(12) United States Patent
`
`
`
`Zeira et al.
`
`
`
`
`
`
`(10) Patent N0.:
`
`
`(45) Date of Patent:
`
`
`
`
`
`US 6,928,102 B2
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`*Aug. 9, 2005
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`US006928102B2
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`........... .. 455/522
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`............... .. 375/130
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`1/1999 Soliman
`5,859,838 A
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`8/2000 Soliman
`6,101,179 A
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`
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`8/2000 Mallinckrodt ............. .. 455/522
`6,108,561 A *
`
`
`
`
`1/2001 Lomp
`6,175,586 B1
`
`
`
`
`1/2001 Bringby et al.
`6,175,745 B1 *
`
`2/2001 Presott
`6,188,678 B1
`
`
`
`
`4/2002 Chen et al.
`6,373,823 B1
`9/2002 Gunnerson et al.
`6,449,462 B1
`
`
`
`
`7/2003 Zeira et al.
`6,600,772 B1
`
`
`
`
`
`4/2004 Zeira et al.
`6,728,292 B2 *
`
`
`
`
`
`2002/0080764 A1
`6/2002 Zeira et al.
`
`
`
`
`
`FOREIGN PATENT DOCUMENTS
`
`
`0462952
`12/1991
`
`
`0610030
`8/1994
`
`
`0682419
`11/1995
`
`
`4/1998
`0500689
`
`
`9749197
`12/1997
`97/49197
`12/1997
`08/45962
`10/1998
`9845962
`10/1998
`
`EP
`
`EP
`
`EP
`
`EP
`
`WO
`WO
`WO
`WO
`
`
`
`
`
`
`
`(54) USER EQUIPMENT USING COMBINED
`
`
`
`
`CLOSED LOOP/OPEN LOOP POWER
`
`
`
`
`CONTROL
`
`
`
`
`(75)
`
`
`
`Inventors: Ariela Zeira, Huntington, NY (US);
`
`
`
`
`
`Fatih M. Ozluturk, Port Washington,
`
`
`
`
`NY (US); Sung-Hyuk Shin, Northvale,
`
`
`
`
`NJ (US)
`
`
`
`
`
`(73) Assignee:
`
`
`
`InterDigital Technology Corporation,
`
`
`
`
`Wilmington, DE (US)
`
`
`
`( * ) Notice:
`
`
`
`Subject to any disclaimer, the term of this
`
`
`
`
`
`
`patent is extended or adjusted under 35
`
`
`
`
`U.S.C. 154(b) by 0 days.
`
`
`
`
`
`
`
`
`
`
`This patent is subject to a terminal dis-
`
`
`
`
`
`claimer.
`
`
`
`
`
`
`
`
`
`(22)
`
`(21) Appl. No.: 10/831,902
`
`
`
`
`
`
`
`
`
`Filed:
`Apr. 26, 2004
`
`
`
`Prior Publication Data
`
`
`US 2004/0196890 A1 Oct. 7, 2004
`
`
`
`
`
`(65)
`
`
`
`Related U.S. Application Data
`
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`
`
`(63) Continuation of application No. 10/459,035, filed on Jun. 11,
`
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`
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`
`
`2003, now Pat. No. 6,728,292, which is a continuation of
`
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`
`
`
`
`
`application No. 09/531,359, filed on Mar. 21, 2000, now Pat.
`
`
`
`
`
`
`
`
`No. 6,600,772.
`
`
`
`
`
`
`
`(51)
`Int. Cl.7 ................................................ .. H04B 1/69
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`
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`(52) U.S. Cl.
`..................... .. 375/130; 375/295; 455/522;
`370/342
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`(58) Field of Search ............................... .. 375/130, 295,
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`375/146; 370/335, 342, 252; 455/69, 522
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`
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`(56)
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`
`
`
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`
`
`9/1989 McDaVid et al.
`
`
`
`10/1991 Gilhousen et al.
