as) United States
`a2) Patent Application Publication 10) Pub. No.: US 2008/0304467 Al
`
`(43) Pub. Date: Dec. 11, 2008
`Papasakellariouetal.
`
`US 20080304467A1
`
`(54) CONTROL AND DATA SIGNALINGIN
`SC-FDMA COMMUNICATION SYSTEMS
`
`(75)
`
`Inventors:
`
`Aris Papasakellariou, Dallas, TX
`(US); Joon-Young Cho, Suwon-si
`(KR)
`
`Correspondence Address:
`THE FARRELL LAW FIRM,P.C.
`333 EARLE OVINGTON BOULEVARD, SUITE
`701
`UNIONDALE,NY 11553 (US)
`
`(73)
`
`Assignee:
`
`SAMSUNG ELECTRONICS
`CO., LTD., Suwon-si (KR)
`
`(21)
`
`Appl. No.:
`
`12/133,120
`
`(22)
`
`Filed:
`
`Jun. 4, 2008
`
`Related U.S. Application Data
`
`(60) Provisional application No. 60/942,843, filed on Jun.
`8, 2007.
`
`Publication Classification
`
`(51)
`
`Int. Cl.
`HO4B 7/208
`
`(2006.01)
`
`(52) US. CMe coecccccssccsssssssssssssteeseesessesssssssnsssnenes 370/344
`
`(57)
`
`ABSTRACT
`
`Apparatus and method for multiplexing control information
`bits and data information bits into sub-frame symbols
`depending on the location of symbols carrying a reference
`signal (RS), to provide an estimate for the channel medium
`and enable coherent demodulation for signals carrying infor-
`mation bits. The control information bits include ACK or
`NAKand/or channel CQIbits. The ACK/NAKbits are placed
`with priority in symbols around the symbols carrying the RS,
`to allow for improved accuracy of the channel estimate, fol-
`lowed by the CQI bits when both ACK/NAK and CQIbits
`exist. Moreover, the sub-frame resources required to achieve
`the desired reception reliability for the control information
`depend on the operating conditions and can varied to mini-
`mize the associated control overhead.
`
`Nx12 SUB-CARRIERS (150)
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`US 2008/0304467 Al
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`Dec. 11, 2008
`
`CONTROL AND DATA SIGNALING IN
`SC-FDMA COMMUNICATION SYSTEMS
`
`PRIORITY
`
`[0001] The present Application for Patent claimspriority to
`US. Provisional Application No. 60/942,843 entitled “Con-
`trol and Data Signaling in SC-FOMA Communication Sys-
`tems”filed Jun. 8, 2007, the contents ofwhich is incorporated
`by reference herein.
`
`BACKGROUND OF THE INVENTION
`
`pilot signals, which are used for several purposes including
`for providing channel estimation for coherent demodulation
`of the received signal.
`[0008] The transmission bandwidth (BW)is assumed to
`include frequency resource units, which will be referred to
`herein as resource blocks (RBs). An exemplary embodiment
`assumes that each RB includes 12 sub-carriers and UEs are
`
`allocated a multiple N of consecutive RBs 150. Nevertheless,
`the above valuesare only illustrative and notrestrictive to the
`invention.
`
`[0009] An exemplary block diagram of the transmitter
`functions for SC-FDMAsignaling is illustrated in FIG. 2.
`Coded CQI bits 205 and coded data bits 210 are multiplexed
`220. IYACK/NAKbits also need to be multiplexed, the exem-
`plary embodiment assumesthat data bits are punctured to
`accommodate ACK/NAKbits 230. Alternatively, CQIbits Gf
`any) may be punctured or different rate matching, as it is
`known in the art, may apply to data bits or CQI bits to
`accommodate ACK/NAKbits. The discrete Fourier trans-
`
`1. Field of the Invention
`[0002]
`[0003] The present invention is directed, in general, to
`wireless communication systems and, more specifically, to
`multiplexing control and data information in single-carrier
`frequency division multiple access (SC-FDMA) communica-
`tion systems.
`form (DFT) of the combineddata bits and controlbits is then
`[0004]
`2. Description of the Related Art
`obtained 240,
`the sub-carriers 250 corresponding to the
`assigned transmission bandwidth are selected 255,
`the
`[0005]
`In particular, the present invention considers the
`inverse fast Fourier transform (IFFT) is performed 260 and
`transmission of positive or negative acknowledgementbits
`finally the cyclic prefix (CP) 270 andfiltering 280 are applied
`(ACK or NAK,respectively) and channel quality indicator
`to the transmitted signal 290.
