method of multiplexing a discovery message and a discovery
signal.
[0042] FIG. 15 is a diagram for describing NW assist.
[0043] FIG. 16 is a diagram for describing the outline according to
embodiment 2.
[0044] FIG. 17 is a diagram illustrating an example (type 1) of a
procedure of transmitting a discovery message.
[0045] FIG. 18 is a diagram illustrating an example (type 2) of a
procedure of transmitting a discovery message.
[0046] FIG. 19 is a diagram illustrating an example (type 2) of a
procedure of transmitting a discovery message.
[0047] FIG. 20 is a diagram illustrating a transmission example
(type 1) of a discovery message.
[0048] FIG. 21 is a diagram illustrating a transmission example
(type 2) of a discovery message.
[0049] FIG. 22 is a diagram illustrating a transmission example
(type 2) of a discovery message.
[0050] FIG. 23 is a diagram illustrating a transmission example
(type 2) of a discovery message.
[0051] FIG. 24 is a diagram illustrating a transmission example
(type 2) of a discovery message.
[0052] FIG. 25 is a diagram for describing an association between
discovery and communication.
[0053] FIG. 26 is a diagram illustrating an example of a functional
configuration of a user apparatus UE according to an
embodiment.
[0054] FIG. 27 is a diagram illustrating a configuration example of
a transmitting unit 101.
[0055] FIG. 28 is a diagram illustrating an example of a functional
configuration of a base station 10 according to an embodiment.
[0056] FIG. 29 is a diagram illustrating an example of a hardware
configuration of the base station 10 and the user apparatus UE
according to an embodiment.
DESCRIPTION OF EMBODIMENTS
[0057] Hereinafter, embodiments of the present invention will be
described with reference to the drawings. Note that the embodiments
described below are merely examples, and embodiments to which the
present invention is applied are not limited to the following
embodiments. For example, the radio communication system according
to the present embodiment is assumed to be a system of a method
complying with the LTE; however, the present invention is not
limited to the LTE, but can be applied to other methods. Note that
in the present specification and the claims, "LTE" has a broad
meaning including not only communication methods corresponding to
releases 8 to 14 of 3GPP, but also communication methods of the
fifth generation (5G, NR) of release 15 and beyond.
[0058] Furthermore, although the present embodiment is mainly
targeted at V2X, the technology according to the present embodiment
is not limited to V2X, but is widely applicable to D2D in general.
Furthermore, "D2D" includes the meaning of V2X. Furthermore, the
term "D2D" is not limited to LTE, but refers to general
communication between terminals.
[0059] Furthermore, in the following description of the
embodiments, the existing D2D discovery defined in releases 12 to
14, etc., of 3GPP will be referred to as "LTE-D2D discovery".
[0060] Furthermore, the terms "discovery message" and "discovery
signal" are used in the following embodiments 1 and 2; however,
messages/signals having the same functions as these may be referred
to by names other than these.
(Outline of D2D)
[0061] In the present embodiment, D2D is the basic technology, and
therefore an outline of D2D defined in LTE will be described first.
Note that also with V2X, it is possible to use the technology of
D2D described here, and the user apparatus according to the present
embodiment can transmit and receive D2D signals according to the
technology.
[0062] As already described, D2D is generally classified into
"LTE-D2D Discovery" and "D2D communication". As for "LTE-D2D
discovery", as illustrated in FIG. 2A, a resource pool for a
discovery message is secured for each discovery period, and the
user apparatus transmits a discovery message (discovery signal) in
the resource pool. More specifically, there are Type 1 and Type 2b.
In Type 1, a user apparatus UE autonomously selects a transmission
resource from the resource pool. In Type 2b, a semi-static resource
is allocated by higher layer signaling (for example, RRC
signal).
[0063] As for "D2D communication", as illustrated in FIG. 2B,
resource pools for SCI (Sidelink Control Information)/data
transmission are periodically secured. The user apparatus on the
transmitting side reports, to the receiving side, the data
transmission resource (PSSCH resource pool), etc., by SCI, with the
resource selected from the Control resource pool (PSCCH resource
pool), and transmits the data with the data transmission resource.
More specifically, there are Mode 1 and Mode 2 with respect to "D2D
communication". In Mode 1, resources are dynamically allocated by
(E)PDCCH sent from the base station to the user apparatus. In Mode
2, the user apparatus autonomously selects a transmission resource
from the resource pool. The resource pool is reported by SIB or a
predefined resource pool is used.
[0064] Furthermore, as described above, Rel-14 has Mode 3 and Mode
4 in addition to Mode 1 and Mode 2. In Rel-14, it is possible to
transmit SCI and data simultaneously (in one subframe) by resource
blocks adjacent to each other in the frequency direction.
[0065] In LTE, a channel used for "LTE-D2D Discovery" is referred
to as PSDCH (Physical Sidelink Discovery Channel), a channel for
transmitting control information such as SCI in "D2D communication"
is referred to as PSCCH (Physical Sidelink Control Channel), and a
channel for transmitting data is referred to as PSSCH (Physical
Sidelink Shared Channel).
[0066] As illustrated in FIG. 3, MAC (Medium Access Control) PDU
(Protocol Data Unit) used in D2D is composed of at least a MAC
header, a MAC Control element, a MAC SDU (Service Data Unit), and
Padding. The MAC PDU may include other information. The MAC header
is composed of one SL-SCH (Sidelink Shared Channel) subheader and
one or more MAC PDU subheaders.
[0067] As illustrated in FIG. 4, the SL-SCH subheader is composed
of MAC PDU format version (V), transmission source information
(SRC), transmission destination information (DST), and reserved
bits (R), etc. V is allocated to the beginning of the SL-SCH
subheader and indicates a MAC PDU format version used by the user
apparatus. In the transmission source information, information
relating to the transmission source is set. In the transmission
source information, an identifier relating to ProSe UE ID may be
set. In the transmission destination information, information
relating to the transmission destination is set. In the
transmission destination information, information relating to the
ProSe Layer-2 Group ID of the transmission destination may be
set.
[0068] An example of the channel structure of D2D is illustrated in
FIG. 5. As illustrated in FIG. 5, resource pools of PSCCH and
resource pools of PSSCH used for "D2D communication" are allocated.
Furthermore, resource pools of PSDCH used for "LTE-D2D discovery"
are allocated in periods longer than the periods of the channels of
"D2D communication".
[0069] Furthermore, PSSS (Primary Sidelink Synchronization Signal)
and SSSS (Secondary Sidelink Synchronization Signal) are used as
synchronization signals for D2D. Furthermore, for example, PSBCH
(Physical Sidelink Broadcast Channel) that transmits broadcast
information including the D2D system band, the frame number, and
resource configuration information, etc., is used for an outside
coverage operation. PSSS/SSSS and PSBCH are transmitted in one
subframe.
[0070] FIG. 6A illustrates an example of a resource pool of PSDCH
used in "LTE-D2D discovery". The resource pool is set by the bitmap
of the subframe, and therefore the image of the resource pool
becomes an image as illustrated in FIG. 6A. The same applies to
resource pools of other channels. Furthermore, in PSDCH,
transmission is repeatedly performed (repetition) while performing
frequency hopping. The number of repetitions can be set, for
example, from 0 to 4. Furthermore, as illustrated in FIG. 6B, the
PSDCH has a PUSCH base structure and has a structure in which a
DM-RS (demodulation reference signal) is inserted.
[0071] FIG. 7A illustrates an example of a resource pool of PSCCH
and PSSCH used for "D2D communication". In the example illustrated
in FIG. 7A, in PSCCH, transmission is repeatedly performed twice
including the first time, while frequency hopping. In PSSCH,
transmission is repeatedly performed four times including the first
time, while frequency hopping. Furthermore, as illustrated in FIG.
7B, PSCCH and PSSCH have a PUSCH base structure, that is a
structure in which DMRS is inserted.
[0072] FIGS. 8A and 8B illustrate examples of resource pool
configurations in PSCCH, PSDCH, and PSSCH. As illustrated in FIG.
8A, in the time direction, a resource pool is represented as a
subframe bitmap. Furthermore, the bitmap is repeated as many times
as num.repetition. Furthermore, an offset indicating the start
position in each period is specified. Note that the bitmap is also
referred to as T-RPT (Time-Resource Pattern).
[0073] In the frequency direction, contiguous allocation and
dis-contiguous allocation are possible. In the example of FIG. 8B,
as illustrated, the start PRB, the end PRB, and the number of PRBs
(numPRB) are specified.
(System Configuration)
[0074] FIG. 9 is a diagram illustrating a configuration example of
the radio communication system according to the present embodiment.
As illustrated in FIG. 9, the radio communication system according
to the present embodiment includes a base station 10, a user
apparatus UE1, and a user apparatus UE2. In FIG. 9, the user
apparatus UE1 is intended for the transmitting side of the
discovery message/discovery signal, and the user apparatus UE2 is
intended for the receiving side of the discovery message/discovery
signal; however, both the user apparatus UE1 and the user apparatus
UE2 have a transmitting function and a receiving function.
Hereinafter, when not particularly distinguishing between the user
apparatus UE1 and the user apparatus UE2, the user apparatus is
simply described as "user apparatus UE". Furthermore, the user
apparatus UE may be described as "UE" in some cases.
[0075] The user apparatus UE1 and the user apparatus UE2
illustrated in FIG. 9 respectively have functions of cellular
communication as the user apparatus UE in LTE (in addition to
existing LTE, LTE including meaning of 5G, NR, the same applies
hereinafter), and have a D2D function including signal transmission
and reception in the channels described above. Furthermore, the
user apparatus UE1 and the user apparatus UE2 have a function of
executing the operations described in the present embodiment.
