(12) United States Patent
`Baldemair et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 8,472,368 B2
`Jun. 25, 2013
`
`US008472368B2
`
`(54)
`
`(75)
`
`(73)
`
`(*)
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`(21)
`(22)
`(86)
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`(87)
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`(65)
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`(60)
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`(51)
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`(52)
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`(58)
`
`METHOD AND ARRANGEMENTS IN A
`COMMUNICATION SYSTEM
`
`Inventors: Robert Baldemair, Solna (SE); Dirk
`Gerstenberger, Stockholm (SE); Daniel
`Larsson, Solna (SE); Stefan Parkvall,
`Stockholm (SE)
`Assignee: Telefonaktiebolaget L M Ericsson
`(publ), Stockholm (SE)
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 40 days.
`12/937,440
`
`Appl. No.:
`
`Notice:
`
`PCT Filed:
`
`Apr. 1, 2010
`
`PCT/SE2010/050368
`
`PCT No.:
`§ 371 (c)(1),
`(2), (4) Date:
`PCT Pub. No.: WO2011/046486
`PCT Pub. Date: Apr. 21, 2011
`
`Aug. 4, 2011
`
`Prior Publication Data
`|US 2011/029.2887 A1
`Dec. 1, 2011
`
`Related U.S. Application Data
`Provisional application No. 61/250,962, filed on Oct.
`13, 2009.
`
`(2006.01)
`(2009.01)
`(2006.01)
`(2006.01)
`
`Int. Cl.
`H04B 7/185
`H04 W 4/00
`H04B I/16
`H04B 7/00
`U.S. CI.
`USPC ......... 370/318; 370/329; 455/343.5; 455/522
`Field of Classification Search
`USPC ........................ 370/318, 329; 455/343.5, 522
`See application file for complete search history.
`
`(56)
`
`References Cited
`
`FOREIGN PATENT DOCUMENTS
`WO WO2007/112762
`* 10/2007
`
`OTHER PUBLICATIONS
`NTT Docomo, Comparison of PDCCH Transmission and Coding
`Schemes for LTE-Advanced, 3GPP Draft R1-090895, Feb. 9, 2009,
`3GPP TSG RAN WG1 Meeting #56, Athens, GR.
`ZTE, Primary and Secondary PDCCH Design for LTE-A, 3GPP
`Draft R1-092227, May 7, 2009, 3GPP TSG-RAN WG1 Meeting #57,
`San Francisco, CA, US.
`Panasonic, PDCCH design for carrier aggregation, 3GPP Draft
`R1-092230, May 8, 2009, 3GPP TSG-RAN WG1 Meeting #57, San
`Francisco, CA, US.
`
`(Continued)
`
`Primary Examiner — Ronald Abelson
`(74) Attorney, Agent, or Firm — Potomac Patent Group
`PLLC
`
`(57)
`ABSTRACT
`Methods and arrangements in a network node and mobile
`terminal, respectively, in a wireless communication system
`supporting aggregation of component carriers. The method in
`a network node involves, when resources on at least two
`downlink component carriers are being assigned to a mobile
`terminal at the same time, allocating (908) control informa
`tion bits not related to power control in a bit field, which is
`normally used for power control in a message on a physical
`downlink control channel associated with one of said at least
`two downlink component carriers. The method in a mobile
`terminal involves, using control information bits not related
`to power control obtained from a bit field, which is normally
`used for power control in a message on a physical downlink
`control channel associated with one of said at least two down
`link component carriers, for locating information related to
`downlink or uplink transmissions.
`
`24 Claims, 9 Drawing Sheets
`
`902
`
`904
`
`904:2 NO
`
`
`
`Multiple CCs
`simultaneously assigned
`to one UE2
`
`904;1 YES
`sº
`F--fºr---------------------------------,
`: Regular || Allocate TPC command in TPC bit
`# procedure ||
`field on PDCCH of one CC
`i
`
`906
`2
`
`Allocate other control info in
`on PDCCH of other | *%
`corresponding bit field
`
`Samsung Exhibit 1004, Page 1
`
`

