U.S. patent application number 15/491922 was filed with the patent office on 2017-08-03 for method and apparatus for control of uplink feedback information in contention based access in wireless communications.
This patent application is currently assigned to InterDigital Patent Holdings, Inc.. The applicant listed for this patent is InterDigital Patent Holdings, Inc.. Invention is credited to Christopher R. Cave, Rocco Di Girolamo, Paul Marinier, Diana Pani, Benoit Pelletier, Eldad M. Zeira.
Application Number | 20170223726 15/491922 |
Document ID | / |
Family ID | 40452450 |
Filed Date | 2017-08-03 |
United States Patent
Application |
20170223726 |
Kind Code |
A1 |
Pelletier; Benoit ; et
al. |
August 3, 2017 |
METHOD AND APPARATUS FOR CONTROL OF UPLINK FEEDBACK INFORMATION IN
CONTENTION BASED ACCESS IN WIRELESS COMMUNICATIONS
Abstract
A method and apparatus for control of uplink feedback
information in contention based wireless communications is
disclosed. Uplink feedback information such as a channel quality
information and hybrid automatic retransmission request (HARQ)
acknowledgement/negative acknowledgement (ACK/NACK) information may
be transmitted to the universal terrestrial radio access network
(UTRAN) by a wireless transmit/receive unit (WTRU) based on
explicit and implicit triggers. Providing more frequent and robust
information relating to the channel conditions and HARQ status
allows the UTRAN to more efficiently utilize the radio resources
for downlink data transmissions.
Inventors: |
Pelletier; Benoit; (Roxboro,
CA) ; Cave; Christopher R.; (Dollard-des-Ormeaux,
CA) ; Pani; Diana; (Montreal, CA) ; Di
Girolamo; Rocco; (Laval, CA) ; Marinier; Paul;
(Brossard, CA) ; Zeira; Eldad M.; (Huntington,
NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
InterDigital Patent Holdings, Inc. |
Wilmington |
DE |
US |
|
|
Assignee: |
InterDigital Patent Holdings,
Inc.
Wilmington
DE
|
Family ID: |
40452450 |
Appl. No.: |
15/491922 |
Filed: |
April 19, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12258922 |
Oct 27, 2008 |
9674865 |
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15491922 |
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60982629 |
Oct 25, 2007 |
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61018924 |
Jan 4, 2008 |
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61025378 |
Feb 1, 2008 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 1/0003 20130101;
H04L 1/1685 20130101; H04W 72/1284 20130101; H04L 1/1671 20130101;
H04L 1/1829 20130101; H04L 1/0026 20130101; H04L 1/1861 20130101;
H04W 24/08 20130101; H04L 1/0009 20130101; H04L 5/0055 20130101;
H04W 74/04 20130101; H04L 1/1816 20130101 |
International
Class: |
H04W 72/12 20060101
H04W072/12; H04W 24/08 20060101 H04W024/08; H04L 1/00 20060101
H04L001/00; H04W 74/04 20060101 H04W074/04; H04L 1/18 20060101
H04L001/18; H04L 5/00 20060101 H04L005/00 |
Claims
1. A method of transmitting uplink feedback information by a
wireless transmit/receive unit (WTRU) in a CELL_FACH state
comprising: measuring a channel quality to determine uplink (UL)
feedback information based on the channel quality; receiving an
allocation from a network for an enhanced dedicated channel (E-DCH)
resource for UL transmission; transmitting dedicated control
channel (DCCH) or dedicated traffic channel (DTCH) traffic;
receiving an assignment from the network of a contention-free
access; receiving a configuration from the network to send the UL
feedback information; and transmitting the UL feedback
information.
2. The method of claim 1 wherein the UL feedback information is
transmitted on a high speed dedicated physical control channel
(HS-DPCCH).
3. The method of claim 1 wherein the UL feedback information
comprises a channel quality indicator (CQI).
4. The method of claim 1 wherein the UL feedback information
comprises a hybrid automatic retransmission request (HARQ)
acknowledgement or negative acknowledgement (ACK/NACK).
5. The method of claim 1 wherein the contention free access
comprises the WTRU successfully completing a contention resolution
phase.
6. The method of claim 1 wherein receiving the configuration from
the network comprises broadcasting of at least one feedback
configuration parameter over a system information block (SIB).
7. The method of claim 1, wherein the configuration is received in
a special information element (IE) broadcast as part of a set, of
common E-DCH resources.
8. The method of claim 1, further comprising: receiving from the
network at least one of a E-DCH radio network temporary identifier
(E-RNTI), a high speed dedicated shared channel (HS-DSCH) radio
network temporary identifier (H-RNTI), and a cell radio network
temporary identifier (C-RNTI).
9. A wireless transmit/receive unit (WTRU) configured to transmit
uplink (UL) feedback information in a CELL_FACH state comprising: a
measurement unit configured to measure a channel quality, wherein
the UL feedback information is derived based on the channel
quality; a receiver configured to receive from a network, an
allocation of an enhanced dedicated channel (E-DCH) resource for UL
transmission; a transmitter configured to transmit traffic on a
dedicated control channel (DCCH) or a dedicated traffic channel
(DTCH); the receiver further configured to receive a
contention-free access assignment from the network; the receiver
further configured to receive a configuration from the network to
send the UL feedback information; the transmitter further
configured to transmit the UL feedback information.