`(CQDbits together with data information bits in an SC-
`FDMA communications system and is further considered in
`[0010] Alternatively, as illustrated in FIG. 3, in order to
`the development of the 3“ Generation Partnership Project
`transmit the control (ACK/NAKand/or CQDbits 310, punc-
`(3GPP) Evolved Universal Terrestrial Radio Access
`turing of coded data bits 320 may apply 330 (instead of also
`(E-UTRA)long term evolution (LTE). The invention assumes
`applying rate matching as in FIG. 2) and certain coded data
`the uplink (UL) communication correspondingto the signal
`bits (for example, the parity bits in case of turbo coding) may
`transmission from mobile user equipments (UEs) to a serving
`be replaced by control bits. The discrete Fourier transform
`base station (Node B). A UE, also commonly referred to as a
`(DFT) 340 of the combined bits is then obtained, the sub-
`terminal or a mobilestation, may be fixed or mobile and may
`carriers 350 corresponding to the assigned transmission
`be a wireless device, a cellular phone, a personal computer
`bandwidth are selected 355 (localized mapping is assumed
`device, a wireless modem card, etc. A NodeBis generally a
`but distributed mapping mayalso be used), the inverse fast
`fixed station and mayalso be called a base transceiver system
`Fourier transform (IFFT) 360 is performed andfinally the
`(BTS), an access point, or someother terminology. The ACK/
`cyclic prefix (CP) 370 andfiltering 380 are applied to the
`NAKbits and CQI bits may also be referred to simply as
`transmitted signal 390.
`control information bits.
`[0011] This time division multiplexing (TDM)illustrated
`in FIG. 2 and FIG. 3 between control (ACK/NAK and/or
`CQI) bits and data bits prior to the DFT is necessary to
`preservethe single carrier property of the transmission. Zero
`padding, as it is knownintheart, is assumedto beinserted by
`a reference UE in sub-carriers used by another UE and in
`guard sub-carriers (not shown). Moreover, for brevity, addi-
`tional transmitter circuitry such as digital-to-analog con-
`verter, analogfilters, amplifiers, and transmitter antennas are
`notillustrated in FIG. 2 and FIG. 3. Similarly, the encoding
`process for the data bits and the CQI bits, as well as the
`modulation process forall transmittedbits, are well known in
`the art and are omitted forbrevity.
`[0012] At the receiver, the inverse (complementary) trans-
`mitter operations are performed. This is conceptually illus-
`trated in FIG. 4 where the reverse operations of those illus-
`trated in FIG. 2 are performed. Asit is knownin the art (not
`shown for brevity), an antenna receives the radio-frequency
`(RF) analog signal andafter further processing units (such as
`filters, amplifiers, frequency down-converters, and analog-to-
`digital converters) the digital received signal 410 passes
`through a time windowing unit 420 and the CP is removed
`430. Subsequently, the receiver unit applies an FFT 440,
`selects 445 the sub-carriers 450 used by the transmitter,
`applies an inverse DFT (IDFT) 460, extracts the ACK/NAK
`bits and places respective erasures for the data bits 470, and
`
`[0006] The ACK or NAKbitsare in responseto the correct
`or incorrect, respectively, data packet reception in the down-
`link (DL) of the communication system, which corresponds
`to signal transmission from the serving Node B to a UE. The
`CQI transmitted from a reference UE is intended to inform the
`serving Node B of the channel conditions the UE experiences
`for signal reception, enabling the Node B to perform channel-
`dependent scheduling of DL data packets. Either or both of
`the ACK/NAK and CQI may betransmitted by a UE in the
`same transmission time interval (TTI) with data or in a sepa-
`rate TTI with no data. The disclosed invention considers the
`
`former case, which mayalso be referred to as data-associated
`transmission of the ACK/NAKand/or CQI.
`[0007] The UEs are assumed to transmit control and data
`bits over a TTI corresponding to a sub-frame. FIG. 1 illus-
`trates a block diagram of the sub-frame structure 110
`assumed in the exemplary embodiment of the disclosed
`invention. The sub-frame includes two slots. Each slot 120
`further includes seven symbols and each symbol 130 further
`includes of a cyclic prefix (CP) for mitigating interference
`due to channel propagation effects, as it is knownin theart.