`

`US 8,472.368 B2
`Page 2
`
`OTHER PUBLICATIONS
`Motorola, PDCCH Design for Carrier Aggregation and Post Rel-8
`Features, 3GPP Draft R1-093417, Aug. 24, 2009, 3GPP TSG RAN 1
`Meeting #58, Shenzen, CN.
`
`EPO, Int’l Prelim. Report on Patentability in PCT/SE2010/050368,
`Jan. 30, 2012.
`EPO, Int’l Search Report in PCT/SE2010/050368, Aug. 12, 2010.
`
`* cited by examiner
`
`Samsung Exhibit 1004, Page 2
`
`

`

`U.S. Patent
`
`Jun. 25, 2013
`
`Sheet 1 of 9
`
`US 8,472,368 B2
`
`One OFDM symbol including cyclic prefix
`
`-
`-
`Figure 1 (prior art)
`
`_------"
`... -- "
`
`Sub-frame (I.e., - 1 ms)
`4- - - - - - - ?
`
``-------,
`*** -- .
`
`#9
`#1 . . .
`#0
`<!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -p
`Radio frame (Tºs = 10 ms)
`
`Figure 2 (prior art)
`
`
`
`L1/L2 control (PDCCH, etc.) Bº BCH El SSS
`
`
`
`PSS D PDSCH
`
`Figure 3 (prior art)
`
`Samsung Exhibit 1004, Page 3
`
`

`

`U.S. Patent
`
`Jun. 25, 2013
`
`Sheet 2 of 9
`
`US 8,472,368 B2
`
`/
`
`One subframe
`
`
`
`2.
`
`&T.
`
`
`
`§º &T ZD2
`sessssssssss EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE?º
`
`Control
`Reference
`-
`§ signalling & symbols
`Control region
`(1-4 OFDM symbols) &
`
`Figure 4 (prior art)
`
`
`
`
`
`.42 subcapiéfs
`
`Uplink system bandwidth
`
`-- 1 ms subframe —-
`
`frequency
`
`
`
`Figure 5 (prior art)
`
`
`
`
`
`* [II] PRACH
`PUSCH
`PUCCH
`
`
`
`* time
`
`1 mS
`
`Figure 6 (prior art)
`
`Samsung Exhibit 1004, Page 4
`
`

`

`U.S. Patent
`
`Jun. 25, 2013
`
`Sheet 3 of 9
`
`US 8,472,368 B2
`
`702
`
`704
`
`706
`
`708
`
`710
`
`700~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ **
`Aggregated bandwidth of 100 MHz
`
`Figure 7 (prior art)
`
`
`
`DOWnlink
`
`5 MHz
`
`fº
`
`Figure 8 (prior art)
`
`Samsung Exhibit 1004, Page 5
`
`

`

`U.S. Patent
`
`Jun. 25, 2013
`
`Sheet 4 of 9
`
`US 8,472,368 B2
`
`904:2 NO
`
`
`
`Multiple CCs
`simultaneously assigned
`to One UE2
`
`
`
`904
`
`904:1 YES
`!----------------------------------------------,
`Regular || Allocate TPC command in TPC bit
`| procedure ||
`field on PDCCH of One CC
`:
`
`
`
`906
`2
`
`Allocate other control info in
`corresponding bit field on PDCCH of other
`CC
`
`908
`
`Figure 9
`
`Samsung Exhibit 1004, Page 6
`
`

`

`U.S. Patent
`
`Jun. 25, 2013
`
`Sheet 5 of 9
`
`US 8,472,368 B2
`
`
`
`1002
`
`1004
`
`1006
`
`1000
`
`1012
`
`1014
`
`1016
`
`Transmitting unit
`
`NetWork node
`1001
`
`Output signal
`
`Figure 10
`
`Samsung Exhibit 1004, Page 7
`
`