[0076] Furthermore, the user apparatus UE may be any apparatus
having the function of the D2D. For example, the user apparatus UE
may be a vehicle, a terminal held by a pedestrian, and an RSU (a UE
type RSU having a UE function), etc.
[0077] Furthermore, the base station 10 has a function of cellular
communication as the base station 10 in LTE, and a function (NW
assist function) for enabling communication of the user apparatus
UE according to the present embodiment. Furthermore, the base
station 10 may be an RSU (eNB type RSU having the function of
eNB).
[0078] Furthermore, the signal waveform used for D2D by the user
apparatus UE may be CP-OFDM (same as in DL in LTE), SC-FDMA (same
as in UL in LTE), or other signal waveforms. In the present
embodiment, it is assumed that the same SC-FDMA as in the UL of the
LTE, is used in the D2D. Similar to the UL of the LTE, the time
direction resources in the D2D are represented by symbols, slots,
subframes, etc., and the frequency direction resources are
represented by subcarriers, subbands, etc. However, in the present
embodiment, symbols, slots, subframes, subcarriers, subbands, etc.,
need not be the same as UL of LTE.
(Basic Operation Example)
[0079] FIG. 10 is a diagram for describing a basic operation
example relating to discovery between user apparatus UEs according
to the present embodiment (including the embodiments 1 and 2). The
"discovery message" used in the description is the discovery
message of the embodiment 1 or the embodiment 2, and the "discovery
signal" is the discovery signal of the embodiment 1.
[0080] FIG. 10 illustrates a status where UE1 to UE6 are present.
UE1 to UE5 are located in neighboring areas indicated by A, and UE6
is located at a position distant from UE1 to UE5.
[0081] Each of UE2 to UE6 transmits a discovery message and/or a
discovery signal. UE1 receives the discovery message and/or the
discovery signal transmitted from UE2 to UE5 and identifies the IDs
(transmission source IDs) of UE2 to UE5. Furthermore, as an
example, the discovery message and/or the discovery signal includes
the transmission power information of the transmission source, and
UE1 can measure the path loss (an example of radio quality) of UE2
to UE5, by measuring the reception power of the discovery message
and/or the discovery signal transmitted from UE2 to UE5.
[0082] For example, when UE1 detects that all of the path losses of
UE2 to UE5 are small (when it is detected that UE2 to UE5 are in a
near range), UE1 can determine to decrease the transmission
power/MCS for performing transmission in D2D communication with
respect to UE2 to UE5. Furthermore, when the CSI of a specific UE
that is the destination can be identified, the UE1 can select an
appropriate transmission beam. Note that in order to implement
reliable discovery, it is desirable that the discovery range is
sufficiently larger than the D2D communication range.
[0083] Note that the UE1 cannot receive the discovery message
and/or the discovery signal transmitted from the UE6, and therefore
UE1 does not discover UE6.
[0084] Hereinafter, the embodiments 1 and 2 will be described as
embodiments relating to discovery according to the present
embodiment.
Embodiment 1
<Outline of Embodiment 1>
[0085] In the embodiment 1, hybrid discovery composed of signal
type discovery and message type discovery is introduced.
[0086] In the embodiment 1, a signal transmitted by signal type
discovery is referred to as a discovery signal, and a message
transmitted by message type discovery is referred to as a discovery
message.
[0087] The discovery signal transmitted in the signal type
discovery is a physical signal that does not include a message,
similar to a reference signal or a synchronization signal. However,
the discovery signal is not limited to a physical signal, and the
discovery signal may be a message having a small payload. The
discovery message transmitted by message type discovery is a
message including information such as an AS parameter, UE-ID,
position information, etc. In the embodiment 1, the channel for
transmitting the discovery message is not particularly limited;
however, for example, the channel of D2D communication may be used.
Furthermore, a channel of LTE-D2D discovery may be used.
Furthermore, a newly defined channel may be used.
[0088] Basically, the user apparatus UE transmits both a discovery
message and a discovery signal. The transmission period of
discovery signals is independent of the transmission period of
discovery messages. "Independent of" means, for example, that the
transmission period of discovery signals and the transmission
period of discovery messages are independently determined. For
example, the transmission period of discovery signals is shorter
than the transmission period of discovery messages. In this case,
for example, the transmission period of discovery signals is 10 ms,
and the transmission period of discovery messages is 200 ms.
[0089] Furthermore, the transmission time (the time length of the
resource used for one transmission, transmission duration) and the
bandwidth (the frequency width of the resource used for one
transmission) of discovery signals may be different from the
transmission time and the bandwidth of discovery messages. For
example, the user apparatus UE transmits the discovery signal over
a wide bandwidth by using one OFDM symbol (hereinafter, symbol) or
a plurality of symbols.
[0090] The discovery signal does not include a message, and
therefore the discovery signal can be transmitted in a short time.
Therefore, even if the transmission period of the discovery signals
is shortened independently of the transmission period of discovery
messages, the increase in overhead can be kept small.
[0091] The discovery message transmitted from the user apparatus
UE1 on the transmitting side includes, for example, information on
resources used by the user apparatus UE1 for transmitting discovery
signals. Accordingly, the user apparatus UE2 on the receiving side
receives the discovery message transmitted from the user apparatus
UE1, thereby identifying the resource of the discovery signal
transmitted from the user apparatus UE1, and based on the resource,
the user apparatus UE2 can receive the discovery signal transmitted
from the user apparatus UE1. Accordingly, for example, the user
apparatus UE2 can identify the path loss between the user apparatus
UE1 and the user apparatus UE2.
[0092] The information on the mapping between the discovery message
and the discovery signal transmitted by a certain user apparatus
UE, such as the above resource information, may be provided to the
user apparatus UE by the base station 10. For example, the base
station 10 transmits the information of the resource of the
discovery signal transmitted by the user apparatus UE1 to the user
apparatus UE2, so that the user apparatus UE2 existing within the
coverage of the base station 10, can receive the discovery signal
transmitted from the user apparatus UE1 without receiving the
discovery message transmitted from the user apparatus UE1.
[0093] Note that the information transmitted from the base station
10 to the user apparatus UE in the NW assist is not limited to the
information on the discovery message/discovery signal. For example,
the base station 10 may transmit, to the user apparatus UE, mapping
information between any two, or between any three or four of the
discovery message, the discovery signal, the control channel, and
the data channel.
<Details of Discovery Message>
[0094] The user apparatus UE1 that is the transmission source may
include, in the discovery message to be transmitted, one or more
transmission parameters and/or one or more reception parameters
used by the user apparatus UE1. The transmission parameter is a
parameter used for signal transmission by the user apparatus UE1,
and the reception parameter is a parameter used for signal
reception by the user apparatus UE1. The transmission parameter
corresponds to the reception parameter on the receiving side.
[0095] These parameters are parameters used in Access Stratum's
protocol (PDCP, RLC, MAC, PHY, etc.) in the PC5 interface
(Non-Patent Literature 2), for example, and are referred to as AS
(Access Stratum) parameters.
[0096] As AS parameters, for example, there are L1-ID (ID of layer
1) and L2-ID (ID of layer 2).
[0097] Furthermore, as the AS parameters for message type
discovery, for example, there is transmission power or transmission
power density. Furthermore, as the AS parameters for signal type
discovery, for example, there are the following:
[0098] Frequency used for transmission or reception
[0099] Resources and configurations (for example, time/frequency
resource hopping pattern, periodicity, sequence) used for
transmitting or receiving discovery signals
[0100] Transmission power, transmission power density, transmission
power offset relative to the transmission power of the discovery
message.
[0101] One or any plurality of or all of the plurality of AS
parameters described above are included in the discovery
message.
[0102] In hybrid discovery, the AS parameter of the discovery
signal transmitted by a discovery message from the user apparatus
UE1 on the transmitting side (for example, the configuration used
by the user apparatus UE1 for discovery signal transmission, etc.)
is useful for the user apparatus UE2 on the receiving side of the
discovery signal, and the AS parameter can be used to receive
(measure) the discovery signal transmitted from the user apparatus
UE1.
[0103] The discovery message transmitted from the user apparatus
UE1 may include the AS parameter of the PSCCH to be transmitted (or
received) by the user apparatus UE1 and/or the AS parameter of the
PSSCH to be transmitted (or received) by the user apparatus UE1. In
this case, the user apparatus UE2 receiving the discovery message
can use the AS parameter of the PSCCH and/or the AS parameter of
the PSSCH for transmission/reception of PSCCH/PSSCH. In this way
blind detection can be reduced. Furthermore, the performance of
link adaptation/beam forming can be improved. Furthermore,
collision of resources can be reduced.
[0104] As AS parameters for D2D communication included in the
discovery message, for example, there are the following
parameters:
[0105] A frequency for transmission or a frequency for
reception
[0106] Power gap between channels, power gap between signals
[0107] As AS parameters for D2D communication included in a
discovery message, for PSCCH, for example, there are the following
parameters:
[0108] Scrambling parameters
[0109] Transmission power or transmission power density
[0110] MCS
[0111] Resource size
[0112] Beam pattern, beam ID
[0113] Candidate resources (for example, resource pool).
[0114] Time during which reception may not be performed (D2D
gap)
[0115] Reference signal configuration (for demodulation, for phase
compensation, etc.)
[0116] As AS parameters for D2D communication included in a
discovery message, for PSSCH, for example, there are the following
parameters:
[0117] Transmission power or transmission power density
[0118] MCS
[0119] Beam pattern, beam ID
[0120] Candidate resources (for example, resource pool).
[0121] Time during which reception may not be performed (D2D
gap)
[0122] Reference signal configuration (for demodulation, for phase
compensation, etc.)
[0123] One or any plurality of or all of the AS parameters
described above are included in the discovery message.
[0124] Hereinafter, an example of transmitting/receiving a
discovery signal and a discovery message without performing NW
assist will be described as the embodiment 1-1, and an example of
performing NW assist will be described as the embodiment 1-2.
