U.S. patent application number 15/356008 was filed with the patent office on 2017-03-09 for method and apparatus for handling uplink transmissions using multiple uplink carriers.
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, Paul Marinier, Diana Pani, Benoit Pelletier, Fengjun Xi.
Application Number | 20170070965 15/356008 |
Document ID | / |
Family ID | 41722955 |
Filed Date | 2017-03-09 |
United States Patent
Application |
20170070965 |
Kind Code |
A1 |
Marinier; Paul ; et
al. |
March 9, 2017 |
Method And Apparatus For Handling Uplink Transmissions using
Multiple Uplink Carriers
Abstract
A method and an apparatus for uplink transmission using multiple
uplink carriers are disclosed. A wireless transmit/receive unit
(WTRU) selects a dedicated channel medium access control (MAC-d)
flow with highest priority data to be transmitted and performs
uplink carrier selection and enhanced dedicated channel (E-DCH)
transport format combination (E-TFC) restriction and selection to
select a carrier among a plurality of carriers and select an E-TFC
based on a maximum supported payload, a remaining scheduled grant
payload of the selected carrier and a remaining non-scheduled grant
payload. The WTRU then generates a medium access control (MAC)
protocol data unit (PDU) for E-DCH transmission via the selected
carrier based on the selected E-TFC.
Inventors: |
Marinier; Paul; (Brossard,
CA) ; Pani; Diana; (Montreal, CA) ; Cave;
Christopher R.; (Dollard-des-Ormeaux, CA) ;
Pelletier; Benoit; (Roxboro, CA) ; Xi; Fengjun;
(San Diego, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
InterDigital Patent Holdings, Inc. |
Wilmington |
DE |
US |
|
|
Assignee: |
InterDigital Patent Holdings,
Inc.
Wilmington
DE
|
Family ID: |
41722955 |
Appl. No.: |
15/356008 |
Filed: |
November 18, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14687551 |
Apr 15, 2015 |
9532318 |
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15356008 |
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13693721 |
Dec 4, 2012 |
9049700 |
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14687551 |
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12610302 |
Oct 31, 2009 |
8358614 |
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13693721 |
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61250804 |
Oct 12, 2009 |
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61248289 |
Oct 2, 2009 |
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61235995 |
Aug 21, 2009 |
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61232351 |
Aug 7, 2009 |
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61218208 |
Jun 18, 2009 |
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61168451 |
Apr 10, 2009 |
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61159659 |
Mar 12, 2009 |
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61141638 |
Dec 30, 2008 |
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61109978 |
Oct 31, 2008 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 72/1268 20130101;
H04L 5/001 20130101; H04W 72/0473 20130101; H04L 5/0044 20130101;
H04W 52/346 20130101; H04W 72/1242 20130101; H04W 52/367 20130101;
H04L 5/0085 20130101; H04W 72/04 20130101; H04W 72/0413
20130101 |
International
Class: |
H04W 52/34 20060101
H04W052/34; H04W 72/12 20060101 H04W072/12; H04W 72/04 20060101
H04W072/04 |
Claims
1-28. (canceled)
29. A method for allocating power in a wireless transmit/receive
unit (WTRU), the method comprising: determining that the WTRU is
configured with a plurality of uplink carriers including a primary
carrier; determining a power for transmitting one or more
non-scheduled MAC-d flows; allocating the power for transmitting
the one or more non-scheduled MAC-d flows to the primary carrier;
and transmitting the one or more non-scheduled MAC-d flows on the
primary carrier.
30. The method of claim 29, further comprising: determining an
available power for transmitting scheduled transmissions on the
plurality of uplink carriers; and allocating the available power
for transmitting the scheduled transmissions among the plurality of
uplink carriers.
31. The method of claim 30, wherein the available power for
transmitting the scheduled transmissions is determined by
subtracting, from a maximum WTRU transmit power: a sum of power
associated with a dedicated physical control channel (DPCCH) for
the plurality of uplink carriers, a power associated with a high
speed dedicated physical control channel (HS-DPCCH), and the power
for transmitting the one or more non-scheduled MAC-d flows.
32. The method of claim 31, wherein the available power for
transmitting the scheduled transmissions is further determined
based on a power associated with an enhanced dedicated channel
(E-DCH) DPCCH (E-DPCCH).
33. The method of claim 30, wherein the available power for
transmitting the scheduled transmissions is allocated among the
plurality of uplink carriers based on a serving grant and a
corresponding DPCCH power associated with each of the plurality of
uplink carriers.
34. The method of claim 30, wherein the plurality of uplink
carriers comprises one or more secondary carriers, and the
scheduled transmissions are transmitted on the primary carrier and
each of the one or more secondary carriers using the available
power allocated for transmitting the scheduled transmissions.
35. The method of claim 29, wherein the plurality of uplink
carriers includes an E-DCH.
36. The method of claim 29, wherein the power for transmitting the
one or more non-scheduled MAC-d flows is a sum of the power used to
transmit available data associated with each of the one or more
non-scheduled MAC-d flows up to a payload of a non-scheduled grant
for the each of the one or more non-scheduled MAC-d flows.
37. The method of claim 36, wherein the non-scheduled grant for the
each of the one or more non-scheduled MAC-d flows is received from
a wireless communication network.
38. A wireless transmit/receive unit (WTRU), the WTRU comprising: a
processor configured to: determine that the WTRU is configured with
a plurality of uplink carriers including a primary carrier;
determine a power for transmitting one or more non-scheduled MAC-d
flows; allocate the power for transmitting the one or more
non-scheduled MAC-d flows to the primary carrier; and transmit the
one or more non-scheduled MAC-d flows on the primary carrier.
39. The WTRU of claim 38, wherein the processor is configured to:
determine an available power for transmitting scheduled
transmissions on the plurality of uplink carriers; and allocate the
available power for transmitting the scheduled transmissions among
the plurality of uplink carriers.
40. The WTRU of claim 39, wherein the processor is configured to:
determine the available power for transmitting the scheduled
transmissions by subtracting, from a maximum WTRU transmit power, a
sum of power associated with a dedicated physical control channel
(DPCCH) for the plurality of uplink carriers, a power associated
with a high speed dedicated physical control channel (HS-DPCCH),
and the power for transmitting the one or more non-scheduled MAC-d
flows.
41. The WTRU of claim 40, wherein the processor is further
configured to determine the available power for transmitting the
scheduled transmissions based on a power associated with an
enhanced dedicated channel (E-DCH) DPCCH (E-DPCCH).
42. The WTRU of claim 39, wherein the processor is configured to
allocate the available power for transmitting the scheduled
transmissions among the plurality of uplink carriers based on a
serving grant and a corresponding DPCCH power associated with each
of the plurality of uplink carriers.
43. The WTRU of claim 39, wherein the plurality of uplink carriers
comprises one or more secondary carriers, and the scheduled
transmissions are transmitted on the primary carrier and each of
the one or more secondary carriers using the available power
allocated for transmitting the scheduled transmissions.
44. The WTRU of claim 38, wherein the plurality of uplink carriers
include an E-DCH.
45. The WTRU of claim 38, wherein the power for transmitting the
one or more non-scheduled MAC-d flows is a sum of the power used to
transmit available data associated with each of the one or more
non-scheduled MAC-d flows up to a payload of a non-scheduled grant
for the each of the one or more non-scheduled MAC-d flows.
46. The WTRU of claim 45, wherein the non-scheduled grant for the
each of the one or more non-scheduled MAC-d flows is received from
a wireless communication network.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional
application No. 61/109,978 filed Oct. 31, 2008, 61/141,638 filed
Dec. 30, 2008, 61/159,659 filed Mar. 12, 2009, and 61/168,451 filed
Apr. 10, 2009, 61/218,208 filed Jun. 18, 2009, 61/232,351 filed
Aug. 7, 2009, 61/235,995 filed Aug. 21, 2009, 61/248,289 filed Oct.
2, 2009, and 61/250,804 filed Oct. 12, 2009, which are incorporated
by reference as if fully set forth herein.
FIELD OF INVENTION
[0002] This application is related to wireless communications.
BACKGROUND
[0003] Wireless communication systems keep evolving to meet the
needs for providing continuous and faster access to a data network.
In order to meet these needs, wireless communication systems may
use multiple carriers for the transmission of data. A wireless
communication system that uses multiple carriers for the
transmission of data may be referred to as a multi-carrier system.
The use of multiple carriers is expanding in both cellular and
non-cellular wireless systems.
[0004] A multi-carrier system may increase the bandwidth available
in a wireless communication system according to a multiple of how
many carriers are made available. For instance, a dual carrier
system will double the bandwidth when compared to a single carrier
system and a tri-carrier system will triple the bandwidth when
compared to a single carrier system, etc. In addition to this
throughput gain, diversity and joint scheduling gains may also be
expected. This may result in improving the quality of service (QoS)
for end users. Further, the use of multiple carriers may be used in
combination with multiple-input multiple-output (MIMO).
[0005] By way of example, in the context of third generation
partnership project (3GPP) systems, a new feature called dual cell
high speed downlink packet access (DC-HSDPA) has been introduced in
Release 8 of the 3GPP specifications. With DC-HSDPA, a base station
(which may also be referred to as a Node-B, an access point, site
controller, etc. in other variations or types of communications
networks) communicates to a wireless transmit/receive unit (WTRU)
over two downlink carriers simultaneously. This not only doubles
the bandwidth and the peak data rate available to WTRUs, but also
has a potential to increase the network efficiency by means of fast
scheduling and fast channel feedback over two carriers.
[0006] For DC-HSDPA operation, each WTRU is assigned two downlink
carriers: an anchor carrier and a supplementary carrier. The anchor
carrier carries all physical layer dedicated and shared control
channels associated with transport channels such as the high speed
downlink shared channel (HS-DSCH), the enhanced dedicated channel
(E-DCH), and the dedicated channel (DCH) operations. Such physical
layer channels include, by way of example, the fractional dedicated
physical channel (F-DPCH), the E-DCH HARQ indicator channel
(E-HICH), the E-DCH relative grant channel (E-RGCH), the E-DCH
absolute grant channel (E-AGCH), the common pilot channel (CPICH),
the high speed shared control channel (HS-SCCH), and the high speed
physical downlink shared channel (HS-PDSCH), and the like). The
supplementary carrier may carry a CPICH, an HS-SCCH and an HS-PDSCH
for the WTRU. The uplink transmission remains on a single carrier
in the current system. The high speed dedicated physical control
channel (HS-DPCCH) feedback information is provided on the uplink
carrier to the Node-B and contains information for each downlink
carrier.
[0007] FIG. 1 shows the medium access control (MAC) layer structure
for DC-HSDPA operation in a 3GPP context. The MAC-ehs entity
includes one hybrid automatic repeat request (HARQ) entity per
HS-DSCH transport channel. This implies that HARQ retransmissions
may take place over the same transport channel which somewhat
restricts the benefit of frequency diversity potentially brought by
the use of more than one carrier if each HS-DSCH transport channel
has a fixed mapping to physical channel resources. However, it has
been suggested that the mapping between an HS-DSCH and physical
resources (e.g., codes and carrier frequencies) may be dynamically
modified in order to provide a diversity benefit.
[0008] As mentioned above, multi-carrier transmissions increase the
throughput and efficiency of the downlink. However, in the uplink,
physical layer channels are carried using a single carrier.
Therefore, a need exists for a method and apparatus for handling
uplink transmissions using multiple uplink channels.
SUMMARY
[0009] A method and apparatus for handling uplink transmissions
using multiple uplink carriers are disclosed. A WTRU selects a
dedicated channel medium access control (MAC-d) flow with the
highest priority data to be transmitted and performs uplink carrier
selection and enhanced dedicated channel (E-DCH) transport format
combination (E-TFC) restriction and selection to select a carrier
among a plurality of carriers and select an E-TFC based on, for
example, a maximum supported payload, a remaining scheduled grant
payload of the selected carrier and a remaining non-scheduled grant
payload. The WTRU then generates a medium access control (MAC)
protocol data unit (PDU) for E-DCH transmission via the selected
carrier based on the selected E-TFC. The WTRU selects another
carrier and repeats the above steps, and transmits the generated
MAC PDUs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A more detailed understanding may be had from the following
description, given by way of example in conjunction with the
accompanying drawings wherein:
[0011] FIG. 1 shows the MAC layer structure for DC-HSDPA operation
according to the prior art;
[0012] FIG. 2 shows an example wireless communication system
according to the prior art;
[0013] FIG. 3 shows an example wireless communication system
wherein uplink transmissions are handled using multiple uplink
carriers;
[0014] FIG. 4 is a functional block diagram of an example WTRU and
an example Node-B of the wireless communication system of FIG.
3;
[0015] FIG. 5 is a functional block diagram wherein two uplink
carriers are controlled by transmit power control (TPC) commands
transmitted to a WTRU on two downlink carriers;
[0016] FIGS. 6 and 7 are functional block diagrams wherein two
uplink carriers are controlled by transmit power control (TPC)
commands transmitted to a WTRU on a single downlink carrier;
[0017] FIG. 8 shows an example F-DPCH slot format in accordance
with one embodiment;
[0018] FIG. 9 is a functional block diagrams wherein transmit power
control (TPC) commands are sent in the uplink in a multiple uplink
carrier environment;
[0019] FIG. 10 is a flow diagram of an example process for E-TFC
selection and MAC-e or MAC-i PDU generation while utilizing two
uplink carriers; and
[0020] FIG. 11 shows scheduling information format in accordance
with one embodiment.
DETAILED DESCRIPTION
[0021] 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, a machine-to-machine
(M2M) device, a sensor or any other type of device capable of
operating in a wireless environment. 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.
[0022] The network may assign at least one downlink and/or at least
one uplink carrier as an anchor downlink carrier and an anchor
uplink carrier, respectively. In multi-carrier operation a WTRU may
be configured to operate with two or more carriers or also referred
to as frequencies. Each of these carriers may have distinct
characteristics and logical association with the network and the
WTRU, and the operating frequencies may be grouped and referred to
as anchor or primary carrier and supplementary and secondary
carrier. Hereinafter, the terminologies "anchor carrier" and
"primary carrier", and "supplementary carrier" and "secondary
carrier" will be used interchangeably, respectively. If more than
two carriers are configured the WTRU may contain more than one
primary carrier and/or more than one secondary carrier(s). The
embodiments described herein are applicable and can be extended to
these scenarios as well. For example, the anchor carrier may be
defined as the carrier for carrying a specific set of control
information for downlink/uplink transmissions. Any carrier that is
not assigned as an anchor carrier may be a supplementary carrier.
Alternatively, the network may not assign an anchor carrier and no
priority, preference, or default status may be given to any
downlink or uplink carriers. Hereinafter, the terms "anchor
carrier", "primary carrier", "uplink carrier 1", "first carrier",
and "first uplink carrier", are used interchangeably herein for
convenience. Similarly, the terms "supplementary carrier",
"secondary carrier", "uplink carrier 2", "second carrier", and
"second uplink carrier" are also used interchangeably herein. For
multi-carrier operation more than one supplementary carriers or
secondary carriers may exist.
[0023] FIG. 2 shows an example wireless communication system 100
according to the prior art where uplink transmissions are handled
with a single carrier 160 and downlink transmissions are handled
using multiple carriers 170. The wireless communication system 100
includes a plurality of WTRUs 110, a Node-B 120, a controlling
radio network controller (CRNC) 130, a serving radio network
controller (SRNC) 140, and a core network 150. The Node-B 120 and
the CRNC 130 may collectively be referred to as the UTRAN.
[0024] As shown in FIG. 2, the WTRUs 110 are in communication with
the Node-B 120, which is in communication with the CRNC 130 and the
SRNC 140. Although three WTRUs 110, one Node-B 120, one CRNC 130,
and one SRNC 140 are shown in FIG. 2, it should be noted that any
combination of wireless and wired devices may be included in the
wireless communication system 100.
[0025] FIG. 3 shows an example wireless communications system 200
according to an example embodiment where uplink transmissions are
handled using multiple carriers 260 and downlink transmissions are
handled using multiple carriers 270. The wireless communication
system 200 includes a plurality of WTRUs 210, a Node-B 220, a CRNC
230, a SRNC (240), and a core network 250. The Node-B 220 and the
CRNC 230 may collectively be referred to as the UTRAN.
[0026] As shown in FIG. 3, the WTRUs 210 are in communication with
the Node-B 220, which is in communication with the CRNC 230 and the
SRNC 240. Although three WTRUs 210, one Node-B 220, one CRNC 230,
and one SRNC 240 are shown in FIG. 3, it should be noted that any
combination of wireless and wired devices may be included in the
wireless communication system 200.
[0027] FIG. 4 is a functional block diagram of the WTRU 410 and the
Node-B 220 of the wireless communication system 200 of FIG. 3. As
shown in FIG. 3, the WTRU 410 is in communication with the Node-B
420 and both are configured to perform a method wherein uplink
transmissions from the WTRU 410 are transmitted to the Node-B 420
using multiple uplink carriers 460. The WTRU 410 includes a
processor 415, a receiver 416, a transmitter 417, a memory 418, an
antenna 419, and other components (not shown) that may be found in
a typical WTRU. The antenna 419 may include a plurality of antenna
elements or plurality of antennas may be included in the WTRU 410.
The memory 418 is provided to store software including operating
system, application, etc. The processor 415 is provided to perform,
alone or in association with software and/or any one or more of the
components, a method of performing uplink transmissions with
multiple uplink carriers. The receiver 416 and the transmitter 417
are in communication with the processor 415. The receiver 116 and
the transmitter 117 are capable of receiving and transmitting one
or more carriers simultaneously. Alternatively, multiple receivers
and/or multiple transmitters may be included in the WTRU 410. The
antenna 419 is in communication with both the receiver 416 and the
transmitter 417 to facilitate the transmission and reception of
wireless data.
[0028] The Node B 420 includes a processor 425, a receiver 426, a
transmitter 427, a memory 428, an antenna 429, and other components
(not shown) that may be found in a typical base station. The
antenna 429 may include a plurality of antenna elements or
plurality of antennas may be included in the Node B 420. The memory
428 is provided to store software including operating system,
application, etc. The processor 425 is provided to perform, alone
or in association with software and/or any one or more of the
components, a method wherein uplink transmissions from the WTRU 410
are transmitted to the Node-B 420 using multiple uplink carriers in
accordance with embodiments disclosed below. The receiver 426 and
the transmitter 427 are in communication with the processor 425.
The receiver 426 and the transmitter 427 are capable of receiving
and transmitting one or more carriers simultaneously.
Alternatively, multiple receivers and/or multiple transmitters may
be included in the Node B 420. The antenna 429 is in communication
with both the receiver 426 and the transmitter 427 to facilitate
the transmission and reception of wireless data.
[0029] Embodiments described herein provide several approaches for
implementing multi-carrier uplink transmission, for performing
power control on multiple uplink carriers, and for allocating power
and data across multiple different uplink carriers. It is noted
that although embodiments described herein are described in terms
of a dual uplink carrier scenario, it should be understood that the
embodiments described herein are applicable to scenarios where any
number of uplink carriers are implemented.
[0030] It is also noted that although the embodiments described
herein are described with reference to channels associated with
3GPP Releases 4 through 7, it should be noted that the embodiments
are applicable to further 3GPP releases (and the channels used
therein) such as LTE Release 8 as well as any other type of
wireless communication system, and the channels used therein. It
should also be noted that the embodiments described herein may be
applicable in any order or in any combination.
[0031] Referring now to FIG. 5, embodiments to perform power
control on both uplink carriers 520, 540 (i.e., in a dual-carrier
scenario) and allocate power and data across the uplink carriers
are described hereafter. It is noted that while specific channels
are shown being carried by uplink and downlink carriers in FIGS.
5-7 and FIG. 9, any channels may be carried in such carriers.
[0032] In accordance with one embodiment, the transmission powers
of the uplink dedicated physical control channel (DPCCH)
transmissions 525, 545 on both uplink carriers 520, 540 are
controlled by two separate transmit power control (TPC) commands
transmitted by the Node-B. One TPC command controls the power of
the first uplink carrier 520 and the other TPC command controls the
power of the second uplink carrier 540. The WTRU varies the power
of the DPCCH 525, 545 on each uplink carrier 520, 540 based on the
corresponding TPC command
[0033] A Node-B may transmit a TPC command for an uplink carrier
over an F-DPCH 560, 580 on a downlink carrier 570, 590
corresponding to that uplink carrier 520, 540 respectively. A
mapping between the uplink carrier and the downlink carrier may be
pre-defined. The WTRU typically obtains the TPC commands by
listening to two channels (e.g., F-DPCH) transmitted over two
different downlink carriers, but of course different channels may
be used for transmitting such commands.
[0034] Alternatively, referring now to FIG. 6, the TPC commands for
the two uplink carriers 520, 540 may be transmitted on two
different channels 562, 564 on the same downlink carrier 570
(either one of the downlink carriers 570 or 590 may be used, but
570 is shown as being used in this embodiment). In this embodiment,
the WTRU is not required to listen to both downlink carriers 570
and 590 if there is no other activity on at least one of the
downlink carriers.
[0035] In a further alternative embodiment, shown in FIG. 7, the
TPC commands for the two uplink carriers 520, 540 may be carried
over a single channel 562 (e.g., F-DPCH) in a single downlink
carrier 570 (again, either one of the downlink carriers 570 or 590
may be used, but 570 is shown as being used in this embodiment).
FIG. 8 shows an example F-DPCH slot format in accordance with this
alternative embodiment. An F-DPCH slot format includes two TPC
fields per slot, where TPC1 and TCP2 each contain a power control
command (UP or DOWN) for uplink carrier 1 and uplink carrier 2,
respectively.
[0036] Referring again to FIG. 7, in another alternative
embodiment, where power control commands for both uplink carriers
are transmitted on a single channel 562 such as the F-DPCH channel,
the power control commands are time multiplexed. The
time-multiplexing of power control commands may be achieved in a
number of different ways. The power control commands may evenly
alternate between uplink carrier 1 520 and uplink carrier 2 540.