`

`U.S. Patent
`
`Jun. 25, 2013
`
`Sheet 6 of 9
`
`US 8,472,368 B2
`
`m
`
`g
`
`Receive DL assignment
`
`1 1 04:2 NO
`
`m
`Multiple DL CCs
`
`1 102
`
`1 104
`
`1 1 04:1 YES
`
`Regular || obtainifocommand from PDCCH; t?os
`procedure |:
`of one CC, in TPC bit field
`i_*
`
`Obtain other control info from PDCCH
`of other CC, in corresponding bit field
`
`1 108
`
`
`
`Act utilizing B
`
`1110
`
`Locate/identify
`assignment
`
`Schedule
`feedback
`
`Associate PDCCH
`with the proper CC
`
`l- — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — —
`
`Figure 11
`
`Samsung Exhibit 1004, Page 8
`
`

`

`U.S. Patent
`
`Jun. 25, 2013
`
`Sheet 7 of 9
`
`US 8,472,368 B2
`
`1200
`
`
`
`1202
`
`1204
`
`1206
`
`1208
`
`1210
`
`Transmitting unit
`
`–
`
`Mobile terminal
`1201
`
`Figure 12
`
`Samsung Exhibit 1004, Page 9
`
`

`

`U.S. Patent
`
`Jun. 25, 2013
`
`Sheet 8 of 9
`
`US 8,472,368 B2
`
`determining that multiple downlink
`component carriers (CC) are
`simultaneously assigned to a
`terminal
`
`No
`
`assigning a TPC command to
`only one of the Downlink Control
`Messages (DCI) messages
`conveying the downlink
`assignments
`
`
`
`Regular
`procedure
`
`1302
`
`1304
`
`
`
`Explicitly determine the
`PDCCH that is to carry
`the true TPC Command
`
`Implicitly determine the
`PDCCH that is to carry
`the true TPC Command
`
`applying, where appropriate, the bit fields
`corresponding to the TPC command in the
`other PDCCH to convey other relevant
`information.
`
`1308
`
`Figure 13
`
`Samsung Exhibit 1004, Page 10
`
`

`

`U.S. Patent
`
`Jun. 25, 2013
`
`Sheet 9 of 9
`
`US 8,472,368 B2
`
`
`
`------------4-----------
`
`1400
`
`1404
`
`` 1408
`
`Figure 14
`
`Samsung Exhibit 1004, Page 11
`
`