10. The WTRU of claim 9 wherein the UL feedback information is
transmitted on a high speed dedicated physical control channel
(HS-DPCCH).
11. The WTRU of claim 9 wherein the UL feedback information
comprises a channel quality indicator (CQI).
12. The WTRU of claim 9 wherein the UL feedback information
comprises a hybrid automatic retransmission request (HARQ)
acknowledgement or negative acknowledgement (ACK/NACK).
13. The WTRU of claim 9 wherein the receiver receives the
contention free access assignment by successfully completing a
contention resolution phase
14. The WTRU of claim 9 wherein the receiver is further configured
to receive the configuration from the network through a broadcast
of the feedback configuration parameters in a system information
block (SIB).
15. The WTRU of claim 9, wherein the receiver is further configured
to receive an indication to transmit the channel quality
information over the HS-DPCCH through a special information element
(IE) broadcast as part of a set of E-DCH resources.
16. The WTRU of claim 9, the receiver further configured to receive
at least one of an E-DCH radio network temporary identifier
(E-RNTI), a high speed dedicated share channel (HS-DSCH) radio
network temporary identifier (H-RNTI), and a cell radio network
temporary identifier (C-RNTI).
17. A method of transmitting uplink (UL) feedback information by a
wireless transmit/receive unit (WTRU) in a CELL_FACH state
comprising: measuring a channel quality; generating UL feedback
information based on the measured channel quality; and transmitting
the UL feedback information based on an existence of at least one
predetermined condition.
18. The method of claim 17, wherein the at least one predetermined
condition comprises the WTRU receiving from the network, at least
one of an enhanced dedicated channel (E-DCH) radio network
temporary identifier (E-RNTI), a high speed dedicated share channel
(HS-DSCH) radio network temporary identifier (H-RNTI), and a cell
radio network temporary identifier (C-RNTI).
19. The method of claim 17, wherein the at least one predetermined
condition is the WTRU transmitting data on a dedicated control
channel (DCCH) Or a dedicated traffic channel (DTCH).
20. The method of claim 17, wherein the at least one predetermined
condition is a radio resource control (RRC) state that the WTRU is
currently in.
21. The method of claim 17, wherein the at least one predetermined
condition is including a high speed dedicated shared channel
(HS-DSCH) radio network temporary identifier (H-RNTI) in a medium
access control (MAC) protocol data unit (PDU) wherein the H-RNTI is
linked to the uplink feedback information
22. The method of claim 17, wherein the at least one predetermined
condition is receiving a logical channel identifier (LCH-ID) with
associated data, wherein the LCH-ID indicates a signaling radio
hearer (SRB) that contains messages larger than a predetermined
size threshold.
23. A wireless transmit/receive unit (WTRU) comprising: a
measurement unit for measuring a channel quality, wherein UL
feedback information is generated based on the channel quality; a
transmitter configured to transmit the UL feedback information to a
Node B when a predetermined condition exists; a receiver configured
to receive data and control information from a Node B; a controller
configured to control the receiver and the transmitter.
24. The WTRU of claim 23, wherein the at least one predetermined
condition comprises the WTRU receiving from the Node B, at least
one of an E-DCH radio network temporary identifier (E-RNTI), a high
speed dedicated share channel (HS-DSCH) radio network temporary
identifier (H-RNTI), and a cell radio network temporary identifier
(C-RNTI).
25. The WTRU of claim 23, wherein the at least one predetermined
condition is the WTRU transmitting data on a dedicated control
channel (DCCH) or a dedicated traffic channel (DTCH).
26. The WTRU of claim 23, wherein e at least one predetermined
condition is a radio resource control (RRC) state the WTRU is
currently in.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional
application Nos. 60/982,629 filed Oct. 25, 2007, 61/018,924 filed
Jan. 4, 2008, and 61/025,378 filed Feb. 1, 2008 which are
incorporated by reference as if fully set forth.
FIELD OF INVENTION
[0002] This application is related to wireless communications.
BACKGROUND
[0003] Enhanced uplink has been introduced as part of the release 6
of the third generation partnership project (3GPP) standards. The
enhanced uplink operates on a rate request and grant mechanism. A
wireless transmit/receive unit (WTRU) sends a rate request
indicating the requested capacity, while a network responds with a
rate grant to the rate request. The rate grant is generated by a
Node B scheduler. The WTRU and a Node B use a hybrid automatic
repeat request (HARQ) mechanism for transmissions over an enhanced
dedicated channel (E-DCH).
[0004] For enhanced uplink transmission, two uplink physical
channels, (E-DCH dedicated physical control channel (E-DPCCH) and
an E-DCH dedicated physical data channel (E-DPDCH)), and three
downlink physical channels, (E-DCH absolute grant channel (E-AGCH),
E-DCH relative grant channel (E-RGCH), and E-DCH HARQ indicator
channel (E-HICH)), have been introduced. The Node B may issue both
absolute grants and relative grants. Rate grants are signaled in
terms of a power ratio. Each WTRU maintains a serving grant that
can be converted to a payload size.
