PCT
`
`WORLD INTELLECTUAL PROPERTY ORGANIZATION
`Intematlonal Bureau
`
`
`
`(51) International Patent Classification 5 :
`
`H04B 7/005
`
`(21) International Application Number:
`
`(11) International Publication Number:
`
`WO 94/19876
`
`(43) International Publication Date:
`
`1 September 1994 (01.09.94)
`
`L.‘;
`
`US
`
`Published
`
`With international search report.
`
`
`INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
`
`
`
`
`
`
`PCT/US94/0115O (81) Designated States: AT, AU, BB, BG, BR, CA, CH, CZ, DE.
`
`DK, ES, FI, GB, HU, JP, KP, KR, KZ, LK, LU, MG, MN,
`
`
`MW, NL, NO, NZ, L, RO, RU, SD, SE, SK, UA, VN,
`(22) International Filing Date:
`1 February 1994 (01.02.94)
`
`
`European patent (AT, B , CH, D , DK, ES, FR, GB, GR,
`
`IE, IT, LU, MC, NL, PT, SE), OAPI patent (BF, BJ, CF,
`
`CG, CI, CM, GA, GN, ML, MR, NE, SN, TD, TG).
`(30) Priority Data:
`020,482
`22 February 1993 (22.02.93)
`
`
`
`(71) Applicant: QUALCOMM INCORPORATED [US/US]; 10555
`
`
`Sorrento Valley Road, San Diego, CA 92121 (US).
`
`
`
`(72) Inventors: PADOVANI, Roberto; 12634 Futul'a Street, San
`Diego, CA 92116 (US). ZIV, Noam; 10968 Corie Playa
`
`Barcelona, San Diego, CA 92124 (US).
`
`(74) Agent: MILLER, Russell, B.; Qualcomm Incorporated, 10555
`Sorrento Valley Road, San Diego, CA 92121 (US).
`
`
`
`
`PROCESSOR
`
`(54) Title: METHOD AND SYSTEM FOR THE DYNAMIC MODIFICATION OF CONTROL PARAMETERS IN A TRANSMITTER
`POWER CONTROL SYSTEM
`
`DETERMINATION
`PROCESSOR
`
`CONTROL
`
`(57) Abstract
`
`In a communication system in which direct sequence spread spectrum modulation techniques are used, interference is generated in
`communications by remote stations since the communications share the same frequency spectrum. In order to increase system capacity the
`power level of the remote station transmitters are controlled by the local station. A setpoint in generated at the local station by a power
`control processor (118) and compared by a comparator (120) with the remote station signal strength measured at the local station by a
`power averager (114). The result of this comparison is used to generate power level adjustment commands by a command generator (122)
`which are transmitted to the remote station. The remote station is responsive to the power level adjustment commands for increasing or
`decreasing remote station transmitter power. In a spread spectrum communication system in which data is encoded at variable data rates,
`the local station determines via a rate determination processor (116) the rate at which received data was encoded by the transmitting remote
`station. The data is decoded by decoder (112) at each possible rate with error metrics generated that are representative of the quality of the
`data decoded at each rate. A rate decision algorithm is used by processor (116) to evaluate the error metrics and make a decision on the
`rate at which the data was transmitted. A pattern match of rate decisions is used by processor (118) to modify a setpoint so as to closely
`control the transmitting power of the remote station as a function of the quality of the received data.
`
`
`
`
`|PR2018-01473
`
`Apple v. INVT
`INVT Exhibit 2003 - Page 1
`
`IPR2018-01473
`Apple v. INVT
`INVT Exhibit 2003 - Page 1
`
`

`

`
`FOR THE PURPOSES OF INFORMATION ONLY
`
`
`Codes used to identify States party to the PCI' on the front pages of pamphlets publishing international
`applications under the PCI‘.