Embodiment 1-1
[0125] In a case where the user apparatus UE1, etc., transmits a
discovery signal and a discovery message, the user apparatus UE2 on
the receiving side, which receives the discovery signal and the
discovery message, needs to identify that the discovery signal and
the discovery message have been transmitted from the same user
apparatus.
[0126] Therefore, in the embodiment 1-1, the discovery signal and
the discovery message are associated with each other as in option
1, option 2, or option 3 described below.
<Discovery Signal/Discovery Message Association: Option
1>
[0127] In option 1, as illustrated in FIG. 11A, the
transmission/reception parameters of a discovery signal are derived
from the transmission parameters of a discovery message and/or the
payload of the discovery message. Note that the
transmission/reception parameter means a parameter used by the
transmitting side for transmission and a parameter used by the
receiving side for reception, which may be the same.
[0128] As illustrated in FIG. 11A, there are time offset, DMRS
parameter, frequency position, hopping pattern, etc., as the
transmission parameters of the discovery message used for deriving
the transmission/reception parameters of the discovery signal.
[0129] For example, the user apparatus UE1 on the transmitting side
transmits a discovery message by using the transmission parameters
selected by the user apparatus UE1. Furthermore, according to a
predetermined rule (mapping function in FIG. 11A), transmission
parameters of a discovery signal are derived from transmission
parameters of a discovery message, and a discovery signal is
transmitted by using the transmission parameters.
[0130] The user apparatus UE2 that receives the discovery message
estimates the transmission parameters of the received discovery
message. Alternatively, the user apparatus UE1 may include the
transmission parameters of the discovery message in the payload of
the discovery message, and the user apparatus UE2 may acquire the
transmission parameters from the payload.
[0131] From the transmission parameters of the received discovery
message, the user apparatus UE2 derives the reception parameters of
the discovery signal according to the predetermined rule, and
receives the discovery signal by using the reception parameters.
The user apparatus UE2 identifies the discovery signal received by
using the reception parameters, as the discovery signal transmitted
from the user apparatus UE1 that is the transmission source of the
discovery message from which the reception parameters have been
derived.
[0132] In option 1, compared with option 2, there is an advantage
that the transmitting side can flexibly select the transmission
parameters of the discovery message.
[0133] The discovery message and the discovery signal do not need
to be one to one, and may correspond to 1:N. For example, a
configuration may be considered in which a plurality of discovery
signals with respect to a certain discovery message, are used for
transmission by different transmission beams and/or reception beams
and/or different panels (antenna groups, antenna ports). That is,
to a certain discovery message, a plurality of discovery signals,
which are transmitted by different transmission beams and/or
different reception beams and/or different panels, are
associated.
[0134] Furthermore, for example, when a discovery signal in a
certain transmission beam is applied, the user apparatus UE2 on the
receiving side can perform discovery according to the communication
range in the case where the transmission beam is applied (the
discovery range becomes wide). At this time, the discovery message
may be transmitted by a predetermined port and/or transmission beam
index. The discovery message may be repeatedly transmitted in order
to compensate for the coverage difference between the discovery
message and the discovery signal depending on the presence or
absence of a beam. The number of repetitions may be a predetermined
number of times. Furthermore, a periodic switching pattern in terms
of time (beam switching pattern) may be applied to the transmission
beam of the discovery signal. Accordingly, a beam diversity effect
is obtained. Furthermore, by reporting the beam switching pattern
of the discovery signal to the user apparatus UE2 on the receiving
side with the discovery message, or by transmitting the discovery
signal with a predetermined beam switching pattern, the user
apparatus UE2 on the receiving side can also estimate the channel
quality for each transmission beam.
[0135] Information on the transmission beam and/or the transmission
port of the discovery signal can be reported by the discovery
message. Furthermore, in a mode in which information on the
transmission beam and/or the transmission port of the discovery
signal is not reported by a discovery message, it may be regarded
that the configuration relating to the transmission beam forming of
the discovery signal such as the transmission beam index and/or the
transmission port, is the same as that of the discovery message, or
the association of transmission beams between the discovery message
and the discovery signal may be defined in advance.
<Discovery Signal/Discovery Message Association: Option
2>
[0136] In option 2, as illustrated in FIG. 11B, the
transmission/reception parameters of the discovery message are
derived from the transmission parameters of the discovery
signal.
[0137] As illustrated in FIG. 11B, there are time offset, sequence,
frequency position, hopping pattern, etc., as transmission
parameters of a discovery signal used for deriving
transmission/reception parameters of a discovery message.
[0138] For example, the user apparatus UE1 on the transmitting side
transmits a discovery signal by using the transmission parameters
selected by the user apparatus UE1. Furthermore, according to a
predetermined rule (mapping function in FIG. 11B), transmission
parameters of a discovery message are derived from transmission
parameters of a discovery signal, and a discovery message is
transmitted by using the transmission parameters.
[0139] The user apparatus UE2 that receives the discovery signal
estimates the transmission parameters of the received discovery
signal.
[0140] From the transmission parameters of the received discovery
signal, the user apparatus UE2 derives the reception parameters of
the discovery message according to the predetermined rule, and
receives the discovery message by using the reception parameters.
The user apparatus UE2 identifies the discovery message received
using the reception parameters as the discovery message transmitted
from the user apparatus UE1 that is the transmission source of the
discovery signal from which the reception parameters have been
derived. Furthermore, when the discovery message includes the ID of
the user apparatus UE1 that is the transmission source, the user
apparatus UE2 can identify, based on the ID, that the transmission
source of the discovery signal is the user apparatus UE1 having the
corresponding ID.
[0141] Option 2 has the advantage of being able to quickly detect
the discovery signal compared to option 1.
<Discovery Signal/Discovery Message Association: Option
3>
[0142] In option 3, the transmission parameters and/or reception
parameters of the discovery message and the transmission parameters
and/or reception parameters of the discovery signal associated with
the discovery message, are set (configured) or preset
(pre-configured) in the user apparatus UE1.
<Selection of Transmission Resource>
[0143] Regarding the transmission resource of the discovery
message, for example, the resource pool is set (configured) or
preset (pre-configured) in the user apparatus UE1. With regard to
setting (configuring) in the present embodiment, for example, it is
assumed that a configuration is performed by the base station 10
for the user apparatus UE by RRC signaling, etc. Furthermore, with
regard to presetting (preconfiguring) in the present embodiment,
for example, it is assumed that settings are made in advance
without the user apparatus UE receiving settings from the base
station 10. Hereinafter, setting (configuring) or presetting
(pre-configuring) is described as (pre) setting.
[0144] The user apparatus UE1 transmits a discovery message by
using the resource selected from the resource pool. A resource pool
for reception (which may be the same as the resource pool for
transmission) is also set for the user apparatus UE2 on the
receiving side. The resource pool for reception may not be set for
the user apparatus UE2 on the receiving side.
[0145] Furthermore, regarding the transmission resource of the
discovery signal, for example, a resource pool is (pre) set in the
user apparatus UE1. The user apparatus UE1 transmits a discovery
signal by using a resource selected from the resource pool. A
resource pool for reception (which may be the same as the resource
pool for transmission) is also set for the user apparatus UE2 on
the receiving side. The resource pool for reception may not be set
for the user apparatus UE2 on the receiving side.
[0146] For example, the transmission resource pool of the discovery
signal is defined such that the discovery signal is transmitted by
one symbol or a plurality of symbols in a certain slot.
[0147] In both cases of the discovery message and the discovery
signal, there are options 1 and 2 as methods by which the user
apparatus UE1 selects a transmission resource from the resource
pool. Which one of option 1 or option 2 is to be executed, may be
determined by an instruction from the base station 10, or the one
that is to be executed may be preset in the user apparatus UE1.
[0148] In option 1, the user apparatus UE1 randomly selects a
resource from the resource pool for the transmission of the
discovery message/discovery signal.
[0149] In option 2, the user apparatus UE1 makes a sensing-based
resource selection. In this case, for example, the user apparatus
UE1 selects resources satisfying the following conditions 1 and 2,
as candidate resources.
[0150] Condition 1: RSRP or RSSI is less than the predefined (or
(pre) set) threshold.
[0151] Condition 2: In a slot (or symbol) that is the time resource
of the resource satisfying condition 1, RSRP or RSSI in a frequency
resource other than the frequency resource of the resource
satisfying condition 1, is lower than a threshold value determined
in advance (or (pre) set).
[0152] Then, the user apparatus UE1 transmits a discovery
message/discovery signal using resources randomly selected from the
resources satisfying the conditions 1 and 2.
[0153] Furthermore, the user apparatus UE1 may make a sensing-based
resource selection according to the method defined in Non-Patent
Literature 1.
[0154] For example, there may be a plurality of transmission
settings of a discovery message and a discovery signal, from the
viewpoint of the user apparatus UE1 on the transmitting side, and
the user apparatus UE1 on the transmitting side may transmit a
discovery signal and a discovery message based on any setting, and
may select an unused resource (setting) based on a sensing result,
a measurement result, or a result of decoding a discovery message,
etc.
<Multiplexing Method>
[0155] As methods of multiplexing a discovery signal and a
discovery message, there are options 1 and 2 as follows.
<Multiplexing Method: Option 1>
[0156] Option 1 will be described with reference to FIG. 12. As
illustrated in FIG. 12, in this example, the discovery signal is
transmitted in periods shorter than the transmission periods of
discovery messages. Furthermore, the discovery signal is
transmitted by a transmission bandwidth wider than the transmission
bandwidth of the discovery message.
[0157] In the time resource indicated by A in FIG. 12, a part of
the resource of the discovery signal overlaps a part of the
resource of the discovery message. When the resources overlap in
this way, the user apparatus UE1 drops the transmission of the
discovery signal. That is, the user apparatus UE1 does not transmit
a discovery signal in this time resource.
