(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2005/0003782 A1
`
` Wintzell (43) Pub. Date: Jan. 6, 2005
`
`
`US 20050003782A1
`
`(54) METHODS AND APPARATUS FOR
`CHANNEL QUALITY INDICATOR
`DETERMINATION
`
`(76)
`
`Inventor: Ola Wintzell, Sodra Sandby (SE)
`
`Correspondence Address:
`BURNS, DOANE, SWECKER & MATHIS,
`L.L.P.
`HO. Box 1404
`Alexandria VA 22313_1404 (US)
`’
`
`(21) Appl. No.:
`
`10/455,351
`
`(22)
`
`Filed:
`
`Jun. 6, 2003
`
`Publication Classification
`
`(51)
`
`Int. Cl.7 ..................................................... H04B 17/00
`
`(52) US. Cl.
`
`.................... 455/226.3; 455/226.1; 455/135
`
`(57)
`
`ABSTRACT
`
`A channel quality indicator value is determined on a per
`transport block basis. Asignal-to-interference ratio estimate
`of a control channel and a channel quality estimate of
`user-data channel are employed in the determination of the
`channel quality indicator. The channel quality estimate of
`the user-data channel can include information about Auto-
`
`matic Retransmission Request (ARQ) processing, and the
`number of iterations of a Turbo decoder. Additionally,
`information about the Cyclic Redundancy Check (CRC),
`which is determined on a per transport block basis, can be
`employed in the channel quality indicator determination.
`The determined channel quality indicator is reported to the
`radio communication system.
`
`Measure First Quality Value of a‘First
`Wireless Channel
`
`Report Channel Quality Indicator
`
`Determine Second Quality Value of a
`Second Wireless Channel On a Per
`
`Transport Block Basis‘
`
`Determine Channel Quality Indicator
`(,CQI)
`
`SAMSUNG 1008
`
`SAMSUNG 1008
`
`1
`
`

`

`Patent Application Publication
`
`Jan. 6, 2005 Sheet 1 0f 3
`
`US 2005/0003782 A1
`
`‘ PRIOR ART
`
`H0
`
`Iv
`Channel and SIR Estimate
`
`11°
`
`
`
`HO
`
`r’ .
`Turbo Decoder
`
`
`
`)5‘0
`
`
`
`
`160
`
`
`
`Code Decision Processor
`
`CRC Evaluator
`
`Figure 1A
`
`
`
`Figure 1B
`
`2
`
`

`

`Patent Application Publication
`
`Jan. 6, 2005 Sheet 2 of 3
`
`US 2005/0003782 A1
`
`Wireless Channel
`
` . Measure First Quality Value of a First
`
`
`
`
`Determine Second Quality Value of a
`Second Wireless Channel On a Per
`Transport Block Basis
`
`110
`
`0
`
`11
`
`
`Determine Channel Quality Indicator
`(COD
`
`
`1 0
`3
`
`Report Channel Quality Indicator
`
`'2 H 0
`
`Figure 2
`
`:Signal—to-InterferenceRatlo '
`
`
`
`'. ChalmelQuahtyIndicator
`
`CQI0
`cor]
`
`
`
`
`
`
`
`
`
`—§_
`
`
`CQI4
`
`
`
`Figure 3A
`
`3
`
`

`

`Patent Application Publication
`
`Jan. 6, 2005 Sheet 3 0f 3
`
`US 2005/0003782 A1
`
`_____—________________.._———————-———
`
`SIR
`HARQ Info
`Turbo Decoder Info
`V
`CQI
`
`
`511%
`
`HARQo
`
`me
`TD.
`TDz
`
`.
`
`(3010
`CQll
`CQI2
`
`CQIN
`»
`TD’,
`____________—.__—__———
`
`HARQ,
`
`TDD
`TD.
`TDz
`
`TD,
`
`
`CQID
`CQIW
`CQIM
`
`CQIZM
`
`_________—______—_____.—__———
`
`HARQ“
`
`'
`
`TD0
`m
`TD:
`
`Cle
`CQIW
`CQan+z
`
`CQI(..'.+W1
`TDp
`___—________.__—________——————
`
`SIR.
`
`HARQD
`
`TDo ‘
`TD.
`TD:
`
`CQLW
`CQImu)pH
`CQImupu
`
`CQqu+2)p-l
`TDP
`___________—_______._._————
`
`HARQ1 ,
`’
`
`TDO
`TDI
`TD:
`
`CQIunn»
`. CQIm-mpu
`CQI(m+1)p+l
`
`113,.
`
`
`CQ[(m+3)p
`
`
`
`HARQ.“
`
`TDu
`TD]
`TD:
`
`CQIamm,
`CQIamHmH
`CQIamnpn
`
`TDp
`CQI‘mnm
`
`
`SIRz
`
`HARQ“
`
`TDu
`TD]
`TD:
`
`CQIgmzyp
`CQI(Zm+Z)p+l
`CQIammpu
`
`TDD
`‘
`CQI(ZIT|+3)P—|
`
`
`HARQ:
`
`TDo
`TD!
`TD:
`
`TDP
`
`
`CQIama»
`CQIam+Jyp+l
`CQImn+3)p+1
`
`CQIQnH-‘w-l
`
`Figure 3B
`
`4
`
`