`

`US 8,472,368 B2
`
`1
`METHOD AND ARRANGEMENTS IN A
`COMMUNICATION SYSTEM
`
`TECHNICAL FIELD
`
`The invention relates to transmission of control informa
`tion in a communication system, and especially to adapting
`said transmission to the requirements following the enabling
`of carrier aggregation.
`
`10
`
`BACKGROUND
`
`2
`ferent parts of the spectrum at the slot boundary, using so
`called frequency hopping, as illustrated in FIG. 5.
`FIG. 5 shows an example of frequency hopping in the
`uplink, with one resource consisting of 12 subcarriers at the
`upper part of the spectrum within the first slot of a subframe
`and an equally sized resource at the lower part of the spectrum
`during the second slot of the subframe. If more resources are
`needed for the uplink L1/L2 control signaling, e.g. in case of
`very large overall transmission bandwidth supporting a large
`number of users, additional resource blocks can be assigned
`next to the previously assigned resource blocks.
`The reasons for locating the PUCCH resources at the edges
`of the overall available spectrum are two-fold:
`Together with the frequency hopping described above, the
`location at the edges maximizes the frequency diversity
`experienced by the control signaling, and
`Assigning uplink resources for the PUCCH at other posi
`tions within the spectrum, i.e. not at the edges, would
`fragment the uplink spectrum, making it impossible to
`assign very wide transmission bandwidths to a single
`mobile terminal and still retain the single-carrier prop
`erty of the uplink transmission
`The bandwidth of one resource block during one subframe
`is larger than the control signaling needs of a single terminal.
`Therefore, to efficiently exploit the resources set aside for
`control signaling, multiple terminals can share the same
`resource block. This is done by assigning the different termi
`nals different orthogonal phase rotations of a cell-specific
`length-12 frequency-domain sequence and/or different
`orthogonal time-domain covers covering the subframes
`within a slot or subframe.
`The LTE Release-8 standard supports bandwidths up to 20
`MHz. In order to meet the IMT-Advanced requirements,
`bandwidths larger than 20 MHz need to be supported. How
`ever, one important requirement is to assure backward com
`patibility with LTE Release-8 for legacy terminals. This
`should also include spectrum compatibility. That would
`imply that an LTE-Advanced carrier should appear as a num
`ber of LTE carriers to an LTE Release-8/9 terminal. Each such
`carrier can be referred to as a component carrier (CC). FIG. 7
`shows a schematic view illustrating five component carriers
`702-710 of 20 MHz each, together forming an aggregated
`bandwidth 700 of 100 MHz. In particular for early LTE
`Advanced deployments it can be expected that there will be a
`smaller number of LTE-Advanced-capable terminals as com
`pared to the number of LTE legacy terminals in use. There
`fore, it is necessary to assure an efficient use of a wide carrier
`also for legacy terminals, i.e. making it possible to implement
`carriers where legacy terminals can be scheduled in all parts
`of a wideband LTE-Advanced carrier. The straightforward
`way to obtain this would be by means of carrier aggregation.
`Carrier aggregation implies that an LTE-Advanced terminal
`can receive multiple CCs, where each CC has, or is at least
`able to have, the same structure as a Release-8 carrier.
`Scheduling of a CC is done on the Physical Downlink
`Control Channel (PDCCH) via downlink assignments. Con
`trol information on the PDCCH is formatted as a Downlink
`Control Information (DCI) message comprising predeter