`
`
`
`7/1996 Ivanov et al.
`
`
`
`11/1998 Hakkinen
`
`
`
`4,868,795 A
`
`5,056,109 A
`
`5,542,111 A
`
`5,839,056 A
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`OTHER PUBLICATIONS
`
`
`
`
`“Specification of Air—Interface for the 3G Mobile System”,
`
`
`
`
`
`Version 1.0, ARIB, Jan. 14, 1999.
`
`
`
`
`
`
`
`
`
`(Continued)
`
`
`
`
`
`
`Primary Examiner—Temesghen Ghebretinsae
`(74) Attorney, Agent, or Firm—Volpe and Koenig, P.C.
`
`
`
`
`
`
`
`
`
`
`
`
`
`(57)
`
`
`
`ABSTRACT
`
`
`
`Aspread spectrum time division duplex user equipment uses
`
`
`
`
`
`
`
`
`frames with time slots for communication. It receives power
`
`
`
`
`
`
`
`
`commands and receives a first communication having a
`
`
`
`
`
`
`transmission power level in a first time slot. It measures a
`
`
`
`
`
`
`
`
`power level of the first communication as received and
`
`
`
`
`
`
`
`
`determines a pathloss estimate based on in part the measured
`
`
`
`
`
`
`
`received first communication power level and the first
`
`
`
`
`
`
`
`
`communication transmission power level. The user equip-
`
`
`
`
`
`
`
`ment sets a transmission power level for a second commu-
`
`
`
`
`
`
`
`
`nication in a second time slot from the user equipment based
`
`
`
`
`
`
`
`
`
`on in part the pathloss estimate weighted by a quality factor
`
`
`
`
`
`
`
`
`and adjusted by the power commands.
`
`
`
`
`
`
`7 Claims, 7 Drawing Sheets
`
`
`
`
`
`
`38
`
`/ 40
`
`42
`
`‘“
`
`GENERATE A PKWEII CDNTRDL CDIAIAAHD
`BAIED GI A EIDNAL TO INTERFERENCE
`RATIO OF A WIMUNICATTON IENT
`
`
`
`
`FROM THE TRANOMITIING STATION
`
`
`
`
`
`
`
`
`
`TRANUAIT A DUAIIUNIC
`ATIDN AND THE POWER
`COMMAND FIIOII THE REOEIVING lYA11ON
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`DETERMINE THE RECEIVED POWER LEVEL
`OF THE CDIIAUNICATIDN FITOIA TIE
`REKIVIND STATION AT THE
`
`
`
`
`TRANSMITIWG STATION
`
`
`
`
`
`
`
`
`
`
`
`naranuna AN asmman mm was savwaau
`ma nacalvma AND mmammuc mnau av
`euatnwnua ma nacazvan oouuumcniows
`
`
`
`
`
`vawan LEVEL III as raw ma O0!lM1.IN|GA'l10N'S
`
`
`
`
`
`nuunnlunou rowan LEVEL m an
`
`
`
`
`
`
`
`
`
`
`
`
`DETERIAIIE THE GJALITV OF THE
`EMIIAATED PATH LOSS
`
`
`
`
`
`
`SEWING THE TIINISIITITNG SI'AI1DN'5 POWER
`LEVEL BASED ON IN PART THE POWER
`COIAIAAND AND WHGITING THE ESTIMATED
`
`
`
`
`
`PATH LOG! BASED N THE ESTIMATE‘! QUALITY
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Petitioner's Exhibit 1007
`
`
`
`
`
`
`
`Petitioner's Exhibit 1007
`
`

`
`
`
`US 6,928,102 B2
`Page 2
`
`
`OTHER PUBLICATIONS
`
`
`.
`.
`
`
`
`
`
`Zeira et al., “Comb1ned Closed—Loop/Open—Loop Power
`
`
`
`
`
`
`
`
`Control Process for Time Division Duplexing”, Apr. 1999.