`

`US 2005/0003782 A1
`
`Jan. 6, 2005
`
`METHODS AND APPARATUS FOR CHANNEL
`QUALITY INDICATOR DETERMINATION
`
`BACKGROUND
`
`[0001] The invention relates to the determination of chan-
`nel quality in communication systems, and more particularly
`to a determination of a channel quality indicator in a radio
`communications network.
`
`[0002] As the popularity of communication in radio com-
`munications networks continues to grow,
`there has been
`increased interest in providing packet data communications
`in radio communications networks. High-Speed Downlink
`Packet Access (HSDPA) is a service which is currently being
`developed for providing packet data communications in
`radio communications networks.
`
`[0003] Due to the differences between voice communica-
`tions and packet data communications, the design of these
`systems can be quite different. For example, since voice
`communications in radio communications networks are
`
`treated as a single stream of information, a single channel is
`typically reserved for each voice communication. In con-
`trast, packet data communications can be discontinuous, and
`hence, many packet data communications can share access
`to a single channel.
`
`the HSDPA service provides for
`[0004] Accordingly,
`adaptive modulation in the downlink, i.e., the channel from
`the communication network to a radio receiver. Specifically,
`the transport format, (i.e., the channel coding and modula-
`tion),
`that
`is to be used for transmission by the radio
`communications network is determined for each transmitted
`
`packet. The choice of transport format selected by the radio
`communications network is based upon a Channel Quality
`Indicator (CQI) value reported by a radio receiver. The
`transport format may also be based on the received power
`control commands or on other information that can be
`
`estimated by the base station, e.g., power and quality of the
`data symbols on the uplink.
`
`[0005] The determination of the CQI is based on two
`components. The first component is likely to be based on a
`signal-to-interference ratio (SIR) measurement of a pilot
`channel. The second component of the CQI determination
`requires that the determined CQI result in a transport block
`error probability which is approximately 10 percent, without
`exceeding 10 percent. Therefore, it would be desirable to
`provide methods and apparatus for determining a particular
`CQI value which will result
`in a transport block error
`probability which is approximately 10 percent, without
`exceeding 10 percent.
`
`SUMMARY
`
`It should be emphasized that the terms “comprises”
`[0006]
`and “comprising”, when used in this specification, are taken
`to specify the presence of stated features, integers, steps or
`components; but the use of these terms does not preclude the
`presence or addition of one or more other features, integers,
`steps, components or groups thereof.
`
`In accordance with one aspect of the present inven-
`[0007]
`tion, a channel quality indicator is determined on a per
`transport block basis. Specifically, a channel quality value of
`a pilot channel and a channel quality value of a user-data
`channel are employed in the determination of the channel
`
`quality indicator. The channel quality value of the user-data
`channel can be determined based on Hybrid Automatic
`Retransmission (HARQ) processing and/or Turbo decoder
`processing. The channel quality value of the user-data
`channel can also be determined based on Cyclic Redun-
`dancy Check (CRC) processing, or based on a combination
`of HARQ, Turbo decoder and CRC processing.
`
`In accordance with another aspect of the present
`[0008]
`invention, the channel quality indicator is determined. Afirst
`channel quality value is based on a channel quality of a pilot
`channel, a second channel quality value is based on a
`channel quality of a user-data channel, and a third channel
`quality value is determined based on a transport block
`integrity check. The first and second channel quality values
`are employed in the determination of the channel quality
`indicator. The third channel quality value can also be
`employed in the determination of the channel quality indi-
`cator.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0009] The objects and advantages of the invention will be
`understood by reading the following detailed description in
`conjunction with the drawings in which:
`
`[0010] FIG. 1A is a block diagram of a conventional
`receiver.
`
`[0011] FIG. 1B is a block diagram of a receiver in
`accordance with one embodiment of the present invention.
`
`[0012] FIG. 2 is a flow diagram of the Channel Quality
`Indicator
`(CQI) determination in accordance with the
`present invention.
`
`[0013] FIG. 3A is an exemplary table used in the CQI
`determination in accordance with an embodiment of the
`
`present invention.
`
`[0014] FIG. 3B is a portion of an exemplary table used in
`the CQI determination in accordance with another embodi-
`ment of the present invention.
`
`DETAILED DESCRIPTION
`
`[0015] The various features of the invention will now be
`described with reference to the figures, in which like parts
`are identified with the same reference characters.
`
`[0016] The various aspects of the invention will now be
`described in greater detail in connection with a number of
`exemplary embodiments. To facilitate an understanding of
`the invention, many aspects of the invention are described in
`terms of sequences of actions to be performed by elements
`of a computer system. It will be recognized that in each of
`the embodiments, the various actions could be performed by
`specialized circuits (e.g., discrete logic gates interconnected
`to perform a specialized function), by program instructions
`being executed by one or more processors, or by a combi-
`nation of both. Moreover, the invention can additionally be
`considered to be embodied entirely within any form of
`computer readable carrier, such as solid-state memory, mag-
`netic disk, optical disk or carrier wave (such as radio
`frequency, audio frequency or optical frequency carrier
`waves) containing an appropriate set of computer instruc-
`tions that would cause a processor to carry out the tech-
`niques described herein. Thus, the various aspects of the
`invention may be embodied in many different forms, and all
`
`5
`
`