For example, the uplink carrier for which the power control command
is destined may be determined as: [0037] If (current connection
frame number (CFN)+slot number) modulo 2=0, then TPC is for uplink
carrier 1; [0038] Else, TPC is for uplink carrier 2.
[0039] For example, power control commands for uplink carrier 1 520
may be carried in radio slots #0, 2, 4, 6, 8, 10, 12, and 14;
whereas power control commands for uplink carrier 2 540 may be
carried in radio slots #1, 3, 5, 7, 9, 11, and 13, or vice versa.
Alternatively, more power control commands may be allocated to
uplink carrier 1 520 than uplink carrier 2 540. For example, power
control commands for uplink carrier 1 520 may be carried in radio
slots #0, 1, 3, 4, 6, 7, 9, 10, 12, and 13, whereas power control
commands for uplink carrier 2 540 may be carried in radio slots #2,
5, 8, 11, and 14. This alternative may be used if there is a reason
why providing more power control commands will increase overall
efficiency. Such a scenario may be, for example, where uplink
carrier 1 520 is carrying more physical layer channels than uplink
carrier 2 540.
[0040] Synchronization may also be defined on a per-carrier basis.
The WTRU may apply the synchronization procedure on both carriers
separately. The WTRU may be allowed to transmit on a carrier
depending on the synchronization status on that carrier. Radio link
failure may be declared upon loss of synchronization on both
carriers.
[0041] Still referring to FIG. 7, in yet another alternative of the
scenario where power control commands for both uplink carriers are
transmitted on a single channel 562 such as the F-DPCH, the
transmission powers of the DPCCH transmissions on both uplink
carriers may be controlled by a single TPC command transmitted by
the Node-B on, in this scenario, the F-DPCH. When the TPC command
from the Node-B indicates to increase the power, the power is
(e.g., equally) increased on both uplink carriers, and when the TPC
command indicates to decrease the power, the power is (e.g.,
equally) decreased on both uplink carriers. For example, the power
control commands may be joint-coded into a single TPC field.
Example joint coding of the TPC commands is shown in Table 1 for
N.sub.TPC=2 and N.sub.TPC=4, where N.sub.TPC is the number of TPC
command bits.
TABLE-US-00001 TABLE 1 TPC Bit Pattern TPC Command N.sub.TPC = 2
N.sub.TPC = 4 Uplink Carrier 1 Uplink Carrier 2 00 0000 0 0 01 0011
0 1 10 1100 1 0 11 1111 1 1
[0042] Referring now to FIG. 9, the following embodiments are in
relation to the uplink transmission of transmit power control (TPC)
commands from the WTRU to the Node-B on the uplink DPCCH for
purposes of downlink power control. The WTRU may transmit a TPC
command on the uplink DPCCH 925 of only one of the uplink carriers
(in this example 920). On another uplink carrier (in this case
940), the WTRU may use either discontinuous transmission (DTX) in
place of transmitting the TPC bits, or a new slot format with no
TPC field. The TPC command may be derived from the quality measured
on the downlink carrier 970 on which a downlink channel such as,
for example, the F-DPCH 975 is transmitted. This approach has an
advantage of somewhat reducing the interference from the WTRU. The
WTRU may transmit the uplink DPCCH 925, 945 with only the pilot
bits used for channel estimation by the Node-B.
[0043] Alternatively, the WTRU may transmit the same TPC command on
the uplink DPCCH 925, 945 of both uplink carriers 920, 940. The TPC
command may be derived from the quality measured on the downlink
carrier 970 on which the F-DPCH 975 is transmitted. The Node-B may
combine the TPC command signals from the two uplink DPCCHs 925, 945
to improve reliability of the TPC signals from the WTRU.
[0044] Alternatively, the WTRU may transmit independent TPC
commands on the uplink DPCCH 925, 945 of each uplink carrier 920,
940. In this case, the TPC command sent on an uplink carrier 920,
940 may be derived based on the signal quality measured from the
corresponding downlink carrier(s) (not shown) independently of the
downlink carrier on which the F-DPCH 970 is transmitted. This
scheme has the benefit of providing the network with some
additional information regarding the downlink channel.
[0045] Since the uplink channels 925, 927, 945 on the two uplink
carriers may not behave the same, it is possible that the channel
quality changes on one carrier 920 differently than on another
carrier 940. It is also possible that the channel quality on one
carrier 920 changes whereas channel quality does not change on
another carrier 940. In one example, channel quality degrades on
one uplink carrier 920 while it improves on the other uplink
carrier 940. In this case the Node-B has different options for
setting the value of the TPC bits on the F-DPCH 975. The Node-B may
set the TPC bit to "up" whenever the quality from one of the
carriers 920, 940 is below a threshold, and "down" otherwise. This
option may result in the uplink DPCCH power being high on one of
the carriers 920, 940 making channel estimation easier for the
Node-B. Alternatively, the Node-B may set the TPC bit to "down"
whenever the quality from one of the carriers 920, 940 is above a
threshold, and "up" otherwise. This option may result in the uplink
DPCCH 925, 945 power being lower than a threshold for one of the
carriers 920, 940 so the Node-B may derive an acceptable channel
estimate on this carrier using the information from the other
carrier.
[0046] If the average uplink interference (noise rise) level is not
the same on both uplink carriers 920, 940, there may be a long-term
and significant discrepancy in channel quality between the uplink
carriers. The WTRU may apply an offset to the transmission power of
one of the uplink carriers (e.g., 920) compared to the other uplink
carrier (e.g., 940). This offset may be signaled by the network via
higher layer signaling, (e.g., RRC signaling), or the like. The
network may set the offset so that the average signal quality from
both uplink carriers 920, 940 would be the same or similar.
[0047] The network may define different sets of reference E-DCH
transport format combination index (E-TFCI) and corresponding gain
factors for the two uplink carriers 920, 940, so that the
signal-to-interference ratio (SIR) of the E-DPDCH 927, 947 (which
contains data bits) is approximately the same on both uplink
carriers 920, 940. For instance, if the DPCCH SIR of uplink carrier
1 920 is -22 dB in average while the DPCCH SIR of uplink carrier 2
940 is -19 dB in average, setting a reference gain factor 3 dB
lower for uplink carrier 2 (for the same reference E-TFCI) would
result in approximately the same E-DPDCH SIR for both uplink
carriers 920, 940 and a given E-TFC (the reference gain factor of
uplink carrier 2 940 may actually be set slightly lower than 3 dB
below uplink carrier 1 920 given the better channel estimate with
uplink carrier 2 940).
[0048] Synchronization may be defined on a per-carrier basis. The
WTRU may apply the synchronization procedure on both carriers
separately. The WTRU may be allowed to transmit on a carrier
depending on the synchronization status on that carrier. Radio link
failure may be declared upon loss of synchronization on both
carriers.
[0049] Still referring to FIG. 9, embodiments for E-TFC restriction
and selection are described hereafter. A WTRU transmission may be
restricted by a maximum allowed transmit power. The maximum allowed
transmit power of the WTRU may be a minimum of a signaled
configured value and a maximum power allowed due to WTRU design
limitation. The maximum allowed transmit power of the WTRU may be
configured as a total maximum power in a given transmission time
interval (TTI) for both uplink carriers 920, 940, or may be
carrier-specific. In the latter case, the same maximum power value
may be assigned to each uplink carrier 920, 940 or a different
maximum power value may be assigned to each uplink carrier 920,
940. This may depend on the particular configuration of the device,
(e.g., the number of power amplifiers and antennas of the WTRU),
and/or on network control and configuration. The total maximum
transmit power and the per-carrier maximum transmit power may be
simultaneously configured.
[0050] The WTRU behavior and operation may be quite different in
both cases (i.e., one total maximum transmit power or independent
per-carrier maximum transmit power). Therefore, the WTRU may
indicate the power capabilities of the WTRU, (i.e., one maximum
power or a maximum power defined per carrier), to the network so
that the network knows whether the WTRU has a total maximum power
for both uplink carriers 920, 940 or a carrier-specific maximum
power for each uplink carrier 920, 940, and may schedule operations
and correctly interpret the uplink power headroom reported by the
WTRU. If the power requirements are specified in the standards the
WTRU may not need to signal these capabilities.
[0051] FIG. 10 is a flow diagram of an example process 1000 for
E-TFC selection and MAC-i PDU generation while utilizing two uplink
carriers is shown. As mentioned above, specific terms for referring
to the carriers are used interchangeably herein, but it is noted
that in an HSPA+ type system, the two carriers may be referred to
as an anchor (or primary) carrier and a supplementary (or
secondary) carrier and these terms will be used for convenience in
describing FIG. 10. A WTRU determines whether there are two (N in
general, N being an integer larger than one) new transmissions to
be transmitted for the upcoming TTI (step 502). If there is one new
transmission for the upcoming TTI, (e.g., there are one new
transmission and one retransmission of the previous failed
transmission), the WTRU selects an uplink carrier (the carrier for
the new transmission) for E-TFC selection and performs an E-TFC
selection procedure for the new transmission while the supported
E-TFCIs for the new transmission are determined after subtracting
the power being used by the retransmission (step 516). If there are
two new transmissions to be transmitted, the WTRU determines
whether the WTRU is power limited, (i.e., sum of the total power
that would be used by the WTRU in each carrier given the grants
(scheduled and non-scheduled) and control channels exceed the
maximum power allowed by the WTRU, optionally including backoff)
(step 504). If not, the process 500 proceeds to step 508. If so,
the WTRU performs power allocation between the uplink carriers
(step 506). Alternatively, the WTRU may proceed to step 506 for
power allocation between the carriers without checking if the WTRU
is power limited. Once power allocation is performed the WTRU fills
up the transport blocks sequentially one carrier after the
other.
[0052] The WTRU determines the MAC-d flow with the highest priority
data to be transmitted, and the multiplexing list and the power
offset to use based on the HARQ profile of the selected MAC-d flow
(step 508). When determining the highest priority MAC-d flow the
WTRU may, for every carrier, determine the highest priority MAC-d
flow configured with data available amongst all MAC-d flows. In an
alternate embodiment, the WTRU may, for every carrier for which
E-TFC selection or highest priority MAC-d flow selection is being
performed, determine the highest priority MAC-d flow amongst all
MAC-d flows allowed to be transmitted on the given carrier. The
WTRU performs an uplink carrier selection procedure to select an
uplink carrier among a plurality of uplink carriers to fill up with
data first (step 510). It should be noted that the steps of carrier
selection, MAC-d flow determination may not necessarily be
performed in the order described, but may be performed in any
order). The WTRU selects an E-TFCI or determines the number of bits
that can be transmitted on the selected carrier based on a maximum
supported payload (i.e., set of supported E-TFCIs), a remaining
scheduled grant payload, a remaining non-scheduled grant payload,
data availability and logical channel priorities (step 511).
[0053] The WTRU generates a MAC-e or MAC-i PDU for E-DCH
transmission via the selected carrier based on the selected E-TFC
(step 512). If scheduling information (SI) needs to be sent for the
selected carrier, the WTRU may initially include the SI on this
carrier before including any other data. Once the WTRU has
completed the available space on the selected carrier or has
exceeded the data in the buffer allowed to be transmitted in the
TTI, the WTRU determines whether there is another uplink carrier
available and data is still available (step 514). If not, the
process 500 ends. If so, the process 500 returns to step 510 (or
alternatively to step 508) to select the E-TFCI of the next
carrier.
[0054] At this point, (in step 508), the WTRU may optionally
re-determine the highest priority MAC-d flow that has data to be
transmitted. The re-selected highest priority MAC-d flow may be
different than the one determined initially before filling up the
previously selected carrier. If a new highest MAC-d flow is
selected, the WTRU determines the power offset based on the HARQ
profile of the newly selected MAC-d flow, and may then determine
the maximum supported payload (or set of supported E-TFCs) and
remaining scheduled grant payload according to the new power
offset. Alternatively, the WTRU may determine the MAC-d flow
priority only once at the beginning of the procedure (e.g., step
508) and apply the selected HARQ profile and multiplexing list to
both carriers. This implies that the WTRU determines the maximum
supported payload (or supported E-TFCs and remaining scheduled
payload) for both carriers either simultaneously in parallel or
only at the time these values are needed according to E-TFC
selection sequence. In this case for the second selected carrier
the WTRU may return to step 510. It should be noted that the
process 500 is applicable to the case that more than two uplink
carriers are utilized.
[0055] Details of the power allocation, carrier selection, and
E-TFC restriction and selection will be explained below.
[0056] The maximum supported payload refers to the maximum allowed
number of bits that may be transmitted based on the available power
for any uplink carrier. This, as an example, may also be referred
to as the maximum supported E-TFCI. The maximum supported payload
or the set of supported or blocked E-TFCIs, for example in HSPA
systems are determined as part of the E-TFC restriction procedure
and may be dependent on the selected HARQ offset. Additionally, the
set of supported E-TFCI may also be dependent on the minimum set
E-TFCI. Embodiments for E-TFC restriction and determination of
supported/blocked E-TFCI are described below.
[0057] Where referred to hereafter, a MAC-d flow may also refer to
a logical channel, a group of logical channels, a data flow, a data
stream, or data service or any MAC flow, application flow, etc. All
the concepts described herein are equally applicable to other data
flows. For example in HSPA system for E-DCH, each MAC-d flow is
associated to a logical channel (e.g., there is a one-to-one
mapping) and has a priority from 1 to 8 associated to it.
[0058] Generally, there are scheduling mechanisms used for uplink
transmissions and data transmissions. The scheduling mechanisms may
be defined by the quality of service (QoS) requirements and/or the
priority of the data streams to be transmitted. Depending of QoS
and/or priority of the data streams, some of the data streams may
or may not be allowed to be multiplexed and transmitted together in
one TTI. Generally, data flows and streams can be grouped in best
effort or non real time services and guaranteed bit rate service
with some strict delay requirements. In order to meet QoS
requirements different scheduling mechanisms are used, some dynamic
in nature and some less dynamic.
[0059] Generally, wireless systems, such as LTE and high speed
uplink packet access (HSUPA), operate on a request-grant basis
where WTRUs request a permission to send data, via uplink feedback,
and the Node-B (eNB) scheduler and/or RNC decides when and how many
WTRUs will be allowed to do so. Hereafter, this is referred to as
scheduled mode transmissions. For example in HSPA systems, a
request for transmission includes indication of the amount of
buffered data in the WTRU and WTRU's available power margin (i.e.,
UE power headroom (UPH)). The power that may be used for the
scheduled transmissions is controlled dynamically by the Node-B
through absolute grant and relative grant.
[0060] For some data streams with strict delay requirements and
guaranteed bit rate, such as voice over IP (VoIP) or signaling
radio bearers or any other service that need to meet these
requirements, the network may ensure the timely delivery of such
transmissions via special scheduling mechanisms that are less
dynamic in nature and allow the WTRUs to transmit data from a
particular flow on at pre-scheduled time periods, resources, and up
to a configured data rate. These flows in some systems such as HSPA
for example are referred to as non-scheduled flows. In other
systems, such as LTE, they may be referred to as semi-persistent
scheduling and flows. Even though the embodiments described herein
are described in terms of scheduled and non-scheduled data, it
should be understood that they are equally applicable to other
systems that use similar scheduling procedure and distinctions
between data flows.
[0061] Dynamic scheduling, where control channels are used to
allocate the resources for certain transmissions and for the
possible retransmissions, gives full flexibility for optimizing
resource allocation. However, it requires control channel capacity.
In order to avoid control channel limitation problem,
semi-persistent scheduling (SPS) may be used in systems such as LTE
and non-scheduled transmission in systems such as UMTS. Flows that
use dynamic scheduling or the dynamic grant-based mechanism (e.g.,
via physical channel control signaling) will be referred to as
scheduled transmissions. Data streams that use a more semi-static
and periodic allocation of resources will be referred to as
non-scheduled transmissions.
[0062] For example, in HSPA, each MAC-d flow is configured to use
either scheduled or non-scheduled modes of transmissions, and the
WTRU adjusts the data rate for scheduled and non-scheduled flows
independently. The maximum data rate of each non-scheduled flow is
configured by higher layers, and typically not changed
frequently.
[0063] In the E-TFC selection procedure, the WTRU may also
determine the remaining non-scheduled grant payload for each MAC-d
flow with a non-scheduled grant, which refers to and corresponds to
the number of bits allowed to be transmitted according to the
configured non-scheduled grant for the given MAC-d flow.
[0064] The remaining scheduled grant payload in the procedure above
refers to the highest payload that could be transmitted according
to the network allocated resources. For example, a network
allocated resource refers to the serving grant, or to an allocated
E-DPDCH to DPCCH power ratio for HSPA systems. The value of the
serving grant used for calculating the remaining scheduled grant
payloads for the uplink carriers may be based on the value of the
actual serving grant allocated for the uplink carriers and selected
HARQ power offset. Alternatively, as the remaining scheduled grant
payload for the primary carrier and/or the secondary carrier may be
based on the scaled or fictitious or virtual grant after power
allocation is performed, the WTRU may use the "virtual" or
"fictitious" or scaled serving grant to determine the remaining
scheduled grant payload. The three terms may be used
interchangeably and refer to the power allocation or power split
for scheduled transmissions for each carrier. The scaling of the
grants is described as part of the power allocation schemes below.
Alternatively, if the WTRU is sharing one serving grant for both
uplink carriers, (i.e., one serving grant is given for both uplink
carriers), the WTRU may use half the serving grant for each uplink
carrier. Alternatively, the WTRU may assume that all serving grant
is being allocated to one uplink carrier when performing this
calculation.
[0065] The non-scheduled grant may be carrier specific, (e.g., the
configured non-scheduled grant value is assigned and configured for
only one carrier, the carrier for which non-scheduled transmission
is allowed). The carrier in which non-scheduled transmission is
configured/allowed may be predetermined, (e.g., the non-scheduled
transmission may be allowed on the primary carrier or alternatively
on the secondary carrier). Alternatively, it may be configured by
the network dynamically. The value of non-scheduled grant may be
carrier independent, in which case a total number is determined for
both carriers.
[0066] Data flows may be configured to be carrier specific (e.g.,
network configures a flow and an associated carrier over which this
flow may be transmitted). If data flows are carrier specific the
WTRU may perform the E-TFC selection procedure independently for
each carrier. The network may provide a non-scheduled grant based
on a HARQ process that belongs to a carrier, or provide a
non-scheduled grant that is applicable to a TTI, and the WTRU
chooses a carrier.
[0067] If the WTRU is power limited as determined in step 504 in
FIG. 5, the WTRU may perform power allocation and split the power
between the two (or more than two) carriers within the restriction
that the total transmission power over the two carriers does not
exceed the maximum power. Further details on how UE determines that
it is power limited are described hereafter.
[0068] Embodiments for power allocation are disclosed hereafter.
The maximum transmission power that is allocated to each carrier
may be calculated in a number of ways. In one embodiment, the UL
carriers may be equally allocated power up until the individual
maximum allowed scheduled transmission power on each carrier, which
is based on the serving grants and current channel conditions
(e.g., UL DPCCH power). Once the maximum allowed scheduled
transmission power is reached on any of the UL carriers, any
additional available transmission power is allocated to the other
carrier until either the maximum scheduled transmission power is
reached on that carrier or the maximum total transmission power has
been reached.
[0069] Let P.sub.max represent the total allowed maximum
transmission power combined across both uplink carriers, optionally
including backoff, and P.sub.granted,z represent the maximum
transmission power allowed on carrier z (z=x or y, or z=1 or 2)
based on the grant (scheduled and/or non-scheduled) and control
channels. Carrier x or y may correspond to either primary or
secondary carrier. If more than two carriers are configured, it is
understood that more that P.sub.granted,z is calculated for all
carriers z=1 . . . k, where k is the number of configured carriers.
As an example, P.sub.granted,z may be calculated as:
P.sub.granted,z=SG.times.P.sub.DPCCH,z+P.sub.DPCCH,z+P.sub.E-DPCCH,z+P.s-
ub.HS-DPCCH,z. Equation (1)
The term P.sub.HS-DPCCH,z may be removed from equation (1) if the
HS-DPCCH is not transmitted on carrier z. Optionally, taking into
account non-scheduled transmissions and, the total transmission
power that would result in carrier z is equivalent to:
P.sub.granted,z=SG.times.P.sub.DPCCH,z+P.sub.non-SG+P.sub.E-DPCCH,z+P.su-
b.E-DPCCH,z+P.sub.HS-DPCCH,z. Equation (2)
[0070] The WTRU determines that it is power limited if the
P.sub.granted,x+P.sub.granted,y>P.sub.max.
[0071] This power allocation scheme aims at equalizing the power
used between the two carriers. The power allocated to each carrier
may be determined as follows (optionally the following power
allocation scheme may be performed if the WTRU is in a power
limited state, (i.e.,
P.sub.max.ltoreq.P.sub.granted,x+P.sub.granted,y), otherwise the
power or grants may not be scaled): [0072] If min(P.sub.max/2,
P.sub.granted,x, P.sub.granted,y)=P.sub.max/2: [0073]
P.sub.max,x=P.sub.max/2 and P.sub.max,y=P.sub.max/2; [0074] Else if
min(P.sub.max/2, P.sub.granted,x, P.sub.granted,y)=P.sub.granted,x:
[0075] P.sub.max,x=P.sub.granted,x and
P.sub.max,y=P.sub.max-P.sub.granted,x; [0076] Else (i.e.,
min(P.sub.max/2, P.sub.granted,x,
P.sub.granted,y)=P.sub.granted,y): [0077]
P.sub.max,y=P.sub.granted,y and
P.sub.max,x=P.sub.max-P.sub.granted,y.