`The signal transmission in the two slots may be in the same
`part or it may be at two different parts of the operating band-
`width. Furthermore, the middle symbol in each slot carries
`the transmission ofreference signals (RS) 140, also known as
`
`

`

`US 2008/0304467 Al
`
`Dec. 11, 2008
`
`
`de-multiplexes 480 the data bits 490 and CQIbits 495. As for FIG. 11sablock diagram illustrating an exemplary[0023]
`
`the transmitter, well known in the art receiver functionalities
`sub-frame structure for the SC-FDMA communication sys-
`tem;
`such as channel estimation, demodulation, and decoding are
`FIG. 2isablock diagram illustrative ofa first exem-
`not shownfor brevity and they are not material to the present
`[0024]
`invention.
`plary SC-FDMA transmitter for multiplexing data bits, CQI
`bits, and ACK/NAKbits in a transmission sub-frame;
`[0025]
`FIG. 3 is another block diagram illustrative of a
`second exemplary SC-FDMA transmitter or multiplexing
`data bits, CQI bits, and ACK/NAK bits in a transmission
`sub-frame;
`[0026]
`FIG. 4 is a block diagram illustrative of an exem-
`plary SC-FDMA receiver, corresponding to the first exem-
`plary SC-FDMA transmitter, for de-multiplexing data bits,
`CQIbits, and ACK/NAKbits in a reception sub-frame;
`[0027]
`FIG. 5 presents un-codedbit error rate (BER)results
`as a function of the symbol number (symbolposition) in the
`sub-frameslot and the UE velocity;
`[0028]
`FIG. 61s a block diagram illustrating a first method
`for the selection of the sub-frame symbols carrying the trans-
`mission of CQ] bits and ACK/NAKbits;
`[0029]
`FIG. 7 is a block diagram illustrating a first method
`for the selection of the sub-frame symbols carrying the trans-
`mission of ACK/NAKbits;
`[0030]
`FIG. 8 is a block diagram illustrating a first method
`for the selection of the sub-frame symbols carrying the trans-
`mission of CQ]bits;
`[0031]
`FIG. 9 is a block diagram illustrating a second
`method for the selection of the sub-frame symbols carrying
`the transmission of ACK/NAK bits with reduced overhead;
`and
`
`[0013] The control bits typically require better reception
`reliability than the data bits. This is primarily because hybrid-
`automatic-repeat-request (HARQ) usually applies to data
`transmission but not to control transmission. Additionally,
`ACK/NAKbits typically require better reception reliability
`that CQI bits as erroneous reception of ACK/NAK bits has
`more detrimental consequences to the overall quality and
`efficiency of communication than does erroneous reception
`for the CQIbits.
`[0014] The size of resources in a transmission sub-frame
`required for control signaling for a given desired reception
`reliability depend on the channel conditions the signal trans-
`mission from a UE experiences and in particular, on the
`signal-to-interference and noise ratio (SINR)ofthe received
`signal at the serving Node B.
`[0015] There is a need to determine the placement of con-
`trol bits when transmitted in the same sub-frame withdata bits
`
`so that better reception reliability is provided for the control
`bits than for the data bits.
`
`[0016] There is another need to determine the placementof
`acknowledgementbits relative to channel quality indication
`bits, in case they are simultaneously multiplexed, in order to
`provide better reception reliability for the former.
`[0017] There is another need to dimension the resources
`required for the transmission of acknowledgementbits, in a
`sub-frame also containing data bits, as a function ofthe chan-
`nel conditions experiencedby the signal transmission from a
`UE.
`
`SUMMARY OF THE INVENTION
`
`invention has been
`the present
`[0018] Accordingly,
`designed to solve the above-mentioned problems occurring in
`the prior art, and embodiments of the invention provide an
`apparatus and a method for allocating resources in a sub-
`frame for the transmission of control bits and data bits.
`
`In accordance with an embodimentofthe present
`[0019]
`invention, provided are an apparatus and method for the
`placementof signals carrying the control bits and data bits in
`transmission symbols relative to the symbols used for trans-
`mission of reference signals in order to enable better recep-
`tion reliability of the controlbits.