`

`US 2005/0003782 A1
`
`Jan. 6, 2005
`
`such forms are contemplated to be within the scope of the
`invention. For each of the various aspects of the invention,
`any such form of embodiments may be referred to herein as
`“logic configured to” perform a described action, or alter-
`natively as “logic that” performs a described action.
`
`[0017] FIG. 1A is a block diagram of a conventional
`receiver. As illustrated in FIG. 1A the receiver receives and
`
`processes a pilot signal and code symbols. The pilot signal
`is received on a first channel, for example, a control channel.
`The code symbols are transmitted in user-data packets,
`which are referred to in the art as transport blocks. Process-
`ing block 110 uses the pilot signal to perform a channel and
`SIR estimation. The channel and SIR estimates are provided
`to CQI determination block 120 for use as the first compo-
`nent employed in the CQI determination.
`
`[0018] Systems which employ the HSDPA service provide
`for a Hybrid Automatic Retransmission Request (HARQ)
`scheme. If a transport block is not able to be decoded by the
`receiver, the transport block will be retransmitted, possibly
`with additional redundancy. The retransmitted transport
`block is soft-combined in the receiver, e.g., in the HARQ
`processing block 130, with the previously failed version of
`the transport block. Accordingly,
`the code symbols are
`received on a second channel, i.e., the High Speed Downlink
`Shared Channel (HS-DSCH) and processed by HARQ pro-
`cessing block 130. The HARQ processing block provides
`the received transport block to a decoder 140, for example
`a Turbo decoder.
`
`[0019] Turbo decoders in receivers operate in response to
`a Turbo encoder at the transmitter to produce error resistant
`communications. Specifically, a Turbo decoder typically
`will include a first and second decoder. The first decoder
`
`operates on a code symbol of a transport block to produce
`extrinsic information as well as an output vector L1. In the
`terminology of Turbo decoders, this procedure is called one
`half iteration. The extrinsic information is in the form of soft
`
`values, or estimates of the original transmitted data symbols,
`whereas the output vector L1 is a hard value (i.e.,
`the
`decided upon values that are considered to represent the
`original transmitted data symbols).
`
`the extrinsic
`In the Turbo decoder arrangement,
`[0020]
`information generated by the first decoder as a result of its
`half iteration is shuffled by an interleaver, and the shuffled
`information is then supplied to the second decoder. The
`second decoder is then permitted to operate. The extrinsic
`information supplied by the first decoder via the interleaver
`is taken into account together with the received signal when
`the second decoder performs its half iteration, which in turn
`produces extrinsic information as well as an output vector
`that, after un-shuffling by the deinterleaver, is an output
`vector L12. Since the second decoder operates on interleaved
`data,
`its output extrinsic information is also interleaved.
`Thus,
`the extrinsic information generated by the second
`decoder is supplied to a deinterleaver so that it may be
`passed on to the first interleaver for use in a next half
`iteration.
`
`[0021] One full run of the first decoder followed by a full
`run of the second decoder constitutes one Turbo decoder
`
`iteration. The output of the classic Turbo decoder is supplied
`only by the output vector Liz, so two “independently”
`decoded soft value vectors are only available once per
`iteration.
`In operation, some number of Turbo decoder