[0078] Optionally, the power may be capped as shown below (for
example, if the method above is performed regardless of the power
limitation state): [0079] If min(P.sub.max/2,
P.sub.granted.sub._.sub.x, P.sub.granted.sub._.sub.y)=P.sub.max/2:
[0080] P.sub.max.sub._.sub.x=P.sub.max/2 and
P.sub.max.sub._.sub.y=P.sub.max/2; [0081] Else if min(P.sub.max/2,
P.sub.granted.sub._.sub.x,
P.sub.granted.sub._.sub.y)=P.sub.granted.sub._.sub.x: [0082]
P.sub.max.sub._.sub.x=P.sub.granted.sub._.sub.x and
P.sub.max.sub._.sub.y=min(P.sub.granted.sub._.sub.y,
P.sub.max-P.sub.granted.sub._.sub.x); [0083] Else (i.e.,
min(P.sub.max/2, P.sub.granted.sub._.sub.x,
P.sub.granted.sub._.sub.y)=P.sub.granted.sub._.sub.y): [0084]
P.sub.max.sub._.sub.y=P.sub.granted.sub._.sub.y and
P.sub.max.sub._.sub.x=min(P.sub.granted.sub._.sub.x,P.sub.max-P.sub.grant-
ed.sub._.sub.y).
[0085] Once P.sub.max,x is determined in accordance with any of the
options described above (this is also applicable to the one
described below), the final P.sub.max,x to be used may ensure that
it does not exceed the allowed power allocated by the actual
serving grant for that carrier x, P.sub.granted x. This may be done
in the following way: [0086] P.sub.max x=min (P.sub.max x,
P.sub.granted x).
[0087] Optionally, if the WTRU is in a power limited state, (e.g.,
P.sub.max<P.sub.granted.sub._.sub.x+P.sub.granted.sub._.sub.y)
the WTRU may perform the following (otherwise the serving grants
and powers are not scaled): [0088] If
min(P.sub.granted.sub._.sub.x,
P.sub.granted.sub._.sub.y)=P.sub.granted.sub._.sub.x (i.e.,
P.sub.grant.sub._.sub.x<P.sub.grant.sub._.sub.y) [0089]
P.sub.max.sub._.sub.x=min(P.sub.granted.sub._.sub.x P.sub.max/2)
and P.sub.max.sub._.sub.y=P.sub.max-P.sub.granted.sub._.sub.x
[0090] else [0091] P.sub.max.sub._.sub.y=min
(P.sub.granted.sub._.sub.y,P.sub.max/2) and
P.sub.max.sub._.sub.x=P.sub.max-P.sub.granted.sub._.sub.y
[0092] The following may also be performed. [0093] If
min(P.sub.granted.sub._.sub.x,
P.sub.granted.sub._.sub.y)=P.sub.granted.sub._.sub.x or
P.sub.grant.sub._.sub.x<P.sub.grant.sub._.sub.y [0094]
P.sub.max.sub._.sub.x=min(P.sub.granted.sub._.sub.x, P.sub.max/2)
and P.sub.max.sub._.sub.y=min(P.sub.granted.sub._.sub.y,
P.sub.max-P.sub.granted.sub._.sub.x) [0095] else [0096]
P.sub.max.sub._.sub.y=min (P.sub.granted.sub._.sub.y P.sub.max/2)
and P.sub.max.sub._.sub.x=min(P.sub.granted.sub._.sub.x,
P.sub.max-P.sub.granted.sub._.sub.y)
[0097] Alternatively, the power may be split in such a way that the
total power used is equalized even in situations where there is not
enough power to fill up both carriers up to the minimum grant. More
specifically, if 2.times.P.sub.lowest<P.sub.max, where
P.sub.lowest=min(P.sub.granted,x, P.sub.granted,y) then the formula
above may result in some power imbalances, since more power would
be allocated to one of the carriers. In order to optimize power
allocation the following may be performed and the grant may be
scaled if P.sub.max<P.sub.granted,x+P.sub.granted,y: [0098] If
2.times.P.sub.lowest<=P.sub.max [0099] Then
.theta.=P.sub.max/(2.times.P.sub.lowest) [0100]
P.sub.max,x=.theta..times.P.sub.granted,x and
P.sub.max,y=.theta..times.P.sub.granted,y [0101] Else [0102] If
P.sub.granted,x<P.sub.granted,y [0103]
P.sub.max,x=P.sub.granted,x (i.e., SG.sub.input,x=SG.sub.x) and
P.sub.max,y=P.sub.max-P.sub.granted,x [0104] Else [0105]
P.sub.max,x=P.sub.max-P.sub.granted,y and
P.sub.max,y=P.sub.granted,y [0106] Otherwise the power or grants
are not scaled.
[0107] Alternatively, the following may be used for power
allocation: [0108] If P.sub.max>P.sub.granted,x+P.sub.granted,y
[0109] Do nothing and keep the same SGs; [0110] Else [0111] if
min(P.sub.granted,x, P.sub.granted,y)=P.sub.granted,x or
P.sub.granted,x<P.sub.granted,y [0112] Then
P.sub.max,x=P.sub.granted,x or SG.sub.max,x=SGx and
P.sub.max,y=P.sub.max-P.sub.granted,x; [0113] Else (i.e.,
min(P.sub.max/2, P.sub.granted,x, P.sub.granted,y)=P.sub.granted,y)
[0114] Then P.sub.max,y=P.sub.granted,y or SG.sub.max,y=SGy and
P.sub.max,x=P.sub.max-P.sub.granted,y; [0115] Else if
P.sub.granted,x=P.sub.granted,y.
[0116] For both cases the calculated P.sub.max,x may be used as a
new limit for E-TFC restriction. Alternatively, P.sub.max,x may be
used to calculate a new scaled, fictitious serving grant
SG.sub.input
x=(P.sub.max,x-P.sub.DPCCH,x-P.sub.E-DPCCH,x+P.sub.HS-DPCCH,x)/P.sub.DPCC-
H,x. In the latter case the grant may be the limiting factor on
both carriers.
[0117] Alternatively, instead of attempting to equalize the total
power used between the two carriers the WTRU may attempt to
equalize the serving grants being used. Assuming that the maximum
E-DPDCH/DPCCH power ratio is provided by the serving grant the WTRU
may calculate or estimate the power the WTRU may use for E-DCH
scheduled transmissions for carrier z={x,y} as follows:
P.sub.E-DPDCH,z=SG.sub.zP.sub.DPCCH,z. Equation (3)
[0118] If P.sub.granted,x P.sub.granted,y<P.sub.max or
equivalently
P.sub.E-DPDCH,x+P.sub.E-DPDCH,y>P.sub.max-(P.sub.DPCCH,z+P.sub.HS-DPCC-
H,z+P.sub.E-DPCCH,z)=P.sub.DATA,max then the power used across both
carriers need to be scaled down and equalized. The WTRU may then
perform a similar procedure as above, but instead of using
P.sub.granted,y and P.sub.max the WTRU may use P.sub.E-DPDCH,z and
P.sub.DATA,max, respectively.
[0119] Optionally, a minimum power allocation or power ratio may be
defined for one or both carriers.
[0120] Optionally, both a minimum power allocation for transmission
of control channels P.sub.min,z (z=x or y) and a minimum power
ratio for the transmission of data may be defined for one or both
of the carriers. P.sub.min,z may be calculated as follows:
P.sub.min,z=P.sub.DPCCH,z+P.sub.E-DPCCH,z+P.sub.HS-DPCCH,z Equation
(4)
The term P.sub.HS-DPCCH,z may be omitted if the HS-DPCCH is not
transmitted on carrier z. Let Beta.sub.ed.sub._.sub.min.sub._.sub.z
represent the power ratio required to send the minimum allowed
transport block size on carrier z (z=x or y). Power is allocated
for transmission of control channels as follows:
P.sub.max,x=P.sub.min,x and P.sub.max,y=P.sub.min,y. Remaining
power is then allocated to satisfy minimum power ratio requirement
of the first carrier, carrier x, as follows: [0121] Set
P.sub.remaining=P.sub.max-(P.sub.max,x P.sub.max,y) [0122] If
P.sub.remaining>Beta.sub.ed.sub._.sub.min,x.times.P.sub.DPCC-
H,x [0123] Then set
P.sub.max,x=Beta.sub.ed.sub._.sub.min,x.times.P.sub.DPCCH,x+P.sub.max,x
[0124] Else P.sub.remaining may optionally be allocated to carrier
y: [0125] P.sub.max,y=P.sub.max,y+P.sub.remaining
[0126] Remaining power may then be allocated to satisfy minimum
power ratio requirement of the second carrier, carrier y, as
follows: [0127] Set P.sub.remaining=P.sub.max-(P.sub.max,x
P.sub.max,y) [0128] If
P.sub.remaining>Beta.sub.ed.sub._.sub.min,y.times.P.sub.DPCCH,y
[0129] Then set
P.sub.max,y=Beta.sub.ed.sub._.sub.min,y.times.P.sub.DPCCH,y+P.sub.max,y
[0130] Else P.sub.remaining may optionally be allocated to carrier
x: [0131] P.sub.max,x=P.sub.max,x+P.sub.remaining
[0132] Remaining power may then be allocated to both carriers
according to any of embodiments disclosed herein, (e.g., by
computing a ratio for each carrier).
[0133] In the above embodiment, carriers x and y may be
interchanged. The carrier to allocate the remaining power first may
be chosen using any of the following criteria or any of the carrier
selection criteria disclosed above. Carrier x or anchor carrier may
be selected first. Alternatively, the carrier with the largest
power headroom may be selected first. Alternatively, the carrier
with the largest serving grant may be selected first.
[0134] In an alternate power allocation embodiment, power may be
allocated to each carrier such that power ratios are equally
distributed to the two carriers up to the maximum allowed power
ratios. This is in contrast to the previous embodiment where
absolute power is allocated rather than the power ratios for
transmission of data (i.e., Beta.sub.ed). P.sub.max represents the
total maximum transmission power combined across both carriers.
SG.sub.z represents the serving grant (or equivalently scheduling
grant) on carrier z (z=x or y). PR.sub.z represents the power ratio
that is allocated to carrier z for transmission of E-DCH.
P.sub.DPCCH,z represents the transmission power of the UL DPCCH on
carrier z. PC.sub.z represents the transmission power of control
channels (including UL DPCCH) on carrier z.
[0135] PR.sub.x may be calculated assuming both carriers are
equally assigned power ratios up to the total transmission power as
follows:
[0136]
PR.sub.x=PR.sub.y=(P.sub.max-PC.sub.x-PC.sub.y)/(P.sub.DPCCH,x+P.su-
b.DPCCH,y).
[0137] If PR.sub.x exceeds SG.sub.x, remaining power may be
allocated to carrier y as follows: [0138] If PR.sub.x>SG.sub.x,
then set [0139] PR.sub.x=SG.sub.x; and [0140]
PR.sub.y=(P.sub.max-PC.sub.x-PC.sub.y-PR.sub.x.times.P.sub.DPCCH,x)/P.sub-
.DPCCH,y.
[0141] If PR.sub.y exceeds SG.sub.y, remaining power may be
allocated to carrier x as follows: [0142] If PR.sub.y>SG.sub.y,
then set [0143] PR.sub.y=SG.sub.y; and [0144]
PR.sub.x=min(SG.sub.x,
((P.sub.max-PC.sub.x-PC.sub.y-PR.sub.x.times.P.sub.DPCCH,x)/P.sub.DPCCH,x-
))
[0145] The maximum transmission power for carrier z may be
calculated as: [0146] P.sub.max,z=PR.sub.z.times.P.sub.DPCCH,z
PC.sub.z.
[0147] Optionally, a minimum power ratio may be defined for each
carrier, PR.sub.min,z. In this case, the above equations may be
modified as follows. PR.sub.z is calculated assuming both carriers
are equally assigned power ratios up to the total transmission
power as follows: [0148]
PR.sub.x=PR.sub.y=(P.sub.max-PC.sub.x-PC.sub.y)/(P.sub.DPCCH,x+P.s-
ub.DPCCH,y).
[0149] It is then verified that minimum power ratio has been
assigned to carrier x (if PR.sub.min,x is configured and greater
than 0) as follows: [0150] If PR.sub.x<PR.sub.min,x, then assign
allocated power of carrier x to carrier y [0151]
PR.sub.y=(P.sub.max-PC.sub.x-PC.sub.y)/P.sub.DPCCH,y; and [0152]
PR.sub.x=0.
[0153] It is then verified that minimum power ratio has been
assigned to carrier y (if PR.sub.min,y is configured and greater
than 0) as follows: [0154] If PR.sub.y<PR.sub.min,y, then assign
allocated power of carrier y to carrier x [0155]
PR.sub.x=(P.sub.max-PC.sub.x-PC.sub.y)/P.sub.DPCCH,x; and [0156]
PR.sub.y=0.
[0157] The carriers x and y may be interchanged. Carrier x or
anchor carrier may be selected first. Alternatively, the carrier
with the largest power headroom or the carrier with the largest
serving grant may be selected first.
[0158] Power allocation embodiments for reducing wasted power are
disclosed hereafter. These may be combined with the power
allocation embodiments disclosed above. While the parallel
allocation of power and/or grant may result in a lower power
imbalance, a waste in power may occur when the grant is scaled down
and the WTRU suffers from buffer limitation in the first carrier
due to MAC-d flow multiplexing restrictions.
[0159] In accordance with one embodiment, a WTRU may determine a
scaling factor to scale the power or grant in order to balance the
power between the carriers. It is understood that the scaling
factor or scaling value may be applicable to the serving grant or
power for each carrier and may be calculated via any methods. The
scaling factor will be referred to as .theta. or may be referred to
as .rho..sub.z.
[0160] Assuming that the maximum E-DPDCH/DPCCH power ratio is
provided by the serving grant the WTRU may calculate or estimate
the power the WTRU may use for E-DCH scheduled transmissions for
carrier z={x,y} as follows (where for example x=1 and y=2, or
alternatively x=2, and y=1):
P.sub.E-DPDCH,z=SG.sub.z.times.PDPCCH,.sub.z. Equation (5)
Optionally, P.sub.E-DPDCH,z may include the power required to
transmit scheduled and non-scheduled transmissions, according to
allocated serving grant and non-scheduled grant on the carrier (if
allowed) or alternatively, the power required for non-scheduled
transmissions is captured in the calculation of total transmission
power for carrier z as shown below.
[0161] In the power limited case, the WTRU needs to reduce the
transmit power associated to each carriers so that the total power
used does not exceed the maximum power, P.sub.max. The WTRU may be
considered in power limited situation when
P.sub.x+P.sub.y>P.sub.max, or equivalently
P.sub.E-DPDCH,x+P.sub.E-DPDCH,y>P.sub.max-(P.sub.DPCCH,z+P.sub.HS-DPCC-
H,z+P.sub.E-DPCCH,z)=P.sub.DATA,max. P.sub.z corresponds to the
total power used for transmission on carrier z, which may or may
not include non-scheduled transmissions, and is determined as
follows:
P.sub.z=P.sub.DPCCH,z+P.sub.HS-DPCCH,z+P.sub.E-DPCCH,z+P.sub.E-DPDCH,z.
Equation (6)
In the optional embodiment where non-scheduled power is taken into
account for carrier z (if allowed):
P.sub.z=P.sub.DPCCH,z+P.sub.HS-DPCCH,z+P.sub.E-DPCCH,z+P.sub.E-DPDCH,z+P-
.sub.non-SG,z. Equation (7)
[0162] P.sub.DATA,max represents the power that may be allocated to
E-DCH traffic. Initially, as a first step when the WTRU is power
limited, the WTRU computes a scaling factor
.theta.=P.sub.DATA,max/(P.sub.E-DPDCH,x+P.sub.E-DPDCH,y) which may
be used to scale the P.sub.E-DPDCH,x and/or P.sub.E-DPDCH,y or to
scale the serving grant.
[0163] As part of this embodiment, the P.sub.max used may account
for the worst case backoff situation (i.e., the backoff incurred if
the WTRU were to transmit P.sub.E-DPDCH,z according to the serving
grant). However, this may result in the power of the WTRU being
wasted, because if the WTRU is power limited the actual
P.sub.E-DPDCH,z,used will correspond to a lower value than the one
provided by the serving grant, and therefore the real backoff may
be much lower. The same applies to the estimated P.sub.E-DPCCH,z
value in case E-DPCCH power boosting is configured. The WTRU may
use a worst case scenario value, assuming a final P.sub.E-DPDCH,z
level according to the SG.sub.z. However, a power waste may also
occur in this case since the used P.sub.E-DPDCH,z,used will most
likely result in a lower value than the one allowed by the serving
grant and therefore the P.sub.E-DPCCHz may be lower than the
assumed power used in the equation. Therefore, in order to not
waste power the WTRU may use P.sub.max without any backoff taken
into account, or alternatively with the lowest backoff and the
minimum allowed P.sub.E-DPCCH,z value.
[0164] Once a scaling factor or value is determined, the WTRU may
use this scaling factor or value on one carrier and allow the other
carrier to fully use the remaining power and the allowed serving
grant. More specifically, the E-TFCI determination (and data
filling) may have to be performed sequentially, one carrier at a
time, because data from the joint buffer has to be taken
sequentially and filled up for one carrier at a time to ensure
in-order delivery, and determination of highest priority MAC-d flow
may be different in the two carriers depending on buffer and
multiplexing restrictions, and therefore the HARQ profile (offset
and retransmissions may be different), and E-TFC restrictions, or
more specifically the determination of supported E-TFCIs, needs to
be done sequentially since the set of supported E-TFCI will depend
on the HARQ offset being used and also the back off in the second
carrier will be dependent on the E-TFC (amount of codes transmitted
in the other carrier).
[0165] According to this embodiment, the scaling factor or value
determined may only be applied to the first carrier selected. This
may impose an absolute maximum E-DPDCH to DPCCH power ratio that
the WTRU is allowed to use on the first carrier. A modified power
level associated with the E-DPDCH of carrier x may be computed as
P.sub.E-DPDCH,mod,x=.theta..times.P.sub.E-DPDCH,x where x is the
first carrier selected to perform E-TFC selection first. This power
may then be mapped into the a fictitious "serving grants"
SG.sub.input,x=.theta..times.SG.sub.x.
[0166] The WTRU as part of the E-TFC selection for carrier x
determines the highest priority MAC-d flow, multiplexing list and
HARQ profile and performs the E-TFC selection procedure to
determine how many bits the WTRU may fit into this first carrier.
The WTRU then determines the set of supported E-TFCs as part of
E-TFC restriction for carrier x. The E-TFC restriction may be
performed sequentially for the carriers. For example, in this
approach the WTRU may assume that it has the full available power
and no E-DPDCH and E-DPCCH is being transmitted in the other
carrier, when determining the set of supported E-TFCs, (i.e., the
scaled serving grant will ensure that the WTRU will not exceed a
certain power allocation).
[0167] The WTRU then uses SG.sub.input,x=.theta..times.SG.sub.x as
the value for the maximum E-DPDCH/DPCCH to be used to determine the
maximum number of bits, k for scheduled transmissions. Based on the
logical channel or MAC-d flow priorities, buffer availability,
fictitious scheduled grant, and non-scheduled grant, the WTRU then
determines the E-TFCI for carrier x.
[0168] Once a first carrier is selected and the number of bits that
may be included in this carrier have been determined, the WTRU
performs E-TFC selection on the other carrier, carrier y. Since due
to buffer limitations in the first carrier, not all the allowed
power given by the SG.sub.input,x may have been used, when
performing E-TFC selection on the other carrier the WTRU assumes
that it may use all the remaining power up to the actual provided
serving grant. More specifically, the SG.sub.input,y=SG.sub.y or
equivalently the scaling factor, .theta.=1 such that
SG.sub.input,y=.theta..times.SG.sub.y. Optionally, it may be
considered that P.sub.max,y=P.sub.max.
[0169] This scheme will allow any unused power to be used by the
second carrier, while the parallel allocation scheme is still
ensuring that the power of the first carrier never exceeds the
allocated power and therefore the power on the second carrier will
also never exceed it. Therefore, for carrier y, the WTRU may
determine a new higher priority MAC-d flow and new multiplexing
list and HARQ profile for the new carrier. E-TFC restriction is
performed for this carrier, assuming that the full remaining power
is available to the carrier and the power used for the E-DPDCH and
E-DPCCH in the other carrier x is taken into account. The WTRU then
determines the number of bits or the E-TFCI to use for carrier y,
based on the set of supported E-TFCs, the real serving grant of
carrier y, and the buffer availability.
[0170] This mechanism ensures the following. If there is enough
data for carrier x, (i.e., SG.sub.input,x is fully used or
P.sub.E-DPDCHused,x=P.sub.E-DPDCHmod,x (this is an approximation
used as in the initial power allocation scheme), then:
P.sub.E-DPDCHusedmax,y=P.sub.DATA,max-P.sub.E-DPDCHused,x=P.sub.DATA,max-
-P.sub.E-DPDCHmod,x=P.sub.E-DPDCHmod,y. Equation (8)
This means that the imbalance and allocation are as if both grants
were scaled. If there is not enough data for carrier x (i.e.,
SG.sub.input,x is not fully used or
P.sub.E-DPDCHused,x<P.sub.E-DPDCHmod,x), then
P.sub.E-DPDCHmod,x-P.sub.E-DPDCHused,x will be used by the second
carrier. This ensures that
P.sub.E-DPDCHusedmax,y=P.sub.DATA,max-P.sub.E-DPDCHused,x<P.sub.DATA,m-
ax-P.sub.E-DPDCHmod,x<P.sub.E-DPDCHmod,y) therefore
P.sub.E-DPDCHmod,y<P.sub.E-DPDCHusedmax,y<P.sub.E-DPDCH,y.
[0171] Therefore, even though this may sometimes result in the
second carrier slightly utilizing a higher power than the scaled
P.sub.y,new, it is ensuring that no power goes to waste and the
power imbalance is still within a limit of tolerance.
[0172] Alternatively, the WTRU may perform an additional
calculation of P.sub.input,E-DPDCHy=P.sub.Data-P.sub.E-DPDCHused,x.
P.sub.input,E-DPDCHy corresponds to P.sub.E-DPDCHmod,y, which may
be used to calculate
SG.sub.input,y=P.sub.input,E-DPDCHy/P.sub.DPCCHy.
[0173] Alternatively, the power may be allocated based on an SG and
a DPCCH power. The power on each carrier may be scaled with respect
to the ratio of the serving grant to DPCCH power on that carrier.