`[0020] Another embodiment of the present invention pro-
`vides an apparatus and methodfor the placement of acknow]-
`edgementbits with higher priority than channel quality indi-
`cation bits to enable better reception reliability of the
`acknowledgementbits.
`[0021] Another embodiment of the present invention pro-
`vides an apparatus and method for dimensioning and placing
`acknowledgementbits in a sub-frame accordingto the corre-
`sponding resources needed to achieve desired receptionreli-
`ability.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0022] The above and other aspects, features, and advan-
`tages of the present invention will be more apparent from the
`following detailed description taken in conjunction with the
`accompanying drawings, in which:
`
`FIG. 10 is a block diagram illustrating a second
`[0032]
`method for the selection of the sub-frame symbols carrying
`the transmission CQIbits and ACK/NAKbits.
`
`DETAILED DESCRIPTION OF THE
`EXEMPLARY EMBODIMENTS
`
`[0033] The present invention now will be described more
`fully hereinafter with reference to the accompanying draw-
`ings. This invention may, however, be embodied in many
`different forms and should not be construedas limited to the
`embodimentsset forth herein. Rather, these embodiments are
`provided so that this disclosure will be thorough and com-
`plete, and will fully convey the scope ofthe invention to those
`skilled in the art.
`
`[0034] Additionally, although the invention assumes a
`single-carrier
`frequency division multiple access
`(SC-
`FDMA) communication system, it also applies to all FDM
`systems in general and to OFDMA, OFDM, FDMA, DFT-
`spread OFDM, DFT-spread OFDMA,|
`single-carrier
`OFDMA (SC-OFDMA), and single-carrier OFDM in par-
`ticular.
`
`[0035] Basically, the system and methods of the embodi-
`ments of the present invention solve problemsrelated to the
`need for providing the desired reliability for the reception of
`control signaling under indicative transmission sub-frame
`structures and provide additional advantages such as the
`reduction ofresource overheadfor the transmission ofcontrol
`signals.
`[0036] A first observation for the sub-framestructure illus-
`trated in FIG.1 is that the reference signal (RS)exists only in
`the middle symbolof eachslot. In case of a mobile terminal,
`or user equipment (UE), with high speed, this can substan-
`tially degraded channel estimation for symbols located fur-
`ther away from the RS(that is, for symbols near the beginning
`
`

`

`US 2008/0304467 Al
`
`Dec. 11, 2008
`
`and endof each slot) due to the faster variation of the channel
`medium as the UE velocity increases. This may be acceptable
`for data transmission that is coded, which has typically a
`relatively large target block error rate (BLER), such as 10% or
`above, and can benefit from retransmissions though a con-
`ventional HARQ process. Conversely, the CQI and particu-
`larly the ACK/NAKhave muchstricter performance require-
`ments, HARQtypically does not apply to the corresponding
`transmissions, and providing an accurate channel estimate is
`essential in achieving the desired reception reliability.
`[0037] A brief set of simulation results for the un-coded
`(raw) bit error rate (BER) is provided toillustrate the impact
`of inaccurate channel estimation on the reception quality as a
`function of the symbolposition in the slot and the UE speed.
`Table I provides the simulation setup under optimistic condi-
`tions for the performance loss due to imperfect channelesti-
`mation at symbols further away from the RSforthe following
`reasons:
`
`[0038] Transmission bandwidth is 1 RB. This maximizes
`powerper sub-carrier.
`[0039] Channel frequency selectivity is large and there
`are 2 uncorrelated Node B receiver antennas. This maxi-
`
`mizes the slope of the un-coded (raw) BER curve and
`minimizes the relative performance loss due to imper-
`fect channel estimation for a target BER value.
`[0040] Operating signal-to-interference and noise ratio
`(SINR)is large. This minimizes the impact of inaccurate
`channelestimation.