`mined bit fields for different types of control information.
`DCI messages for downlink assignments contain, among
`other things, resource blockassignment, modulation and cod
`ing scheme related parameters, hybrid-ARQ redundancy ver
`sion, etc. In addition to parameters relating to the actual
`downlink transmission, most DCI formats for downlink
`assignments also contain a bit field for carrying Transmit
`Power Control (TPC) commands. These TPC commands are
`used to control the uplink power of the corresponding Physi
`
`15
`
`20
`
`25
`
`30
`
`In LTE (Long Term Evolution), OFDM (Orthogonal Fre
`quency Division Multiplexing) is used in the downlink and
`DFT-spread (Discrete Fourier Transform) OFDM is used in
`the uplink. The basic LTE downlink physical resource can
`thus be seen as a time-frequency grid as illustrated in FIG. 1,
`where each resource element corresponds to one OFDM sub
`carrier during one OFDM symbol interval.
`In the time domain, LTE downlink transmissions are orga
`nized into radio frames of 10 ms, where each radio frame
`consists often equally-sized subframes of length T
`=1
`subframe
`ms, as illustrated in FIG. 2.
`Furthermore, the resource allocation in LTE is typically
`described interms of resource blocks, where a resource block
`corresponds to one slot of 0.5 ms in the time domain and 12
`contiguous subcarriers in the frequency domain. Resource
`blocks are numbered in the frequency domain, starting with 0
`from one end of the system bandwidth.
`Downlink transmissions are dynamically scheduled in
`LTE, i.e., in each subframe, a base station transmits control
`information concerning which mobile terminals data is trans
`mitted to, and upon which resource blocks the data is trans
`mitted in the current downlink subframe. Typically, this con
`trol signaling is transmitted in the first 1, 2, 3 or 4 OFDM
`35
`symbols in each subframe. A downlink system with 4 OFDM
`symbols as control region is illustrated in FIG. 4.
`In LTE, hybrid-ARQ is used, where, after receiving down
`link data in a subframe, a mobile terminal attempts to decode
`it and reports to a base station whether the decoding was
`successful or not. When the decoding has been successful, the
`report comprises an “ACK” (ACKnowledgment), and when
`the decoding was not successful, the report comprises a
`“NAK” (Negative AcKnowledgment). In case of an unsuc
`cessful decoding attempt, the base station can retransmit the
`erroneous data.
`LTE uplink control signaling from a mobile terminal to a
`base station comprises:
`hybrid-ARQ acknowledgements for received downlink
`data;
`mobile terminal reports related to the downlink channel
`conditions, to be used as assistance for the downlink
`scheduling; and
`scheduling requests, indicating that a mobile terminal
`needs uplink resources for uplink data transmissions.
`When a mobile terminal has not been assigned an uplink
`resource for data transmission, the L1/L2 (Layer1/Layer2)
`control information, i.e., channel-status reports, hybrid-ARQ
`acknowledgments and scheduling requests, is transmitted in
`uplink resources, i.e. resource blocks, specifically assigned
`60
`for uplink L1/L2 control on a Physical Uplink Control CHan
`nel (PUCCH). As illustrated in FIG. 6, these resources are
`located at the edges of the total available cell uplink trans
`mission bandwidth. Each such resource consists of 12 sub
`carriers, i.e., one resource block, within each of the two slots
`of an uplink subframe. In order to provide frequency diver
`sity, these frequency resources may be shifted between dif
`
`40
`
`45
`
`50
`
`55
`
`65
`
`Samsung Exhibit 1004, Page 12
`
`