<Multiplexing Method: Option 2>
[0158] Next, option 2 will be described. In option 2, a single
symbol or a plurality of symbols in a discovery message are not
transmitted. The single symbol or the plurality of symbols are used
for transmitting a discovery signal. Hereinafter, options 2-1 and
2-2 will be described.
<Multiplexing Method: Option 2-1>
[0159] In option 2-1, one symbol or a plurality of symbols in a
discovery message are not always transmitted. FIG. 13 illustrates
an example. As illustrated in FIG. 13, in this example, the last
one symbol in the discovery message is not always transmitted,
regardless of whether the discovery signal is transmitted. Note
that the blank at the trailing end of the discovery message in FIG.
13 indicates a GAP in the slot (or subframe).
<Multiplexing Method: Option 2-2>
[0160] In option 2-2, when the discovery signal overlaps the
discovery message, the overlapping single symbol or a plurality of
symbols are not used for transmitting the discovery message.
[0161] An example is illustrated in FIG. 14. In the example of FIG.
14, in the time resource indicated by A, a resource of one symbol
in the discovery message overlaps the resource of the discovery
signal. In this case, the symbol is not used for transmitting the
discovery message. On the other hand, in the symbol at the time
position indicated by B, the discovery signal is not transmitted,
and therefore the symbol is used for transmitting the discovery
message.
<Regarding Cross Carrier Transmission>
[0162] Discovery messages and discovery signals may be transmitted
at different frequencies (carriers). For example, the user
apparatus UE1 transmits the discovery message at a low frequency,
and transmits the discovery signal at a frequency higher than the
frequency of the discovery message. The high frequency may be, for
example, a frequency used in D2D communication.
[0163] Furthermore, the discovery message and the discovery signal
may be transmitted by different RATs. For example, the user
apparatus UE1 transmits the discovery message by the LTE sidelink
and transmits the discovery signal by the NR sidelink.
<Regarding Measurement>
[0164] In a case where both message type discovery and signal type
discovery are (pre) set for the user apparatus UE1 on the
transmitting side and/or the user apparatus UE2 on the receiving
side, for example, the user apparatus UE2 on the receiving side
performs measurement by a discovery signal.
[0165] Alternatively, the user apparatus UE2 on the receiving side
performs measurements on both the discovery signal and the
discovery message, for example, and calculates and uses the average
of the measurement result of the discovery signal and the
measurement result of the discovery message. Note that even in the
case of performing measurements on both the discovery signal and
the discovery message, with regard to the usage of the measurement
result, only one of the measurement results may be used.
Furthermore, for the measurement by the discovery message, the DMRS
in the discovery message is used.
[0166] Furthermore, in a case where only message type discovery is
(pre) set for the user apparatus UE1 on the transmitting side
and/or the user apparatus UE2 on the receiving side, the user
apparatus UE2 on the receiving side uses the DMRS in the discovery
message to perform measurements.
[0167] In a case where only signal type discovery is (pre) set for
the user apparatus UE1 on the transmitting side and/or the user
apparatus UE2 on the receiving side, the user apparatus UE2 on the
receiving side performs measurements by the discovery signal.
Embodiment 1-2
[0168] Next, an example in which NW assist is performed will be
described as the embodiment 1-2. Even in the case of performing NW
assist, the embodiment 1-1 can be applied to the operation in which
the user apparatus UE1 transmits a discovery signal/a discovery
message, and the operation in which the user apparatus UE2 receives
(or measures) the discovery signal/discovery message.
[0169] FIG. 15 is a diagram for describing the operation in the
embodiment 1-2. As illustrated in FIG. 15, in step S101, the base
station 10 transmits configuration information to the user
apparatus UE1. In step S102, the base station 10 transmits
configuration information to the user apparatus UE2. Transmission
of the configuration information in steps S101 and S102 may be
performed by SIB common to the UEs, by UE specific higher layer
signaling (RRC message), by a MAC signal, or by DCI.
[0170] In step S103, the user apparatus UE1 transmits a discovery
message and/or a discovery signal based on the configuration
information received in step S101, and the user apparatus UE2
receives the discovery message and/or the discovery signal
transmitted from the user apparatus UE1 based on the configuration
information received in step S102.
[0171] The configuration information received by the user apparatus
UE2 on the receiving side in the above-described step S102 is, for
example, parameters (for example, time/frequency resources,
periods, sequences), etc., necessary for detecting the discovery
signal. More specifically, there are options 1 and 2 as
follows.
[0172] Option 1) In option 1, the configuration information
received by the user apparatus UE2 is a list of candidate parameter
sets. In this case, for example, the user apparatus UE2 attempts to
detect the discovery signal by using each candidate parameter set
in the list, and detects the discovery signal. Subsequently, for
example, a discovery message corresponding to the detected
discovery signal is received by using the mapping function
described in the embodiment 1-1, and the transmission source of the
discovery signal and the discovery message is identified by an ID
included in the discovery message.
[0173] Option 2) In option 2, the configuration information
received by the user apparatus UE2 is a list of "transmission
source IDs and parameter sets corresponding to the transmission
source IDs". In this case, the user apparatus UE2 attempts to
detect a discovery signal by using each parameter set in the list,
and detects the discovery signal. The user apparatus UE2 identifies
the transmission source ID corresponding to the parameter set used
when the discovery signal has been detected, as the transmission
source ID of the discovery signal.
[0174] In step S101, the configuration information received by the
user apparatus UE1 on the transmitting side is, for example, the
transmission configuration (for example, time/frequency resources,
periods, hopping parameters, etc.) of the discovery signal and/or
the discovery message.
[0175] In the above example, the base station 10 reports, to the UE
side, both the configuration information for receiving the
discovery message and/or the discovery signal and the configuration
information for transmitting the discovery message and/or the
discovery signal; however, this is only an example. The base
station 10 may report, to the UE side, either the configuration
information for receiving the discovery message and/or the
discovery signal or the configuration information for transmitting
the discovery message and/or the discovery signal.
(Regarding Usage of Discovery in Embodiment 1)
[0176] The user apparatus UE can estimate, for example, the user
apparatus UE that is the destination of the D2D communication, by
discovery. For example, the user apparatus UE can determine the
destination UE based on the measurement result (path loss) of the
discovery message and/or the discovery signal that is received
and/or the location information of the transmission source UE of
the discovery message and/or the discovery signal. For example, the
user apparatus UE can determine, as the destination, the UE that
has the smallest path loss among the UEs in its own heading
direction.
[0177] Furthermore, the user apparatus UE2 performing transmission,
such as D2D communication, based on the discovery message and/or
discovery signal that is received, may determine the transmission
parameters based on the maximum path loss, among the path losses in
a group of user apparatuses UEs to be destinations that are
identified from the discovery message and/or the discovery signal
that is received. Accordingly, it is possible to appropriately
perform data transmission (group cast, multicast, etc.) to the
above group.
[0178] Note that when the user apparatus UE2 that has performed
transmission by D2D communication, etc., receives a NACK for the
MAC PDU from a certain UE, the user apparatus UE2 may adjust the
transmission parameters in order to improve the reliability.
[0179] As described above, in the embodiment 1, the transmission
period of the discovery message and the transmission period of the
discovery signal are independent of each other, and discovery
signals of short periods and discovery messages of long periods are
used, and therefore it is possible for the user apparatus UE to
appropriately measure the radio quality while avoiding an increase
in the overhead of the radio resources.
Embodiment 2
[0180] Next, the embodiment 2 will be described. A message
transmitted by discovery according to the embodiment 2 is referred
to as a discovery message. The discovery message described in the
embodiment 2 may be used as a discovery message of the message type
discovery of the embodiment 1. That is, the embodiment 1 and the
embodiment 2 can be implemented in combination. Furthermore, the
discovery message of the message type discovery of the embodiment 1
may be different from the discovery message described in the
embodiment 2.
<Outline of Embodiment 2>
[0181] The discovery message in the embodiment 2 has two or more
parts, and each part is separately encoded. However, it is not
essential to encode the parts separately. FIG. 16 illustrates an
example where the discovery message includes two parts. As
illustrated in FIG. 16, this discovery message includes segments #1
and #2.
[0182] At least one part (for example, segment #1) in the discovery
message is transmitted with a fixed payload size by using a certain
resource, and the content of this part does not change within a
certain time period. However, the redundancy version and beam
forming can be changed within the period.
[0183] The user apparatus UE1 on the transmitting side repeatedly
transmits discovery messages in a predetermined time/frequency
resource pattern, for example, so that the user apparatus UE2 on
the receiving side can identify repeated transmissions from the
same user apparatus UE1 and receive the discovery messages by HARQ
soft combining of segment #1. Furthermore, the user apparatus UE1
on the transmitting side may determine the time/frequency resource
pattern of the discovery message by itself, transmit the
information of the determined time/frequency resource pattern by a
sidelink control channel (that is, by SCI), and transmit a
discovery message by the time/frequency resource pattern.
[0184] Hereinafter, the contents of the discovery message will be
described in more detail by taking a discovery message including
segment #1 and segment #2 as illustrated in FIG. 16, as an
example.
<Content Example of Discovery Message>
[0185] Segment #1 includes AS parameters that are not frequently
updated. Examples of the AS parameters are as follows. Segment #1
includes one or any plurality of or all of the following
parameters:
[0186] Transmission parameters for transmitting a discovery
message, and/or transmission parameters for transmitting control
information in D2D communication, and/or transmission parameters
for data transmission in D2D communication (transmission parameters
are parameters used on the transmitting side; for example,
transmission power, transmission carrier, MCS, resource size,
reference signal configuration, etc.).