`
`TABLE 1
`
`Simulation Assumptions
`
`Assumptions
`
`5 MHz @ 2.6 GHz
`
`Quadrature Phase Shift Keying (QPSK)
`1RB
`
`3, 30, 120 and 350 Kilometers per hour
`(Kmph)
`Localized (at same RB) over the sub-
`frame at 3, 30 Kmph
`Frequency Hopping Between Slots at 120
`and 350 Kmph
`GSM-Terrestrial-Urban with 6 paths
`(TU6)
`2
`
`1
`
`Parameters
`
`Operating Bandwidth @
`Carrier Frequency
`Modulation Scheme
`Data Transmission
`Bandwidth (BW)
`UESpeed
`
`Transmission Type
`
`Channel Model
`Numberof Node B Receiver
`Antennas
`Numberof UE Transmitter
`Antennas
`
`[0041] FIG.5 presents the un-coded BER. At symbolloca-
`tions symmetric to the RS, the BERis typically the same. At
`120 Kmphand 350 Kmph,the transmission in thefirst slot is
`assumedto occur at a different BW than the one in the second
`
`slot (frequency hopped transmission perslot). As only 1 RS
`per slot is available for channel estimation, the BER is the
`same at symbols symmetric (equidistant) to the RS. At low
`speeds, such as 3 Kmph,this is also the case because the
`channel does not change over the sub-frame duration. Some
`small variability does exist for medium UEspeeds, such as 30
`Kmph,but, for simplicity, the average BER of symbols equi-
`distant to the RS is only shown.
`[0042] Even under the previous optimistic assumptions for
`the un-coded (raw) BER degradation due to degraded channel
`estimation at symbols further away from the RS, at 350 Kmph
`
`the BERsaturatesat the 1°/7” and 2”“/6” symbols. However,
`the impact on the BER ofthe 3’“/5” symbols is rather con-
`tained andsaturation is avoided(the difference relative to the
`BERat 3 Kmphis also partly dueto thefactthat the latter uses
`both RS in the sub-framefor channel estimation which there-
`fore effectively operates with twice as much SINR). The BER
`at 120 Kmph is also degraded by about 3 dB for the 1°/7”
`symbols and by about 1.5 dB for the 2”“/6” symbolsrelative
`to the one of the 3’%/5” symbols at about the 1% point.
`Obviously, due to the flattening of the BER curves for the
`1/7” and 2”4/6” symbols, the degradation will be much
`larger for BER operating points below 1% as it is typically
`needed for the NAK reception.
`[0043] Based on the results in FIG. 5 it becomes apparent
`that the control transmission should be placed with priority
`immediately next to the RS.
`[0044]
`FIG.6 illustrates such a placement when a UEtrans-
`mits both ACK/NAKbits 610 and CQIbits 620 during a
`sub-frame. These control bits are placed on symbols next to
`the RS 630 while the data bits 640 are included in symbols
`transmitted over the entire sub-frame (with the obvious
`exception of the symbols carrying the RS transmission). Due
`to the requirement for better reception reliability, the ACK/
`NAKbits are placed closer to the RS than the CQ]bits.
`[0045]
`FIG.7 illustrates the case in which the UE transmits
`only ACK/NAKbits 710 together with data bits 720 during a
`sub-frame. The ACK/NAKbits are placed at the two symbols
`next to the RS 730 in each ofthe two sub-frameslots while the
`
`data bits are included in symbols transmitted over the entire
`sub-frame.
`
`FIG. 8 illustrates the case in which the UE transmits
`[0046]
`only CQIbits 810 together with data bits 820 during a sub-
`frame. The CQIbits are placed at the two symbols nextto the
`RS 830 in each of the two sub-frame slots while the data bits
`
`are included in symbols transmitted over the entire sub-
`frame.
`
`To minimize channel estimation losses, the ACK/
`[0047]
`NAKbits should be placed with priority in the symbol after
`the first symbol carrying the RS. This does not impact
`demodulation latency as a channel estimate is available only
`after this first RS symbol. To address low SINR or coverage
`issues, the ACK/NAKbits can also be placed in the symbol
`before the second RS. For medium UEspeeds, this second
`placement ofACK/NAKbits benefits from improved channel
`estimation and time diversity while for high UE speeds, it
`benefits from frequency and timediversity. This is illustrated
`in FIG. 9 where the ACK/NAKbits 910 are placedin only one
`symbol next to the RS 920 in each slot, these two symbols
`(one in each slot) are located between the two RS, while the
`data bits 930 are transmitted throughout the sub-frame (with
`the obvious exception of the symbols carrying the RS).