`
`
`GB
`GE
`GN
`GR
`BU
`[E
`['1‘
`JP
`KE
`KG
`KP
`
`KR
`[(2
`LI
`LK
`LU
`LV
`
`
`United Kingdom
`Georgia
`Guinea
`Grew:
`Hungary
`Ireland
`Italy
`Japan
`Kenya
`Kyrgystan
`Demoa'atic People's Republic
`of Korea
`Republic of Korea
`Kazakhstan
`Liechtenstein
`Sti Lanka
`Luxembourg
`Latvia
`Monaco
`Republic of Moldova
`
`MR
`MW
`NE
`NL
`N0
`NZ
`PL
`PI‘
`R0
`RU
`SD
`SE
`SI
`SK
`SN
`TD
`TG
`TJ
`11‘
`
`Munitania
`Malawi
`Niger
`Netbalands
`Norway
`New Zealand
`Poland
`Portugal
`Romania
`Russian Feds-anon
`Sudan
`Sweden
`Slovenia
`Slovakia
`Senegal
`Chad
`Togo
`Tajikistan
`Trinidad and Tobago
`'
`
`
`
`
`
`
`
`
`
`
`
`
`
`AT
`AU
`BB
`BE
`BF
`BG
`BJ
`BR
`BY
`CA
`CF
`CG
`CH
`C!
`CM
`CN
`CS
`CZ
`DE
`
`'
`
`Austria
`Australia
`Barbados
`Belgium
`Burkina Faso
`Bulgaria
`Benin
`Brazil
`Belarus
`Canada
`Central African Republic
`Congo
`Switzerland
`can: d'lvoire
`Cameroon
`China
`Whoslovakia
`Cum Republic
`Germany
`
`
`
`
`
`|PR2018-01473
`
`Apple v. INVT
`INVT Exhibit 2003 - Page 2
`
`IPR2018-01473
`Apple v. INVT
`INVT Exhibit 2003 - Page 2
`
`

`

`wo 94/19876
`
`PCT/US94/01150
`
`1
`
`METHOD AND SYSTEM FOR THE DYNAMIC
`
`MODIFICATION OF CONTROL PARAMETERS IN A
`
`TRANSMITTER POWER CONTROL SYSTEM
`
`5
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`
`The present invention relates generally to digital communication
`
`10
`
`systems and, more specifically, to a method and apparatus for adjusting
`
`transmitter power in such systems both to minimize interference among
`
`transmitters operating simultaneously and to maximize the quality of
`
`individual communications.
`
`15
`
`II. Description of the Related Art
`
`In a cellular telephone or personal communication system (PCS),
`
`a large number of "mobile stations" communicate through cell sites or "base
`
`stations." The transmitted signal experiences multipath fading as the
`
`20 mobile station moves in relation to features in the environment that reflect
`
`the signal. Controlling mobile station transmitter power to overcome
`multipath fading is described in US. Patent No. 5,056,109, titled "METHOD
`AND APPARATUS FOR CONTROLLING TRANSMISSION POWER IN A
`
`CDMA MOBILE CELLULAR TELEPHONE SYSTEM," issued on October 8,
`
`25
`
`1991 to the assignee of the present invention and incorporated herein by
`reference.
`
`If the mobile station transmits an excessively powerful signal, it will
`
`interfere with the transmitted signals of other mobile stations.
`
`If the mobile
`
`station transmits an insufficiently powerful signal, the base station will be
`
`30
`
`unable to recover the transmitted information from the received signal._ In
`
`the above-referenced patent, the base station measures the power of the
`
`signal received from a mobile station and transmits power adjustment
`
`commands to the mobile station over a separate channel. The commands
`
`instruct the mobile station to increase or decrease transmission power to
`
`35 maintain the average received signal power at a predetermined level. The
`
`base station must periodically adjust the transmission power of the mobile
`
`station to maintain an acceptable balance between interference and signal
`
`quality as the mobile station'moves.
`
`|PR2018-01473
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`Apple v. INVT
`INVT Exhibit 2003 - Page 3
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`IPR2018-01473
`Apple v. INVT
`INVT Exhibit 2003 - Page 3
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`PCT/US94/01150
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`2
`
`The base station processor may monitor error rates in the received
`
`signal to select an optimal power level at which to maintain the average
`
`received signal. The base station processor detects errors as disclosed in
`
`copending US. patent application Serial No.