More specifically, a fraction of the remaining power allocated for
the E-DPDCH on each carrier, .rho..sub.z, may be based on the
scaling factor W.sub.z, z=x,y as follows:
.rho..sub.z=W.sub.z/(W.sub.x+W.sub.y), Equation (9)
where W.sub.z=SG.sub.z/(P.sub.DPCCH,z) z=x,y, SG.sub.z and
P.sub.DPCCH,z are the serving grant and DPCCH power on carrier z,
respectively.
[0174] While this approach has shown promising results, it remains
difficult for the network to predict the amount of power used on
each carrier by a WTRU, as the DPCCH power level varies quickly,
and this information is unavailable at the Node-B scheduler.
[0175] Alternatively, an average value for the DPCCH power may be
used when calculating W.sub.z. This averaging may be done in a
number of ways. For example, the WTRU may calculate the DPCCH power
averaged over a fixed period of time (sliding window). This period
of time may be fixed in the specifications, or optionally, this
period of time may be configured by the network. The WTRU may use
the averaged DPCCH power used in the calculation of the UPH. The
WTRU may use the averaged DPCCH power used in the calculation of
the UPH for the last transmitted SI. The WTRU may use the averaged
DPCCH power used in the calculation of the UPH for the last
successfully transmitted SI. The WTRU may use the averaged DPCCH
power used in the calculation of the UPH for the last successfully
transmitted periodic SI. This approach to DPCCH power estimation
may be used for any of the power allocation schemes requiring the
power of the DPCCH.
[0176] Parallel power allocation schemes while taking into account
non-scheduled transmissions are explained hereafter. The network
gives a non-scheduled grant based on a HARQ process that belongs to
a carrier, or gives a non-scheduled grant that is applicable to a
TTI and the WTRU chooses the carrier.
[0177] In the embodiments for the parallel power allocation
schemes, where the maximum power is scaled and allocated across
both carriers prior to filling up the carriers, non-scheduled data
and the priority associated with their transmission has not been
taken into account. The transmission of non-scheduled data may be
allowed on the primary carrier only. This means that if the WTRU is
in power limited situation and if the power is split over both
carriers, the WTRU may not be able to fully transmit all allowed
non-scheduled data, since a portion of the power that could have
been used for non-scheduled transmission has been allocated to the
other carrier which cannot transmit non-scheduled data. The
determination may be made in step 504 in FIG. 10. The WTRU may
determine it is in a power limited situation if
P.sub.x+P.sub.y>P.sub.max. P.sub.x may be calculated according
to the power required to transmit the E-DCH scheduled data based on
the SG, the power required to transmit the E-DCH non-scheduled
transmissions, the E-DPCCH, the DPCCH code power and HS-DPCCH power
if present. For example, P.sub.x=(SG.times.P.sub.DPCCH P.sub.non-SG
P.sub.DPCCH P.sub.HS-DPCCH+P.sub.E-DPCCH). P.sub.y is calculated as
described in the above embodiment. It is understood that in this
example, carrier x corresponds to the carrier in which
non-scheduled transmissions are performed.
[0178] In accordance with one embodiment, prior to splitting the
power across the carriers the WTRU attempts to allocate to the
primary carrier the power that the WTRU requires to transmit the
allowed and available (if available) non-scheduled transmissions.
P.sub.non-SG is referred to as the power required to transmit the
allowed non-scheduled MAC-d flows for the given TTI, (e.g., the sum
of remaining non-scheduled grant payload for each of the allowed
MAC-d flow, or each of the allowed MAC-d flows with available
data). The allowed MAC-d flows are determined according to the
multiplexing list of the highest priority MAC-d flow.
[0179] The P.sub.non-SG may be calculated by determining the power
required to transmit all allowed and available non-scheduled MAC-d
flows. As described above this may be the power required to
transmit the total or sum of remaining non-scheduled grant payload
for each allowed and available non-scheduled flow. Alternatively,
it may be calculated by adding the configured non-scheduled grants
up to available number of bits and determining the gain factors or
the power required to transmit the calculated number of bits given
the HARQ offset of the highest priority MAC-d flow. Using this
method allows the WTRU to more precisely calculate the power
required according to availability of data. The available number of
bits may be a limiting factor even if the WTRU has more
non-scheduled grant. Therefore, the "number of non-scheduled bits"
for each allowed MAC-d flow that may be transmitted may correspond
to min(remaining non-scheduled payload, available number of
bits).
[0180] The total number of bits that may be transmitted based on
the non-scheduled grants and the available bits is equal to N,
where N=.SIGMA. (non-scheduled data per MAC-d flow allowed
according to highest priority MAC-d flow and multiplexing list),
where non-scheduled data per MAC-d flow may be determined as min
(available non-scheduled data, non-scheduled grant) or as remaining
non-scheduled grant payload (which as defined refers to the
non-scheduled grant). Optionally, headers may be taken into
account. The WTRU may then determine the power required to transmit
N bits, or the E-TFCI that would allow the transmission of this
data, P.sub.non-SG. The allowed MAC-d flow may correspond to the
MAC-d flows that are allowed to be transmitted on the given TTI,
and/or to the MAC-d flows allowed according to the multiplexing
list of the highest priority MAC-d flow with data available or the
highest priority MAC-d flow with data available for the given
carrier or the highest priority non-scheduled MAC-d flow (excluding
scheduled transmissions). The P.sub.non-SG may optionally take into
account the DPCCH powers and HS-DPCCH power if available in the
calculation or alternatively be equivalent to:
P.sub.non-SG=Gainfactor.times.DPCCH power(primary carrier DPCCH
power), Equation (10)
where GainFactor is the E-DPDCH gain factor calculated for the
non-scheduled transmissions, using for example the E-DPDCH power
extrapolation formula or alternatively the E-DPDCH power
interpolation formula in 3GPP TS 25.214. The GainFactor calculation
may potentially use the HARQ offset of the highest priority MAC-d
flow for which there is non-scheduled data available, or
alternatively the highest priority MAC-d flow for which there is
any kind of data available, or alternatively a preconfigured HARQ
offset.
[0181] Given the P.sub.non-SG, the power allocation across both
carriers may then be determined in one of the following options. In
accordance with a first option, the WTRU determines the P.sub.max
to be used for splitting the power across both carriers for
scheduled transmissions as follows:
P.sub.remaining=P.sub.max-P.sub.non-SG; Equation (11)
where the initial P.sub.max is the maximum power allowed by the
WTRU, potentially taking into account a power backoff. The WTRU
then uses the new remaining power to determine how to share and
split the power across both carriers according to any of the
embodiments described herein for the scheduled grants and data. For
instance in order to determine .theta. as described above, the WTRU
may use P.sub.remaining in equation (11) instead of P.sub.max or
for one of the following solutions:
P DATA , max = P remaining - i P DPCCH , i + P HS - DPCCH , i + P E
- DPCCH , i , or Equation ( 12 ) P DATA , max = P max - ( P non -
SG + i = 1 2 P DPCCH , i + P HS - DPCCH , i + P E - DPCCH , i .
Equation ( 13 ) ##EQU00001##
This means that calculated P.sub.DATA,max is the available power
that may be used for scheduled transmissions. In the case where no
non-scheduled transmissions are available,
P.sub.remaining=P.sub.max.
[0182] In accordance with a second option, the WTRU may attempt to
balance the power across both carriers by first allocating the
power to the primary carrier for non scheduled transmission and
allocating the remaining power to the other carrier if enough grant
is available. P.sub.E-DPDCH,i is equivalent to the power required
for E-DPDCH transmission in carrier i. Therefore, in this option
the WTRU provides P.sub.2 to carrier 2 as follows:
P.sub.2=Min(P.sub.max-P.sub.non-SG,P.sub.E-DPDCH,2). Equation
(14)
[0183] If power still remains, the WTRU allocates it to carrier 1
up to minimum of available grant and power. The second option may
be followed if the following condition is true:
P.sub.tot=P.sub.1+P.sub.2>P.sub.max where P.sub.1 and P.sub.2
are the total transmit power allowed by scheduled and non-scheduled
transmissions on each carrier, respectively.
[0184] Alternatively, if the WTRU allocates P.sub.non-SG to the
primary carrier then the WTRU allocates to carrier 2 at least the
same power as allocated to the primary carrier for non-scheduled
transmission initially (i.e., P.sub.2=Min(P.sub.non-SG,
P.sub.E-DPDCH,2, P.sub.remaining)), where P.sub.remaining is the
remaining power after non scheduled data in the primary carrier is
taking into account. If power is still available (i.e.,
P.sub.remaining>P.sub.2+P.sub.non-SG) then scaling of the
remaining power across both carriers may be done using any of the
methods described for the parallel power sharing approaches.
[0185] In accordance with a third option, .theta. or scaling factor
is determined for scheduled transmissions independently without
taking into account the power that would be required by
non-scheduled transmissions. More specifically, the scaling factor
is calculated assuming that the total headroom, P.sub.DATA,max, is
available for scheduled transmissions and the scaling factor is
determined accordingly.
[0186] In addition, in one embodiment, E-TFC restriction on the
first carrier may be performed assuming all the power (i.e.,
P.sub.max) is available to this carrier only and assuming that no
data is being transmitted on the other carrier (i.e.,
P.sub.E-DPDCH,2 and P.sub.E-DPCCH,2 are zero). This ensures that
all the available power will go to the non-scheduled transmissions
if non-scheduled grant, data, and power are all available.
Additionally, if scheduled transmissions have higher priority than
non-scheduled transmissions they may get a higher priority in
utilizing the available power up to the serving grant (or scaled
grant). The remaining power may then be allocated to non-scheduled
transmissions. This is different when compared to the serving grant
being scaled as in option 1 or option 2. In the case that the
scheduled data have higher priority then non-scheduled data, the
WTRU will have a limited amount of data it may actually transmit,
since some power has been pre-allocated to non-scheduled
transmissions.
[0187] When scheduled transmissions have higher priority than
non-scheduled transmissions, in a situation where the serving grant
or fictitious serving grant in the first carrier has been fully
utilized, and data from this scheduled higher priority MAC-d flow
still remains, the WTRU may still have power available and
scheduled higher priority data in the buffer, but the SG of the
first carrier has been exceeded. In such situation, the WTRU may
continue to fill up the first carrier with non-scheduled data even
though non-scheduled transmissions may have a lower priority. Once
data up to non-scheduled grants has been included in the first
carrier, the WTRU may then move to the second carrier and continue
the transmission of the higher priority scheduled MAC-d flow. Even
though this implies that the available power is being used by lower
priority data while higher priority data is still available, for
simplicity reasons it is better to complete one carrier first then
move on to the other.
[0188] Alternatively, in order to minimize the amount of power used
for lower priority data, the WTRU may chose to fill up the
secondary carrier first. This may be desirable, if the WTRU has
scheduled transmissions with higher priority than non-scheduled
transmissions. This will allow the WTRU to optimize one carrier
with the higher priority data using the serving grant and then once
the grant/power/or available data is utilized the WTRU moves to the
primary carrier. In the primary carrier, if scheduled MAC-d flows
with higher priority still exist, the WTRU may utilize the power
and serving grant of the primary carrier to transmit this data.
Based on remaining power, if the next highest priority data is a
non-scheduled data the WTRU may then use the remaining of the power
to transmit the non-scheduled data.
[0189] In accordance with a fourth option, the WTRU may perform
E-TFC selection on the anchor carrier for non-scheduled MAC-d flows
first. This allows the WTRU to determine the number of
non-scheduled data that may be transmitted in the primary carrier
and the power required for this transmission. The WTRU then
performs dual carrier E-TFC selection for scheduled transmissions
by determining a scaling factor where the maximum power accounts
for what is known to be transmitted by non-scheduled by the first
E-TFC selection.
[0190] When determining whether the WTRU is power limited or for
power allocation, if, for the given TTI, the HARQ process is
deactivated, or the WTRU is not allowed or configured to transmit
scheduled transmissions for that TTI, then the power for E-DPDCH
transmission for scheduled transmissions may not be included in the
calculations. This may imply that P.sub.E-DPDCH,z=0 if only
considering scheduled transmissions. Alternatively, the WTRU may
still assume it may transmit scheduled data on the carrier.
[0191] Optionally, the WTRU may not consider P.sub.E-DPCCHz for
that carrier, if no scheduled transmissions are allowed and no
non-scheduled transmissions are available or allowed.
Alternatively, the WTRU may consider the power of E-DPCCH, even if
no E-DCH data will be transmitted. Alternatively, if an SI is
triggered for this carrier, the WTRU may consider the power of
E-DPCCH and/or E-DPDCH to be the power required to transmit an SI
only, as formulated below P.sub.E-DPDCH,z=P.sub.E-DPDCH,0,z and
P.sub.E-DPCCH,z=P.sub.E-DPCCH,0,z.
[0192] Embodiments for selecting an uplink carrier for initial
E-TFC selection are disclosed hereafter. The embodiments for
carrier selection described below may be performed individually or
in combination with any other embodiments disclosed herein. The
procedures affecting the choice of the number of bits to be
transmitted in each uplink carrier and the power to use in each
uplink carrier, and the like are all dependent on which uplink
carrier the WTRU selects and treats first.
[0193] In accordance with one embodiment, a WTRU may give priority
to, and treat first, the anchor carrier. This may be desirable if
non-scheduled transmissions are allowed on the anchor carrier.
Alternatively, the secondary carrier may be given a priority and
selected first.
[0194] Alternatively, the WTRU may determine the highest priority
carrier to minimize inter-cell interference, maximize WTRU battery
life, and/or provide the most efficient energy per bit
transmission. More specifically, the WTRU may choose the uplink
carrier that has the largest calculated carrier power headroom. The
WTRU may base this determination on the current power headroom,
(e.g., UE power headroom (UPH)) measurement for each carrier (UPH
indicates the ratio of the maximum WTRU transmission power and the
corresponding DPCCH code power) or on the results of the E-TFC
restriction procedure, (e.g., normalized remaining power margin
(NRPM) calculation for each carrier, or remaining power), which
equivalently translates to the carrier with the lowest DPCCH power
(P.sub.DPCCH). For instance, the uplink carrier selection may be
made in terms of the number of bits, (e.g., a priority may be given
to the carrier which provides a greater "maximum supported payload"
between the anchor carrier and the supplementary carrier). The
maximum supported payload is the payload determined based on the
remaining power (e.g., NRPM or other value disclosed below) of the
WTRU.
[0195] Alternatively, the WTRU may give a priority to the uplink
carrier which provides the WTRU with the largest available grant,
which allows the WTRU to send the highest amount of data and
possibly create the least number of PDUs and thus increase
efficiency and reduce overhead. The WTRU may select a carrier based
on the maximum value between the serving grant for the anchor
carrier (SGa) and serving grant for the supplementary carrier
(SGs).
[0196] Alternatively, the WTRU may provide a priority to the
carrier that provides the greater "remaining scheduled grant
payload" between the anchor carrier and the supplementary carrier.
The remaining scheduled grant payload is the available payload
determined based on the scheduling grant from the network and
remaining after processing of the DCH and HS-DPCCH.
[0197] Alternatively, the WTRU may optimize between maximum power
and maximum grant. More specifically, the WTRU may select a carrier
that allows the highest number of bits to be transmitted. The WTRU
determines the number of bits that may be transmitted for anchor
carrier and supplementary carrier limited by both power and grant,
(i.e., "available payload" for the anchor carrier and "available
payload" for the supplementary carrier), and may select the carrier
that provides the highest available payload. The available payload
may be determined as a minimum between the remaining scheduled
grant payload and the maximum supported payload.
[0198] Optionally, the sum of "remaining non-scheduled payload" for
each MAC-d flow that may be multiplexed (or all non-scheduled MAC-d
flows that may have data available) may also be taken into account
when calculating the available payload. More specifically, the
available payload may be determined as a minimum of (remaining
scheduled grant payload+SUM(remaining non-scheduled payloads for
all allowed non-scheduled flows)) and the maximum supported
payload. If non-scheduled flows are allowed in one carrier only,
(e.g., in the anchor carrier only), the available payload for the
anchor carrier is considered.
[0199] Even though the embodiments above were described in terms of
the number of bits, it is equally applicable to the carrier
selection based in terms of the power ratios. For example, the WTRU
may use the serving grant (SG), which provides the maximum number
of bits that may be transmitted in terms of grant (serving grant
for anchor carrier (SGa) and serving grant for supplementary
carrier (SGs)), where SG=P.sub.E-DPDCH/P.sub.DPCCH. Alternatively,
the WTRU may use the remaining power, which provides the maximum
number of bits based on remaining power. The remaining power (RP)
may be computed in any manner by subtracting out any power
parameters from the maximum transmit power (typically referred to
as P.sub.MAX) for a particular carrier. For example, the RP that
may be used to select a carrier may be one or a combination of the
following (where z=x or y): [0200] (1)
RPz=P.sub.MAX/P.sub.DPCCH,target,z; [0201] (2)
RPz=(P.sub.MAX-P.sub.E-DPCCH,z-P.sub.HS-DPCCH-P.sub.DPCCH,target,z)/P.sub-
.DPCCH,target,z; or [0202] (3) RPz=Normalized remaining power
margin (NRPM).
[0203] P.sub.MAX is the maximum WTRU transmitter power.
[0204] P.sub.DPCCH,target,z is derived as follows. P.sub.DPCCH,x(t)
and P.sub.DPCCH,y(t) represents a slotwise estimate of the current
WTRU DPCCH power in carrier x and y respectively at time t. If at
time t, the WTRU is transmitting a compressed mode frame in carrier
z, where z can take value x or y, then
P.sub.DPCCH,comp,z(t)=P.sub.DPCCH,z(t).times.(N.sub.pilot,C/N.sub.pilot,N-
) else P.sub.DPCCH,comp.z(t)=P.sub.DPCCH,z(t). If the WTRU is not
transmitting uplink DPCCH during the slot at time t over carrier z,
either due to compressed mode gaps or when discontinuous uplink
DPCCH transmission operation is enabled then the power may not
contribute to the filtered result. Samples of P.sub.DPCCH,comp,z(t)
may be filtered using a filter period of 3 slotwise estimates of
P.sub.DPCCH,comp,z(t) when the E-DCH TTI is 2 ms or 15 slotwise
estimates of P.sub.DPCCH,comp,z when the E-DCH TTI is 10 ms to give
P.sub.DPCCH,filtered,z. If the target E-DCH TTI for which
NRPM.sub.j evaluated does not correspond to a compressed mode frame
then P.sub.DPCCH,target,z=P.sub.DPCCH,filtered,z. If the target
E-DCH TTI for which NRPM.sub.j is being evaluated corresponds to a
compressed mode frame then
P.sub.DPCCH,target,z=P.sub.DPCCH,filtered,z.times.(N.sub.pilot,N/N.sub.pi-
lot,C). N.sub.pilot,C is the number of pilot bits per slot on the
DPCCH in compressed frames, and N.sub.pilot,N is the number of
pilot bits per slot in non-compressed frames.
[0205] P.sub.HS-DPCCH is an estimated HS-DPCCH transmit power based
on the maximum HS-DPCCH gain factor based on P.sub.DPCCH,target,z
and the most recent signalled values of .DELTA..sub.ACK,
.DELTA..sub.NACK and .DELTA..sub.CQI. If the target E-DCH TTI for
which NRPM.sub.j is being evaluated corresponds to a compressed
mode frame then the modification to the gain factors which occur
due to compressed mode may be included in the estimate of
P.sub.HS-DPCCHz. The HS-DPCCH may be allowed to be transmitted in
one carrier which may be carrier x or carrier y, in which case z=x
and z=y, respectively. If HS-DPCCH is transmitted in both carriers
then P.sub.HS-DPCCHz corresponds to the estimated DPDCH power in
both carriers.
[0206] P.sub.E-DPCCH,z is an estimated E-DPCCH transmit power for
E-TFCI determined for carrier z, (z=x or y).
[0207] Referring now to another embodiment, a maximum supported
available power (MSAP) may be computed. The MSAP is the power that
may be used for a transmission on that carrier based on the serving
grant and the remaining power for carrier x and y as follows:
[0208] MSAPx=MIN (SGx, RPx); and [0209] MSAPy=MIN (SGy, RPy), where
MSAPx is MSAP for the anchor carrier (or the first carrier), MSAPy
is MSAP for the supplementary carrier (or the second carrier), RPx
is RP of the anchor carrier (or the first carrier), and RPy is RP
of the supplementary carrier (or the second carrier).
[0210] The WTRU may chose to initially fill up (i.e., give a
priority to) the carrier with the maximum MSAP. Once the selected
carrier is filled up and if there is remaining power, the remaining
power is allocated to the other carrier. If the MSAP is equal on
both carriers, then the WTRU may chose the carrier with the highest
remaining power or equivalently the carrier with the lowest
P.sub.DPCCH. If the remaining powers and P.sub.DPCCH are equal on
both carriers, the WTRU may chose the carrier with the highest
grant or just chose the anchor carrier for transmission.
[0211] If the non-scheduled grants are provided on a per carrier
basis or if the non-scheduled transmissions are allowed on one
carrier, the WTRU may give priority to the carrier that contains
the highest priority non-scheduled MAC-d flow to be transmitted in
that TTI or allows a non-scheduled MAC-d flow. For instance, if the
non-scheduled transmissions are allowed on the primary carrier only
and for the given HARQ process the WTRU is configured with
non-scheduled data and data is available, the WTRU may give
priority to the primary carrier (i.e., fill the primary carrier
first). If in a given TTI the highest priority MAC-d flow does not
correspond to a non-scheduled flow, but a non-scheduled flow is
allowed to be multiplexed with the selected highest priority MAC-d
flow, the WTRU may still give priority to the carrier which allows
non-scheduled transmissions. Therefore, if any non-scheduled flows
are allowed to be transmitted in a current TTI and non-scheduled
data is available, the WTRU may first fill up the carrier which
allows transmission of the non-scheduled flows. The WTRU fills up
the selected carrier with non-scheduled and scheduled data up to
the available power and/or grant according to the configured
logical channel priority. The remaining carrier(s) is then filled
up if data, power and grant are available for that carrier.
[0212] Alternatively, the primary carrier may be selected first to
be filled up. For example, for the non-scheduled transmission the
WTRU may select the carrier with non-scheduled transmission first.