`[0048]
`Provisioning for the transmission ofACK/NAKbits
`in the sub-carriers over 2 symbols is typically adequate to
`achieve the desired BER for the ACK reception. Neverthe-
`less, because the NAK reception has typically a lower BER
`target, it is appropriate to have the ACK/NAKtransmission
`over the number of sub-carriers in 1 symbolin each slot. If
`further ACK/NAKtransmissions are needed, because of low
`SINRorcoverageissues, the other symbols next to the RS in
`the 2 slots may also be usedas illustrated in FIG. 6 and FIG.
`7.
`
`[0049] Depending on the numberof information bits car-
`ried in the CQI reporting, which are typically several times
`more than the ACK/NAK information bits,
`the symbols
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`immediately adjacent to the RS may notsuffice for the CQI
`transmission, especially for coverage or SINR limited UEs
`that are also typically assigned small bandwidth allocations (a
`small number of RBs). In such cases, the CQI transmission
`mayalso extend to one or more symbols that are adjacent to
`the symbols also carrying CQI information that are adjacent
`to the symbols carrying the RS. An exemplary embodiment of
`this principle is illustrated in FIG. 10. As previously dis-
`cussed, the location of the ACK/NAKbits 1010 remains in
`symbols next to the RS 1030 but the CQ]bits 1020 are located
`in symbols throughoutthe transmission sub-frame, similarly
`to the data symbols 1040.
`[0050] While the present invention has been shown and
`described with reference to certain exemplary embodiments
`thereof, it will be understood by those skilled in the art that
`various changes in form and details may be made therein
`without departing from thespirit and scope ofthe invention as
`defined by the appended claims.
`Whatis claimed is:
`
`1. An apparatus for forming a signal in a communication
`system,
`the signal being transmitted over a time period
`including a plurality of symbols with at least one symbol of
`the plurality of symbols carrying a reference signal and
`remaining symbols of the plurality of symbols carrying an
`information signal, the information signal includingat least
`control information bits and data informationbits, said appa-
`ratus comprising:
`a mapping unit for placingat least one of the controlbits in
`at least one of the remaining symbols located only next
`to the at least one symbolcarrying the reference signal,
`for placing at least one of the data informationbits in at
`least one of the remaining symbols not located next to
`the at least one symbol of the symbols carrying the
`reference signal; and
`a transmitter unit for transmitting during the at least one of
`the plurality of symbols carrying the reference signal
`and transmitting during the remaining symbols of said
`the plurality of symbols carrying the information signal.
`2. The apparatus as in claim 1, wherein the control infor-
`mation bits comprise acknowledgementbits.
`3. The apparatus as in claim 1, wherein the control infor-
`mation bits comprise channel quality indicationbits.
`4. The apparatusas in claim 1, wherein the communication
`system comprises a single-carrier frequency division mul-
`tiple access (SC-FDMA) communication system and the
`transmitter uses the SC-FDMAtransmission method.
`
`5. An apparatus for forming a signal in a communication
`system,
`the signal being transmitted over a time period
`including a plurality of symbols with at least one symbol of
`the plurality of symbols carrying a reference signal and
`remaining symbols of the plurality of symbols carrying an
`information signal,
`the
`information signal
`including
`acknowledgement bits, channel quality indication bits, and
`data informationbits, the apparatus comprising:
`a mapping unit for placing at least one ofthe acknowledge-
`ment bits in at least one of the remaining symbols
`located only nextto the at least one symbolcarrying the
`reference signal, for placing at least one of the channel
`quality indication bits in at least one of the remaining
`symbols not located nextto the at least one symbolofthe
`symbols carrying the reference signal, and for placing at
`least one ofthe data information bits in at least one ofthe
`remaining symbols not located next to the at least one
`symbolofthe symbols carrying the reference signal; and
`
`a transmitter unit for transmitting during the at least one of
`the plurality of symbols carrying the reference signal
`and transmitting during the remaining symbols of the
`plurality of symbols carrying the information signal.
`6. The apparatus as in claim 5, wherein the communication
`system comprises a single-carrier frequency division mul-
`tiple access (SC-FDMA) communication system and the
`transmitter uses the SC-FDMAtransmission method.