`
`,
`
`titled
`
`5
`
`"METHOD AND APPARATUS FOR DETERMINING TRANSMISSION
`
`' RATE IN A COMMUNICATIONS RECEIVER," and assigned to the assignee
`
`of the present invention.
`
`In the exemplary CDMA cellular telephone
`
`system described in the above-referenced U.S. patent and copending
`
`application, the mobile station transmits "frames" comprising "symbols,"
`
`10 which represent digitized voice or other data. Further details on the
`
`exemplary CDMA cellular telephone system are described in US. Patent
`
`No. 5,103,459, titled "SYSTEM AND METHOD FOR GENERATING SIGNAL
`
`WAVEFORMS IN A CDMA CELLULAR TELEPHONE SYSTEM," issued
`
`April 17, 1992 to the assignee of the present invention and incorporated
`
`15
`
`herein by reference.
`
`The mobile station encodes frames at one of four rates; the rate is
`
`selected according to the needs of the user. The maximum rate, which is
`
`generally preferred for high quality voice transmissions or rapid data
`
`transmissions, is called "full rate." Rates of one half, one fourth, and
`
`20
`
`one eighth of the full rate are called "half rate," "quarter rate," and "eighth
`
`rate," respectively. Each symbol of a frame to be encoded at half rate, quarter
`
`rate, and eighth rate is repeated two, four, and eight times, respectively, to
`
`fill the frame. The frame is then transmitted to the base station at a constant
`
`rate, regardless of the rate at which the symbols are encoded.
`
`25
`
`The base station has no advance notice of the data rate at which a
`
`received frame is encoded and the rate may be different from that of the
`
`previous received frame. The base station decodes each received frame at
`
`each of the four rates and produces a set of error metrics corresponding to
`
`each rate. The error metrics provide an indication of the quality of the
`
`30
`
`received frame and may include a cyclic redundancy check (CRC) result, a
`
`Yamamoto Quality Metric, and a re-encoded symbol comparison result. The
`
`generation and use of these error metrics are well known in the art with
`
`details on the Yamamoto Quality Metric provided in the article "Viterbi
`
`Decoding Algorithm for Convolutional Codes with Repeat Request",
`
`35 Hirosuke Yamamoto et a1., IEEE Transactions on Information Theory , Vol.
`
`IT-26, No. 5, September 1980. The set of error metrics for the decoding of
`each frame at each rate thus includes one or more of the CRC result/the
`
`Yamamoto Quality Metric, and the re-encoded symbol comparison result.
`
`The base station processor analyzes the sets of error metrics using a novel
`
`|PR2018-01473
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`Apple v. INVT
`INVT Exhibit 2003 - Page 4
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`IPR2018-01473
`Apple v. INVT
`INVT Exhibit 2003 - Page 4
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`

`

`WO 94/19876
`
`PCT/US94/01150
`
`3
`
`decision algorithm and determines the most probable rate at which the
`
`received frame was encoded. The base station then uses the rate decision to
`
`select the corresponding decoded data from the multiple data rate decodings
`
`to recover the transmitted frame information.
`
`5
`
`The base station processor also produces an "erasure" indication if the
`
`quality of the frame data is too poor for the processor to determine the rate.
`
`Similarly, the processor produces a "full rate likely" indication if bit errors'
`exist in the data but the rate is probably full rate.
`If an erasure occurs, the
`
`base station may simply discard the frame or may replace it with
`
`10
`
`interpolated data.
`
`It would be desirable to monitor the error rate of the received frames
`
`and to periodically adjust the transmission power level to maintain the
`
`error rate at an acceptable value. These problems and deficiencies are clearly
`
`felt in the art and are solved by the present invention in the manner
`
`15
`
`described below.