`
`iterations are performed until the output vector Li2 is con-
`sidered to have converged on a reliable result.
`
`[0022] Referring again to FIG. 1A, soft values arrived at
`by the Turbo decoder, as a result of the convergence of
`values on a reliable result, are provided to code decision
`processor 150 which uses the soft values to recover the
`transmitted code symbols of a particular transport block. The
`recovered code symbols are then provided to a Cyclic
`Redundancy Check (CRC) evaluator 160. The CRC evalu-
`ator 160 accumulates a number of code symbols until an
`entire transport block has been received. At the transmitter
`a CRC is associated with a transport block, and as is well
`known in the art is calculated based upon the contents of the
`transport block. Accordingly, the CRC evaluator 160 deter-
`mines whether the transport block, as recovered by receiver,
`has been correctly received by performing an evaluation
`using the recovered CRC. If the CRC evaluator 160 deter-
`mines that the transport block recovered by the receiver is
`not correct based upon the CRC calculation,
`then it
`is
`determined that there was an error in the decoding of the
`transport block.
`
`[0023] As illustrated in FIG. 1A, the CRC evaluator 160
`can provide an indication of the number of transport block
`errors to the CQI determination processing block 120, for
`determining the second component of the CQI determina-
`tion, i.e., the BLER.
`
`[0024] Although the CRC evaluation provides a direct
`measure of transport block errors,
`it would require the
`accumulation of CRCs from 10-100 transport blocks trans-
`mitted based on a particular CQI before a determination can
`be made that the transport block error probability is approxi-
`mately 10 percent, without exceeding 10 percent. Since the
`packet data in HSPDA service can be discontinuous, accu-
`mulating CRCs from a large number of code blocks by a
`particular radio receiver may not provide an accurate char-
`acterization of the current channel quality. Moreover, even
`providing an indication of a transport block error itself may
`not be enough information to evaluate the second compo-
`nent of the CQI evaluation.
`
`[0025] FIG. 1B illustrates a radio receiver in accordance
`with one embodiment of the present invention. In accor-
`dance with this embodiment of the present invention the
`second component of the CQI evaluation is performed on a
`per transport block basis, thereby providing a fast indicator
`of the quality of the channel to supplement the SIR estima-
`tion. Accordingly, as illustrated in FIG. 1B, information
`from HARQ processing block 130 and Turbo decoder 140
`can provide information on a per transport block basis for
`use in the CQI determination processing block 120. Addi-
`tionally,
`information from CRC evaluator 160 can be
`employed in the CQI determination processing block 120.
`
`[0026] The HARQ processing block 130 can provide an
`indication to the CQI determination processing block 120 of
`whether the particular transport block being decoded is an
`originally transmitted transport block, or is a retransmitted
`transport block. If the particular transport block is a retrans-
`mitted transport block,
`the HARQ processing block can
`indicate how many times the original transport block has
`been retransmitted when the particular transport block is
`being decoded, which is referred to in the art as the redun-
`dancy version of the processing block. The greater the
`number of retransmissions required to decode a particular
`
`6
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`