`

`US 8,472,368 B2
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`3
`cal Uplink Control Channel (PUCCH) that is used by termi
`mals to transmit the hybrid-ARQ feedback.
`The fact that an LTE-Advanced terminal could be assigned
`more resources than a legacy terminal, and on several com
`ponent carriers, increases the need for control information,
`e.g. since more resources need to be addressed, and more
`feedback needs to be transmitted, as compared to a Release-8
`scenario. For example, in Release-8 FDD, the number of
`ACK/NAK bits to be transmitted in the uplink as a response to
`a downlink assignment/transmission is limited to 1 bit for
`single code word, and 2 bits for dual code word transmission,
`while in Release-10, when a mobile terminal, also denoted
`UE (User Equipment), is assigned e.g. 3 downlink component
`carriers, the ACK/NAKs associated with these component
`carriers will require no less than 3 bits assuming single code
`word, and 6 bits assuming dual code word transmission on all
`component carriers, respectively. When the case when a
`mobile terminal does not receive any assignment(s) on one or
`multiple component carriers also shall be included in the
`feedback structure, the number of required feedback bits
`increases even further, to 5 and 7 bits, respectively, assuming
`again single code word and dual code word transmission,
`respectively, on all three component carriers. The event that
`an assignment, even though scheduled, is not received by a
`mobile terminal is referred to as DTX.
`The component carriers can be of different bandwidths,
`e.g. 5, 10 or 20 MHz, and thus comprise different amounts of
`resources, which need to be addressed. A wide component
`carrier will therefore require more control bits for addressing
`the resources within the carrier than a comparatively narrow
`component carrier. These differences depending on the band
`width of CCs or amount of assigned resources on each CC
`could be solved by using differently sized control messages,
`comprising an addressing space which corresponds to the
`current resource conditions. However, such a solution would
`require much processing of a receiver, in terms of blind detec
`tion of control messages.
`In LTE, a mobile terminal has to blindly decode DCI con
`trol messages to establish if it is currently scheduled. To
`reduce the complexity, a mobile terminal may be instructed to
`40
`only monitor, i.e. blindly decode, DCI message formats of
`certain payload sizes. Forcing a mobile terminal to monitor
`DCI formats with a large variety of payload sizes increases
`the number of blind decodings a mobile terminal has to per
`form and thus also the mobile terminal complexity.
`In order to maintain or reduce blind detection, it is desir
`able to have control messages and e.g. address fields of equal
`size. This implies that an address field suitable for addressing
`the resources within a 5 MHz component carrier will be too
`scarce for addressing the resources within a 20 MHz compo
`ment carrier, and an address field large enough to address the
`resources within a 20 MHz component carrier will be unnec
`essarily large for addressing the resources within a 5 MHz
`component carrier. Thus, a too small addressing space will
`only allow for a rough addressing in wide CCs, while a larger
`addressing space will waste resources when used for rela
`tively narrow component carriers.
`Consequently, it is a problem how to provide additional
`control information without increasing resource waste, caus
`ing insufficient addressing or increasing the burden of blind
`detection in a receiver.
`
`45
`
`50
`
`55
`
`60
`
`SUMMARY
`
`It would be desirable to enable conveyance of additional
`control information without increasing resource waste, caus
`ing insufficient addressing or increasing the burden of blind
`
`65
`
`4
`detection in a receiver. It is an object of the invention to
`address at least some of the issues outlined above. Further, it
`is an object of the invention to provide methods and arrange
`ments for enabling conveyance of additional control informa
`tion.
`According to a first aspect, a method is provided in a
`network node. Within the method, information bits related to
`power control of a physical uplink control channel are allo
`cated in a bit field for power control, in a message on a first
`physical downlink control channel associated with a first
`downlink component carrier. When resources on at least two
`downlink component carriers are being assigned to a mobile
`terminal at the same time, other control information bits, not
`related to power control, are allocated in a bit field, corre
`sponding to the bitfield used for power control in the message
`on the first physical downlink control channel, in a message
`on a second physical downlink control channel associated
`with a second one of said at least two downlink component
`carriers. The allocated control information is then transmitted
`to the mobile station.
`According to a second aspect, an arrangement is provided
`in a network node. The arrangement comprises a functional
`unit adapted to determine if resources on at least two down
`link component carriers are being assigned to a mobile ter
`minal at the same time. The arrangement further comprises a
`functional allocating unit adapted to allocate bits related to
`power control of a physical uplink control channel, in a bit
`field for power control in a message to be transmitted on a first
`physical downlink control channel associated with a first
`downlink component carrier. The functional allocating unit is
`further adapted to allocate bits when it has been determined
`that resources on at least two downlink component carriers
`are being assigned to a mobile terminal, allocate other control
`information bits not related to power control in a bit field,
`corresponding to the bit field used for power control in the
`message on the first physical downlink control channel, in a
`message on a second physical downlink control channel asso
`ciated with a second one of said at least two downlink com
`ponent carriers. The arrangement further comprises a func
`tional unit, adapted to transmit the allocated control
`information to the mobile terminal being assigned the
`resources on the at least two downlink component carriers
`The above described method and arrangement may be used
`for e.g. reducing the amount of downlink overhead in a wire
`less communication system supporting aggregation of com
`ponent carriers, by utilizing certain resources normally used
`for power control, when anticipated to carry redundant infor
`mation, for conveyance of other relevant non-redundant con
`trol information.
`According to a third aspect, a method is provided in a
`mobile terminal.
`Within the method bits related to power control of a physical
`uplink control channel are obtained from a bit field for power
`control in a message on a first physical downlink control
`channel associated with a first downlink component carrier.
`Further, when receiving assignments for resources on at least
`two downlink component carriers at the same time, other
`control information bits not related to power control are
`obtained from a bit field, corresponding to the bit field for
`power control in the message on the first physical downlink
`control channel, in a message on a second physical downlink
`control channel associated with a second one of said at least
`two downlink component carriers. The obtained other control
`information not related to power control is then used in the
`mobile terminal for locating information related to downlink
`or uplink transmissions.
`
`Samsung Exhibit 1004, Page 13
`
`