`
`7. An apparatus for forming a signal in a communication
`system,
`the signal being transmitted over a time period
`including a plurality of symbols with at least two symbols of
`the plurality of symbols carrying a reference signal and
`remaining symbols of the plurality of symbols carrying an
`information signal,
`the
`information signal
`including
`acknowledgementbits and data bits, the apparatus compris-
`ing:
`a mapping unit for placing the acknowledgementbits only
`at a symbolafter a first of the at least two symbols
`carrying the reference signal and only at a symbolbefore
`a last of the at least two symbols carrying the reference
`signal, and for placing the data bits in at least one of the
`remaining symbols not located next to the at least two
`symbols carrying the reference signal; and
`a transmitter unit for transmitting during the at least two
`symbols carrying the reference signal and transmitting
`during the remaining symbols carrying the information
`signal.
`8. The apparatusas in claim 7, wherein the communication
`system comprises a single-carrier frequency division mul-
`tiple access (SC-FDMA) communication system and the
`transmitter uses the SC-FDMAtransmission method.
`
`9. An apparatus for forming a signal in a user equipment,
`the signal being transmitted over a time period in a channel
`medium,the time period including a plurality of symbols with
`at least one symbol ofthe plurality of symbols carrying an
`information signal,
`the
`information signal
`including
`acknowledgementbits and data bits, the apparatus compris-
`ing:
`a mapping unit for placing the acknowledgementbits in a
`first set of resources when the user equipment operates
`in first channel medium conditions, and for placing the
`acknowledgementbits in a second set ofresources when
`the user equipmentoperates in second channel medium
`conditions; and
`a transmitter unit for transmitting during the at least one
`symbolcarrying the information signal.
`10. The apparatus as in claim 9, wherein the channel
`medium conditions correspond to a signal-to-interference
`and noise ratio (SINR).
`11. The apparatus as in claim 9, wherein the communica-
`tion system comprises a single-carrier frequency division
`multiple access (SC-FDMA) communication system and the
`transmitter uses the SC-FDMAtransmission method.
`
`12. An apparatus for forming a signal in a communication
`system, the apparatus comprising:
`a transmitter for transmitting a reference signal overat least
`one symbol having a transmission period; and
`a mapper for mapping acknowledgementbits for transmis-
`sion only to symbols around adjacentto the at least one
`symbolfor reference signal transmission, and for map-
`ping data information bits for transmission overat least
`one symbol not adjacentto the at least one symbolfor the
`reference signal transmission.
`
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`US 2008/0304467 Al
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`Dec. 11, 2008
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`13. The apparatus as in claim 12, wherein the transmitter
`comprises a single-carrier frequency division multiple access
`(SC-FDMA)transmitter.
`14. The apparatus as in claim 12, wherein the mapper
`further maps channel quality indication bits for transmission
`over at least one symbol not adjacent to the at least one
`symbolfor the reference signal transmission.
`15. An apparatus for forming a signal in a communication
`system, the apparatus comprising:
`areceiver for receiving a reference signal overat least one
`symbolperiod having a reception period; and
`a de-mapper
`for de-mapping acknowledgement bits
`located only in symbols around adjacent to the at least
`one symbol for reference signal reception and for de-
`mapping data information bits located over at least one
`symbol not adjacent to the at least one symbol for the
`reference signal reception.
`16. The apparatus as in claim 15, wherein the receiver
`comprises a single-carrier frequency division multiple access
`(SC-FDMA)receiver.
`17. The apparatus as in claim 15, wherein the de-mapper
`further de-maps channel quality indicationbits located overat
`least one symbol]not adjacentto the at least one symbolfor the
`reference signal reception.
`18. A method for forming a signal in a communication
`system,
`the signal being transmitted over a time period
`including a plurality of symbols with at least one symbol of
`the plurality of symbols carrying a reference signal and
`remaining symbols of the plurality of symbols carrying an
`information signal, the information signal including control
`information bits and data information bits, the method com-
`prising:
`mapping at least one of the control information bits in at
`least one of the remaining symbols located only next to
`the at least one symbolcarrying the reference signal;
`mapping atleast one of the data information bits in at least
`one of the remaining symbols not located next to the at
`least one symbolof the symbols carrying the reference
`signal;
`transmitting the at least one of the plurality of symbols
`carrying the reference signal; and
`transmitting the remaining symbolsofthe plurality of sym-
`bols carrying the information signal.
`19. The method as in claim 18, the control information bits
`include acknowledgementbits.
`20. The method as in claim 18, wherein the control infor-
`mation bits include channel quality indicationbits.
`21. The methodas in claim 18, wherein the commun