[0187] Reception parameters for receiving discovery messages,
and/or reception parameters for receiving control information,
and/or reception parameters for data reception (a reception
parameter means a parameter used by the transmitting side of the
discovery message when receiving information from another UE; for
example, a reception beam pattern/index, and a reception carrier,
etc. Furthermore, the reception parameter may be a parameter used
by the receiving side of the discovery message when receiving
information).
[0188] Segment #2 includes information that may be updated each
time a discovery message is transmitted. The information is, for
example, one or any plurality of or all of the position, the speed,
the heading direction, the acceleration, etc., of the user
apparatus UE1 transmitting the discovery message. Furthermore, the
AS parameters may be included in segment #2.
[0189] By multiplexing segment #1 and segment #2 to obtain a
discovery message, the user apparatus UE2 on the receiving side can
identify that the two segments have been transmitted from the same
user apparatus UE.
[0190] For example, the user apparatus UE2 that performs
transmission in D2D communication by receiving the discovery
message, can determine the destination UE based on the position of
the UE detected in segment #2 and adjust transmission parameters
when transmitting control information/data to the destination UE
based on the AS parameters of segment #1.
[0191] In the embodiment 2, there are types 1 and 2 described below
as transmission types.
<Type 1>
[0192] In type 1, the user apparatus UE1 transmits a discovery
message without transmitting control information for receiving a
discovery message on the receiving side. For example, the discovery
message is transmitted according to the time/frequency resource
set, MCS, a hopping pattern, etc., which have been (pre) configured
or predefined. The user apparatus UE2 on the receiving side
performs blind detection of the discovery message.
<Type 2>
[0193] In Type 2, the user apparatus UE1 transmits a discovery
message together with control information for receiving a discovery
message on the receiving side. That is, transmission is performed
by the same method as D2D communication. The control information
includes, for example, an indication of the time/frequency resource
and an indication of MCS. Before the process of receiving the
discovery message, the user apparatus UE2 on the receiving side
decodes the control information and performs a reception process
(demodulation, decoding) by using the control information.
[0194] The control information in type 2 may be referred to as
scheduling information. The control information in type 2 may be
used for the scheduling of only segment #2 or may be used for the
scheduling of segment #1 and segment #2 or may be used for the
scheduling of only segment #1.
<Regarding Channels to be Used>
[0195] As an example, segment #1 is transmitted on a control
channel (that is, PSCCH) and segment #2 is transmitted on the data
channel (that is, PSSCH).
[0196] For example, in addition to the SCI format for data
scheduling, an SCI format for discovery message scheduling may be
defined. Furthermore, for example, the SCI (segment #1) of SCI
format for discovery message scheduling may not include parameters
relating to link adaptation of data (for example, MCS, RI, PMI).
Furthermore, it may be assumed that the data resource size (for
example, the resource size of segment #2) is fixed.
[0197] As described above, information (indication) indicating that
the SCI is segment #1 may be included in the SCI by using the free
area in the SCI that does not include parameters relating to the
link adaptation. Alternatively, the user apparatus UE2 on the
receiving side may determine that the SCI that does not include the
parameter relating to the link adaptation, indicates segment
#1.
[0198] The flag in the SCI, the payload size of the SCI, or the CRC
mask may be used to identify the type of SCI (for discovery
messages or for D2D communication).
[0199] <Example of Procedure for Transmitting Discovery
Message>
[0200] Next, an example of a procedure of transmitting a discovery
message executed by the user apparatus UE1 on the transmitting side
will be described with reference to FIGS. 17 to 19. The
transmission processes illustrated in FIGS. 17 to 19 are processes
executed by a transmission unit 101 in the user apparatus UE1 to be
described later.
[0201] FIG. 17 illustrates an example of Type 1. As illustrated in
FIG. 17, channel coding is performed on the information of segment
#1 (the bit string to which the CRC is added) (step S1). At the
same time, channel coding is performed on the information of
segment #2 (the bit string to which the CRC is added) (step S2),
and rate matching and code block concatenation are performed on the
channel coded information (steps S3, S4). Note that steps S3 and S4
may not be executed. The information of segment #1 processed in
step S1 and the information of segment #2 processed in steps S1 to
S4 are multiplexed (step S5), channel interleaved (step S6), and a
discovery message is generated. Subsequently, by performing
scrambling, modulation, and mapping to resources, etc., the
discovery message is transmitted from the antenna as a radio
signal. Note that channel interleaving may not be performed.
[0202] In the example illustrated in FIG. 17, on the receiving
side, segment #1 is detected regardless of whether segment #2 is
detected.
[0203] FIG. 18 illustrates an example of Type 2. As illustrated in
FIG. 18, the process for the sidelink control channel and the
process for the sidelink data channel are performed.
[0204] In the process for the sidelink control channel, the
information of the SCI for data scheduling (the bit string to which
the CRC is added) and the information of segment #1 (the bit string
to which the CRC is added) are channel-coded (steps S11, S12), and
multiplexed (step S13).
[0205] In the process for the sidelink data channel, channel
coding, rate matching, code block concatenation, and channel
interleaving are executed on the information of segment #2 (bit
string to which CRC is added) (steps S14 to S17).
[0206] The SCI and segment #1 that have been multiplexed in step
S13, and segment #2 that has undergone the processes of steps S14
to S17, are multiplexed (step S18). Subsequently, the SCI and the
discovery message are transmitted as radio signals from the antenna
by performing scrambling, modulation, mapping to resources,
etc.
[0207] In the example illustrated in FIG. 18, on the receiving
side, segment #1 can be detected regardless of whether SCI for data
scheduling is detected.
[0208] FIG. 19 illustrates another example of type 2. As
illustrated in FIG. 19, the process for the sidelink control
channel and the process for the sidelink data channel are
performed. However, unlike the example of FIG. 18, in the example
of FIG. 19, both segment #1 and segment #2 are transmitted on the
data channel.
[0209] In the process for the sidelink control channel, SCI
information for data scheduling (bit string to which CRC is added)
is channel-coded (step S21).
[0210] In the process for the sidelink data channel, the
information of segment #1 (the bit string to which the CRC is
added) is channel-coded (step S22). Furthermore, channel coding,
rate matching, and code block concatenation are executed on the
information of segment #2 (bit string to which CRC is added) (steps
S23 to S25). Segment #1 that has undergone the process of S22 and
segment #2 that has undergone the processes of steps S23 to S25 are
multiplexed and channel interleaved (steps S26, S27). Then, the SCI
and multiplexed segment #1 and segment #2, are multiplexed (step
S28). Subsequently, the SCI and the discovery message are
transmitted as radio signals from the antenna by performing
scrambling, modulation, mapping to resources, etc.
[0211] In the example illustrated in FIG. 19, on the receiving
side, segment #1 is detected when the SCI is correctly detected.
Furthermore, in the example illustrated in FIG. 19, better
time/frequency diversity is obtained for segment #1 than in other
examples.
<Transmission Example of Discovery Message>
[0212] Next, a transmission example of a discovery message will be
described with reference to FIGS. 20 to 24. In FIGS. 20 to 24, the
horizontal axis represents time and the vertical axis represents
frequency, as illustrated. Furthermore, the illustrated "No
modification period" indicates a period during which there are no
changes in the report content of segment #1. For example, the user
apparatus UE2 on the receiving side can identify that HARQ soft
combining of segment #1 is possible within "No modification
period". Furthermore, the user apparatus UE2 on the receiving side
may regard the parameters in segment #1 that have once been
successfully detected in "No modification period", as valid within
the "No modification period". Note that the number of times of
transmitting the discovery message in "No modification period" in
FIGS. 20 to 24, is merely one example. The number of transmissions
may be larger than the number of transmissions illustrated in FIGS.
20 to 24.
[0213] FIG. 20 illustrates a transmission example of type 1. As
illustrated in FIG. 20, in the first "No modification period", a
discovery message indicated by A and a discovery message indicated
by B are transmitted. As described in C and D, the resources in
multiple transmissions are determined, for example, based on a
predetermined hopping pattern.
[0214] The illustrated A1 and B1 are segment #1, and A2 and B2 are
segment #2, respectively. Within "No modification period", A1 and
B1 are the same payload (information in which the same contents are
encoded). Furthermore, A1 and B1 have a fixed size and a fixed MCS.
However, RV can change between A1 and B1. A2 and B2 are payloads
that may be changed each time the transmission is performed. The
size and the MCS may be fixed or may be changed each time the
transmission is performed.
[0215] The user apparatus UE2 on the receiving side can receive
segment #1 by performing soft combining of HARQ (for example,
incremental redundancy (IR) combining) by using A1 and B1.
[0216] Also in the next "No modification period", as indicated by C
and D, the discovery message is transmitted similar to the case of
the first "No modification period".
[0217] FIG. 21 illustrates a transmission example of type 2. As
illustrated in FIG. 21, in "No modification period", SCI+discovery
message indicated by A, SCI+discovery message indicated by B, and
SCI+discovery message indicated by C are transmitted. Resources for
multiple transmissions are determined, for example, based on a
predetermined hopping pattern.
[0218] The illustrated A1, B1, and C1 are SCIs for data scheduling
(scheduling of segment #1 and/or segment #2), respectively.
[0219] The illustrated A2, B2, and C2 are segment #1, and A3, B3,
and C3 are segment #2, respectively. Within "No modification
period", A2, B2 and C3 are the same payload (information in which
the same contents are encoded). A3, B3, and C3 are payloads that
may be changed each time the transmission is performed. The size
and MCS in A3, B3, C3 may be changed each time the transmission is
performed.
[0220] The user apparatus UE2 on the receiving side can perform
soft combining of HARQ by using A2, B2, and C2 to receive segment
#1.
[0221] FIG. 22 also illustrates a transmission example of type 2.