`
`SUMMARY OF THE INVENTION
`
`The present invention comprises a method and apparatus for
`
`20
`
`adjusting the power level of a remote transmitter to provide a substantially
`
`constant error rate in the received data. The present invention may be used
`
`in the base station of a cellular telephone system to maximize the number
`
`of mobile stations that may transmit simultaneously with minimal
`
`interference by enhancing control over the power of the signal that each
`25 mobile station transmits.
`
`In the CDMA cellular telephone system described in the above-
`
`referenced US. patent, the mobile station transmits a signal comprising
`
`frames of digitized voice or other information to the base station at an
`
`initial power level or setpoint. As described in the above-referenced
`
`30
`
`copending application, the information is encoded into either full rate,
`
`half rate, quarter rate, or eighth rate data frames. The base station receives
`
`the signal and decodes each frame at each of these rates. A corresponding
`
`set of error metrics is produced for each rate that provides an indication of
`
`the quality of the received information if the frame is decoded at that rate.
`
`35 The base station processor then analyzes the sets of error metrics using a
`
`decision algorithm and either provides an indication of the most probable
`
`rate at which the information was encoded or provides an "erasure"
`
`indication, i.e., an indication that the rate could not be determined with the
`
`desired probability of correctness.
`
`|PR2018-01473
`
`Apple v. INVT
`INVT Exhibit 2003 - Page 5
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`IPR2018-01473
`Apple v. INVT
`INVT Exhibit 2003 - Page 5
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`W0 94/ 19876
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`PCT/US94/01150
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`4
`
`the base station processor counts the
`In the present invention,
`number of consecutive frames encoded at a rate such as full rate and the
`
`number of frames that are erasures. A count of a predetermined number of
`
`’
`
`consecutive full rate indications, i.e., without an intervening less than full
`
`5
`
`rate indication, erasure indication or full rate likely indication, is indicative
`
`of a high quality full rate transmission and is called a "full rate run." If the
`
`processor detects a full rate run and then detects an additional full rate
`
`frame, it should decrease the signal power to a level at which a small but
`
`acceptable number of erasure or full rate likely indications occur between
`the full rate frames. For example, one error indication in 100 full rate
`
`10
`
`frames, where each frame consists of 576 symbols and is transmitted at a rate
`
`of 28,800 symbols per second, is inaudible in a transmission consisting of
`
`ordinary speech.
`
`A count of a predetermined number of consecutive erasure
`indications, i.e., without an intervening other rate indication, is indicative
`
`15
`
`If the
`of a poor quality transmission and is called an "erasure run."
`processor detects an erasure run, it should increase the signal power. The
`increased signal power may overcome multipath fading, thereby reducing
`the erasure rate.
`
`20
`
`A predetermined consecutive number of half rate, quarter rate, or
`
`eighth rate indications is called a "variable rate run." As a further
`
`enhancement in controlling transmitter power the processor may, while in
`
`a variable rate run, also reduce the signal power if it detects a half rate,
`
`quarter rate, or eighth rate indication.
`
`In addition while in the variable rate
`
`25
`
`run, the processor may increase the signal power if it detects an erasure
`indication.
`
`Although the present invention may be used to adjust the power
`
`level of transmissions consisting of any type of data, it is optimized for
`
`transmissions consisting of voice information.
`
`In communications systems
`
`30
`
`such as the cellular telephone system described in the above-referenced
`
`copending application and US. patent, voice transmissions are encoded at a
`
`variable rate; the complexity of the speech determines the rate. However,
`
`continuous speech is generally encoded at full rate. Speech occurring after a
`
`period of relative inactivity may be encoded at lower rates, transitioning to
`
`35
`
`full rate as the speech increases in complexity. The algorithm thus expects
`
`to detect variable rate runs alternating with full rate runs as the speaker
`
`pauses between words or syllables. Therefore, the processor may also
`
`increase the signal power if it detects an erasure indication or a full rate
`
`likely indication following a full rate run. The increment by which the
`
`|PR2018-01473
`
`Apple v. INVT
`INVT Exhibit 2003- Page 6
`
`IPR2018-01473
`Apple v. INVT
`INVT Exhibit 2003 - Page 6
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`

`

`WO 94/19876
`
`PCTIUS94/01150
`
`5
`
`processor increases the power upon detecting an erasure or full rate likely
`
`indication following a full rate run need not be the same as the increment
`
`by which the processor increases the power upon detecting an erasure run.