Once the non-scheduled transmissions are included in the selected
carrier, the WTRU may then proceed to carrier selection for
scheduled transmissions using one or a combination of the
embodiments described above. Using this alternative embodiment, the
WTRU may select a carrier for scheduled transmission that is
different from the first one selected for non-scheduled data at the
given TTI. As part of this embodiment, the WTRU may perform E-TFC
selection and restriction on the newly selected carrier, wherein
the E-TFC restriction if performed sequentially for the newly
selected carrier takes into account the power used for the E-DCH
and E-DPCCH power for the non-scheduled transmission in the other
carrier. If the parallel E-TFC restriction is performed the power
has been properly allocated therefore the WTRU does not need to
re-calculate. The WTRU may then fill up the carrier with scheduled
transmission up to allowed power, grant, or available data. If
power, data, and grant are available for the other carrier, the
WTRU may go back to the other carrier (which contains the initial
non-scheduled data) and fill it up with scheduled data.
[0213] Alternatively, the secondary carrier may be selected first.
For example, if a scheduled flow has a highest priority in the
given TTI, the E-TFC selection may be performed such that the
carrier for the scheduled transmissions is selected according to
one of the embodiments described herein. The E-TFC selection on the
secondary carrier may determine, and include, the number of bits
according to grant, power and buffer availability and then fill up
the primary carrier.
[0214] Alternatively, the E-TFC function when treating the
non-scheduled transmissions according to the logical channel
priority ensures that the data for the non-scheduled transmissions
is sent to the proper carrier (e.g., primary carrier). This implies
treating the scheduled data first, wherein the carrier to fill up
first is selected according to one of the embodiments described
above. The E-TFC selection calculates the number of bits that may
be transmitted on the selected carrier and fills it up with data
from the highest priority channel. If data from this channel has
been exceeded, or the maximum amount of data based on scheduled
grants has been reached and if power still remains, then the WTRU
may fill up data from the next highest priority logical channel. If
the next logical channel corresponds to a non-scheduled flow and
non-scheduled flow may be transmitted in the anchor carrier only
and the current carrier corresponds to the secondary carrier, the
WTRU may perform E-TFC selection for the anchor carrier even if
power and/or grant remains on the secondary carrier or
alternatively, the WTRU may complete transmission on the secondary
carrier, e.g., up to available allowed data in buffer or up to
allowed grant/power. The E-TFC restriction procedure (e.g.,
determining a set of supported E-TFCs) is performed for the anchor
carrier. If E-TFC restriction is done sequentially it may take into
account the E-DPDCH power used in the secondary carrier. The WTRU
then fills up the carrier which has non-scheduled flows.
[0215] If power still remains and if some grant is still available
then the WTRU may perform one or a combination of the following two
embodiments for scheduled transmissions. The WTRU may continue
filling up the anchor carrier up to maximum power or maximum grant.
Once the carrier is filled up and there is still power available or
grant available in the other carrier, then the E-TFC selection may
go back to the initial selected carrier to fill it up. This would
then require the WTRU running an additional E-TFC restriction
procedure to take into account the power for the initial
transmission in this carrier and the transmission in the anchor
carrier. Alternatively, the E-TFC selection procedure ends, even
though there is remaining power and grant in the other carrier.
[0216] Alternatively, the WTRU may move back to the originally
selected carrier and continue to fill up that carrier up to maximum
power and/or maximum grant. This may require the WTRU to run E-TFC
restriction procedures again. If power still remains in the anchor
carrier, then the WTRU may then move back to the anchor
carrier.
[0217] Similarly, if a DPDCH transmission is allowed on a
particular carrier only (e.g., primary carrier only) and DCH data
is available, the WTRU may give priority to the primary carrier or
the carrier on which DPDCH is allowed. Alternatively, the WTRU may
perform TFC selection and schedule the DPDCH data for transmission
on the primary carrier and then use one or a combination of the
embodiments described herein to decide which carrier to give
priority for E-DCH transmission.
[0218] Alternatively, in the case where one carrier is
power-limited and the other carrier is grant-limited, the WTRU may
choose the carrier that is power-limited, for the case where the
power is shared on both carriers. A power-limited carrier may be a
carrier for which there is not enough power to transmit all the
data allowed by the grants (scheduled and/or non-scheduled). A
grant-limited carrier may be a carrier which has enough remaining
power to transmit more data than allowed by the grant.
[0219] Alternatively, the carrier selection may depend on the
amount of data available in the buffers. If limited amount of data
is available the WTRU may favor the carrier with the highest
available power headroom or NRPM or equivalently lowest
P.sub.DPCCH, otherwise one of above-described embodiments may be
applied. More specifically, as an example, if TEBS in bits is less
than maximum supported payload and less than the number of bits
allowed by the grants for both carriers, then the WTRU may chose
the carrier with the largest remaining power (or power headroom or
NRPM, or the like).
[0220] Alternatively, the WTRU may decide to give priority to the
carrier that has to transmit an HS-DPCCH in that TTI.
Alternatively, the WTRU may choose to give priority to the carrier
for which DPCCH has to be transmitted (according to either DPCCH
burst cycles on each carrier or inactivity periods on one carrier).
More specifically, if one carrier is in discontinues transmission
(DTX) cycle 1, while the other carrier is in DTX cycle 2 (DTX cycle
2 is longer than DTX cycle 1), the WTRU may give priority to the
carrier in which DTX cycle 1 is ongoing. In case one carrier is in
continuous transmission and the other carrier is in DTX, the WTRU
may give priority to the carrier for which a continuous
transmission is ongoing.
[0221] In the case where an HS-DPCCH is transmitted on one carrier
only (i.e., there is one HS-DPCCH channelization code to provide
feedback or even if two codes are used the WTRU transmits from one
carrier only), if an HS-DPCCH has to be transmitted, the WTRU may
give priority to that carrier. Alternatively, the WTRU may take
into consideration the power used for HS-DPCCH in the NRPM
calculation for that carrier and chose a carrier using one of the
embodiments described above. The network may allow the WTRU to
choose the carrier on which HS-DPCCH feedback is transmitted. More
specifically, for dual carrier operation the WTRU is not limited to
transmit the HS-DPCCH on the anchor carrier only. This will allow
the WTRU to choose the carrier with highest priority or the carrier
that optimizes transmission according to one or a combination of
the embodiments described above and if HS-DPCCH feedback is
required, the feedback is also sent on that carrier.
[0222] Alternatively, the WTRU may base its decision to select a
carrier on one or a combination of CPICH measurement and HARQ error
rates on each carrier, etc.
[0223] In the case where a retransmission is ongoing in one of the
carriers, the WTRU may perform E-DCH transmission on the other
carrier and thus perform E-TFC selection for that carrier only.
[0224] As part of the E-TFC selection and the carrier selection
procedures, the WTRU performs E-TFC restriction (also referred to
as E-DCH transport format combination index (E-TFCI) restriction)
in order to determine the maximum supported payload for the anchor
carrier and the maximum supported payload for the supplementary
carrier, (i.e., the maximum MAC-e or MAC-i protocol data unit (PDU)
size that may be sent on the anchor and supplementary uplink
carriers, respectively) given the ratio of the maximum
allowed/available transmit power and the DPCCH code power. The
maximum number of bits for the anchor and supplementary uplink
carriers may be determined based on the maximum allowed/available
transmit power and DPCCH code power of the anchor carrier and the
supplementary carrier, respectively. If one DPCCH is transmitted,
the maximum number of bits may be determined based on the power of
the transmitted or on a defined or configured offset from the
transmitted DPCCH.
[0225] In case each carrier has an independent maximum transmit
power, the maximum number of bits is determined based on the
maximum power allowed for the anchor carrier and the supplementary
carrier and the DPCCH code power of the anchor carrier and the
supplementary carrier, respectively. In the case where both
carriers have a shared maximum transmit power, the WTRU may
calculate the maximum number of bits assuming that the shared
maximum transmit power is allocated and available to each carrier.
In the case where both carriers have a shared maximum transmission
power with an additional per-carrier maximum transmission power
(e.g., in the case where power is pre-allocated differently between
carriers), the WTRU may calculate the maximum number of bits
assuming that the maximum transmission power is the minimum of the
shared maximum transmission power and the maximum transmission
power configured/calculated for each carrier.
[0226] The E-TFC restriction may be done at each TTI and
pre-calculated for all HARQ power offsets or profiles. Once the
data is being filled up the WTRU may determine the set of supported
E-TFC based on the selected HARQ power offsets, without having to
re-calculate the NRPM, but just pulling it from the lookup table.
Alternatively, the WTRU may calculate the NRPM whenever needed.
[0227] For some of the embodiments for priority carrier selection
disclosed above, the WTRU may first determine the NRPM of each
carrier independently, assuming that no data will be transmitted on
the other carrier. The independent NRPM calculations may be
performed for carriers 1 and 2 as follows:
NRPM.sub.j,1=(PMax.sub.j,1-P.sub.DPCCH,target1-P.sub.DPCCH,target2-P.sub-
.DPDCH-P.sub.HS-DPCCH1-P.sub.E-DPCCH,j,1)/P.sub.DPCCH,target1; and
Equation (15)
NRPM.sub.j,2=(PMax.sub.j,2-P.sub.DPCCH,target2-P.sub.DPCCH,target1-P.sub-
.DPDCH-P.sub.HS-DPCCH2-P.sub.E-DPCCH,j,2)/P.sub.DPCCH,target2.
Equation (16)
[0228] PMax.sub.j,1 is the maximum WTRU transmitter power for
E-TFC-j on carrier 1, and PMax.sub.j,2 is the maximum WTRU
transmitter power for E-TFC-j on carrier 2. PMax.sub.j,1 may be
equal to, or different from, PMax.sub.j,2 depending on the power
requirements and/or the number of power amplifiers (PAs) and/or
power allocation for each carrier. P.sub.DPCCH,target1 and
P.sub.DPCCH,target2 may be taken into consideration if the WTRU has
to transmit the DPCCH in both carriers regardless of whether E-DCH
data is transmitted or not, unless there is inactivity periods due
to DTX. P.sub.HS-DPCCH2 is applicable in the case that a second
HS-DPCCH is being transmitted in the second carrier; otherwise the
same HS-PDCCH power may be subtracted from both carriers' NRPM
calculation. If DPDCH transmission is taking place for the TTI for
which E-TFC selection/restriction is being performed, the WTRU may
take this into account in the NRPM calculation (i.e., P.sub.DPDCH
may be subtracted as well). If no DPDCH transmission is taking
place (or if DPDCH transmission is not allowed with dual carrier)
the P.sub.DPDCH may not be taken into account. In the case where
DPDCH is only allowed in the primary carrier then only NRPM for the
primary carrier may take that into account. Alternatively, the
power for DPDCH is taken into account in the calculation of both
NRPM when selecting a carrier, regardless of where DPDCH is being
transmitted. The same is applicable to the HS-DPCCH. The maximum
available supported payload or supported E-TFCIs may then be
determined for each carrier independently according to this
calculation, or otherwise stated the supported E-TFCs.
[0229] Embodiments for E-TFC restriction are described hereafter.
The embodiments for the E-TFC restriction described herein may be
applicable to any E-TFC selection schemes disclosed above. The
E-TFC restriction procedure may be carried out for each uplink
carrier sequentially or in parallel for both uplink carriers.
[0230] When E-TFC restriction is carried out in parallel for both
uplink carriers, a fraction of the total WTRU power may be
pre-allocated to each uplink carrier or calculated on a TTI-by-TTI
basis by the WTRU. The maximum power allocated to carrier x
(regardless of maximum power reduction (MPR) of the E-TFC.sub.j)
for E-DCH transmission becomes P.sub.max,x (x=carrier 1 or carrier
2) in a DC-HSUPA system. Optionally, if non-scheduled transmissions
are present, P.sub.max,x may also take into consideration the power
required by the WTRU to transmit the non-scheduled transmissions.
For instance, P.sub.max,x=P.sub.non-s+P.sub.sg where P.sub.non-s is
the power required for the non-scheduled transmissions calculated
as described below and P.sub.sg is the power allocated to carrier x
to transmit the scheduled transmissions. The sum of the powers
allocated to the uplink carriers (e.g., P.sub.max,x and
P.sub.max,y) is smaller than or equal to the maximum allowed WTRU
power (according to the WTRU power class or as configured by the
network). P.sub.max,x and P.sub.max,y may represent the final
allocated power to carrier x and carrier y, respectively (including
the powers for the control channels for carrier x and y,
respectively). In that case, the normalized remaining power may be
calculated independently for each carrier. The NRPM for E-TFCj and
carrier x and y may take the following form:
NRPM.sub.j,x=P.sub.max,x/P.sub.DPCCH,target x; and Equation
(17)
NRPM.sub.j,y=P.sub.max,y/P.sub.DPCCH,target y. Equation (18)
[0231] If P.sub.max,x and P.sub.max,y do not include the powers for
the control channels, then the normalized remaining power may be
calculated independently for each carrier. The NRPM for E-TFC; and
carriers 1 and 2 may take the following forms:
NRPM.sub.j,1=(PMax.sub.j,1-P.sub.DPCCH,target1-P.sub.HS-DPCCH1-P.sub.E-D-
PCCH,j,1)/P.sub.DPCCH,target1; and Equation (19)
NRPM.sub.j,2=(PMax.sub.j,2-P.sub.DPCCH,target2-P.sub.E-DPCCH,j,2)/P.sub.-
DPCCH,target2. Equation (20)
[0232] In equations (19) and (20), it is assumed that no DPDCH is
transmitted and the HS-DPCCH may only be transmitted over carrier 1
(e.g., anchor carrier). If no HS-DPCCH is to be transmitted, then
P.sub.HS-DPCCH1=0. PMax.sub.j,1 and PMax.sub.j,2 represent the
maximum power on carriers 1 and 2, respectively, taking into
account the maximum power reduction allowed for E-TFC.sub.j and the
maximum allocated power for each carrier. For E-TFC.sub.j,
PMax.sub.j,x, x=1,2, is calculated by reducing the maximum power
allocated to carrier x (P.sub.max,x) by the maximum power reduction
(MRP) allowed for E-TFC.sub.j, for example (in dB) as follows:
PMax.sub.j,x,dB=P.sub.max,x,dB-MPR.sub.E-TFCj; Equation (21)
where MPR.sub.E-TFCj is the amount of power reduction for E-TFCj in
dB, P.sub.max,x,dB is the maximum power allocated for carrier x in
dB, and PMax.sub.j,x,dB is the resulting maximum power for carrier
x and E-TFCj in dB. Alternatively, the maximum power reduction may
be taken into account in the initial calculation of P.sub.max,x,dB
and in that case PMax.sub.j,x=P.sub.max,x. The E-TFC restriction
procedure then determines the set of supported and blocked E-TFCs
for each carrier at each TTI. Since this operation depends on the
HARQ profile of a given MAC-d flow, the WTRU may calculate the
supported set for each MAC-d flow for both carriers at each TTI.
P.sub.max,x may be determined, or pre-configured, or calculated
dynamically in a number of ways.
[0233] In accordance with another embodiment, the E-TFC restriction
procedures for the carriers may be performed sequentially. This
embodiment is applicable in the parallel case when a retransmission
is ongoing. The WTRU first selects one carrier for E-DCH
transmission, which will be referred to as carrier x as described
above. If a retransmission is ongoing, carrier x will correspond to
the carrier in which a retransmission is ongoing and no E-TFC
restriction or E-TFC selection may be performed for carrier x. The
other carrier will be referred to as carrier y. It is understood,
that E-TFC restriction may be performed for carrier x for other
purposes in the WTRU, however, for E-TFC selection purposes E-TFC
restriction or otherwise stated the maximum supported payload for
this carrier x does not need to determined for the carrier in which
a retransmission is ongoing at the given TTI. The selection of the
carrier may be performed using one of the embodiments described
above. Once carrier x is selected, the E-TFC selection procedure
for carrier x has to perform an estimation of the power leftover
from TFC selection if DPDCH is present in carrier x or carrier y if
DPDCH transmission is allowed in one carrier (if DPDCH transmission
is not allowed at all, the power of DPDCH is not considered), from
the HS-DPCCH if being transmitted in carrier x or carrier y (if
HS-DPCCH transmission is allowed in one carrier), and from DPCCH
transmission in carrier y (if being transmitted).
[0234] The WTRU estimates the normalized remaining power margin
available for E-TFC selection for carrier x, if being performed,
based on the following equation for E-TFC candidate j:
NRPM.sub.j,x=(PMax.sub.j,x-P.sub.DPCCH,target x-P.sub.DPCCH,target
y-P.sub.DPDCH,x,y-P.sub.HS-DPCCH,x.y-P.sub.E-DPCCH,j,x)/P.sub.DPCCH,targe-
t x. Equation (22)
[0235] The WTRU then estimates the normalized remaining power
margin available for E-TFC selection for carrier y based on the
following equation for E-TFC candidate j (the NRPM for carrier y is
calculated after E-TFC selection for carrier x is completed (i.e.,
once the WTRU has selected the E-TFCI to be transmitted in carrier
x) or alternatively, if a retransmission is ongoing in carrier x).
It is understood that the calculation of NRPM or remaining power in
case of a retransmission accounts for the power used by the data
channel(s) and control channel by the retransmission. This is
applicable for all power allocation schemes.
[0236] NRPM for carrier y, maybe be calculated as follows:
NRPM.sub.j,y=(PMax.sub.j,y-P.sub.DPCCH,target x-P.sub.DPCCH,target
y-P.sub.HS-DPCCH,z-P.sub.E-DPCCH,x-P.sub.E-DPDCH,x-P.sub.E-DPCCH,j,y)/P.s-
ub.DPCCH,target y. Equation (23)
[0237] PMax.sub.j,x is the maximum WTRU transmitter power for
E-TFC-j. This may correspond to the total shared WTRU transmission
power and may be equal to PMax.sub.j,y or may be a total allowed
maximum power on carrier x. PMax.sub.j,y is the maximum WTRU
transmitter power for E-TFC-j. This may correspond to the total
shared WTRU transmission power and may be equal to PMax.sub.j,x or
may be a total allowed maximum power on carrier y.
[0238] P.sub.DPCCH,target,z (z=x or y) is derived as follows.
P.sub.DPCCH,x(t) and P.sub.DPCCH,y(t) represents a slotwise
estimate of the current WTRU DPCCH power in carrier x and y
respectively at time t. If at time t, the WTRU is transmitting a
compressed mode frame in carrier z, where z can take value x or y,
then
P.sub.DPCCH,comp,z(t)=P.sub.DPCCH,z(t).times.(N.sub.pilot,C/N.sub.pilot,N-
) else P.sub.DPCCH,comp.z(t)=P.sub.DPCCH,z(t). If the WTRU is not
transmitting uplink DPCCH during the slot at time t over carrier z,
either due to compressed mode gaps or when discontinuous uplink
DPCCH transmission operation is enabled then the power may not
contribute to the filtered result. Samples of P.sub.DPCCH,comp,z(t)
may be filtered using a filter period of 3 slotwise estimates of
P.sub.DPCCH,comp,z(t) when the E-DCH TTI is 2 ms or 15 slotwise
estimates of P.sub.DPCCH,comp,z when the E-DCH TTI is 10 ms to give
P.sub.DPCCH,filtered,z. If the target E-DCH TTI for which
NRPM.sub.j evaluated does not correspond to a compressed mode frame
then P.sub.DPCCH,target,z=P.sub.DPCCH,filtered,z. If the target
E-DCH TTI for which NRPM.sub.j is being evaluated corresponds to a
compressed mode frame then
P.sub.DPCCH,target,z=P.sub.DPCCH,filtered,z.times.(N.sub.pilot,N/N.sub.pi-
lot,C). N.sub.pilot,C is the number of pilot bits per slot on the
DPCCH in compressed frames, and N.sub.pilot,N is the number of
pilot bits per slot in non-compressed frames.
[0239] P.sub.DPDCH,z is an estimated DPDCH transmit power, based on
P.sub.DPCCH,target,z and the gain factors from the TFC selection
that has already been made for carrier z. If the target E-DCH TTI
for which NRPM.sub.j is being evaluated corresponds to a compressed
mode frame then the modification to the gain factors which occur
due to compressed mode may be included in the estimate of
P.sub.DPDCH. The DPDCH may be allowed to be transmitted in one
carrier, which may be carrier x or carrier y and the P.sub.DPDCHz
corresponds to the estimated DPDCH power in the respective carrier
(z=x or z=y, respectively). If DPDCH is transmitted in both
carriers then P.sub.DPDCHz corresponds to the sum of the estimated
DPDCH power in both carriers.
[0240] P.sub.HS-DPCCH,z is an estimated HS-DPCCH transmit power
based on the maximum HS-DPCCH gain factor based on
P.sub.DPCCH,target,z and the most recent signalled values of
.DELTA..sub.ACK, .DELTA..sub.NACK and .DELTA..sub.CQI. If the
target E-DCH TTI for which NRPM.sub.j is being evaluated
corresponds to a compressed mode frame then the modification to the
gain factors which occur due to compressed mode may be included in
the estimate of P.sub.HS-DPCCH,z. The HS-DPCCH may be allowed to be
transmitted in one carrier which may be carrier x or carrier y, in
which case z=x and z=y, respectively. If HS-DPCCH is transmitted in
both carriers then P.sub.HS-DPCCH,z corresponds to the estimated
DPDCH power in both carriers.
[0241] P.sub.E-DPCCH,j,x is an estimated E-DPCCH transmit power for
E-TFCI.sub.j. If E-TFCI.sub.j is smaller than or equal to
E-TFCI.sub.ec,boost the estimate is based on P.sub.DPCCH,target x
and the E-DPCCH gain factor calculated using the most recent
signalled value of .DELTA..sub.E-DPCCH. If E-TFCI.sub.j is greater
than E-TFCI.sub.ec,boost the estimate is based on the E-DPCCH gain
factor, .beta..sub.ec,j, which is calculated for E-TFCI.sub.j. If
the target E-DCH TTI for which NRPM.sub.j is being evaluated
corresponds to a compressed mode frame then the modification to the
gain factors which occur due to compressed mode may be included in
the estimate of P.sub.E-DPCCH,j,x.