As illustrated in FIG. 22, SCI+discovery message indicated by A and
SCI+discovery message indicated by B are transmitted in "No
modification period". Resources for multiple transmissions are
determined, for example, based on a predetermined hopping
pattern.
[0222] The illustrated A1 and B1 are SCIs for data scheduling
(scheduling of segment #2), respectively. The payload of this SCI
can be changed each time the transmission is performed.
[0223] The illustrated A2 and B2 are segment #1, and A3 and B3 are
segment #2, respectively. Within "No modification period", A2 and
B2 are the same payload (information in which the same contents are
encoded). A3, B3 are payloads that can be changed each time the
transmission is performed. The size and MCS in A3, B3 can be
changed each time the transmission is performed.
[0224] In the example of FIG. 22, SCI and segment #1 are
transmitted on the sidelink control channel and segment #2 is
transmitted on the sidelink data channel, as illustrated.
[0225] FIG. 23 also illustrates a transmission example of type 2.
In the example of FIG. 23, the SCI includes ID=A that is the ID of
the transmission source that executes the discovery. Otherwise,
this example is the same as the example of FIG. 22.
[0226] Upon detecting ID=A in the received SCI, the user apparatus
UE2 on the receiving side can identify that the data scheduled by
this SCI is segment #2 of the discovery message transmitted from
the UE with ID=A.
[0227] FIG. 24 also illustrates a transmission example of type 2.
As illustrated in FIG. 24, in "No modification period",
SCI+discovery message indicated by A, SCI+discovery message
indicated by B, and SCI+discovery message indicated by C are
transmitted. Resources for multiple transmissions are determined,
for example, based on a predetermined hopping pattern.
[0228] The illustrated A1, B1, C1 are SCIs for data scheduling
(scheduling of segment #1 and/or segment #2), respectively.
[0229] The illustrated A2, B2, and C2 are segment #1, and A3, B3,
and C3 are segment #2, respectively. Within "No modification
period", A2, B2, and C3 are the same payload (information in which
the same contents are encoded). A3, B3, and C3 are payloads that
can be changed each time the transmission is performed. The size
and MCS in A3, B3, and C3 can be changed each time the transmission
is performed.
[0230] In the example of FIG. 24, soft combining is possible for
segment #1 with A2, B2, and C2. Furthermore, in the example of FIG.
24, for example, by the second transmission of SCI, it is indicated
that segment #2 is transmitted again, and therefore it is possible
to perform soft combining of segment #2 (A3) of the first
transmission and segment #2 (B3) of the second transmission.
<Regarding Multiplexing Method, Encoding, Etc.>
[0231] In FIGS. 20 to 24, examples in which segment #1 and segment
#2 are frequency-multiplexed (FDM) are illustrated; however, these
are only examples. Segment #1 and segment #2 may be time division
multiplexed (TDM) or code division multiplexed (CDM).
[0232] Furthermore, in FIG. 20 to FIG. 24, examples in which the
SCI and segment #1 are frequency multiplexed (FDM) are illustrated;
however, this is only an example. The SCI and segment #1 may be
time division multiplexed (TDM) or code division multiplexed (CDM).
Furthermore, segment #1 may be used for the scheduling of segment
#2.
[0233] Regarding encoding, for example, MCS, the encoding rate (or
MCS offset, encoding rate offset), etc., are set (or preset) in the
user apparatus UE from base station 10, with respect to each of
segment #1 and segment #2. Furthermore, a value defined by a
specification, etc., may be set in the user apparatus UE.
[0234] As an example, when different reliabilities are required for
segment #1 and segment #2 (for example, segment #2 has a higher
reliability), it is considered that the encoding rate of either
segment #1 or segment #2 is set to be lower than the other (for
example, the encoding rate of segment #2 is lowered when segment #2
has higher reliability).
<Regarding Modification Period>
[0235] Regarding the modification period (corresponding to the No
modification period in FIGS. 20 to 24), it is necessary for the
user apparatuses UEs to share a common recognition regarding the
start timing (time offset) and the time length. Therefore, the
modification period is determined based on a predetermined
reference time, etc. The reference time is, for example, UTC-time,
a frame number, a subframe number, and a slot number, etc.
Furthermore, the period (time length) and the time offset of the
modification period may be (pre) configured in the user apparatus
UE.
<Regarding Validation of Segment #1>
[0236] There are the following options 1 to 4 for confirming the
validity of segment #1 in the user apparatus UE2 on the receiving
side.
[0237] Option 1) The user apparatus UE2 determines that the most
recently (latest) detected segment #1 is valid. That is, every time
segment #1 is detected, it is determined that segment #1 is
valid.
[0238] Option 2) The user apparatus UE2 determines that segment #1
detected in the nth modification period is valid in the (n+m)th
modification period. For example, m=1. Furthermore, m may be
configured from the base station 10 or may be preconfigured. Also,
m may be indicated by a discovery message (segment #1 and/or
segment #2).
[0239] Option 3) When the user apparatus UE2 detects that a change
has been made in the DMRS sequence in the received discovery
message or in a predetermined portion in the received discovery
message, the user apparatus UE2 determines that segment #1 has been
changed.
[0240] Option 4) When the user apparatus UE2 detects that the
modification indicator in the SCI for discovery message scheduling
indicates "no update", the user apparatus UE2 determines that
segment #1 detected immediately before is valid. For example, in
the example of FIG. 21, if the modification indicator in SCI in B
indicates "no update", the user apparatus UE2 determines that
segment #1 in A is valid.
<Regarding Validation of Segment #2>
[0241] The user apparatus UE2 on the receiving side, for example,
determines that segment #2 detected most recently (latest) is
valid. That is, every time segment #2 is detected, it is determined
that the detected segment #2 is valid.
[0242] The embodiment 2 uses a discovery message, in which segment
#1 that can be soft combined and that includes information that is
not frequently changed, and segment #2 including information that
may change every time message transmission is performed, are
multiplexed, and therefore even when the information to be
transmitted may be changed frequently, the user apparatus UE on the
transmitting side can appropriately transmit messages. Furthermore,
the user apparatus UE on the receiving side accurately identifies
parameters (for example, parameters for reception of segment #2 and
parameters for D2D communication transmission) in segment #1, and
therefore the user apparatus UE on the receiving side can
appropriately receive segment #2 and appropriately determine the
destination UE in the D2D communication and execute transmission in
D2D communication to the destination UE, etc. Note that also in the
embodiment 2, the user apparatus UE2 on the receiving side can
perform the measurement in the same manner as the measurement using
the discovery message in the embodiment 1.
(Association Between Discovery and D2D Communication)
[0243] Next, the association between discovery and D2D
communication will be described. The contents here can be applied
to both of the embodiment 1 and the embodiment 2.
[0244] When the user apparatus UE2 on the receiving side detects
the location of the transmission source UE, the user apparatus UE2
on the receiving side can selectively receive the data of the D2D
communication transmitted from a plurality of transmission source
UEs. As methods for performing this, there are the following
options 1 and option 2 (option 2-1, 2-2).
[0245] Option 1) Information on time/frequency resources of D2D
communication is included in the discovery message transmitted from
the user apparatus UE on the transmitting side. The time/frequency
resources are, for example, resources used by the user apparatus
UE1 for transmission (transmission of control information and/or
data) in D2D communication. Note that the time/frequency resources
used for transmitting the discovery message and the time/frequency
resources used for transmission in the D2D communication may be
different.
[0246] For example, as illustrated in FIG. 25, the user apparatus
UE2 on the receiving side can receive the control information/data
of the D2D communication by using the time/frequency resources for
D2D communication included in the received discovery message.
[0247] Option 2) In option 2, the ID (discovery ID) of the user
apparatus UE on the transmitting side included in the discovery
message transmitted from the user apparatus UE on the transmitting
side, is used for reception of control information/data in D2D
communication at the UE on the receiving side. Specifically, there
are the following options 2-1 and 2-2.
[0248] In option 2-1, the CRC of the SCI used for the data
scheduling in D2D communication is masked by a UE-ID (or a
processed UE-ID). The user apparatus UE2 on the receiving side can
receive the SCI and the data by unmasking the CRC with the UE-ID
acquired by the discovery message.
[0249] In option 2-2, SCI used for data scheduling in D2D
communication or data is scrambled by the UE-ID (or a processed
UE-ID). The user apparatus UE2 on the receiving side can receive
the SCI and the data by descrambling the SCI/data with the UE-ID
acquired by the discovery message. Note that the above "processed"
means, for example, setting the bit length of the UE-ID to a
predetermined bit length.
(Regarding Cross Carrier Discovery)
[0250] The content here can also be applied to both the embodiment
1 and the embodiment 2. In the discovery message, the AS parameters
for D2D communication and frequencies used for transmission and/or
reception in D2D communication may be included.
[0251] Furthermore, the transmission of the discovery message and
the transmission in D2D communication associated with the discovery
may be performed at different frequencies with different RATs. For
example, D2D communication may be performed with NR sidelink and
the discovery may be performed with LTE V2X or IEEE 802.11p.
[0252] For example, when the discovery message is transmitted at a
frequency that is lower than the frequency used in the D2D
communication, a sufficient discovery range can be obtained without
HARQ combining.
(Device Configuration)
[0253] Next, a functional configuration example of the user
apparatus UE and the base station 10 that execute the processing
operations described so far will be described. The user apparatus
UE and the base station 10 may include all the functions of the
embodiment 1 and the embodiment 2, or may include the functions of
only one of the embodiments.
<User Apparatus>
[0254] FIG. 26 is a diagram illustrating an example of the
functional configuration of the user apparatus UE. As illustrated
in FIG. 26, the user apparatus UE includes a transmitting unit 101,
a receiving unit 102, and a configuration information managing unit
103. The functional configuration illustrated in FIG. 26 is merely
an example. As long as the operations according to the present
embodiment can be executed, the functional sections and the names
of the functional units are not limited to this example.