`
`The foregoing, together with other features and advantages of the
`
`5
`
`present invention, will become more apparent when referring to the
`
`following specification, claims, and accompanying drawings.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`10
`
`The features, objects, and advantages of the present invention will
`
`become more apparent from the detailed description set forth below when
`
`taken in conjunction with the drawings in which like reference characters
`
`identify correspondingly throughout and wherein:
`
`Figure 1 is a block diagram showing the present invention in the base
`station receiver of a cellular telephone system;
`
`15
`
`Figure 2 is a generalized flow diagram of an exemplary power control
`
`setpoint algorithm; and
`
`Figures 3a -3c illustrate a detailed flow diagram of an exemplary
`power control setpoint algorithm for a determined rate decision pattern.
`
`20
`
`DETAILED DESCRIPTION OF THE PREFERRED
`
`-
`
`EMBODIMENTS
`
`In a CDMA cellular communication system where system user
`
`25
`
`capacity is a function of the total system power, any reduction of mobile
`
`station power facilitates an increase in system capacity. The present
`
`invention provides a method and system for closely and dynamically
`controlling the mobile station transmitter ,power as a function of the
`
`communication link. Through dynamic control over mobile station
`
`30
`
`transmitter power greater system capacity may be achieved.
`
`In Fig. 1, the present invention is used in a base station receiver of a
`
`CDMA cellular telephone system. This receiver is described in the above-
`
`referenced US. Patent and is now described only briefly. A mobile station
`
`(not shown) transmits a communication signal, typically a CDMA signal of
`
`35
`
`a spreading bandwidth for example of 1.25 MHz at one frequency band, to
`
`the base station radio receiver (not shown).
`
`In order to aid in understanding of the present invention, a brief
`
`discussion of the mobile station data encoding for transmission is provided.
`
`In the exemplary embodiment user data provided at various data rates is
`
`|PR2018-01473
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`Apple v. INVT
`INVT Exhibit 2003 - Page 7
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`IPR2018-01473
`Apple v. INVT
`INVT Exhibit 2003 - Page 7
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`

`W0 94/ 19876
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`PCT/US94/01150
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`6
`
`encoded and formatted for transmission in data frames typically 20
`
`milliseconds in length. The user data along with frame overhead data are
`
`preferably forward error correction encoded. the effective data rates for this
`
`example are 9.6 kbps (full rate), 4.8 kbps (half rate), 2.4 kbps (quarter rate) and
`
`5
`
`1.2 kbps (half rate).
`
`It should be noted that a constant symbol rate for the
`
`frames is preferred but is not necessary.
`
`'
`
`In this example rate 1/3 convolutional encoding is used to produce
`
`three symbols for each user data or frame overhead bits. For a full rate
`
`frame, corresponding to a 9.6 kbps data rate, a total of 192 user data and
`
`10
`
`frame overhead bits are encoded to produce 576 symbols for the frame. For
`
`a half rate data frame, corresponding to a 4.8 kbps data rate, a total of 96 user
`
`data and frame overhead bits are encoded to produce 288 symbols for the
`
`frame. Similarly for quarter rate and eighth rate data frames, respectively
`corresponding to 2.4 and 1.2 kbps data rates, a total of 48 and 24 user data and
`
`15
`
`frame overhead bits are encoded to produce 144 and 72 symbols for the
`
`respective rate frame.
`
`It should be noted that groups of symbols are
`
`converted into a respective orthogonal function sequence or code of a set of
`
`orthogonal function codes according to the value of the symbol set.
`
`In the
`
`exemplary embodiment six symbols for a binary value that is used to select
`
`20
`
`one of sixty-four Walsh function sequences each sixty-four chips in length.