`

`US 2005/0003782 A1
`
`Jan. 6, 2005
`
`transport block is an indication of a lower channel quality.
`Conversely, if a particular transport block is decoded with-
`out retransmissions the channel quality is determined to be
`acceptable or too high.
`
`[0027] The Turbo decoder processing block 140 can pro-
`vide an indication of the number iterations employed in
`decoding a particular code block. For a Turbo decoder which
`stops iterating when a steady state solution is achieved that
`does not change the output bits over consecutive iterations
`of the Turbo decoder, the greater the number of iterations of
`the Turbo decoder indicates a lower channel quality. Con-
`versely, the lower the number of iterations of the Turbo
`decoder the greater the channel quality. Additionally, the soft
`values obtained during the Turbo decoding can be employed
`in the CQI determination. For example, a flat distribution of
`soft values indicates a poor channel quality. In addition, an
`average distance between the actual soft values and the ideal
`soft values for a noiseless channel can be calculated. Asmall
`
`average distance is an indication of good channel quality.
`
`[0028] Although a Turbo decoder with a specific type of
`stop condition has been described, the present invention is
`equally applicable to any type of iterative decoder where the
`number of iterations of the iterative decoder are directly or
`indirectly indicative of the quality of a channel. Accordingly,
`how the CQI determination processing block 120 interprets
`the number of iterations provided by the iterative decoder
`will depend on the type of iterative decoder which is
`employed. One of ordinary skill in the art with an under-
`standing of the operation of a particular iterative decoder
`could determine how to adjust the CQI determination pro-
`cessing based upon the operation of the particular iterative
`decoder.
`
`[0029] The specific way in which the information from the
`HARQ processing block 130 and the Turbo decoder 140 are
`employed for determining whether a particular CQI will
`result in a transport block error probability of approximately
`10 percent, without exceeding 10 percent, will depend upon
`the particular Turbo decoder employed. However, using
`well-known tools, e. g., computer simulations, empirical data
`can be collected for transport blocks encoded based on
`different CQI values for varying radio conditions based on,
`for example SIR values, and the number of retransmissions
`and iterations of Turbo decoding required to decode the code
`blocks based on the different CQI values for varying radio
`conditions. Using the empirical data a relationship between
`the number of retransmissions and iterations of Turbo
`
`decoding and the transport block error probability can be
`determined. The determined relationship is then employed
`for determining whether a transport format associated with
`a particular CQI value, based on a number of retransmis-
`sions and iterations of the Turbo decoder, will result in a
`transport block error probability of approximately 10 per-
`cent, but is not greater than 10 percent.
`
`[0030] The CQI determination processing block 120 pro-
`cesses the information received from the HARQ processing
`block 130, Turbo decoder processing block 140, and if
`available, information from CRC evaluator 160 to determine
`the second component of the CQI determination.
`
`[0031] FIG. 2 illustrates an exemplary method for deter-
`mining a channel quality indicator in accordance with the
`present invention. Initially, the radio receiver measures a
`first quality value, e.g., the SIR, of a first wireless channel,
`
`e.g., the pilot channel (step 210). The radio receiver also
`determines a second quality value of a second wireless
`channel, e.g., the HS-DSCH, on a per transport block basis
`(step 220). The radio receiver then determines a CQI value
`based on the first and second quality values (step 230). The
`determined CQI value is reported to the radio communica-
`tions network (step 240). Although the determination of the
`first and second quality values are illustrated in the method
`of FIG. 2 as being performed sequentially, these steps can
`be performed in parallel.
`
`In accordance with exemplary embodiments of the
`[0032]
`present invention the CQI value is determined by employing
`a look-up table in a memory of the radio receiver. FIGS. 3A
`and 3B respectively illustrate exemplary look-up tables in
`accordance with embodiments of the present invention. In
`accordance with one embodiment of the present invention,
`as illustrated in FIG. 3A, a look-up table stored in the radio
`receiver contains a mapping between the SIR and a CQI
`value. Since a pilot channel is typically at a higher power
`than a data channel an offset should be applied to the pilot
`SIR value to account for this power difference. This offset
`can vary over time depending on the number of users
`involved and on the type of services they demand. Accord-
`ingly, an SIR value determined using the pilot signal, and
`adjusted by the offset, is used to determine a CQI value. This
`CQI value is then modified based upon the additional
`information provided by the second component of the CQI
`determination,
`i.e.,
`the HARQ, Turbo decoding, and if
`available the CRC information. Alternatively, the offset to
`the pilot SIR value can be applied when the determined CQI
`value is modified based on the additional information.
`
`the SIR
`is determined that
`if it
`[0033] For example,
`adjusted for the offset is SIR2, which corresponds to a value
`of CQIZ, and that the currently received transport block was
`a retransmission and required a large number of iterations of
`the Turbo decoder, the CQI value of CQI2 could be modified
`to provide a CQI value which indicates a lesser quality of the
`channel than CQIZ. Specifically, based upon the empirical
`data, the radio receiver uses the number of retransmissions
`and iterations of the Turbo decoder to determine how to
`
`adjust the CQI value determined using the SIR. This CQI
`value would be employed by the radio communications
`network to select a modulation and coding scheme which
`meets the requirements of a transport block error probability
`of approximately 10 percent, but not greater than 10 percent.
`
`[0034] Alternatively, the determination of the SIR value
`used in connection with the look-up table can be made to
`account for the information from the second component of
`the CQI evaluation. In this embodiment an initial SIR value
`is determined using the pilot signal, and this value is
`modified depending upon the channel conditions indicated
`by the information from the second component in the CQI
`determination and by the offset to the pilot power value. For
`example, if the number of retransmission, iterations of the
`Turbo decoder and/or CRC result indicate a poor channel
`quality, the initial SIR value is modified to reflect this poor
`channel quality and to reflect the offset to the pilot power
`value. The modified SIR is then compared to the table
`illustrated in FIG. 3A to determine a CQI value.
`
`[0035] FIG. 3B illustrates a portion of a look-up table
`which can be stored in the radio receiver in accordance with
`
`another embodiment of the present invention. As compared
`
`7
`
`