[0005] WTRUs that make E-DCH transmissions have an E-DCH active
set. The E-DCH active set includes all cells for which the WTRU has
an established E-DCH radio link. The E-DCH active set is a subset
of a dedicated channel (DCH) active set. A distinction is made
between those radio links that are part of the E-DCH radio link set
(RLS) and those that are not. The former includes radio links that
share the same Node B as a serving Node B. Cells for non-serving
radio links may only send relative grants in an effort to limit or
control the uplink interference.
[0006] As part of ongoing evolution of the wideband code division
multiple access (WCDMA) standard in 3GPP Release 8, a new work item
has been established to incorporate E-DCH concepts for WTRUs in a
CELL_FACH state. In Release 7 and earlier, the only uplink
mechanism for WTRUs in a CELL_FACH state was a random access
channel (RACH). The RACH is based on a slotted-Aloha mechanism with
an acquisition indication. Before sending a message on a RACH, a
WTRU tries to acquire the channel by sending a short preamble (made
up of a randomly selected signature sequence in a randomly selected
access slot). The WTRU then listens and waits for an acquisition
indication from the universal terrestrial radio access network
(UTRAN). If no indication is received, the WTRU ramps up its power
and tries again (sending a randomly selected signature sequence in
a randomly selected access slot). If an acquisition indication is
received, the WTRU has effectively acquired the channel, and may
transmit a RACH message part, of finite duration. The initial
preamble transmit power is established based on an open loop power
control, whereas the ramp-up mechanism is used to further fine-tune
the transmit power. The RACK message is transmitted at a fixed
power offset from the last preamble and is of fixed size.
Macro-diversity is not employed and the WTRU has no concept of
active set for the RACH.
[0007] The new work item attempts to increase the uplink user plane
and control plane throughput, by assigning dedicated E-DCH
resources after the initial WTRU power ramp up, (it is referred to
"enhanced Uplink in CELL_FACH state and Idle Mode" or "enhanced
RACH"). A WTRU transmits a RACH preamble in order to acquire a
channel implementing power ramp-up. Once the RACH preamble is
detected, a Node B transmits an acquisition indication (AI). After
receiving the AI, the WTRU is assigned with an E-DCH resource for a
subsequent E-RACH message transmission. The E-DCH resource
assignment may be made either with the AI or with an enhanced set
of AIs. The WTRU then transmits an E-RACH message and enters a
contention resolution phase. The contention resolution phase is
provided to solve potential collision of the E-RACH message. After
transmission of all the data in the buffer, explicit indication
from UTRAN, radio link failure, post verification failure, or
expiry of a timer, the E-DCH resource is released.
[0008] A WTRU in a CELL_FACH state may use high speed downlink
packet access (HSDPA) in the downlink.
[0009] However, this approach currently suffers from several
problems. First, the initial transmissions on the high speed
downlink channel may not be privy to channel quality information.
In 3GPP Release 7, this was partially addressed by having the Node
B use the channel quality information carried in an information
element (IE), "Measured Results on RACH". This IE is included in a
number of layer 3 radio resource control (RRC) messages. In
addition, a WTRU in a CELL_PCH state receiving dedicated control or
data traffic is triggered to send channel quality information
through a layer 3 measurement report upon reception of high speed
downlink control traffic, (i.e., high speed shared control channel
(HS-SCCH) with the WTRU address). However, as the feedback is sent
through RRC signaling, it may be too slow for efficient modulation
and coding control of the initial high speed downlink
transmission.
[0010] Second, the 3GPP Release 7 approach is geared more toward
WTRU-initiated control traffic, (for instance a CELL UPDATE). In a
typical scenario, the WTRU would tag along channel quality
information to the uplink RRC message. The network would then use
this information to determine the allowed modulation and transport
block size, and then send an RRC network response using the
selected parameters. However, there may be some inefficiency if the
uplink traffic is user-plane data traffic and does not carry any
channel quality information, or is an RRC message that does not
carry the IE: "Measured Results on RACH", or if user-plane and
control-plane traffic is network-initiated.
[0011] In both cases, the network may not have timely channel
quality information and it would have to rely on the information
received in the last IE: "Measured Results on RACH". This
inefficiency is likely to be more prevalent with enhanced RACH, as
the network may decide to keep more WTRUs in a CELL_FACH state, for
example to deal with asymmetric type applications, such as web
browsing. It is likely that these WTRUs are kept in a CELL_FACH
state, but that their enhanced RACH resources are released (for
instance, after the WTRU has finished its transmission). As a
result, any subsequent network-initiated downlink transmissions
will not have "up-to-date" channel, quality information. This would
result in some inefficiency as the network would not be able to
maximize the downlink transmission rate. Thus high speed downlink
packet access (HSDPA) in a CELL_FACH state would benefit
significantly from fast uplink feedback for both channel quality
and HARQ feedback.