`Further details on this modulation scheme is disclosed in the above
`
`mentioned US. Patent No. 5,103,459.
`
`At the base station the signal is received at antenna 100 and provided
`
`to receiver 102 for frequency downconversion and filtering. Analog-to-
`digital (A/ D) converter 104 receives the analog spread spectrum signal from
`
`25
`
`receiver 102 and converts it to a digital signal. A pseudorandom noise (PN)
`
`correlator 106 receives the digital signal and a PN'code provided by a PN
`
`generator 108. PN correlator 106 performs a correlation process and
`
`provides an output to a Fast Hadamard Transform digital processor or
`filter 110.
`'
`
`30
`
`In a preferred embodiment of a multipath diversity receiver PN
`
`generator 108 generates a plurality of a same PN codes with timing offsets
`
`dependent upon the particular path of the signal. PN correlator 108
`
`correlates each of the PN codes with a respective path signal to produce a
`
`35
`
`respective orthogonal function symbol data.
`
`Filter 110 converts the
`
`orthogonal function symbol data into soft decision symbol data for each
`
`multipath signal. The multipath symbol data is then combined and
`
`provided as soft decision symbol data for decoding by user data decoder 112.
`
`|PR2018-01473
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`INVT Exhibit 2003 - Page 8
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`INVT Exhibit 2003 - Page 8
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`PCT/US94/01150
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`7
`
`Filter 110 as part of the conversion process determines from each
`
`orthogonal function symbol from each multipath signal an energy value.
`
`Keeping in mind that each orthogonal function symbol is converted into a
`
`group of data symbols, the energy values from the different paths are
`
`5
`
`combined to produce a corresponding symbol energy value. Filter 110 in
`
`addition to providing soft decision data to decoder 112, also provides the
`symbol energy value to power averager circuit 114.
`
`Decoder 112, which typically includes a Viterbi decoder, receives the
`
`filter soft decision symbol data output and produces user data and decoder
`
`10
`
`error metrics which are provided to rate determination processor 116.
`
`Processor 116 may send the user data to a digital—to—analog converter or
`other output circuitry (not shown). Decoder 112 is described in further
`
`_ detail in the above-referenced copending US. Patent application and is only
`briefly described herein.
`
`15
`
`Upon reception at the base station, decoder 112 decodes each frame at
`
`each possible rate and provides a corresponding set of error metrics
`
`representative of the quality of the symbols as decoded at each rate. Error
`
`metrics for decodings at each rate include, for example, a symbol error result
`based upon a re-encoding of the decoded bits to produce re-encoded symbols
`that are and then compared with the received symbols and a Yamamoto
`
`20
`
`Quality metric.
`
`In addition, for full rate and half rate frames a CRC check
`
`result is performed on CRC bits in the frame overhead bits.
`
`After decoder 112 has decoded each frame, processor 116 executes the
`rate determination algorithm described in the above-referenced copending
`25 U.S. Patent application to determine the most likely rate at which the frame
`
`was encoded. The algorithm uses the error metrics provided by decoder 112
`to estimate or decide the rate at which the frame of data was transmitted.
`
`Once processor 116 determines the rate for the frame of data, the data is
`
`interpreted by control bits included in the frame as either control or user
`
`30
`
`data with the user data output for further use. From the error metrics
`
`processor 116 determines whether the received data frame contained data
`
`that was transmitted at either full rate, half rate, quarter rate or eighth rate
`and generates a corresponding rate indication. This rate indication is
`
`provided to outer loop power control processor 118, whose function is
`
`35
`
`described in further detail later herein.
`
`In the case where the error metrics provided by decoder 112 indicate
`
`to processor 116 that the received frame was corrupted beyond that which
`the error correction techniques employed by decoder 112 may correct,
`
`processor 116 does not decide the rate of the data for the frame.