[0242] P.sub.E-DPCCH,j,x is an estimated E-DPCCH transmit power for
E-TFCI determined for carrier x, and P.sub.E-DPDCH, x is an
estimated E-DPDCH transmit power for the E-TFCI determined for
carrier x.
[0243] P.sub.E-DPCCH,j,y is an estimated E-DPCCH transmit power for
E-TFCI.sub.j. If E-TFCI.sub.j is smaller than or equal to
E-TFCI.sub.ec,boost the estimate is based on P.sub.DPCCH,target y
and the E-DPCCH gain factor calculated using the most recent
signalled value of .DELTA..sub.E-DPCCH. If E-TFCI.sub.j is greater
than E-TFCI.sub.ec,boost the estimate is based on the E-DPCCH gain
factor, .beta..sub.ec,j, which is calculated for E-TFCI.sub.j. If
the target E-DCH TTI for which NRPM.sub.j is being evaluated
corresponds to a compressed mode frame then the modification to the
gain factors which occur due to compressed mode may be included in
the estimate of P.sub.E-DPCCH,j,y. All power variables are
expressed in linear power units.
[0244] In the case where scheduling information (SI) is transmitted
per carrier, SI might be triggered for one carrier and has to be
transmitted over that carrier. This implies that the WTRU may have
to transmit the SI over that carrier regardless of whether it will
be able to transmit any other data on that carrier. Therefore, it
is proposed that the WTRU pre-allocates or allocates power for at
least the transmission of that SI in the carrier that triggered the
SI.
[0245] In an example used to pre-allocated power, the E-TFC
restriction, for this particular embodiment, may account for the
fact that SI will need to be sent on the other carrier and thus
allocate power or pre-allocated power for at least one SI and the
corresponding E-DPCCH required to transmit the E-TFC for one SI.
The WTRU may include the power of the E-DPDCH required to transmit
the SI in the calculation of P.sub.z, P.sub.granted,z, or
alternatively include in the NRPM calculation as described
below.
[0246] Since the WTRU may run out of power in the first carrier,
the NRPM calculation may remove the power that will be needed for
the E-DPDCH and E-DPCCH in the other carrier for SI. This will
allow for enough power to be available in the other carrier to
transmit at least the SI and the maximum power is not exceeded. The
NRPM may be calculated as follows:
NRPM.sub.j,x=(PMax.sub.j,x-P.sub.DPCCH,target x-P.sub.DPCCH,target
y-P.sub.DPDCH,x,y-P.sub.HS-DPCCH,x.y-P.sub.E-DPCCH,j,x-P.sub.E-DPCCH,0,y--
P.sub.E-DPDCH,0,y)/P.sub.DPCCH,target x; Equation (24)
where, P.sub.E-DPCCH,0,y and P.sub.E-DPDCH,0,y are taken into
account when SI is triggered and has to be transmitted on the other
carrier and they correspond to the E-DPDCH and E-DPCCH power
required to transmit E-TFCI=0 (i.e., the E-TFC to transmit SI).
[0247] In the case where the SI may be transmitted in any carrier
once triggered, the SI may be sent over the first selected carrier
and therefore there no need to account for the power that would
have to be used in the other carrier.
[0248] When the WTRU calculates the NRPM of carrier x in the
sequential approach or in the parallel approach, the WTRU may
subtract the P.sub.E-DPCCH,y anticipated to be transmitted based on
the scaled grant (i.e., .theta.SGy), where .theta. being a scaling
factor. Optionally, the P.sub.E-DPDCH,y that may be allowed by the
new scaled grant may also be subtracted from P.sub.max. This may be
necessary when the scaling factor did not account for the E-DPCCH
and E-DPDCH power of both carriers when calculated.
[0249] As part of E-TFC selection the WTRU determines the state of
each E-TFC based on the available normalized remaining power
margin. A given E-TFC may be in either a supported state or a
blocked state. Even in situations, where according to the E-TFC
restriction no E-TFCs are in a supported state (the available power
does not allow the transmission of any of the E-TFCs), the WTRU may
consider the E-TFCs included in the minimum set E-TFCs to be in a
supported state. With dual carrier operation, the usage of minimum
set E-TFC is described below.
[0250] Where one minimum E-TFC set is configured, a number of rules
on the usage of the minimum set are described herein. In one
embodiment, the WTRU may allow minimum set E-TFC in the first
selected carrier only. If the WTRU does not have enough power
available to transmit data on the second carrier the WTRU may not
be allowed to transmit any data on the second carrier, even if it
is allowed by the minimum E-TFC set. Alternatively, in that case,
the WTRU may apply the minimum E-TFC set on the second selected
carrier (i.e., the minimum set E-TFCIs may be used and will be
considered as supported on both carriers).
[0251] Alternatively, the WTRU may not transmit anything (i.e.,
does not consider the minimum set E-TFC as supported) on the second
carrier if the WTRU is in cell edge condition and does not have
enough power to transmit in the first carrier (i.e., the WTRU had
to use the minimum E-TFC set or because of the retransmission power
in the first carrier the remaining power is not enough to fully
allow the transmission of any of the E-TFCIs on the second
carrier). Alternatively, if the NRPM is below a predetermined or
configured threshold the WTRU may not consider the minimum set
E-TFCI as supported on the second carrier (e.g., if NRPM is <0).
Alternatively, if the UE power headroom (UPH) is below a threshold,
the WTRU may not transmit on the second carrier. Alternatively, the
WTRU may choose not to transmit on the second carrier if the amount
of remaining data is below a threshold (i.e., TEBS is below a
predetermined or configured threshold). Alternatively, the WTRU may
be allowed to use the minimum E-TFC set, if configured by the
network, on the primary carrier. This will allow the WTRU to
transmit at least a minimum E-TFC on the primary carrier even if
this carrier is the second selected carrier or is the only carrier,
since a retransmission may be ongoing on the other carrier. This
may be beneficial when non-scheduled transmissions may only be
transmitted on the primary carrier.
[0252] Alternatively, the minimum E-TFC set may be only applied to
the first selected carrier when two new transmissions are taking
place. For the case where a new transmission is taking place on one
carrier and a retransmission on the other carrier, the WTRU may
make use of the minimum E-TFC on this carrier in which E-TFC
selection is taking place. Alternatively, one of the criteria
described below may be used in combination to decide when to allow
or disallow the minimum set E-TFC on the carrier in which a new
transmission is taking place.
[0253] Alternatively, the WTRU may be allowed a minimum E-TFC on
the carrier that allows non-scheduled transmission. Optionally, the
minimum E-TFC may be applied to that carrier if at the given TTI
the WTRU has non-scheduled data and it is allowed to transmit non
scheduled data on that carrier. This rule may apply regardless of
whether it is a second carrier or alternatively it may apply when
the second carrier is being treated. The rules for the first select
carrier may be similar to the one discussed above.
[0254] Alternatively, the minimum E-TFC may be independently
configured by the network, and the WTRU follows the network
configuration of the minimum E-TFC regardless what carrier is
selected first.
[0255] Alternatively, a single minimum E-TFC may be configured by
the network. For example, if a minimum E-TFC is configured for one
carrier by the network while it is absent for the other carrier,
the WTRU follows the network configuration of the minimum E-TFC and
may apply it for both carriers whether parallel E-TFC restriction
procedure or sequential restriction procedure is used.
[0256] If no minimum E-TFC is used, and there is no power available
the E-TFC selection will output no supported E-TFCs and thus no
transmission will take place, unless an SI is present. Optionally,
the WTRU may not even perform E-TFC selection on the second carrier
if it has determined that the maximum power allowed has already
been exceeded by the first selected carrier or the carrier in which
a retransmission is taking place.
[0257] Alternatively, the WTRU may be configured and allowed to
transmit in one carrier at a time. Once the highest priority
carrier is selected according to one or a combination of the
criteria above, the WTRU may not transmit on the other carrier.
[0258] Example embodiments for E-TFC selection for independent
maximum power limitation are explained hereafter. The WTRU may have
a different transmission powers and maximum allowed power for each
carrier, which may depend on the particular device configuration or
design. This depends on implementation design, (e.g., a WTRU may be
designed with two different power amplifiers and two different
antennas), and/or on network control and configuration. It is also
applicable if the WTRU pre-allocates the power between the
carriers, or allocates the power in parallel, as described in the
embodiments above. In these situations, the maximum power or
available power that may be used by each carrier corresponds to the
allocated power per carrier. The embodiments are also applicable to
the case where power is shared between the carriers but the power
is allocated or scaled between the carriers prior to filling up the
carriers.
[0259] Where the powers are pre-allocated or the maximum amount of
power is independent on each carrier, the MAC PDUs may have to be
filled up sequentially due to the fact that the delivery order of
RLC PDUs has to be maintained in order to allow proper operation of
higher layers. Additionally, the WTRU may be buffer limited in
which case enough data to transmit over one carrier may be
available.
[0260] In this situation, the WTRU may initially choose the highest
priority carrier P1 based on one of the embodiments described
above. For instance, the WTRU may select the carrier with the
higher power headroom, equivalently the carrier with the lower
DPCCH power to be filled up with data first or the primary or
secondary carrier may be filled up first. This allows, even a
buffer limited WTRU to transmit most of its data, or its highest
priority data, over the carrier with the best channel quality or
over the carrier that allows transmission of the highest priority
data, such as non-scheduled transmissions.
[0261] According to the highest priority MAC-d flow, associated
HARQ profile and multiplexing list, the WTRU then fills up the
available space on the transport block of carrier p1 (i.e., creates
MAC-e or MAC-i to be sent on carrier p1), according to the "Maximum
Supported Payload p1", "Remaining Scheduled Grant Payload p1", and
remaining non-scheduled grant payload, if allowed and configured in
the selected carrier, P1. As previously mentioned, this corresponds
to the number of bits that may be transmitted according to the
allowed power, allowed scheduled grant, and allowed non-serving
grant, respectively. In this situation, allowed power and allowed
grant may correspond to scaled values of the power and/or grant of
each carrier or the configured powers or grants. This may be done
if the power or grant is proportionally split between the two
carriers or allocated in parallel. If SI needs to be sent, the WTRU
may send it in carrier p1, or alternatively send it in the carrier
in which the SI is configured to be transmitted.
[0262] Once the WTRU has completed the available space on carrier
p1, it then fills up next carrier. At this point the WTRU may
re-determine the highest priority MAC-d flow that has data to be
transmitted and is allowed in the carrier being treated. At this
point the highest priority MAC-d flow may be different than the one
determined initially, prior to carrier p1 being filled up.
[0263] When determining the highest priority MAC-d flow the WTRU
may, for every carrier, determine the highest priority MAC-d flow
configured with data available amongst all MAC-d flows. In an
alternate embodiment, the WTRU may, for every carrier for which
E-TFC selection or highest priority MAC-d flow selection is being
performed, determine the highest priority MAC-d flow amongst all
MAC-d flows allowed to be transmitted on the given carrier.
[0264] If the carrier for which E-TFC selection is being performed
does not allow a certain type of MAC-d flow, when determining the
highest priority MAC-d flow the WTRU may not consider the MAC-d
flows that are not allowed for transmission on the given carrier.
For instance, if the WTRU is performing E-TFC selection for the
second carrier, it may not include non-scheduled MAC-d flows in the
selection of highest priority MAC-d flow. So if a non-scheduled
MAC-d flow has data available and has the highest configured MAC-d
priority the WTRU may not use this MAC-d flow as its highest
priority MAC-d flow and may not use the HARQ profile, power offset
and HARQ retransmission, and multiplexing list for the TTI for the
carrier. For specific example, for HSPA dual carrier UL when
treating the second carrier the WTRU may determine the highest
priority MAC-d flow amongst all scheduled MAC-d flows.
[0265] Once the highest MAC-d flow is determined, the WTRU
determines the new allowed MAC-d flows that may be multiplexed in
this TTI, and the power offset based on the HARQ profile of the
selected MAC-d flow to be used for the new carrier. The WTRU may
then determine the Maximum Supported Payload and Remaining
Scheduled Grant Payload according to the new power offset and fill
up the carrier with data if available accordingly.
[0266] Alternatively, the WTRU may determine the Maximum Supported
Payload and Remaining Scheduled payload for both carriers at the
beginning of the E-TFC selection procedure or prior to filling up
the carrier, which implies that the WTRU can use the same power
offset for both carriers regardless of whether data from that first
highest selected MAC-d flow is being transmitted on both carriers.
In this case, the multiplexing list will remain the same on both
carriers and may be a limiting factor when not enough data is
available from those logical channels, but the WTRU has more power
and grant available for transmission of other logical channels.
[0267] Once carrier p1 (which may be determined as above and filled
up sequentially) is filled up with data, the WTRU immediately moves
to the other carrier and continues to fill it up with data.
[0268] Alternatively, the carriers may be filled up in parallel,
which implies that the data from all the allowed logical channels
is split between the two carriers. In order to avoid out-of-order
delivery, the data or the RLC buffer has to be split. For instance,
if 10 RLC PDUs with SN 0 to 9 are available, RLC PDUs 0 to 4 are
sent to carrier one and 5 to 9 are sent to carrier two. The WTRU
then moves to the next logical channel if space still remains and
the buffer is again split in the same way.
[0269] Alternatively, the E-TFC and carrier filling may be
performed in parallel, but each carrier takes data from different
logical channels. This implies that the WTRU selects the two
highest priority MAC-d flows, determines the HARQ profile for each
and the multiplexing list for each and maps them to the two
individual carriers. This will allow the WTRU to fill up and
perform E-TFC in parallel without risking out-of-order RLC
delivery. However, this may result in situations where data from
the highest logical channel is still available but the WTRU may no
longer send them, since the carrier is full.
[0270] In another embodiment, data flows may be carrier specific.
In this case the WTRU may perform the E-TFC selection procedure
independently for each carrier.
[0271] Example embodiments for E-TFC selection for total combined
maximum power limitation are described hereafter. Some of the
aspects of this embodiments may also be applicable as described
above if the power between the two carriers is allocated in
parallel or some form of dynamic power allocation is performed.
[0272] In a sequential approach, when the WTRU maximum power is
shared amongst both carriers, the WTRU may initially select the
highest priority carrier (P1) using one of the embodiments
described above. E-TFC restriction and selection may still be
performed sequentially, wherein the available power and grant used
are equivalent to the allocated or scaled power or grant.
[0273] Once the WTRU has selected the highest priority carrier, the
WTRU performs the E-TFC selection and restriction procedure, where
the highest priority MAC-d flow is selected and the power offset,
the Maximum Supported payload p1 is determined, the Scheduled
Available Payload is selected according to the serving grant of
carrier P1 and the non-scheduled available payload is selected. If
SI needs to be transmitted, it may be treated with the first
selected carrier or alternatively it may be treated on the carrier
in which it is allowed to be transmitted. In this case, the WTRU
may perform a sequential E-TFC restriction procedure as described
above, where the WTRU assumes all the power is available to be used
by carrier P1 and assuming that no data is being transmitted on the
secondary carrier. The WTRU creates a MAC-e or MAC-i PDU to be
transmitted on this carrier according to the E-TFC selection.
Alternatively, if the SI is sent in one carrier only (i.e., the
anchor carrier only), then the E-TFC selection takes it into
account when performing E-TFC for the carrier in which the SI is
being sent.
[0274] The maximum supported payload, (i.e., E-TFC restriction),
for the selected carrier may be determined, for example, according
to the NRPM calculation. In the case where the WTRU has a
retransmission in carrier x, then no E-TFC selection is performed
for carrier x. The WTRU performs E-TFC selection and creates a
MAC-i or MAC-e PDU for the carrier y, the remaining carrier.
[0275] The WTRU then has to create a MAC-e or MAC-i PDU for the
remaining carrier. At this point the WTRU may re-determine (or
determine for the first time if a retransmission is ongoing on
carrier x) the highest priority MAC-d flow that has data to be
transmitted and the power offset based on the HARQ profile of the
selected MAC-d flow and the MAC-d flow multiplexing list.
Alternatively, the WTRU uses the same power offset determined
initially in the procedure.
[0276] The WTRU then performs the E-TFC restriction procedure for
this second carrier. The WTRU may take into account the power that
will be used from the first carrier and the remaining available
power is used when calculating the maximum supported payload or
when determining the set of supported E-TFCIs. Alternatively, the
WTRU may subtract a "backoff power" (i.e., the particular power
losses experienced when the WTRU transmits on two carriers in the
same TTI), prior to performing the E-TFC restriction on the second
carrier, (i.e., the second selected carrier), when two new
transmissions take place or when one new transmission is taking
place due to a HARQ retransmission in the other carrier.
[0277] In these embodiments described herein, the WTRU may be
configured to not to transmit a DPCCH when it is determined that
data does not need to be sent. The WTRU may also be configured to
not transmit any data on a second carrier if it does not have
enough power where the maximum power is allocated per carrier. For
instance, if one of the carriers does not have enough power, the
WTRU may use one carrier to transmit (the one that has the highest
UPH or highest NRPM), instead of using the minimum set E-TFCI, or
alternatively, the WTRU may not transmit in one of the carriers if
both do not have enough power. The WTRU may use the minimum set on
one of the carriers and may not transmit on the second.
[0278] The MAC-i or MAC-e PDU is then filled up according to the
determined maximum supported payload, the scheduled available
payload (according to the serving grant of this carrier), and the
non-scheduled available payload, if applicable.
[0279] In another embodiment, the WTRU may select the E-TFC on each
carrier in such a way that the transmission power (over all UL
channels, i.e., DPCCH, E-DPCCH, HS-DPCCH, E-DPDCH) on each carrier
is the same or the difference between the two is less than a
pre-configured maximum value. This may be achieved, for instance,
by calculating for a given transmission power level which E-TFCs
may be transmitted on each carrier given the transmission power of
the DPCCH and other channels on each carrier. For instance,
assuming that the DPCCH power levels are 7 dBm and 10 dBm on, say,
carriers 1 and 2 respectively, and that the power levels of the
HS-DPCCH and E-DPCCH are each -3 dB below that of the DPCCH, if the
transmission power level on each carrier is 18 dBm, the power
headrooms on each carrier are 8 dB and 5 dB respectively, and the
corresponding E-TFC sizes may be 600 bits and 300 bits. Thus the
WTRU may transmit with equal power (of 18 dBm) on both carriers by
selecting an E-TFC of 600 bits on the carrier 1 and an E-TFC of 300
bits on carrier 2.
[0280] This principle may be applied in different cases. If the
WTRU transmission is limited by the maximum UL power, the WTRU may
select the E-TFC on each carrier by splitting the maximum UL power
equally between the two carriers (thus the UL power available to
each carrier would be 3 dB below the maximum) and determining the
maximum supported E-TFC on each carrier using the method disclosed
above. If the WTRU transmission is limited by the amount of data in
the WTRU buffer, the WTRU may seek the transmission power level of
both carriers such that the amount of data that may be transmitted
with the resulting E-TFCs on each carrier corresponds to the amount
of data in the buffer.
[0281] In another embodiment, the WTRU may select the E-TFC on each
carrier in such a way that the interference load incurred on each
carrier is same or approximately the same. The interference load
incurred on a carrier may, for instance, be estimated as the power
ratio between the E-DPDCH power and the DPCCH power, which
corresponds to the power ratio used for scheduling. Thus, provided
that the scheduling grant and the power headroom is sufficient on
both carriers, the WTRU selects the E-TFC on each carrier by
determining how many bytes may be transmitted from the WTRU buffer,
based on grant and by determining the needed E-TFC size on each
carrier by dividing this number of bytes by 2 and applying the
appropriate MAC headers.
[0282] This method would result equal power ratios on each carrier
provided that mapping between reference power ratios and reference
E-TFCs is the same between the carriers, and provided that all the
data belong to logical channels that have the same HARQ offset. In
case where the data belongs to logical channels that do not all
have the same HARQ offset, the WTRU has to find which sharing of
bytes that result in the same power ratio for both E-TFCs.
[0283] Example embodiments are described below that combine the
embodiments described herein. These embodiments are merely
illustrative, and other combinations of the embodiments described
herein are contemplated by the present invention. The actions may
optionally be performed in any combinations (e.g., across more than
one embodiment). In particular, actions related to the anchor
carrier may also be applicable to the secondary carrier.
[0284] A first of these embodiments takes a parallel approach with
allocation handled at the E-TFC restriction level. In this
embodiment, the WTRU determines if it is power-limited. The WTRU
calculates the amount of power for the E-DPDCH data as follows:
P DATA , max = P max - ( z = 1 2 P DPCCH , z + P HS - DPCCH , z + P
E - DPCCH , z ) , Equation ( 25 ) ##EQU00002##
where P.sub.max accounts for the necessary power backoff for
dual-carrier operations, and the power of the E-DPCCH for the
carrier z (z=x or y) is calculated based on the maximum E-DPDCH
power for that carrier according to the serving grant. And then if
P.sub.x+P.sub.y>P.sub.DATA,max, the WTRU is power limited.
P.sub.z (z=x or y) in these example embodiments may correspond to
the power required for scheduled E-DPDCH transmissions. In a
mathematical formulation P.sub.z may correspond to, may mean, or
may be defined as P.sub.E-DPDCH,z according to equation (5). More
specifically:
P.sub.z=P.sub.E-DPDCH,z=SG.sub.z.times.P.sub.DPCCH,z. Equation
(26)
[0285] The WTRU calculates the fraction of remaining power to be
allocated to each carrier, according to any of the embodiments
described above. The normalized remaining power for each carrier
may be calculated, for example, as follows:
NRPM,x=.rho..sub.x(P.sub.DATA,max)/P.sub.DPCCH,x, and Equation
(27)
NRPM,y=.rho..sub.y(P.sub.DATA,max)/P.sub.DPCCH,y, Equation (28)
where .rho..sub.z (z=x or y) is the fraction of remaining power
allocated to carrier z, based on some power allocation rule.