SUMMARY
[0012] A method and apparatus for control of uplink feedback
information in contention based wireless communications is
disclosed. Uplink feedback information such as a channel quality
information and HARQ ACK/NACK information may be transmitted to the
UTRAN by a WTRU based on explicit and implicit triggers. By
providing more frequent and robust information relating to the
channel conditions and HARQ status, the UTRAN can more efficiently
utilize the radio resources for downlink data transmissions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] A more detailed understanding may be had from the following
description, given by way of example in conjunction with the
accompanying drawings wherein:
[0014] FIG. 1 shows a UTRAN network containing a Node B and
multiple WTRUs;
[0015] FIG. 2 shows a WTRU configured to report feedback
information in the uplink;
[0016] FIG. 3 is a block diagram of a method of reporting feedback
information using explicit triggers;
[0017] FIG. 4 is a block diagram of a first method of reporting
feedback information using implicit triggers; and
[0018] FIG. 5 is a block diagram of a second method of reporting
feedback information using implicit triggers.
DETAILED DESCRIPTION
[0019] When referred to hereafter, the terminology "WTRU" includes
but is not limited to a user equipment (UE), a mobile station, a
fixed or mobile subscriber unit, a pager, a cellular telephone, a
personal digital assistant (PDA), a computer, or any other type of
user device capable of operating in a wireless environment.
[0020] When referred to hereafter, the terminology "Node B"
includes but is not limited to a base station, a site controller,
an access point (AP), or any other type of interfacing device
capable of operating in a wireless environment. When referred to
hereafter, the terminology "Enhanced RACH" refers to the use of
enhanced uplink (E-DCH) in CELL_FACH state and in an idle mode. The
Enhanced RACH transmission may use Release 6 MAC-e/es entities or
MAC-i/is entities that are introduced in Release 8 as part of the
"Improved Layer 2" feature. The terminologies "MAC-e/es PDU" and
"MAC-i/is PDU" include, but are not limited to, the PDUs generated
by the MAC-e/es entities, PDUs generated by the MAC-i/is entities,
or any PDUs generated by the MAC entity used to perform E-DCH
transmission in the CELL_FACH state and an idle mode. When referred
to hereafter, the reception of an acquisition indication refers to
the allocation of an E-DCH resource to the WTRU via a positive
acknowledgement (ACK) on an acquisition indication channel (AICH)
or via a negative acknowledgement (NACK) on the AICH followed by an
index over an enhanced AICH (E-AICH). When referred to hereafter,
the HS-DPCCH information refers to the information required by a
WTRU in order to send HS-DPCCH feedback, such as the delta
ACK/NACK, delta. CQI, CQI feedback cycle, etc. When referred to
hereafter, the terminology "HS-DITCH resource" refers to the
uplink/downlink channels required for support of HS-DPCCH
transmission, the uplink scrambling code information, the HS-DPCCH
information, etc.
[0021] FIG. 1 shows a UTRAN network 100 comprising a Node B 101 and
three WTRUs, 103, 105, and 107. The Node B 101 communicates through
a wireless link 109 with at least one WTRU 103, 105 and 107. The
WTRUs 103, 105 and 107 have receivers for receiving data from the
Node B 101 and transmitters for sending information to the Node B
101. The connection 109 where information flows in a direction from
the WTRU 103, 105, and 107 to the Node B 101 is called the uplink
(UL), while the connection 109 where information flows in a
direction from the Node B 101 to the WTRU 103, 105, and 107 is
called the downlink (DL).
[0022] FIG. 2 is a block diagram of a WTRU 105 configured to
transmit feedback information on the uplink. The WTRU 105 comprises
a transceiver 201 that is configured for wireless communications
and is capable of receiving transmissions from a Node B 101, or
sending transmissions to a Node B 101. Transmission to and from the
WTRU 105 are received/transmitted through an antenna 207. The WTRU
105 further comprises a measurement unit 205 configured to measure
the channel quality of the current link 109 with the Node B 101.
Information relating to the measured quality may be transmitted to
the Node B 101 to allow the Node B 101 to regulate its modulation
and coding scheme (MCS). A processor 203 controls the measurement
unit 205 and the transceiver 201 and controls the reception and
transmission of data including the uplink feedback information. The
processor 203 may be configured to transmit the uplink feedback
information based on an explicit triggering event, or may
implicitly transmit the uplink feedback information based on the
existence of a predetermined condition.
[0023] The transmission of UL feedback information (eg. the channel
quality information), for example over the HS-DPCCH, with E-DCH in
a WTRU in the CELL_FACH state may be configured by the UTRAN. The
determination of when the WTRU transmits the UL feedback
information may be classified in two categories, explicit and
implicit. The various approaches for both explicit and implicit
triggering of UL feedback information transmission may be used
individually or in any combination to transmit the UL feedback
information.