`

`US 2005/0003782 A1
`
`Jan. 6, 2005
`
`to the simple mapping of SIR values to CQI values of FIG.
`3A, the look-up table of FIG. 3B includes a column for SIR
`values, HARQ information, Turbo decoder information and
`CQI values. Accordingly, the radio receiver would use the
`SIR value determined using the pilot signal and adjusted for
`the pilot power value offset, and the HARQ information and
`the Turbo decoder information from the HS-DSCH to locate
`
`corresponding entries in the look-up table to determine an
`appropriate CQI value. Some of the CQI values in the table
`may coincide. The particular CQI values in the table which
`coincide will be implementation specific, and can be deter-
`mined by one skilled in the art with knowledge of the
`specific implementation. Although not illustrated in FIG.
`3B, the table can also include a column which accounts for
`the CRC information for use in determining the CQI value.
`
`[0036] The invention has been described with reference to
`a particular embodiment. However, it will be readily appar-
`ent to those skilled in the art that it is possible to embody the
`invention in specific forms other than those of the preferred
`embodiment described above. This may be done without
`departing from the spirit of the invention.
`
`[0037] For example, various embodiments have been
`described above in connection with a HSDPA system, the
`present invention is equally applicable to any type of packet
`data system in which HARQ and/or iterative decoding
`information are employed in determining a channel quality
`value which is reported to the radio communications net-
`work. Moreover, the embodiments of the present invention
`are equally applicable to any system in which it is desired to
`obtain a channel quality estimate on a per transport block
`basis.
`
`[0038] Thus, the preferred embodiments are merely illus-
`trative and should not be considered restrictive in anyway.
`The scope of the invention is given by the appended claims,
`rather than the preceding description, and all variations and
`equivalents which fall within the range of the claims are
`intended to be embraced therein.
`
`What is claimed is:
`
`1. A method for determining and reporting a channel
`quality indicator comprising:
`
`measuring a first quality value of a first wireless channel;
`
`determining a second quality value of a second wireless
`channel, the second quality value is determined based
`on decoding of each block of a first block type prior to
`an integrity check of a block of a second block type;
`
`determining a channel quality indicator based on the first
`and second quality values; and
`
`reporting the determined channel quality indicator.
`2. The method of claim 1, further comprising:
`
`determining a third quality value based on the integrity
`check of the block of the second block type,
`
`wherein the determination of the channel quality indicator
`is also based on the third quality value.
`3. The method of claim 1, wherein the first block type is
`a code block and the second block type is a transport block.
`4. The method of claim 3, wherein the transport block
`comprises one or more code blocks.
`5. The method of claim 1, wherein the first quality value
`is a signal-to-interference ratio, the first wireless channel is
`
`a pilot channel, and the channel quality indicator is deter-
`mined based on the signal-to-interference ratio offset by a
`difference between the pilot channel power and a power of
`the second wireless channel.
`
`6. The method of claim 1, wherein the second quality
`value is based on information regarding at least one of a
`number of retransmissions of a block of the second block
`
`type and a number of iterations of a decoder in decoding the
`block of the first block type.
`7. The method of claim 1, wherein a table is employed in
`the determination of the channel quality indicator.
`8. The method of claim 7, wherein the determination of
`the channel quality indicator comprises:
`
`comparing the first quality value with entries in the table
`to determine an initial channel quality indicator; and
`
`adjusting the initial channel quality indicator based on the
`second quality value.
`9. The method of claim 7, wherein the determination of
`the channel quality indicator comprises:
`
`modifying the first quality value based on the second
`quality value to produce a modified first quality value;
`and
`
`comparing the modified first quality value with entries in
`the table to determine a channel quality indicator.
`10. The method of claim 7, wherein the determination of
`the channel quality indicator comprises:
`
`comparing the first and second quality values with entries
`in the table to determine the channel quality indicator.
`11. A method for determining and reporting a channel
`quality indicator comprising:
`
`measuring a first quality value of a first wireless channel;
`
`determining a second quality value of a second wireless
`channel, the second quality value is determined based
`on decoding of a block of a first block type;
`
`determining a third quality value based on an integrity
`check of a block of a second block type;
`
`determining a channel quality indicator based on the first
`and second quality values; and
`
`reporting the determined channel quality indicator.
`12. The method of claim 11, wherein the step of deter-
`mining the second quality value comprises:
`
`determining a number of decoder iterations employed to
`decode the block of the first type; and
`
`determining the number of retransmissions of the block of
`the first type.
`13. The method of claim 11, wherein the first block type
`is a code block and the second block type is a transport
`block.
`
`14. The method of claim 13, wherein the transport block
`comprises one or more code blocks.
`15. The method of claim 11, wherein the determination of
`the channel quality indicator is also based on the third
`quality value.
`16. The method of claim 11, wherein the first quality value
`is a signal-to-interference ratio, the first wireless channel is
`a pilot channel, and the channel quality indicator is deter-
`
`8
`
`