Throughout this example embodiments, .rho..sub.z(P.sub.DATA,max)
represents the power allocated to carrier z for E-DCH transmission,
using any of the power allocation schemes/embodiments. This in an
another example formulation may also correspond to P.sub.max,z or
P.sub.E-DPDCHmod,z or (P.sub.E-DPDCHmod,z+P.sub.non-SG).
[0286] Alternatively, the normalized remaining power for each
carrier may be calculated, for example, as follows:
NRPM , x = [ P max - { 2 z = 1 P DPCCH , z + P HS - DPCCH , z + P E
- DPCCH , z } ] / P DPCCH , x - SG input , y , Equation ( 29 ) NRPM
, y = [ P ma x - { 2 z = 1 P DPCCH , z + P HS - DPCCH , z + P E -
DPCCH , z } ] / P DPCCH , y - SG input , x , Equation ( 30 )
##EQU00003##
where SG.sub.input,x and SG.sub.input,y are the fictitious serving
grants for carriers x and y, respectively.
[0287] The WTRU then executes E-TFC restriction based on these two
NRPM for each carrier separately. The conventional E-TFC Selection
may then be executed for one carrier at a time without any changes
to the serving grants, starting with the anchor carrier over which
the non-scheduled transmissions are being transmitted or with any
of the carriers selected according to any of the procedures
described above.
[0288] A further embodiment takes a parallel approach with
allocation handled at the E-TFC restriction level and enables
protection of non-scheduled transmission. In this embodiment, the
WTRU determines if it is power-limited. The WTRU calculates the
amount of power for the E-DPDCH data as in equation (25). If
P.sub.x+P.sub.y>P.sub.DATA,max, or optionally if
P.sub.x+P.sub.y+P.sub.non-SG>P.sub.DATA,max if P.sub.x does not
include the power for the non-scheduled transmissions, the WTRU is
power limited. The WTRU calculates the fraction of remaining power
to be allocated to each carrier, according to any of the
embodiments described above. The normalized remaining power for
each carrier may be calculated as in equations (26) and (26). The
WTRU then executes E-TFC restriction based on these two NRPM for
each carrier separately. The WTRU then executes E-TFC selection for
each carrier separately. For the anchor carrier, the WTRU uses a
virtual serving grant to ensure that non-scheduled transmissions
are transmitted. This virtual serving grant may be calculated as
follows:
SG.sub.input,x=(.rho..sub.xP.sub.DATA,max-P.sub.non-SG)/P.sub.DPCCH,x,
Equation (31)
where it is assumed that the power allocation ensures that this
virtual serving grant is non-negative. E-TFC selection is run using
the conventional approach for the secondary carrier.
[0289] Yet another embodiment takes a parallel approach with
allocation handled at the E-TFC restriction level and provides for
absolute protection of non-scheduled transmission. In this
embodiment, the WTRU determines if it is power-limited by for
example taking into account the power required for scheduled and/or
non-scheduled and control channels on both carriers according to
any of the embodiments described above.
[0290] The WTRU calculates the amount of power for the scheduled
E-DPDCH data as follows:
P DATA , max = P max - ( P non - SG + z = 1 2 P DPCCH , z + P HS -
DPCCH , z + P E - DPCCH , z ) , Equation ( 32 ) ##EQU00004##
where P.sub.max accounts for the necessary power backoff for
dual-carrier operations, and the power of the E-DPCCH for the
carrier z (z=x or y) is calculated based on the maximum E-DPDCH
power for that carrier according to the serving grant.
P.sub.DATA,max here corresponds to the power available for
scheduled E-DPDCH. If P.sub.x+P.sub.y>P.sub.DATA,max, the WTRU
is power limited. The WTRU calculates the fraction of remaining
power to be allocated to each carrier, according to any of the
embodiments described above where the power of the non-scheduled
transmission is taken into account for the first carrier. The
normalized remaining power for each carrier may be calculated as
follows:
NRPM,x=(.rho..sub.xP.sub.DATA,max+P.sub.non-SG)/P.sub.DPCCH,x; and
Equation (33)
NRPM,y=.rho..sub.yP.sub.DATA,max/P.sub.DPCCH,y, and Equation
(34)
where .rho..sub.z is the fraction of remaining power allocated to
carrier z for the scheduled transmissions, based on some power
allocation rule optionally taking into account that non-scheduled
transmissions may be taking place. The WTRU then executes E-TFC
restriction based on these two NRPM for each carrier separately.
For carrier x, the power of the non-scheduled transmission is added
to the remaining power on the first carrier to ensure that the
supported E-TFCIs for carrier x may also carry the non-scheduled
transmissions. It is understood that if in an example
implementation, if .rho..sub.xP.sub.DATA,max includes the power
allocated to carrier x, or primary carrier, for both scheduled and
non-scheduled, P.sub.non-SG does not need to be added to the
formula.
[0291] The WTRU then executes E-TFC selection for each carrier
separately. The WTRU uses as an input to the E-TFC selection the
full serving grant (without scaling) on both carriers, allowing the
headroom on each carrier to be used as a pool of resources for both
scheduled and non-scheduled and respecting the logical channel
priority of MAC-d flows with data available.
[0292] In a different example implementation 3, for the anchor
carrier, the WTRU uses a virtual serving grant to ensure that
non-scheduled transmissions are transmitted. This virtual serving
grant may be calculated as follows:
SG.sub.input,x=(.rho..sub.xP.sub.DATA,max)/P.sub.DPCCH,x. Equation
(35)
[0293] E-TFC selection is run using the conventional approach for
the secondary carrier, optionally also using a virtual serving
grant calculated the same way.
[0294] A further embodiment handles allocation at the E-TFC
restriction level and provides for absolute protection of
non-scheduled transmission and power re-allocation. In this
embodiment, the WTRU determines if it is power-limited. The WTRU
calculates the amount of power for the scheduled E-DPDCH data as in
equation (32). If P.sub.x+P.sub.y>P.sub.DATA,max, the WTRU is
power limited. The WTRU calculates the fraction of remaining power
to be allocated to each carrier, according to any of the rules
described above where the power of the non-scheduled transmission
is taken into account for the first carrier. The normalized
remaining power for each carrier may be calculated as in equation
(33). The WTRU then executes E-TFC restriction for the first
carrier based on NRPM,x. For carrier x, the power of the
non-scheduled transmission is added to the remaining power on the
first carrier to ensure that the supported E-TFCIs for carrier x
may also carry the non-scheduled transmissions.
[0295] The WTRU then executes E-TFC selection for the anchor
carrier (carrier x here). For the anchor carrier, the WTRU uses a
virtual serving grant to ensure that non-scheduled transmissions
are transmitted. This virtual serving grant may be calculated as in
equation (35). E-TFC selection is run using the conventional
approach for the secondary carrier, with E-TFC restriction based on
the total remaining power after E-TFC selection is executed on the
anchor carrier and optionally with the restriction that no
non-scheduled flows are transmitted. When filling up the second
carrier the UE may use the full serving grant for the secondary as
an input to the E-TFC selection.
[0296] Another embodiment takes a parallel approach with allocation
handled at the grant level and provides for absolute protection of
non-scheduled transmission. In this embodiment, the WTRU determines
if it is power-limited. The WTRU calculates the amount of power for
the scheduled E-DPDCH data as in equation (32). If
P.sub.x+P.sub.y>P.sub.DATA,max or if
P.sub.x+P.sub.y>P.sub.DATA,max-P.sub.non-SG, if P.sub.DATA,max
does not take into account non-scheduled already according to
equation (25) for example, the WTRU is power limited. The WTRU
calculates the fraction of remaining power to be allocated to each
carrier, according to any of the rules described above where the
power of the non-scheduled transmission is taken into account for
the first carrier. For example, the virtual grant for each carrier
may be given as follows:
SG.sub.input,x=.PHI.SG.sub.x; and Equation (36)
SG.sub.input,y=.PHI.SG.sub.y, Equation (37)
where .PHI. is given by:
.PHI.=(P.sub.DATA,max)/(P.sub.x+P.sub.y). Equation (38)
[0297] The WTRU executes E-TFC restriction for the two carriers,
assuming no E-DPDCH is being transmitted on any of the two
carriers, e.g. according to equation (25). According to this
embodiment, NRPM for each carrier would be equivalent to:
NRPM,x=P.sub.DATA,max/P.sub.DPCCH,x, and Equation (39)
NRPM,y=P.sub.DATA,max/P.sub.DPCCH,y, Equation (40)
or equivalent to equations (26) or (27) where .rho..sub.z is equal
to 1. If P.sub.DATA,max has taken P.sub.non-SG into account
according to equation (31) then:
NRPM,x=(P.sub.DATA,max+P.sub.non-SG)/P.sub.DPCCH,x, and Equation
(41)
NRPM,y=P.sub.DATA,max/P.sub.DPCCH,y. Equation (42)
[0298] With this example embodiment, the set of supported E-TFCI
for each carrier will correspond to the E-TFCIs that can be
transmitted by the UE if no data is transmitted in the other
carrier. However, since the grant is limited by the virtual grants,
which were calculated accounting for the non-scheduled
transmissions, then the total transmission power will not exceed
the maximum allowed power (unless minimum set E-TFC is used). The
WTRU will fill up each carrier according to the non-scheduled grant
and available non-scheduled data, according to the virtual grant in
order of logical channel priority. The conventional E-TFC selection
is then executed on the primary carrier and then on the secondary
carrier with the optional restriction that non-scheduled flows may
only be mapped on the anchor carrier.
[0299] It should be understood that throughout this disclosure, the
WTRU may not need to determine or calculate whether the WTRU is
power limited and allocate the power according to any of the
embodiments described above, by ensuring that the power allocated
to each carrier for scheduled transmissions does not exceed the
power allowed by the actual serving grant. For example, this may be
achieved by taking the minimum between the SGz and SGinput,z, or
determining the scaling factor to be a minimum of calculated
scaling factor and 1.
[0300] Embodiments for dual-carrier power back-off and maximum
power reduction for multicarrier operations are disclosed
hereafter. To relieve the WTRU power amplifier design and power
consumption, the WTRU is typically allowed a certain maximum power
reduction (MPR). This power reduction margin allows a WTRU
implementation to reduce the maximum transmission power (this is
also referred to as power back-off) to avoid causing unintended
adjacent carrier interference due to power amplifier
non-linearity.
[0301] Typically, the amount of power back-off depends on the
combination of signals being transmitted. Conventionally for single
carrier operations, the maximum power reduction allowed for TFC and
E-TFC restriction procedures for different cases are specified.
When performing E-TFC restriction for example, the maximum
transmission power PMax.sub.j is allowed to be reduced by up to the
MPR (E-TFC-MPR) amount corresponding to the signal configuration
case corresponding to E-TFC j, as shown in Table 2.
TABLE-US-00002 TABLE 2 Inputs for E-TFC selection E-DPDCH E-TFC-MPR
Case .beta..sub.c .beta..sub.hs .beta..sub.d .beta..sub.ec
.beta..sub.ed SFmin Ncodes (dB) 1 >0 0 0 >0 >0 .gtoreq.4 1
0.25 2 >0 .gtoreq.0 0 >0 >0 2 4 0.50 3 >0 0 >0 >0
>0 .gtoreq.4 1 0.75 4 >0 >0 >0 >0 >0 .gtoreq.4 1
1.50 5 >0 .gtoreq.0 >0 >0 >0 4 2 0.75 6 >0 .gtoreq.0
>0 >0 >0 2 2 0.50 NOTE: For inputs {.beta..sub.c,
.beta..sub.hs, .beta..sub.d, .beta..sub.ec, .beta..sub.ed, SFmin,
Ncodes} not specifed above the E-TFC-MPR (dB) = 0
[0302] In accordance with one embodiment, a power back-off may be
applied when transmitting on two uplink carriers rather than one.
The WTRU determines the amount of data to be transmitted on both
carriers according to any of the embodiments described herein, and
may apply a power back-off (i.e., reduction in total transmission
power or per-carrier transmission power) if data is to be sent on
two carriers. The application of a power back-off would then result
in the use of a smaller E-TFCI on each carrier. The WTRU may
determine whether more data may be sent using a single carrier
without power back-off or using two carriers with power back-off,
and select the option allowing for transmission of most total
number of bits.
[0303] For dual-carrier operations, new sets of MPR tables may be
defined, or the conventional table for E-TFC restriction may be
extended to support additional cases such that all the existing
(1-6) or relevant cases in combination with the case where a second
DPCCH on the supplementary carrier is present, all the existing
(1-6) or relevant cases in combination with the case where a second
DPCCH and HS-DPCCH on the supplementary carrier are present, and
all the existing (1-6) or relevant cases in combination with the
case where a second DPCCH and HS-DPCCH on the supplementary carrier
are present in addition to different cases of E-DCH configurations.
In the case where no DPDCH is allowed when a WTRU is configured for
DC-HSUPA operations, then the first 2 cases in Table 2 become
relevant.
[0304] In accordance with one embodiment, when performing the E-TFC
restriction procedure sequentially, (i.e., the E-TFC restriction
procedure for carrier x is carried out before the E-TFC restriction
procedure for carrier y), when performing E-TFC restriction for
carrier x, the calculation of PMax.sub.j,x may take into account,
in addition to the channels transmitted in carrier x, an additional
power reduction due to the presence of DPCCH and potentially other
channels such as the HS-DPCCH on carrier y. This maximum allowed
power reduction may be obtained from a new E-TFC-MPR Table 3, for
instance. In Table 3, the MPR values X1-X4 are fixed numbers
determined for example through simulations or measurements, and
when performing E-TFC restriction for the first carrier selected
(e.g., when performing E-TFC restriction sequentially) the WTRU
determines for each E-TFCi the E-TFC-MPR according to the table and
may apply it to the maximum transmit power. Similarly, when
performing E-TFC restriction for carrier y, the calculation of
PMax.sub.j,y may take into account, in addition to the channels
transmitted in carrier y, (i.e., DPCCH, E-DPCCH, E-DPDCH, and
potentially the HS-DPCCH), an additional power reduction due to the
presence of carrier x, for which the actual E-DCH transport format
has been selected. This maximum allowed power reduction may be
obtained from a new E-TFC-MPR Table 4, for instance.
TABLE-US-00003 TABLE 3 Inputs for E-TFC selection Carrier E-DPDCH
Carrier 1 2 (in Carrier 1) E-TFC- Case .beta..sub.c .beta..sub.hs
.beta..sub.d .beta..sub.ec .beta..sub.ed .beta..sub.c .beta..sub.hs
SFmin Ncodes MPR (dB) 1 >0 0 0 >0 >0 0 0 .gtoreq.4 1 0.25
2 >0 .gtoreq.0 0 >0 >0 0 0 2 4 0.50 3* >0 0 0 >0
>0 >0 0 .gtoreq.4 1 X1 4* >0 .gtoreq.0 0 >0 >0 >0
0 2 4 X2 5* >0 0 0 >0 >0 >0 >0 .gtoreq.4 1 X3 6*
>0 .gtoreq.0 0 >0 >0 >0 >0 2 4 X4 NOTE: For inputs
{.beta..sub.c, .beta..sub.hs, .beta..sub.d, .beta..sub.ec,
.beta..sub.ed, SFmin, Ncodes} not specifed above the E-TFC-MPR (dB)
= 0
[0305] Then for the second carrier the WTRU knows that data will be
transmitted on the first carrier (otherwise the second carrier
would not be filled with data). In Table 4, the MPR values Y1-Y6
are fixed numbers determined for example through simulations or
measurements.
TABLE-US-00004 TABLE 4 Inputs for E-TFC selection E-DPDCH Carrier 1
Carrier 2 Carrier 1 Carrier 2 E-TFC- Case .beta..sub.c
.beta..sub.hs .beta..sub.d .beta..sub.ec .beta..sub.ed .beta..sub.c
.beta..sub.hs .beta..sub.d .beta..sub.ec .beta..sub.ed SFmin Ncodes
SFmin Ncodes MPR (dB) 1** >0 0 0 >0 >0 >0 0 0 >0
>0 .gtoreq.4 1 .gtoreq.4 1 Y1 2** >0 0 0 >0 >0 >0 0
0 >0 >0 .gtoreq.4 1 2 4 Y2 3** >0 0 0 >0 >0 >0
>0 0 >0 >0 2 4 .gtoreq.4 1 Y3 4** >0 0 0 >0 >0
>0 >0 0 >0 >0 2 4 2 4 Y4 5** >0 >0 0 >0 >0
>0 0 0 >0 >0 .gtoreq.4 1 .gtoreq.4 1 Y5 6** >0 >0 0
>0 >0 >0 0 0 >0 >0 2 4 2 4 Y6 NOTE: For inputs
{.beta..sub.c, .beta..sub.hs, .beta..sub.d, .beta..sub.ec,
.beta..sub.ed, SFmin, Ncodes} not specifed above the E-TFC-MPR (dB)
= 0
[0306] When a WTRU is configured for DC-HSUPA operations, E-TFC
selection and thus E-TFC restriction may be carried out for a
single transport block when for example there is a re-transmission
on a carrier and the other carrier is free. In such cases, the MPR
for E-TFC restriction may be based on a similar procedure but
starting with the MPR calculation for carrier 2 (as data is already
being sent on carrier 1). An E-TFC-MPR table such as the one shown
in Table 4 may be used for this purpose.
[0307] In another embodiment, a fixed MPR offset may be applied to
the values in the conventional tables when data or control
information is being transmitted over a second carrier. More
specifically, this fixed DC-HSUPA-MPR value (in dB) may be added to
the E-TFC-MPR value calculated for each carrier individually when
carrying out E-TFC restriction. For example, the WTRU may calculate
the MPR as follows. If DC-HSUPA is activated and E-TFC selection is
carried out, for each carrier and each E-TFCI, the WTRU may
calculate a first "single-carrier MPR" according to the E-TFC
restriction legacy procedure (e.g., using Table 2). For each
carrier, the WTRU then adds the DC-HSUPA-MPR value to this
single-carrier MPR value calculated above. For each carrier, the
WTRU then uses this total MPR in the calculation of the maximum
power for that carrier.
[0308] In another example, where for example the E-TFC restriction
is carried out sequentially, the WTRU may calculate the MPR as
follows. In calculating the MPR for the first carrier to which
E-TFC restriction is applied the WTRU calculates first a
"single-carrier MPR" according to the E-TFC restriction legacy
procedure, (e.g., using Table 2). Optionally, the WTRU adds the
DC-HSUPA-MPR value to this single-carrier MPR value calculated.
Optionally, the WTRU adds the DC-HSUPA-MPR value to this
single-carrier MPR value calculated if one or more of the following
conditions are met (in any order or combination): (1) the power of
the DPCCH on the other carrier is non-zero or will be non-zero for
at least one of the slot in the upcoming TTI, or (2) the HS-DPCCH
is being or will be transmitted on the other carrier.
[0309] In calculating the MPR for the second carrier to which E-TFC
restriction is applied the WTRU may calculate first a
"single-carrier" MPR according to the E-TFC restriction legacy
procedure (e.g., using Table 2). Optionally, the WTRU adds the
DC-HSUPA-MPR value to this single-carrier MPR value calculated.
Optionally, the WTRU adds the DC-HSUPA-MPR to this single-carrier
MPR value calculated if one or more of the following conditions are
met (in any order or combination): (1) the power of the E-DPDCH
(and the E-DPCCH) on the first carrier is non-zero, (2) the power
of the E-DPDCH on the first carrier is above a threshold, where the
WTRU receives the value of this threshold via higher layer
signaling or the value of the threshold is pre-configured, (3) the
number of channelization codes of the E-DPDCH on the first carrier
is larger than or equal to a given value, where this value is
signaled by the network or pre-configured in the specifications,
(4) the smallest spreading factor used on the first carrier E-DPDCH
is smaller than or equal to a pre-configured value, (5) or the
first carrier has non-zero power on the HS-DPCCH.
[0310] In another embodiment, the WTRU may use the legacy or
conventional E-TFC restriction procedure with MPR when a single
carrier is activated and when more than one carrier is activated
the WTRU may use a fixed MPR value. Alternatively, the WTRU may use
a fixed MPR when two carriers are activated and E-DCH transmission
occurs on both carriers. Otherwise, the WTRU applies the MPR based
on the legacy procedure calculated using the carrier with E-DCH
transmission and no additional MPR is taken into considerations for
the other carrier. Alternatively, the WTRU may use a fixed MPR when
two carriers are activated and more than one physical channel is
being transmitted on each carrier. Otherwise, the WTRU applies the
MPR based on the legacy procedure calculated using the carrier with
E-DCH transmission and no additional MPR is taken into
considerations for the other carrier, Alternatively, the WTRU may
use a fixed MPR when two carriers are activated and at least the
DPCCH is transmitted on each carrier simultaneously. Otherwise, the
WTRU applies the MPR based on the legacy procedure calculated using
the carrier with E-DCH transmission and no additional MPR is taken
into considerations for the other carrier. The fixed MPR value may
correspond to the largest MPR value in Table 2. The WTRU may
pre-calculate the MPR for all relevant E-TFCI and carrier
combinations.
[0311] When power reduction is applied for E-TFC.sub.j,z, where z=x
or z=y, the value of P.sub.MAX is reduced by the amount of power
back-off for the E-TFCj and carrier x or y. The maximum WTRU
transmitter power becomes as follows:
Maximum WTRU transmitter power(in dBm)=MIN{Maximum allowed UL TX
Power(in dBm),P.sub.MAX,dBm-P.sub.BACKOFF,j,z}, Equation (43)
where Maximum allowed UL TX power is set by UTRAN, P.sub.MAX,dBm is
the WTRU nominal maximum transmit power is defined by the WTRU
power class (in dBm), and P.sub.BACKOFF,j,z is the amount of power
backoff applied for E-TFCj and carrier z=x or z=y (in dB).
[0312] The scheduling information (SI) may be modified such that it
provides the UL power headroom measurement for each carrier
individually. More specifically, the format of the SI may be
expanded to include UPH for the supplementary carrier, as shown in
FIG. 11, where UPH1 and UPH2, correspond to the ratio of the
maximum WTRU transmission power and the corresponding anchor and
supplementary DPCCH code power, respectively.