[0024] FIG. 3 is a block diagram of a method 300 for explicit
uplink feedback signaling. A WTRU is configured to take
measurements to determine channel quality based on downlink
transmissions. The WTRU may be configured to send feedback
information 301. If the WTRU is configured to send feedback
information, and the WTRU determines that a triggering event has
occurred 303, then a determination is made whether the WTRU
assigned contention free access to an E-DCH resource by the network
305. The particular types of triggering events will be explained in
greater detail hereinafter. If the WTRU has completed the
contention resolution phase and the WTRU has received a RNTI from
the Node B, the access is contention free and the UL feedback
information is transmitted on the HS-DPCCH 307. If the WTRU is not
configured to send feedback information, has not determined that a
triggering event has occurred, or does not have contention free
access, the method ends and no UL feedback information is
transmitted on the UL 307. Between transmissions of the UL feedback
information by the WTRU, the WTRU is continuously taking channel
quality measurements. When a triggering event occurs, it indicates
to the WTRU to transmit the UL feedback information and the WTRU
transmits the UL feedback information via the HS-DPCCH 307.
[0025] Alternatively, the WTRU only begins taking measurements when
a triggering event has occurred. When the trigger event occurs, the
WTRU begins taking measurements and then may be configured to
transmit the uplink feedback information, CQI, and HARQ
ACK/NACK.
[0026] When a network initiates a downlink transmission to a WTRU
in a CELL_FACH state that has no E-DCH resource, the WTRU may use
the downlink transmission as a trigger to send channel quality
information. For example, this may occur after initial RRC
connection has been established, or after the E-DCH resource has
been released for some reason. The WTRU in a CELL_FACH state may
use the downlink transmission as an explicit trigger to start an
uplink access in order to send fresh channel quality information
and/or HARQ feedback for the downlink transmission.
[0027] Alternatively, an uplink transmission may be used as an
explicit trigger to send the channel quality information over the
HS-DPCCH. For uplink transmission, the WTRU is configured to
request an E-DCH resource. A list of available E-DCH resources is
broadcast from the network in a system information block (SIB) and
an index to the list may be provided to the WTRU for E-DCH resource
assignment. The assigned E-DCH resource may have a one-to-one
mapping to the HS-DPCCH information required for the WTRU to
transmit the channel quality information and optionally ACK/NACK
feedback via the HS-DPCCH. Alternatively, the network may assign an
index to the list that contains the E-DCH resources and the
HS-DPCCH information may also be listed as part of the information.
In both cases, the HS-DPCCH may also be used to provide HARQ
ACK/NACK feedback for information received on the HS-DSCH.
[0028] The transmission of the channel quality information and/or
HARQ ACK/NACK feedback may be triggered upon reception of an
acquisition indication after successful random access ramp-up
procedure, or when the WTRU receives a downlink transmission after
having received a resource allocation through an acquisition
indication. The WTRU may detect the downlink transmission when it
receives an HS-SCCH transmission with its address. Additionally,
the WTRU may also trigger transmission of the channel quality
information when the WTRU has uplink data to transmit in CELL_FACH,
CELL_PCH, or URA_PCH.
[0029] According to a first embodiment of an explicit trigger, the
network may be configured to transmit an HS-SCCH order to enable or
disable the transmission of the channel quality information over
the HS-DPCCH. The HS-SCCH order may be defined using reserve bits.
Alternatively, the HS-SCCH order may be defined reinterpreting
existing data fields. Alternatively, an existing HS-SCCH order may
be used but a WTRU in the CELL_FACH state may be configured to
reinterpret the existing HS-SCCH order.
[0030] Upon receiving an indication from the UTRAN to transmit the
channel quality information, the WTRU begins transmitting the
channel quality information on the HS-DPCCH. Optionally, if
dedicated data was received by the WTRU, the ACK/NACK may be
transmitted. The channel quality indicator (CQI) Feedback cycle (k)
that is configured by the higher level signaling may be used.
Alternatively, a pre-defined value valid for WTRUs in CELL_FACH may
be used.
[0031] According to a second embodiment of an explicit trigger, the
UTRAN may be configured to signal a WTRU using the E-AGCH whether
to send the channel quality information over the HS-DPCCH. The
UTRAN may signal the WTRU using the E-AGCH concurrently with
contention resolution. Alternatively, the UTRAN may signal the WTRU
using the E-AGCH at a later time. The structure of the AGCH
structure may be redesigned for this purpose. Alternatively, the
fields in the existing E-AGCH may be reinterpreted for the UTRAN to
signal the WTRU for this purpose. For example, the absolute grant
field may be reinterpreted to indicate that the WTRU transmit
channel quality information over the HS-DPCCH.
[0032] According to a third embodiment of an explicit trigger, the
UTRAN may be configured to signal a WTRU using the E-DCH
acquisition indicator channel (E-AICH) whether to send the channel
quality information over the HS-DPCCH. The UTRAN may signal the
WTRU along with an E-DCH index sent to the WTRU. For example, a
specific signature on the E-AICH may be reserved to carry this
1-bit information. The transmission of the channel quality
information may be triggered upon receipt of an acquisition
indication after successful random access ramp-up procedure, or
when the WTRU receives a downlink transmission after having
received a resource allocation through an acquisition
indication.
[0033] In response to this trigger the WTRU prepares the channel
quality information and sends the channel quality information
concurrently with the initial uplink transmission. This
transmission may include WTRU identity (ID) to help detection of
enhanced RACH message collision, and/or initial scheduling
information to allow proper rate grant generation for the allocated
E-DCH resources. The channel quality information may be encoded and
transmitted as a k-bit CQI.