`

`US 8,472,368 B2
`
`5
`According to a forth aspect, an arrangement is provided in
`a mobile terminal. The arrangement comprises a functional
`unit adapted to determine if resources on at least two down
`link component carriers have been assigned to the mobile
`terminal at the same time. The arrangement further comprises
`a functional obtaining unit adapted to obtain bits related to
`power control, from a bit field for power control in a message
`on a first physical downlink control channel associated with a
`first downlink component carriers. The functional obtaining
`unit is further adapted to obtain, when it has been determined
`that resources on at least two downlink component carriers
`have been assigned to the mobile terminal, other control
`information bits not related to power control from a bit field,
`corresponding to the bitfield for power control in the message
`on the first physical downlink control channel, in a message
`on a second physical downlink control channel associated
`with a second one of said at least two downlink component
`carriers. The arrangement further comprises a functional unit,
`adapted to use said obtained other control information not
`related to power control for locating information related to
`downlink or uplink transmissions.
`The method and arrangement according to the third and
`fourth aspect may be used for supporting the reduction of
`downlink overhead in a wireless communication system sup
`porting aggregation of component carriers, by interpreting
`information allocated in certain resources, which normally
`are used for power control, as other relevant non-redundant
`control information in certain situations.
`The above methods and arrangements may be imple
`mented in different embodiments. The control information
`bits not related to power control could be indicators to
`PUCCH or PUSCH resources; extensions of the resource
`assignment; or extension to other parameters that do not exist
`or are smaller in the message format used on the PDCCH
`35
`conveying the bits related to power control. The identity of the
`PDCCH conveying the true TPC command is then deter
`mined in the mobile terminal in a corresponding way.
`The identity of the physical downlink control channel
`which is to convey the bits related to power control could be
`configured or determined according to e.g. a set of rules. This
`identity could be explicitly or implicitly signaled from a
`network node to a mobile terminal.
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`6
`FIG. 9 is a flow chart illustrating procedure steps executed
`in a network node, according to an embodiment.
`FIG. 10 is a block diagram illustrating an embodiment of
`an arrangement in a network node, according to an embodi
`ment.
`FIG. 11 is a flow chart illustrating procedure steps executed
`in a mobile terminal, according to an embodiment.
`FIG. 12 is a block diagram illustrating an embodiment of
`an arrangement in a mobile terminal, according to an embodi
`ment.
`FIG. 13 is a flow chart illustrating procedure steps executed
`in a network node, according to an embodiment.
`FIG. 14 is a block diagram illustrating an embodiment of
`an arrangement in a network node, according to an embodi
`ment.
`
`DETAILED DESCRIPTION
`
`Briefly described, methods and arrangements are provided
`for utilizing certain unexpected resources, when anticipated
`to carry redundant information, for conveyance of other rel
`evant non-redundant control information.
`Within this document, some expressions will be used when
`discussing the procedure of utilizing certain available
`resources, some of which will be briefly defined here.
`A certain bit field in the control signalling will be dis
`cussed, which may be referred to as the “former TPC bit
`field”, the “bit field normally used for power control”, the
`“available former TPC bit field”, the “available legacy TPC
`bit field”, etc. In e.g. LTE Release-8, this bit field is used for
`conveying a TPC command in a DCI message, i.e. the bit field
`where a legacy terminal would expect to find a TPC com
`mand. In e.g. LTE-Advanced, this bit field could be used to
`convey other relevant information in certain situations, which
`will be explained in more detail later.
`The bit field described above comprises certain bits, which
`may be referred to as the “available TPC bits” or the “former
`TPC bits”, when used for conveying other relevant informa
`tion than power control commands.
`The term “other relevant information”, refers to “control
`information other than power control commands”, and may
`also be denoted “control information not related to power
`control” or “non-redundant control information”. The term
`“non-redundant control information” is used to distinguish
`the information from the redundant power control com
`mands, which would otherwise be conveyed in the bit field
`described above.
`The term “legacy”, used for example in expressions like
`“legacy terminals”, is used as referring to entities which oper
`ate according to a previously released version of a certain
`standard or protocol, such as for example Release-8 of LTE.
`The term “LTE-Advanced” used in expressions like “LTE
`Advanced terminal” is here used as referring to entities which
`operate according to a more recent version of a standard or