[0255] The transmitting unit 101 creates a transmission signal from
the transmission data and wirelessly transmits the transmission
signal. The receiving unit 102 wirelessly receives various signals,
and acquires a signal of a higher layer from the signal of the
received physical layer. Both the transmitting unit 101 and the
receiving unit 102 include a D2D function and a cellular
communication function. The transmitting unit 101 includes a
function of executing the operations of message/SCI/data/signal
transmission described in the embodiments 1 and 2, and the
receiving unit 102 includes a function of executing the operations
of message/SCI/data/signal reception described in the embodiments 1
and 2.
[0256] The configuration information managing unit 103 stores
various kinds of configuration information received from the base
station 10 by the receiving unit 102 and preset configuration
information.
[0257] Furthermore, as illustrated in FIG. 27, the transmitting
unit 101 includes a message generating unit 111, a message
transmitting unit 121, and a signal transmitting unit 131. For
example, as illustrated in FIGS. 17 to 19, the message generating
unit 111 generates a discovery message. The message transmitting
unit 121 transmits the discovery message in the embodiments 1 and
2, and the signal transmitting unit 131 transmits the discovery
signal in the embodiment 1.
[0258] Furthermore, the signal transmitting unit 131 is configured
to transmit a signal used for measurement of the radio quality in
another user apparatus, and the message transmitting unit 121 is
configured to transmit a message including a predetermined
parameter, and the transmission period of signals transmitted by
the signal transmitting unit 131 may be independent of the
transmission period of messages transmitted by the message
transmitting unit 121. Furthermore, the receiving unit 102 may be
configured to receive, from the base station 10, parameters used
for receiving signals transmitted from other user apparatuses.
[0259] Furthermore, the message generating unit 111 is configured
to generate a message including a first segment and a second
segment, and the message transmitting unit 121 is configured to
transmit the message a plurality of times within a predetermined
period, and the information reported by a plurality of first
segments transmitted within the predetermined period by the message
transmitting unit 121, may not be changed within the predetermined
period.
[0260] The message transmitting unit 121 may be configured to
transmit control information including scheduling information of
the second segment, or control information including scheduling
information of the first segment and the second segment, and the
message.
[0261] The message transmitting unit 121 may be configured to
transmit the first segment by using a control channel and transmit
the second segment by using a data channel.
[0262] The message transmitting unit 121 may be configured to
transmit the message a plurality of times within the predetermined
period, by using a predetermined resource hopping pattern or a
resource hopping pattern set from the base station in the radio
communication system.
<Base Station 10>
[0263] FIG. 28 is a diagram illustrating an example of the
functional configuration of the base station 10. As illustrated in
FIG. 28, the base station 10 includes a transmitting unit 201, a
receiving unit 202, and a configuration information managing unit
203. The functional configuration illustrated in FIG. 28 is merely
an example. As long as the operations according to the present
embodiment can be executed, the functional sections and the names
of the functional units are not limited to this example.
[0264] The transmitting unit 201 includes a function of generating
a signal to be transmitted to the user apparatus UE side and
wirelessly transmitting the signal. The receiving unit 202 includes
a function of receiving various signals transmitted from the user
apparatus UE and acquiring, for example, information of a higher
layer, from the received signals.
[0265] The transmitting unit 201 includes a function of executing
operations for transmitting signals such as configuration
information, etc., to the user apparatus UE described in the
embodiments 1 and 2, and the receiving unit 202 includes a function
of executing operations for receiving signals from the user
apparatus UE. The operations of signal transmission include
scheduling.
[0266] The configuration information managing unit 203 stores
various kinds of configuration information to be transmitted to the
user apparatus UE, various kinds of configuration information
received from the user apparatus UE, and configuration information
preset.
<Hardware Configuration>
[0267] The block diagrams (FIGS. 26 to 28) used in the description
of the above embodiment illustrate blocks of functional units.
These functional blocks (constituent parts) are implemented by any
combination of hardware and/or software. Furthermore, the means for
implementing each functional block is not particularly limited.
That is, the respective functional blocks may be implemented by a
single device in which a plurality of elements are physically
and/or logically combined; or two or more devices, which are
physically and/or logically separated, may be directly and/or
indirectly (for example, wired and/or wireless) connected, and the
respective functional blocks may be implemented by these plural
devices.
[0268] Furthermore, for example, both the user apparatus UE and the
base station 10 according to one embodiment of the present
invention may function as a computer that performs processes
according to the present embodiment. FIG. 29 is a diagram
illustrating an example of a hardware configuration of the user
apparatus UE and the base station 10 according to the present
embodiment. Each of the user apparatus UE and the base station 10
described above may be physically configured as a computer device
including a processor 1001, a memory 1002, a storage 1003, a
communication device 1004, an input device 1005, an output device
1006, and a bus 1007, etc.
[0269] Note that in the following description, the term "device"
can be read as a circuit, a device, and a unit, etc. The hardware
configuration of the user apparatus UE and the base station 10 may
be configured to include one or a plurality of devices indicated by
the reference numerals 1001 to 1006 illustrated in the drawing, or
may be configured to not include some of the devices.
[0270] The respective functions of the user apparatus UE and the
base station 10 are implemented by having predetermined software
(programs) to be loaded in the hardware such as the processor 1001
and the memory 1002 so that the processor 1001 performs computation
and controls the communication performed by the communication
device 1004 and the reading and/or writing of data in the memory
1002 and the storage 1003.
[0271] The processor 1001, for example, operates the operating
system to control the entire computer. The processor 1001 may be
configured with a Central Processing Unit (CPU) including an
interface with peripheral devices, a control device, an arithmetic
device, and a register, etc.
[0272] Furthermore, the processor 1001 loads programs (program
codes), software modules, or data from the storage 1003 and/or the
communication device 1004 into the memory 1002, and executes
various processes according to these elements. As the program, a
program for causing a computer to execute at least part of the
operation described in the above embodiment, is used. For example,
the transmitting unit 101, the receiving unit 102, and the
configuration information managing unit 103 of the user apparatus
UE illustrated in FIG. 26 may be implemented by a control program
that is stored in the memory 1002 and that operates on the
processor 1001. Furthermore, for example, the transmitting unit
201, the receiving unit 202, and the configuration information
managing unit 203 of the base station 10 illustrated in FIG. 28 may
be implemented by a control program that is stored in the memory
1002 and that operates on the processor 1001. Although it has been
described that the various processes described above are executed
by a single processor 1001, the various processes described above
may be executed simultaneously or sequentially by two or more
processors 1001. The processor 1001 may be implemented by one or
more chips. Note that the programs may be transmitted from the
network via an electric communication line.
[0273] The memory 1002 is a computer-readable recording medium, and
is configured with at least one of a ROM (Read-Only Memory), an
EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable
Programmable ROM), and a RAM (Random Access Memory), for example.
The memory 1002 may be referred to as a register, a cache, and a
main memory (main memory), etc. The memory 1002 can store
executable programs (program codes) and software modules, etc., for
implementing the processes according to an embodiment of the
present invention.
[0274] The storage 1003 is a computer-readable recording medium,
and may be configured with at least one of, for example, an optical
disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a
flexible disk, a magneto-optical disk (for example, a compact disk,
a digital versatile disk, a Blu-ray (Registered trademark) disk), a
smart card, a flash memory (for example, a card, a stick, a key
drive), a floppy (registered trademark) disk, and a magnetic strip,
etc. The storage 1003 may be referred to as an auxiliary storage
device. The above-described storage medium may be, for example, a
database including the memory 1002 and/or the storage 1003, a
server, or other appropriate media.
[0275] The communication device 1004 is hardware
(transmission/reception device) for performing communication
between computers via a wired and/or wireless network, and is also
referred to as a network device, a network controller, a network
card, and a communication module, etc., for example. For example,
the transmitting unit 101 and the receiving unit 102 of the user
apparatus UE may be implemented by the communication device 1004.
Furthermore, the transmitting unit 201 and the receiving unit 202
of the base station 10 may be implemented by the communication
device 1004.
[0276] The input device 1005 is an input device (for example, a
keyboard, a mouse, a microphone, a switch, a button, and a sensor,
etc.) that accepts input of information from the outside. The
output device 1006 is an output device (for example, a display, a
speaker, and an LED lamp, etc.) that outputs information to the
outside. Note that the input device 1005 and the output device 1006
may be integrated (for example, a touch panel).
[0277] Furthermore, the respective devices such as the processor
1001 and the memory 1002 are connected by the bus 1007 for
communicating information. The bus 1007 may be configured with a
single bus or may be configured with different buses between the
respective devices.
[0278] Furthermore, each of the user apparatus UE and the base
station 10 may include hardware such as a microprocessor, a digital
signal processor (DSP), an application specific integrated circuit
(ASIC), a programmable logic device (PLD), and a field programmable
gate array (FPGA), and some of or all of the functional blocks may
be implemented by this hardware. For example, the processor 1001
may be implemented with at least one of these hardware
elements.
(Summary of Embodiment)
[0279] As described above, according to the present embodiment, a
user apparatus in a radio communication system supporting a D2D
technology is provided, the user apparatus including
[0280] a signal transmitting unit configured to transmit a signal
used for measuring a radio quality in another user apparatus;
and
[0281] a message transmitting unit configured to transmit a message
including a predetermined parameter, wherein
[0282] a transmission period of the signals transmitted by the
signal transmitting unit is independent of a transmission period of
the messages transmitted by the message transmitting unit.
[0283] According to the above configuration, a technology for
enabling a user apparatus to appropriately measure the radio
quality, while avoiding an increase in the overhead of radio
resources in D2D, is provided.