[0034] According to a fourth embodiment of an explicit trigger, a
layer 1 (L1) signal sent by the network over the HS-SCCH (i.e., an
HS-SCCH order, which optionally contains an index) may be used.
Alternatively, a new L1 signal may be used. The L1 signal, the
HS-SCCH, or the new message may carry an index in the list of E-DCH
resources broadcasted over the system information block (SIB),
whose entries specify the needed configuration parameters. The L1
signal may provide an index or alternatively it may just provide an
indication that DL feedback is required. This may trigger the WTRU
to initiate the random access procedure to request E-DCH resources
in order to get the required parameters for HS-DPCCH transmission.
Once the E-DCH configuration information is provided to the WTRU,
the WTRU may establish the initial transmit power and start uplink
transmission and/or uplink feedback.
[0035] According to a fifth embodiment of an explicit trigger, the
UTRAN may be configured to indicate to a WTRU to transmit the
channel quality information via the HS-DPCCH by a special IE
broadcast as part of the set of E-DCH resources. The indication to
the WTRU to transmit the channel quality information may be
performed for each E-DCH resource individually. Alternatively, the
indication to the WTRU to transmit channel quality information may
be based on a block of E-DCH resources. The channel quality
information may be provided through RRC signaling from the WTRU to
the UTRAN, similar to the conventional mechanism using "Measured
Results on RACH" IE. However, transmitting the channel quality
information provides a better estimate of channel quality than the
conventional measurement reporting through the "Measured Results on
RACH" IE including common pilot channel (CPICH) received signal
code power (RSCP) or Ec/No.
[0036] According to a sixth embodiment of an explicit trigger, the
UTRAN may be configured to indicate to a WTRU to transmit the
channel quality information over the HS-DPCCH when the WTRU is
assigned contention-free E-RACH resources by the UTRAN. The WTRU is
considered to have a contention free resource when the network
echoes the WTRU E-RNTI over the E-AGCH before the expiration of a
configured timer. Upon reception of this indication the WTRU
consider contention resolution phase successful and thus the access
is contention free Channel quality information is transmitted along
with an initial uplink transmission, (e.g., E-DCH message), after a
WTRU has been assigned an enhanced RACH resource. For random
access, the WTRU transmits a random access preamble. After
detecting the preamble, a Node B transmits an acquisition
indication, and selects an E-DCH resource from the common pool of
resources and assigns the selected E-DCH resource to the WTRU. The
WTRU then transmits E-DCH message using the allocated E-DCH
resource along with the channel quality information.
[0037] FIG. 4 is a block diagram of a method 400 of implicit uplink
feedback signaling. The WTRU may be configured to send feedback
information 401. If the WTRU is configured to send feedback
information, and the WTRU determines that a predetermined condition
exists 403, then a determination is made whether the WTRU assigned
contention free access to an E-DCH resource by the network 405. If
the WTRU has completed the contention resolution phase and the WTRU
has received a RNTI from the Node B, the access is contention free
and the UL feedback information is transmitted on the UL 407. If
the WTRU is not configured to send feedback information, has not
determined that a predetermined condition exists, or does not have
contention free access, the method ends. Between transmissions of
the UL feedback information by the WTRU, the WTRU is continuously
taking channel quality measurements.
[0038] Implicit rules may be defined for the WTRU to determine when
to send the UL feedback information on the HS-DPCCH based on
predetermined conditions. The rules may be considered individually
or in any combination. The rules may also be applied if the channel
quality information is appended to a MAC-e or MAC-i PDU.
[0039] According to a first embodiment of an implicit trigger, the
WTRU may be configured to transmit. the channel quality information
over the HS-DPCCH based on the logical channel over which data is
being sent on the E-RACH. For example, if the WTRU is in CELL_PCH,
URA_PCH or Idle Mode state and moves to a CELL_FACH state to
transmit data and the data is CCCH data, the WTRU may be configured
not to send the channel quality information in the UL. Conversely,
if data is being sent on either the dedicated control channel
(DCCH) or dedicated traffic channel (DTCH), the WTRU may be
configured to transmit the channel quality information reports
and/or the ACK/NACK on the HS-DPCCH along with UL data. The
decision to transmit the channel quality information on HS-DPCCH
may be based on sending data from the DCCH or DTCH logical channel
or may be based on any other embodiments described herein.
[0040] FIG. 5 is a block diagram of a method 500 of implicit uplink
feedback signaling based on the logical channel associated with the
data being transmitted. In this example of the first embodiment of
an implicit trigger, the logical channel type associated with the
transmitted data (e.g.: DCCH or DTCH) acts as a trigger for uplink
feedback transmission. The WTRU may be configured to send feedback
information 501. If the WTRU is configured to send feedback
information, and the WTRU is transmitting on either the DCCH or the
DTCH 503, then a determination is made whether the WTRU is assigned
contention free access to the DTCH/DCCH by the network 505. If the
WTRU has completed the contention resolution phase and the WTRU has
received a RNTI from the Node B, the access is contention free and
the UL feedback information is transmitted on the UL 507. If the
WTRU is not configured to send feedback information, is not
transmitting on the DCCH or the DTCH, or does not have contention
free access, then the method ends. Between transmissions of the UL
feedback information by the WTRU, the WTRU is continuously taking
channel quality measurements. When the conditions indicate to the
WTRU to transmit the UL feedback information, the WTRU transmits
the UL feedback information with the UL data transmission 507.