`

`US 2005/0003782 A1
`
`Jan. 6, 2005
`
`mined based on the signal-to-interference ratio offset by a
`difference between the pilot channel power and a power of
`the second wireless channel.
`
`17. The method of claim 11, wherein a table is employed
`in the determination of the channel quality indicator.
`18. The method of claim 17, wherein the determination of
`the channel quality indicator comprises:
`
`comparing the first quality value with entries in the table
`to determine an initial channel quality indicator; and
`
`adjusting the initial channel quality indicator based on the
`second quality value.
`19. The method of claim 17, wherein the determination of
`the channel quality indicator comprises:
`
`modifying the first quality value based on the second
`quality value to produce a modified first quality value;
`and
`
`comparing the modified first quality value with entries in
`the table to determine a channel quality indicator.
`20. The method of claim 17, wherein the determination of
`the channel quality indicator comprises:
`
`comparing the first and second quality values with entries
`in the table to determine the channel quality indicator.
`21. An apparatus comprising:
`
`a first channel quality estimator which estimates a first
`quality value of a first wireless channel;
`
`a second channel quality estimator which estimates a
`second quality value of a second wireless channel, the
`second quality value is determined based on decoding
`of each block of a first block type prior to an integrity
`check of a block of a second block type; and
`
`a channel quality indicator determination processor which
`determines a channel quality indicator based on the first
`and second quality values.
`22. The apparatus of claim 21, further comprising:
`
`a third channel quality estimator which estimates a third
`quality value based on the integrity check of the block
`of the second block type,
`
`wherein the determination of the channel quality indicator
`is also based on the third quality value.
`23. The apparatus of claim 21, wherein the first block type
`is a code block and the second block type is a transport
`block.
`
`24. The apparatus of claim 23, wherein the transport block
`comprises one or more code blocks.
`25. The apparatus of claim 21, wherein the first quality
`value is a signal-to-interference ratio,
`the first wireless
`channel is a pilot channel, and the channel quality indicator
`is determined based on the signal-to-interference ratio offset
`by a difference between the pilot channel power and a power
`of the second wireless channel.
`
`26. The apparatus of claim 21, wherein the second quality
`value estimator comprises at
`least one of an automatic
`retransmission request processor, and an iterative decoder.
`27. The apparatus of claim 21, further comprising:
`
`a memory which stores a table which is employed in the
`determination of the channel quality indicator.
`28. The apparatus of claim 27, wherein the channel
`quality indicator is determined by comparing the first quality
`value with entries in the table to determine an initial channel
`
`quality indicator, and adjusting the initial channel quality
`indicator based on the second quality value.
`29. The apparatus of claim 27, wherein the channel
`quality indicator is determined by modif