[0284] The predetermined parameter may include a parameter used for
receiving the signal. According to this configuration, the user
apparatus on the receiving side can appropriately receive the
signals.
[0285] A transmission parameter of the signal may be derived from a
transmission parameter of the message, or the transmission
parameter of the message may be derived from the transmission
parameter of the signal. According to this configuration, the
signaling overhead can be reduced.
[0286] The signal may be a physical signal that does not include a
message. According to this configuration, the signal can be
transmitted with a small number of radio resources.
[0287] The user apparatus may further include a receiving unit
configured to receive, from a base station in the radio
communication system, a parameter used for receiving a signal
transmitted from the other user apparatus. According to this
configuration, signals transmitted from the other user apparatus
can be appropriately received.
[0288] Furthermore, according to the present embodiment, a
transmission method executed by a user apparatus in a radio
communication system supporting a D2D technology is provided, the
transmission method including
[0289] a signal transmitting step of transmitting a signal used for
measuring a radio quality in another user apparatus; and
[0290] a message transmitting step of transmitting a message
including a predetermined parameter, wherein
[0291] a transmission period of the signals transmitted at the
signal transmitting step is independent of a transmission period of
the messages transmitted at the message transmitting step.
[0292] According to the above configuration, a technology for
enabling a user apparatus to appropriately measure the radio
quality, while avoiding an increase in the overhead of radio
resources in D2D, is provided.
[0293] Furthermore, as described above, according to the present
embodiment, a user apparatus in a radio communication system
supporting a D2D technology is provided, the user apparatus
including
[0294] a message generating unit configured to generate a message
including a first segment and a second segment; and
[0295] a message transmitting unit configured to transmit, multiple
times, the message within a predetermined period, wherein
[0296] information reported by a plurality of the first segments
transmitted within the predetermined period by the message
transmitting unit, is not changed within the predetermined
period.
[0297] According to the above configuration, a technology for
enabling messages to be appropriately transmitted and received,
even when the information, which is transmitted in the message by
the user apparatus on the transmitting side, may be frequently
changed, in D2D, is provided.
[0298] The message transmitting unit may transmit control
information including scheduling information of the second segment
or control information including scheduling information of the
first segment and the second segment, and the message. According to
this configuration, the user apparatus on the receiving side can
quickly receive the message.
[0299] The message transmitting unit may transmit the first segment
by using a control channel, and transmit the second segment using a
data channel. According to this configuration, for example, it is
possible to use an existing channel and implementation is
relatively easy.
[0300] The message transmitting unit may transmit, multiple times,
the message within the predetermined period, by using a
predetermined resource hopping pattern or a resource hopping
pattern set from a base station in the radio communication system.
According to this configuration, the user apparatus on the
receiving side can appropriately receive the message.
[0301] HARQ soft combining may be executed at another user
apparatus, with respect to a plurality of the first segments
transmitted within the predetermined period by the message
transmitting unit. According to this configuration, the other user
apparatus can properly receive the first segment.
[0302] Furthermore, according to the present embodiment, a
transmission method executed by a user apparatus in a radio
communication system supporting a D2D technology is provided, the
transmission method including
[0303] a message generating step of generating a message including
a first segment and a second segment; and
[0304] a message transmitting step of transmitting, multiple times,
the message within a predetermined period, wherein
[0305] information reported by a plurality of the first segments
transmitted within the predetermined period at the message
transmitting step, is not changed within the predetermined
period.
[0306] According to the above configuration, a technology for
enabling messages to be appropriately transmitted and received,
even when the information, which is transmitted in the message by
the user apparatus on the transmitting side, may be frequently
changed, in D2D, is provided.
(Supplement to Embodiment)
[0307] The exemplary embodiment of the present invention is
described above, but the disclosed invention is not limited to the
above embodiment, and those skilled in the art would understand
that various modified examples, revised examples, alternative
examples, substitution examples, and the like can be made. In order
to facilitate understanding of the present invention, specific
numerical value examples are used for description, but the
numerical values are merely examples, and certain suitable values
may be used unless otherwise stated. The classification of items in
the above description is not essential to the present invention,
matters described in two or more items may be combined and used as
necessary, and a matter described in one item may be applied to a
matter described in another item (unless there is no
contradiction). The boundary between functional units or processing
units in a functional block diagram does not necessarily correspond
to the boundary between physical parts. Operations of a plurality
of functional units may be performed physically by one component,
or an operation of one functional unit may be performed physically
by a plurality of parts. In the processing procedures described in
the embodiment, the order of processes may be changed as long as
there is no inconsistency. For the sake of convenience of
description, the user apparatus UE and the base station 10 have
been described using the functional block diagrams, but such
apparatuses may be implemented by hardware, software, or a
combination thereof. Software executed by the processor included in
the user apparatus UE according to the embodiment of the present
invention, and the software executed by the processor of the base
station 10 according to the embodiment of the present invention,
may be stored in a random access memory (RAM), a flash memory, a
read only memory (ROM), an EPROM, an EEPROM, a register, a hard
disk (HDD), a removable disk, a CD-ROM, a database, a server, or
any other appropriate storage medium.
[0308] Furthermore, notification of information is not limited to
the aspect/embodiment described in the present specification, and
may be performed by other methods. For example, the notification of
information may be performed by physical layer signaling (for
example, DCI (Downlink Control Information), UCI (Uplink Control
Information)), upper layer signaling (for example, RRC (Radio
Resource Control) signaling, MAC (Medium Access Control) signaling,
broadcast information (MIB (Master Information Block), SIB (System
Information Block)), other signals, or a combination of these
methods. Furthermore, the RRC signaling may be referred to as an
RRC message, and may be, for example, an RRC Connection Setup
message or an RRC Connection Reconfiguration message, etc.
[0309] Each aspect/embodiment described in the present
specification may be applied to LTE (Long Term Evolution), LTE-A
(LIE-Advanced), SUPER 3G, IMT-Advanced, 4G, 5G, FRA (Future Radio
Access), W-CDMA (registered trademark), GSM, (registered
trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11
(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, UWB (Ultra-WideBand),
Bluetooth(registered trademark), and a system using other
appropriate systems and/or a next generation system expanded based
on these systems.
[0310] In the processes, sequences, and flowcharts, etc., in each
aspect/embodiment described in the present specification, the order
of processes may be exchanged, as long as there is no
inconsistency. For example, for the methods described in the
present specification, elements of the various steps are presented
in an exemplary order and are not limited to the presented specific
order.
[0311] The specific operation that is performed by the base station
10 in the present specification may be performed by an upper node
of the base station 10 in some cases. It is obvious that in a
network including one or more network nodes including the base
station 10, various operations performed for communication with the
user apparatus UE, may be performed by the base station 10 and/or a
network node of other than the base station 10 (for example, MME or
S-GW, etc., although not limited as such). In the above example,
there is one network node other than the base station 10; however,
a combination of a plurality of other network nodes (for example,
MME and S-GW) may be used.
[0312] Each aspect/embodiment described in the present
specification may be used singly or in combination, or may be
switched in accordance with execution.
[0313] The user apparatus UE may be referred to, by those skilled
in the art, as a subscriber station, a mobile unit, a subscriber
unit, a wireless unit, a remote unit, a mobile device, a wireless
device, a wireless communication device, a remote device, a mobile
subscriber station, an access terminal, a mobile terminal, a
wireless terminal, a remote terminal, a handset, a user agent, a
mobile client, a client, or some other suitable term.
[0314] The base station 10 may be referred to, by those skilled in
the art, as a NB (Node B), an eNB (enhanced Node B), a Base
Station, gNB, or some other suitable term.
[0315] The terms "determining" and "deciding" used in the present
specification may encompass a wide variety of operations.
"Determining" and "deciding" may include the meaning of, for
example, judging, calculating, calculating, computing, processing,
deriving, investigating, looking up (for example, searching a
table, a database, or another data structure), and ascertaining,
etc. Furthermore, "determining" and "deciding" may include the
meaning of receiving (for example, receiving information),
transmitting (for example, transmitting information), inputting,
outputting, and accessing (for example, accessing data in a
memory). Furthermore, "determining" and "deciding" may include the
meaning of resolving, selecting, choosing, establishing, and
comparing, etc. In other words, "determining" and "deciding"
include the meaning of "determining" and "deciding" some kind of
operation.
[0316] The phrase "based on" used in the present specification does
not mean "based only on", unless explicitly stated otherwise. In
other words, the phrase "based on" means both "based only on" and
"based on at least".
[0317] The terms "include", "including", and variations thereof
used in the present specification or claims, are intended to be
inclusive in a manner similar to the term "comprising".
Furthermore, the term "or" used in the present specification or
claims, is not intended to be exclusive OR.
[0318] In the entire present disclosure, if articles are added by
translation, such as a, an, and the in English, for example, these
articles may include a plural number of items/units, unless it is
indicated that these articles are obviously not plural from the
context.
[0319] Although the present invention has been described in detail
above, it will be obvious to those skilled in the art that the
present invention is not limited to the embodiments described
herein. The present invention can be implemented as modifications
and variations without departing from the spirit and scope of the
present invention as defined by the scope of the claims. Therefore,
the description of the present specification is for the purpose of
illustration and does not have any restrictive meaning to the
present invention.
REFERENCE SIGNS LIST
[0320] UE user apparatus [0321] 101 transmitting unit [0322] 111
message generating unit [0323] 121 message transmitting unit [0324]
131 signal transmitting unit [0325] 102 receiving unit [0326] 103
configuration information managing unit [0327] 10 base station
[0328] 201 transmitting unit [0329] 202 receiving unit [0330] 203
configuration information managing unit [0331] 1001 processor
[0332] 1002 memory [0333] 1003 storage [0334] 1004 communication
device [0335] 1005 input device [0336] 1006 output device
* * * * *