`
`|PR2018-01473
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`Apple v. INVT
`INVT Exhibit 2003 - Page 9
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`IPR2018-01473
`Apple v. INVT
`INVT Exhibit 2003 - Page 9
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`PCT/US94/01150
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`8
`
`Processor 116 in this case does not use or provide an output of the data for
`that frame, with the frame being considered an erasure frame. Processor 116
`for the erasure frame, generates and provides an erasure indication to
`
`processor 118 indicative that could not determine the rate at which the
`
`5
`
`frame was encoded.
`
`In the case where the error metrics provided by decoder 112 indicate
`
`to processor 116 that the received frame is a corrupted full rate frame that
`
`10
`
`was corrected by decoder 112. Typically in this case the metrics indicate only
`that an error exists in the CRC. From this information processor 116
`determines that the most likely the rate of the data for the frame is that of
`full rate, and identifies the frame as a full rate likely frame. Processor 116
`uses or outputs the data as if it were full rate data with a conditional
`
`understanding that it may contain errors. Processor 116 for the full rate
`
`likely frame generates and provides a full rate likely indication to
`processor 118.
`
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`The rate decisions and detected frame errors may be used as an
`indication of the power level at which the mobile station need transmit
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`signals at to maintain a quality conununication link.
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`In those cases where a
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`number of frames are received at a rate or rates in which the occurrence of
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`frames in error is low, the mobile station transmitter power may be reduced.
`This transmitter power reduction may continue until the error rate begins
`to rise to a level which may adversely affect
`the quality of
`the
`communication link. . Similarly the power may be increased where the
`errors adversely affect the quality of the communication link.
`
`Upon receiving the rate indications from processor 116, processor 118
`executes a novel algorithm to control a power level setpoint. This setpoint
`‘is used as discussed with reference to Fig. 1 in generating power commands
`which control the power of the mobile station transmitter power.
`As mentioned previously filter 110 provides the scaled symbol energy
`value to power averager 114. Power averager 114 sums or averages the
`scaled symbol energy values over a 1.25 millisecond interval,
`i.e.
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`corresponding to a group of six Walsh symbols or thirty-six data symbols,
`and provides a received power level signal to comparator 120.
`Processor 118, which includes appropriate internal counters, program
`35 memory and data memory, computes under program control a power level
`setpoint signal as described below and provides it to comparator 120.
`Processor 118 may be either located at the base station through which the
`mobile station is in communication with or at a remote location such as the
`
`mobile telephone switching office (not shown).
`
`In the situation where the
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`|PR2018-01473
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`INVT Exhibit 2003 - Page 10
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`INVT Exhibit 2003 - Page 10
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`mobile station is communicating through multiple base stations, with
`
`power control provided through the multiple base stations, from a control
`
`standpoint the location of processor 118 at the MTSO is more convenient.
`In those situations where processors 116 and 118 are located together the
`function of these two processors may be combined into a single processor.
`Comparator 120 compares the received power level signal and the
`power level setpoint signal, and provides a deviation signal representative
`of the deviation of the received power from the power level setpoint set by
`processor 118. Power up/down command generator 122 receives the
`deviation signal and generates either a power up command or a
`power down command, which the base station transmits to the mobile
`
`station (not shown). Should the signal from power averager circuit 114 fall
`below the threshold established by the power level setpoint signal, the
`deviation signal generated by comparator results in the generation of power
`up command. Similarly, should the power averager circuit signal exceed
`the power level setpoint signal, a power down command is generated.
`These power commands are provided to transmitter 124 where inserted into
`the data being transmitted to the mobile station. Transmitter spread
`spectrum modulates
`and transmits
`the modulated data via
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`antenna 100 to the mobile station. Transmitter 124 typically transmits the
`CDMA signal
`in a different frequency hand than the mobile station
`transmission but of the same spreading bandwidth, e.g. 1.25 MHz.
`Fig. 2 illustrates a generalized flow diagram of this algorithm used to
`dynamically adjust the power level setpoint, and thus indirectly modify the
`25 mobile station transmitter power. The implementation of the algorithm
`seeks to effect a reduction or increase in the mobile station transmitter
`
`power as a function of the link quality with respect to various frame rate
`data.