`protocol, such as for example Release-10 of LTE.
`When a UE is assigned one component carrier, a control
`message on the PDCCH of the component carrier will com
`prise a transmission power command (TPC), which controls
`the transmit power of the PUCCH, which is to carry the
`feedback to e.g. how the downlink information is received.
`A valuable insight is that when multiple component carri
`ers are being simultaneously assigned to a UE, each of the
`PDCCHs associated with the respective component carriers
`will carry a control message comprising the bit field used for
`TPC commands. If the feedback related to the different com
`ponent carriers are to be transmitted on different physical
`uplink control channels, it is adequate for each PDCCH asso
`
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`BRIEF DESCRIPTION OF THE DRAWINGS
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`The invention will now be described in more detail by
`means of exemplary embodiments and with reference to the
`accompanying drawings, in which:
`FIG. 1 is a schematic view illustrating an LTE time-fre
`quency grid, according to the prior art.
`FIG. 2 is a schematic view illustrating an LTE radio frame,
`according to the prior art.
`FIG. 3 is a schematic view illustrating the location of
`certain downlink channels in LTE, according to the prior art.
`55
`FIG. 4 is a schematic view illustrating a downlink LTE
`subframe, according to the prior art.
`FIG. 5 is a schematic view illustrating a shift of a physical
`uplink control channel (PUCCH) in LTE, according to the
`prior art.
`FIG. 6 is a schematic view illustrating the location of
`different uplink channels in LTE, according to the prior art.
`FIG. 7 is a schematic view illustrating carrier aggregation,
`according to the prior art.
`FIG. 8 is a schematic view illustrating LTE carriers of
`different bandwidth and the location of control information,
`according to the prior art.
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`Samsung Exhibit 1004, Page 14
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`7
`ciated with an assigned downlink component carrier to com
`prise a TPC-command. From a UE perspective, both symmet
`ric and asymmetric uplink/downlink CC configurations are
`supported. For some of the configurations, the possibility to
`transmit the uplink control information on multiple PUCCHs
`or multiple uplink CCs may be considered. However, this
`option is likely to result in higher UE power consumption and
`a dependency on specific UE capabilities. This option may
`also create implementation issues due to inter-modulation
`products, and would lead to generally higher complexity for
`implementation and testing.
`Hence, it would be better if the transmission of PUCCH did
`not depend on the uplink/downlink CC configuration, and
`therefore, it has been agreed for LTE Release-10 to use the
`15
`design principle that all uplink control information for a UE
`should be semi-statically mapped onto one specific uplink
`CC, a so called “anchor carrier” or uplink primary component
`carrier.
`Thus, the feedback control information for all assigned
`component carriers should be transmitted over the same
`physical uplink control channel or at least on the same uplink
`component carrier. Consequently, multiple TPC-commands,
`one for each assigned CC, would effectively try to control the
`transmit power of the same physical uplink control channel or
`the same uplink component carrier. Even if different physical
`uplink control channels on the same uplink component carrier
`are used a single TPC-command would be sufficient. At the
`best, this would imply a waste of resources due to redun
`dancy, or, at the worst, lead to unpredictable behavior of a UE,
`due to conflicting TPC-commands.
`An insight of great value is thus that when multiple CCs are
`assigned to a UE, the control bits normally used for TPC
`commands related to all but one CC could be used to convey
`other relevant control information. One PDCCH would still
`need to carry the true TPC-command.
`There are several alternatives to what these freed former
`TPC-bits could be used for. For example, these bits could be
`used to signal which PUCCH or PUSCH resources that
`should be used to convey the hybrid-ARQ bits of the corre
`sponding downlink shared channel transmissions. It would
`also be possible to combine the former TPC-bits from more
`than one CC. For example, the former TPC-bits of all other
`CCs, i.e. all but the one carrying the true TPC command,
`could be combined, and together form a wider bit field. This
`45
`wider bitfield could be used for addressing one large PUCCH
`or PUSCH resource out of a somewhat larger resource pool.
`Another possibility is that some parts of the PUCCH or
`PUSCH resource addresses are explicitly signaled in there
`fore reserved bit fields, and the remaining part is signaled via
`the former TPC bit fields. Further, implicit and explicit
`PUCCH or PUSCH resource signaling could be combined,
`e.g. by that some parts of the PUCCH or PUSCH resource
`addresses are explicitly signaled and the remaining part is
`implicitly indicated via, e.g. in which CC and/or in which
`control channel elements the PDCCH of the corresponding
`DL assignment is transmitted.
`Another possibility is to use the available former TPC bit
`fields to extend reso