[0041] According to a second embodiment of an implicit trigger, the
WTRU is configured to send feedback information while in the
CELL_FACH state when the WTRU has an E-DCH resource allocated and
the WTRU has successfully decoded its H-RNTI on the downlink (DL)
HS-SCCH X.sub.p times over T.sub.p seconds, TTI or frames. The
parameters X.sub.p and T.sub.p may be individually or jointly
pre-defined or configured by the network (eg. X.sub.p always has a
value of one and time T.sub.p is configured by the network). For
example, when a WTRU in a CELL_PCH state has uplink data to
transmit or it detects its address (dedicated H-RNTI) in the
HS-SCCH, the WTRU sends a layer 3 measurement report with either
Ec/No or received signal code power (RSCP) value to update the
network as to the channel quality information.
[0042] Alternatively, transmission of UL layer 1 (L1) feedback
information by the WTRU using E-DCH in CELL_FACH state may be based
on one or any combination of the following embodiments:
[0043] According to a third embodiment of an implicit trigger, the
triggering condition may depend on whether the WTRU has been
assigned with a dedicated (H-RNTI) and/or E-DCH radio network
temporary identity (E-RNTI) and/or cell radio network temporary
identity (C-RNTI). In some cases, the WTRU may not have an E-RNTI
and is not allowed to transmit dedicated traffic channel
(DTCH)/dedicated control channel (DCCH) transmissions using the
Enhanced RACH. In these cases, the WTRU may decide not to initiate
an uplink transmission for channel quality information
transmission. If the WTRU does not have an H-RNTI and E-RNTI
allocated, the WTRU may not send HS-DPCCH feedback even if the WTRU
has an allocated E-DCH resource and the required information.
[0044] According to a fourth embodiment of an implicit trigger,
although the channel quality information may be transmitted at any
time regardless of the logical channel, for CCCH transmission, the
Node B is not aware of which WTRU is transmitting data. In that
case, the WTRU may append a common H-RNTI selected from the
broadcast information to the MAC-i or MAC-e PDU. Because the Node B
knows that the field normally reserved for the H-RNTI as part of
the contention resolution contains the common H-RNTI, if the LCH-ID
of the MAC-e or MAC-i PDU indicates CCCH, the channel quality
information may then be linked with the common H-RNTI. The channel
quality information may then be used when DL data is ready to be
transmitted to the WTRU. The common H-RNTI may also be used to
detect if collisions have occurred in the Node B.
[0045] According to a fifth embodiment of an implicit, trigger, the
WTRU may be configured to transmit channel quality information over
the HS-DPCCH based on the RRC state that; the WTRU is in currently,
or a state to which the WTRU is transitioning. For example, if the
WTRU is in URA_PCH, CELL_PCH or Idle Mode, the WTRU is configured
not to send the channel quality information. Alternatively, if the
WTRU is in CELL_FACH state, the WTRU is configured to send the
channel quality information over the HS-DPCCH.
[0046] According to a sixth embodiment of an implicit trigger, the
WTRU may be configured to transmit the channel quality information
over the HS-DPCCH when the UTRAN sends a buffer status to the WTRU.
The buffer status is an indication of the amount of data the UTRAN
has to send the WTRU. The WTRU may be configured to transmit the
channel quality information if the buffer status indicates that the
buffer occupancy exceeds a predetermined threshold. If the buffer
occupancy is below the predetermined threshold, the WTRU may
alternatively be configured to not send the channel quality
information.
[0047] According to a seventh embodiment of an implicit trigger,
the WTRU may be configured to transmit; the channel quality
information over the HS-DPCCH based on the LCH-ID of received DL
traffic. For example, the WTRU is configured not to send the
channel quality information if the LCH-ID indicates that the data
corresponds to a signaling radio bearer (SRB) that contains small
messages. For example, if the LCH-ID corresponds to a CCCH message,
the WTRU may be configured not to send the channel quality
information. Alternatively, the WTRU may be configured to transmit
the channel quality information when the LCH-ID corresponds to a
SRB that contains large messages. If the LCH-ID corresponds to a
CCCH message, the WTRU may be configured to optionally not send
channel quality information feedback.
[0048] In order to provide feedback, given one of the explicit
triggers or implicit triggers has been met and the WTRU does not
have an ongoing E-DCH transmission, the WTRU may request an E-DCH
resource or an HS-DPCCH resource. The request may be done via the
enhanced uplink random access procedure, where the WTRU waits for
an AICH or an E-AICH to get; an E-DCH resource. Where the WTRU
requests an E-DCH resource, the WTRU is assigned configuration
information for all channels associated with E-DCH transmission,
(i.e., dedicated physical control channel (DPCCH), fractional
dedicated physical channel (F-DPCH), E-AGCH, E-RGCH, E-HICH,
E-DPCCH, and/or E-DPDCH). With the assigned E-DCH resource, the
WTRU may send a CQI in the MAC-i/is or MAC-e/es header.