`In this implementation a pattern of rate decisions is used to modify '
`the power level setpoint. Although the exemplary embodiment is described
`30 with reference to using the rate decision as an indicator of patterns, other
`parameters may be used.
`
`In Fig. 2, a group of one or more of frame rate decisions is provided
`for inspection, step 150. This group may be comprised of a collection of
`sequential frame rate decisions, or according to some other order, and/ or
`35 which may be dependent upon the frame rate. The group of rate decisions
`are impacted to determine if their pattern is matched to predetermined rate
`decision pattern P1, step 152.
`If there is a pattern match, a modification in
`the power level setpoint is made, step 154. This modification may be in the
`form of an increase or decrease in the power level setpoint by an
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`|PR2018-01473
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`INVT Exhibit 2003 - Page 11
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`INVT Exhibit 2003 - Page 11
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`incremental value. This increase or decrease in the power level setpoint
`ultimately results in a corresponding increase or decrease in the mobile
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`5
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`In those cases where a rate decision pattern
`station transmitter power.
`match indicates a good communication link, the power level setpoint is
`increased to result in the generation of power down commands and
`ultimately a decrease in mobile station transmitter power. Similarly, in
`those cases where a rate decision pattern match indicates a low quality
`communication link, the power level setpoint is increased to result in the
`
`generation of power up commands and ultimately an increase in mobile
`station transmitter power.
`'
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`Should a pattern match occur with a modification of the setpoint,
`steps 152 and 154, a rate decision is updated, step 156, and the process
`repeated.
`Further details on the update aspect of the invention are
`discussed later.
`.
`In the event that pattern determination step 152 results in no pattern
`matching, the process may proceed under several options.
`In one option
`the power level setpoint may be modified, step 158, the rate decision
`updated, step 156, and the process repeated. The modification in step 158 is
`preferably a different modification from that of step 154 (increase vs.
`decrease or vise versa) where a pattern match was detected. It should also be
`
`noted that any setpoint modification as discussed herein may also be set to
`provide no change in the setpoint.
`
`In a preferred implementation should pattern determination step 152
`result in no pattern matching, at least one additional pattern determination
`step is performed. For example, the group of rate decisions are inspected to
`determine if their pattern is matched to another predetermined rate
`decision pattern P2, step 160.
`If there is a pattern match, a modification in
`the power level setpoint is made, step 162 This modification may be in the
`form of an increase or decrease in the power level setpoint by an
`incremental value, or the setpoint is left unchanged. This increase or
`decrease in the power level setpoint ultimately results in a corresponding
`increase or decrease in the mobile station transmitter power. As was for the
`case of step 152 where no pattern match occurred, should there be no pattern
`match in step 160 the setpoint may be modified or left unchanged, step 164.
`In the case where no pattern match occurs in step 160 additional
`pattern match determinations and setpoint modifications may be
`performed. Should there be no pattern match in each of these pattern
`match determinations a final or Nth pattern match determination is made.
`The group of rate decisions are inspected to determine if their pattern is
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`|PR2018-01473
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`INVT Exhibit 2003 - Page 12
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`INVT Exhibit 2003 - Page 12
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`If
`matched to yet another predetermined rate decision pattern PN, step 166.
`there is a pattern match, a modification in the power level setpoint is made,
`step 168. This modification may be in the form of an increase or decrease in
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`5
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`the power level setpoint by an incremental value, or the setpoint is left
`unchanged. This increase or decrease in the power level setpoint ultimately
`results in a corresponding increase or decrease in the mobile station
`
`transmitter power. As was for the case of steps 152 and 160 where no pattern
`match occurred, should there be no pattern match in step 166 the setpoint
`may be modified or left unchanged, step 170.
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`10
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`The process steps of Fig. 2 are repeated generally with an updated
`group of rate decisions with the updating accomplished in step 156. This
`updated group may be comprised of the previous group with the addition of
`a new frame rate decision an