[0313] Alternatively, the WTRU may report one UPH measurement, and
the Node-B may infer the UPH of the other carrier based on the
noise rise difference between the carriers.
[0314] Alternatively, a single UPH may be calculated and reported
as:
UPH=P.sub.max,tx/(P.sub.DPCCH1+P.sub.DPCCH2), Equation (44)
where P.sub.max,tx is the total maximum output power that may be
transmitted by the WTRU and P.sub.DPCCH1 and P.sub.DPCCH2 represent
the transmitted code power on DPCCH of carrier 1 and carrier 2,
respectively. In the case where per-carrier maximum transmission
powers are configured, then P.sub.max,tx represents the sum of the
per-carrier maximum transmission powers.
[0315] Alternatively, the scheduling information format remains
unchanged, but the WTRU may report the SI individually in each
carrier. For instance, if the SI is sent over the anchor carrier it
reports the UPH of the anchor carrier, and if it sent over the
supplementary carrier it reports the UPH of the supplementary
carrier.
[0316] When performing the E-TFC restriction procedure, the WTRU
needs to calculate the E-DPDCH and E-DPCCH gain factor (in case
E-DPCCH power boosting is configured) for each E-TFCI and each HARQ
offset configured. These gain factors depends on a set of
parameters configured by the network. The WTRU may receive a
configuration message enabling the calculation of these gain
factors. The configuration message includes at least one or more of
the following parameters: a set of reference E-TFCIs, E-DPDCH power
offsets, a HARQ offset for each MAC-d flow configured,
E-TFCI.sub.ec,boost indicating the E-TFCI above which E-DPCCH power
boosting will be applied, a gain factor for E-DPCCH, traffic to
total pilot power (for E-DPCCH power boosting), etc. Every time the
WTRU requires the gain factor for a given E-TFCI, the WTRU uses the
power interpolation or extrapolation formula and potentially the
E-DPCCH power boosting formula to calculate the gain factor.
[0317] Alternatively, the WTRU may pre-calculate for each of the
E-TFCIs the gain factor required for all HARQ offsets configured or
all MAC-d flow. The WTRU stores the resulting power offsets for
future use (e.g., every time E-TFC restriction is executed). When
the WTRU requires a set of power offsets for a given HARQ offset
and E-TFCI, the WTRU may look-up the requested value in the
pre-calculated table. This approach may be used for any of the
E-TFC restriction/selection procedures described above.
[0318] In this invention, the WTRU may pre-calculate the set of
supported E-TFCIs for every HARQ offset ahead of the time these
values are required in the E-TFC selection procedure. For example,
the set of supported E-TFCIs for each HARQ offset configured may be
calculated and stored in memory at the beginning of every TTI,
independently for each carrier. When needed by the E-TFC selection
procedure the WTRU may then read the desired set of values from the
WTRU memory. Thus when referring to the execution of the E-TFC
restriction procedure in this invention, it should be understood
that in many cases the actual computations of the set of supported
E-TFCIs may have already been carried out (e.g.: at the TTI
boundary) and thus the execution of the E-TFC restriction may refer
to the WTRU reading the set of supported E-TFCIs from memory.
[0319] In other embodiments, modulation schemes may be optimized
across multiple carriers. For purposes of describing these
embodiments, reference will be made to 16 quadrature amplitude
modulation (16QAM) and quadrature phase shift keying (QPSK).
Various 16QAM and QPSK scenarios as well as E-DPCCH boosting are
disclosed hereafter. For the sequential approaches described
herein, the WTRU may select one of the carriers to fill up with
data first. In a situation where the WTRU is power limited and the
grant on that carrier is large enough to allow the transmission of
data using 16QAM or E-DPCCH boosting, data transmission may be
inefficient if 16QAM is used in one carrier and not enough power
remains on the other carrier. In one embodiment, for example, it
may be more efficient in terms of data transmission and power
utilization to transmit on two carriers using QPSK than to transmit
16QAM in one carrier only. Indeed, as higher order modulation
typically requires more energy per bit than lower-order modulations
it may be more energy efficient for the WTRU to use 16QAM only when
the largest E-TFC which uses QPSK is used on both carriers and the
WTRU has sufficient power and grant to transmit additional data.
Doing so may not only improve the WTRU battery life but also
improve the network capacity for a given user experience.
[0320] By way of further example, in another embodiment, the WTRU
may not use 16QAM when the WTRU is power-limited. For example, when
the WTRU is power-limited, two carriers filled with QPSK may carry
more data than one carrier with 16QAM and potentially another
carrier with QPSK or binary phase shift keying (BPSK). Furthermore,
the latter configuration, of one carrier with 16QAM and another
carrier with QPSK or BPSK may consume additional WTRU battery
power, and reduce the throughput of WTRU and reduce network
capacity.
[0321] In yet another embodiment, the WTRU may be configured not to
use 16QAM when the WTRU is buffer-limited. It may be more
operationally efficient for the WTRU to empty its buffer with two
carriers filled with QPSK instead of a single carrier with 16QAM or
one carrier with 16QAM and another carrier with QPSK or BPSK. This
would improve battery life and increase network capacity.
[0322] In accordance with one embodiment, the WTRU may perform an
E-TFC selection procedure for DC-HSUPA at least twice (i.e., E-TFC
restriction procedures for DC-HSUPA are executed twice). In a first
tentative E-TFC selection procedure, the WTRU calculates the E-TFC
by not allowing E-TFCIs that are known to require 16QAM operations.
This additional restriction may be carried out for example during
the E-TFC restriction procedure for each carrier such that these
E-TFCIs would appear blocked to the E-TFC selection procedure. The
WTRU may then record the two transport block sets (TBSs) that
result from the E-TFC selection procedures (one per carrier),
record the total number of data bits (or optionally data bits in
addition to header bits and/or padding bits) that would be
transmitted across the two carriers, and create the PDUs
corresponding to these TBSs.
[0323] In a second tentative E-TFC selection procedure, the WTRU
calculates the E-TFC with no further restriction on the E-TFCIs.
This is achieved by executing the regular E-TFC restriction
procedure. The WTRU may then record the two TBSs that result from
the E-TFC selection procedures (one per carrier), record the total
number of data bits (or optionally data bits in addition to header
bits and/or padding bits) that would be transmitted across the two
carriers, and create the PDUs corresponding to these TBS.
[0324] The WTRU then compares the total number of bits that would
be transmitted for each procedure (either using the sum of TBS
selected or the total number of data bits as calculated above) and
selects the tentative E-TFCs that amount to the largest number of
bits in total. The WTRU then may create and transmit the MAC PDUs.
If the PDUs were created in advance, the WTRU may transmit the pair
of PDUs that correspond to the largest aggregate number of bits and
discard the other two PDUs.
[0325] In accordance with another embodiment, the E-TFC restriction
procedure may be updated to restrict the WTRU from utilizing 16QAM
in one carrier only.
[0326] This restriction may be applied when one or a combination of
the following conditions are true:
[0327] (1) The WTRU shared available headroom is below a threshold,
where the headroom here may be an averaged headroom (e.g., UPH) or
an instantaneous headroom;
[0328] (2) The NRPM is below a threshold;
[0329] (3) The WTRU shared available headroom is below a threshold
and the grant of one or the first selected carrier is above a
threshold;
[0330] (4) The grant on the first selected carrier is greater than
shared available headroom or the NRPM; or
[0331] (5) The sum of the grants is larger than a threshold and the
grant on one of the carriers is above a threshold.
[0332] The threshold described above may be predefined in the WTRU
or configured by the network or determined by the WTRU based on
other configured values.
[0333] Alternatively, this restriction may be applied and performed
consecutively. When one of the conditions described above is met
the WTRU may attempt to disallow 16QAM or E-DPCCH boosting in one
carrier only. The E-TFC restriction may be performed for the first
selected carrier. When E-TFC restriction is performed the WTRU may
block the range of E-TFCI that would result in the WTRU
transmitting using 16QAM or E-DPCCH boosting. The E-TFC restriction
function may determine which E-TFCIs to block using one or a
combination of the following criteria:
[0334] (1) All E-TFCIs greater than or equal to
E-TFCI.sub.boost;
[0335] (2) All E-TFCIs greater than or equal to the E-TFCI that
would trigger the WTRU to use 16QAM. This value may be calculated
and determined by the WTRU initially;
[0336] (3) An E-TFCI to use for blocking may be configured by the
network; or
[0337] (4) The WTRU block all E-TFCIs above certain number of bits,
(e.g., 1000 bits).
[0338] The E-TFC selection is performed according to the allowed
grant and supported E-TFCIs and the first carrier is filled up with
data according to this value and the relevant E-TFC selection
procedure. The WTRU then proceeds to the second carrier and runs
E-TFC restriction for the second carrier. The E-TFC restriction
procedure for the second carrier may also block the E-TFCIs as
described above. Once the second carrier is filled up according to
the supported E-TFCIs and the allowed grants, the WTRU may stop the
E-TFC selection procedure, or alternatively go back to the first
selected carrier if power and grant still remains. When E-TFC
restriction is run for the second time no E-TFCI that make use of
16QAM or E-DPCCH boost are blocked, unless not allowed by power as
the normal E-TFC restriction procedure. Alternatively, the WTRU
just performs normal E-TFC selection. The WTRU may also go back to
the second carrier again if power still remains. This procedure
requires iterative E-TFC selection procedure and may increase
complexity. However, if this procedure is performed when the
criteria described above is met, the WTRU may not need to do
iterative processes.
[0339] Alternatively, when the E-TFC restriction is run on the
second carrier, the WTRU may not block any of the above mentioned
E-TFCIs. This way if the WTRU has enough power and grant it may
transmit more data. Once the second carrier is filled up this way,
the E-TFC selection procedure may end, or alternatively the WTRU
may try to continue filling up the initial carrier if power, grant
and data remains.
[0340] Embodiments for considering power imbalance are described
hereafter. When two carriers are being transmitted with large power
imbalance, the signal-to-noise ratio (SNR) of the carrier with the
smaller power may be deteriorated by the presence of the other
carrier. When a carrier suffers from adjacent carrier interference
(e.g., due to a power imbalance) the SIR measured at the Node-B is
reduced due to the reduction of SIR at the transmitter. The
problems incurred from a large power imbalance may be mitigated as
part of the E-TFC selection and E-TFC restriction procedure.
[0341] In accordance with one embodiment, the occurrence of power
imbalance between the two carriers may be reduced by further
restricting the set of supported E-TFCs during the E-TFC
restriction procedure such that the resulting power imbalance is
maintained within a specific limit or threshold. This may be
accomplished, for example, by reducing the effective PMax.sub.j in
the NRPM.sub.j calculation in the E-TFC restriction procedure.
[0342] Alternatively, the WTRU may estimate the normalized
remaining power margin available for E-TFC selection based on the
following equation for E-TFC candidate j:
NRPM.sub.j=(PMax.sub.j-P.sub.imbalance,j-P.sub.DPCCH,target-P.sub.DPDCH--
P.sub.HS-DPCCH-P.sub.E-DPCCH,j)/P.sub.DPCCH,target; Equation
(45)
where it is assumed that PMax.sub.j represents the remaining
maximum power for a given carrier. PMaxj may include the
contribution of the channels being transmitted over the other
carrier, if applicable. The parameter P.sub.imbalance,j may be
configured by the network or calculated by the WTRU.
[0343] In order to simplify WTRU operation, a power imbalance
situation may be considered to occur when the difference between
the total transmit power (including all channels) and the transmit
DPCCH power in the other carrier is larger than a threshold
(P.sub.Thresh). The WTRU chooses one of the carriers to fill up
first (carrier x corresponds to the highest priority carrier (i.e.,
first carrier to be filled up) and carrier y corresponds to the
second carrier to be filled up if power or grant remains).
[0344] For each E-TFC candidate j, the WTRU may calculate the total
transmission power for E-TFC.sub.j for carrier z (where z is the
carrier index x or y) as follows:
P.sub.tot,z,j=P.sub.DPCCH,target
z+P.sub.HS-DPCCH+P.sub.E-DPCCH,z,j+P.sub.E-DPDCH,z,j. Equation
(46)
P.sub.HS-DPCCH is taken into account when carrier z corresponds to
the anchor carrier or the carrier in which HS-DPCCH is being
transmitted.
[0345] If |P.sub.tot,z,j-P.sub.DPCCH,target k|>P.sub.Thresh:
[0346] Then P.sub.imbalance,j,z=|P.sub.tot,z,j-P.sub.DPCCH,target
k|-P.sub.Thresh;
[0347] else [0348] P.sub.imbalance,j,z=0 k is the carrier index
where k.noteq.z (e.g., if z is carrier x then k represents carrier
y and vice versa).
[0349] NRPM for carrier x is computed as follows:
NRPM.sub.j,x=(PMax.sub.j,x-P.sub.DPCCH,target x-P.sub.DPCCH,target
y-P.sub.DPDCH,x,y-P.sub.HS-DPCCH,x.y-P.sub.E-DPCCH,j,x-P.sub.imbalance,j.-
x)/P.sub.DPCCH,target.sub._.sub.x. Equation (47)
[0350] Optionally, P.sub.imbalance,j,z may be taken into account if
it is greater than zero and the above conditions are met. If
P.sub.imbalance,j,z is less than zero then P.sub.imbalance,j,z may
be set to zero or equivalently not taken into account in the NRPM
calculations.
[0351] P.sub.thresh may be configured by the network, determined by
the WTRU, or, calculated based on specific device designs or
requirements. The P.sub.thresh may be a static number or
alternatively, may dynamically change based on the candidate E-TFC
j.
[0352] The WTRU then chooses the supported E-TFC according to the
NRPM for carrier x. Since the power imbalance is taken into account
in the NRPM, the supported E-TFC(s) will include the E-TFC for
which no power imbalance issues will result.
[0353] The same power imbalance check may be performed for carrier
y once E-TFC selection is performed in carrier x or if a
retransmission is ongoing in carrier x. If a retransmission is
ongoing on carrier x, no E-TFC selection will be performed for
carrier x, but the power of the retransmission in carrier x is
taken into account in the E-TFC restriction of carrier y.
[0354] More specifically, the NRPM.sub.j,y is calculated as
follows:
NRPM.sub.j,y=(PMax.sub.j,y-P.sub.DPCCH,target x-P.sub.DPCCH,target
y-P.sub.DPDCH,x,y-P.sub.HS-DPCCH,x.y-P.sub.E-DPCCH,x-P.sub.E-DPDCH,x-P.su-
b.E-DPCCH,j,y-P.sub.imbalance,j,y)/P.sub.DPCCH,target y; Equation
(48)
where P.sub.imbalance,j,y may be equivalently calculated as
described above, where z=y and k=x, and P.sub.E-DPDCH,z,j is an
estimated E-DPDCH transmit power for the E-TFCI.sub.j determined
for carrier z.
[0355] Alternatively, the WTRU may consider a power imbalance if
the difference between the total transmitted power P.sub.tot,y and
the total transmitted power in carrier x P.sub.tot,x is greater
than a threshold, P.sub.thresh.
[0356] Optionally, if a retransmission in carrier x is ongoing and
the power in carrier x is too high with respect to the determined
power in carrier y, or vice versa, the E-TFC selection may take
this into account and alleviate the problem by padding. This
situation may occur if the WTRU is buffer limited and there is
enough grant and power available in the other carrier. More
specifically, if the difference of total power between the two
carriers (P.sub.diff) is greater than P.sub.thresh, the WTRU may
fill up the difference (P.sub.thresh-P.sub.diff) with padding
bits.
[0357] Some additional examples cases of sequential E-TFC
restriction procedures are described hereafter. The WTRU may
transmit DPCCH in both carriers every TTI. Alternatively, the WTRU
may optimize power consumption by not transmitting DPCCH in both
carriers in the same TTI if certain conditions are satisfied. When
no E-DCH data is transmitted in one of the carriers it may be
beneficial that the WTRU does not transmit DPCCH on that carrier.
In this case, the WTRU may transmit DPCCH on that carrier according
to a configured cycle or according to an inactivity period (i.e.,
period in which no data is transmitted in one of the carriers).
This will avoid long periods of DPCCH silence. For instance, after
x TTIs of silence periods the WTRU may transmit a DPCCH burst to
allow for proper power control.
[0358] A WTRU selects a carrier to treat first according to one of
the embodiments for carrier selection described above. The carriers
are identified as x and y, where x is the carrier selected first
and y is the other carrier and x does not necessarily correspond to
the anchor carrier.
[0359] The WTRU determines whether the WTRU is required to transmit
DPCCH and/or HS-DPCCH on both carriers or on a single carrier. The
WTRU may determine whether any of the control channels have to be
transmitted on both carriers or not based on one or any combination
of the following: whether the WTRU is scheduled for a DPCCH burst
on that TTI on both carriers (i.e., according to the DTX cycles on
each carrier); whether the WTRU behaviour allows the WTRU not to
transmit DPCCH when no E-DCH data is transmitted or when no
HS-DPCCH is transmitted on that carrier; whether the WTRU has to
transmit HS-DPCCH on both carriers; or when the WTRU has chosen one
of the carriers to transmit E-DCH data based on one of the
embodiments described above, whether a DPCCH or HS-DPCCH is
required on the remaining carrier.
[0360] If it is determined that no DPCCH or HS-DPCCH is necessarily
required on carrier y, the WTRU may perform E-TFC restriction
procedure for carrier x where the NRPM.sub.j,x is equivalent
to:
NRPM.sub.j,x=(PMax.sub.j,x-P.sub.DPCCH,target
x-P.sub.DPDCH,x-P.sub.HS-DPCCH,x-P.sub.E-DPCCH,j,x)/P.sub.DPCCH,target
x. Equation (49)
In equation (49), if DPDCH is not allowed in carrier x or if no
DPDCH is scheduled for transmission, the P.sub.DPDCH,x may not be
taken into account.
[0361] If DPDCH is being transmitted in carrier y and carrier x is
selected first for E-DCH transmission:
NRPM.sub.j,x=(PMax.sub.j,x-P.sub.DPCCH,target
x-P.sub.DPDCH,y-P.sub.DPCCH,target
y-P.sub.HS-DPCCH,x-P.sub.E-DPCCH,j,x)/P.sub.DPCCH,target x.
Equation (50)
[0362] Based on E-TFC selection and E-TFC restriction the WTRU
determines the number of bits that may be transmitted on the
selected carrier x, according to the available remaining power
determined based on the above NRPM, the available serving grant for
that carrier and the non-scheduled grant. A MAC-i PDU for carrier x
may then be created or an E-TFCI may be determined.
[0363] The WTRU then performs E-TFC restriction procedure for
carrier y, where NRPM.sub.j,y may be determined as follows:
NRPM.sub.j,y=(PMax.sub.j,y-P.sub.DPCCH,target
x-P.sub.DPDCHx/y-P.sub.HS-DPCCHx/y-P.sub.E-DPCCH,j,x-P.sub.E-DPDCH,x-P.su-
b.DPCCH,target
y-P.sub.HS-DPCCHjy-P.sub.E-DPCCH,j,y-P.sub.backoff)/P.sub.DPCCH,target
y. Equation (51)
[0364] P.sub.backoff (maximum power reduction) may be subtracted
explicitly in the NRPM calculation as shown in equation (51) or it
may be taken into account in the determined value of Pmax.sub.j,y,
which will be explained below. The value may be a static value, or
alternatively may depend on a number of factors and resources used
in the additional carrier.
[0365] The WTRU may then determine whether E-DCH data may be
transmitted in carrier y. The WTRU may determine not to transmit
E-DCH on carrier y in one or a combination of conditions that the
NRPMy is below a configured threshold, the largest supported E-TFC
as obtained from the E-TFC restriction procedure is smaller than or
equal to the largest E-TFC of the minimum E-TFC set, the determined
"Maximum Supported Payload" (from the E-TFC restriction procedure)
is below a configured threshold, the minimum value between the
remaining scheduled grant payload and the maximum supported payload
for carrier y is below a configured or predetermined threshold,
and/or the remaining scheduled grant payload for carrier y is below
a configured or predetermined threshold, etc. If the WTRU is
transmitting E-DCH in the new carrier, the DPCCH transmission also
has to take place in that TTI.
[0366] If the WTRU determines that a DPDCH and/or HS-DPCCH needs to
be transmitted on carrier y the following calculation may be
performed for NRPM.sub.j,x:
NRPM.sub.j,x=(PMax.sub.j,x-P.sub.DPCCH,target
x-P.sub.DPDCH,x-P.sub.HS-DPCCH,x-P.sub.E-DPCCH,j,x-P.sub.DPDCH,y-P.sub.HS-
-DPCCH,y-P.sub.backoff)/P.sub.DPCCH,target x. Equation (52)
[0367] The above equation (52) affects the maximum supported
payload x determined as part of E-TFC restriction. This formulation
of NRPM.sub.j,x in equation (52) may be used for both cases,
wherein if the WTRU determines that no DPCCH or no HS-DPCCH is
being transmitted the corresponding powers are not taken into
account. P.sub.backoff corresponds to the additional power losses
incurred if the WTRU transmits on both carriers, (e.g., due to
power restriction for maintaining linearity at the transmitter).
This value may be a constant or may depend on other factors. The
NRPM calculations described above are scaled accordingly if the TTI
for which the procedure is being performed corresponds to a
compressed mode gap.
[0368] If a retransmission is ongoing in one of the carriers (i.e.,
carrier x) then E-TFC selection and E-TFC restriction is done for
the remaining carrier y, where:
NRPM.sub.j,y=(PMax.sub.j,y-P.sub.DPCCH,target
x-P.sub.DPDCH,x/y-P.sub.HS-DPCCH,x/y-P.sub.E-DPCCH,j,x-P.sub.E-DPDCH,j,x--
P.sub.DPCCH,target
y-P.sub.HS-DPCCH,y-P.sub.E-DPCCH,j,y-P.sub.backoff)/P.sub.DPCCH,target
y. Equation (53)
[0369] 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).
[0370] 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.
[0371] 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 a autonomous environment such as a sensor
network or machine-to-machine network environment, or the WTRU may
be used in conjunction with other 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.
* * * * *