Alternatively, HS-DPCCH information may be associated with the
assigned E-DCH resource and the WTRU may send a CQI and optionally
HARQ ACK/NACK feedback over the associated HS_DPCCH.
[0049] In the case where the WTRU requests an HS-DPCCH resource,
the WTRU receives the necessary channels to allow HS-DPCCH
transmission, including the uplink and downlink control channels
for power control, (such as the F-DPCH and the DPCCH, and the
required HS-DPCCH information), but excluding one or more of the
other E-DCH channels. The HS-DPCCH resource may be part of a
separate pool of resources assigned to the WTRU on a per need
basis. For example, if the WTRU only needs to send feedback over an
HS-DPCCH and has no other uplink traffic, there is no need for the
network to waste E-DCH resources and block other WTRUs. Therefore,
the network assigns the HS-DPCCH resource index from a separate
pool of resources if the WTRU does not, have uplink traffic. Both
channel quality information and HARQ ACK/NACK feedback may be
transmitted over the assigned HS-DPCCH.
[0050] The trigger to initiate uplink access to carry channel
quality information and/or ACK/NACK feedback may be the reception
of a correctly decoded HS-SCCH (HS-SCCH transmission that is masked
with the WTRU's HS-DSCH radio network temporary identity (H-RNTI))
and/or reception of data on the associated high speed physical
downlink shared channel (HS-PDSCH), or upon reception of a downlink
forward access channel (FACH) transmission.
[0051] Optionally, if the WTRU has no E-DCH resources, the WTRU in
a CELL_FACH state may be configured to periodically start a new
uplink transmission in order to send fresh channel quality
information. When the WTRU has no uplink data and has not received
any downlink transmission, and therefore the triggering conditions
of the first and second embodiments are not met, the WTRU may
periodically start an uplink transmission for the purpose of
sending fresh channel quality information. The channel quality
information may be transmitted using any method disclosed above.
For example, the channel quality information may be included in
MAC-e/es or MAC-i/is header/trailer, on HS-DPCCH associated with
E-DCH, on HS-DPCCH without E-DCH transmission.
[0052] A WTRU in a cell that supports E-DCH in CELL_FACH and
CELL_PCH may not send the layer 3 measurement report when the WTRU
in CELL-PCH decodes the dedicated H-RNTI in the HS-SCCH or the WTRU
has uplink data to transmit in CELL_PCH, but may send a channel
quality information using any of the techniques described
above.
[0053] For all the embodiments described above, the WTRU may send
the channel quality information more frequently for the initial
phase. For example, if the WTRU has uplink transmission or decodes
the H-RNTI in the HS-SCCH, the WTRU may send channel quality
information at a more frequent rate, (i.e., consecutive transmit
time intervals (TTIs) or N times faster than the configured rate
for normal channel quality information reporting over HS-DPCCH).
This will allow the network to optimally adjust the modulation and
coding used for the subsequent downlink transmissions.
Alternatively, the channel quality information may be sent
periodically during the contention resolution phase (frequency of
channel quality information reports may be configured to allow for
the WTRU to send sufficient channel quality information reports
during that phase), periodically for the duration of the RACH
access, only if downlink traffic is being transmitted during the
RACH access period of the WTRU, or a combination of the above.
[0054] Although features and elements are described above in
particular combinations, each feature or element can be used alone
without the other features and elements or in various combinations
with or without other features and elements. The methods or flow
charts provided herein may be implemented in a computer program,
software, or firmware incorporated in a computer-readable storage
medium for execution by a general purpose computer or a processor.
Examples of computer-readable storage mediums include a read only
memory (ROM), a random access memory (RAM), a register, cache
memory, semiconductor memory devices, magnetic media such as
internal hard disks and removable disks, magneto-optical media, and
optical media such as CD-ROM disks, and digital versatile disks
(DVDs).
[0055] Suitable processors include, by way of example, a general
purpose processor, a special purpose processor, a conventional
processor, a digital signal processor (DSP), a plurality of
microprocessors, one or more microprocessors in association with a
DSP core, a controller, a microcontroller, Application Specific
Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs)
circuits, any other type of integrated circuit (IC), and/or a state
machine.
[0056] A processor in association with software may be used to
implement a radio frequency transceiver for use in a wireless
transmit receive unit (WTRU), user equipment (UE), terminal, base
station, radio network controller (RNC), or any host computer. The
WTRU may be used in conjunction with modules, implemented in
hardware and/or software, such as a camera, a video camera module,
a videophone, a speakerphone, a vibration device, a speaker, a
microphone, a television transceiver, a hands free headset, a
keyboard, a Bluetooth.RTM. module, a frequency modulated (FM) radio
unit, a liquid crystal display (LCD) display unit, an organic
light-emitting diode (OLED) display unit, a digital music player, a
media player, a video game player module, an Internet browser,
and/or any wireless local area network (WLAN) or Ultra Wide Band
(UWB) module.
* * * * *