`
`
`
`
`
`
`
`Zeira Ct 31» “PeFf0UI1aUCe Of Weighted Open LOOP Scheme
`
`
`
`
`
`
`
`
`for Uplink Power Control in TDD Mode”, May 1999.
`Zeira et al., “Text Proposal for S1.24”, May 1999.
`
`
`
`
`
`
`
`
`“Specification of Air—Interface for the 3G Mobile System”,
`
`
`
`
`
`Version 1.0, ARIB, Jan. 14, 1999.
`
`
`
`
`
`
`
`
`
`“Combined Closed—Loop/Open—Loop Power Control Pro-
`
`
`
`
`
`cess for Time Division Duplexing”, Ariela Zeira, Sung-
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Hyuk Shin and Fatih Ozluturk, Apr. 1999.
`
`
`
`
`
`
`«performance of Weighted Open Loop Scheme for Uphnk
`Power Control in TDD Mode”, Ariela Zeira and Sung—Hyuk
`
`
`
`
`
`
`
`
`
`
`Shin, May 1999.
`
`
`
`
`
`
`
`“Text Proposal for S1.24”, Ariela Zeira, Sung—Hyuk Shin
`
`
`
`
`
`and Stephen D1Ck> May 1999‘
`* cited by examiner
`
`
`
`
`
`
`
`
`
`Petitioner's Exhibit 1007
`
`Petitioner's Exhibit 1007
`
`

`
`
`U.S. Patent
`
`
`
`
`Aug. 9, 2005
`
`
`
`
`
`Sheet 1 of 7
`
`
`
`US 6,928,102 B2
`
`Petitioner's Exhibit 1007
`
`Petitioner's Exhibit 1007
`
`

`
`
`U.S. Patent
`
`
`
`
`Aug. 9, 2005
`
`
`
`
`Sheet 2 of 7
`
`
`
`US 6,928,102 B2
`
`TIME
`
`3434
`
`34
`
`FIG.2
`
`
`Petitioner's Exhibit 1007
`
`Petitioner's Exhibit 1007
`
`

`
`
`U.S. Patent
`
`
`
`
`
`Aug. 9, 2005
`
`
`Sheet 3 of 7
`
`
`
`US 6,928,102 B2
`
`
`FIG. 3
`
`
`38
`
`
`
`
`
`
`
`GENERATE A POWER CONTROL COMMAND
`
`
`
`BASED ON A SIGNAL TO INTERFERENCE
`
`
`
`RATIO OF A COMMUNICATTON SENT
`
`
`
`
`
`
`FROM THE TRANSMITTING STATION
`
`
`
`
`
`
`
`TRANSMIT A COMMUNICATION AND THE POWER
`
`
`
`
`
`COMMAND FROM THE RECEIVING STATION
`
`
`40
`
`
`
`
`
`
`DETERMINE THE RECEIVED POWER LEVEL
`
`
`
`
`
`OF THE COMMUNICATION FROM THE
`
`
`
`RECEIVING STATION AT THE
`
`
`TRANSMITTING STATION
`
`
`
`42
`
`
`
`
`
`
`
`
`
`
`DETERMINE AN ESTTMATED PATH LOSS BETWEEN
`
`
`
`
`
`THE RECEIVING AND TRANSMITTING STATION BY
`
`
`
`
`
`SUBTRACTTNG THE RECEIVED COMMUNICATION'S
`
`
`
`
`
`
`
`
`POWER LEVEL IN dB FROM THE COMMUN|CATTON'S
`
`
`
`
`TRANSMISSION POWER LEVEL IN dB
`
`
`
`
`
`
`DETERMINE THE QUALITY OF THE
`
`
`
`ESTIMATED PATH LOSS
`
`
`
`
`46
`
`
`
`
`
`
`
`
`
`
`
`
`SETTING THE TRANSMITTING STATION'S POWER
`
`
`
`
`
`LEVEL BASED ON IN PART THE POWER
`
`
`
`
`COMMAND AND WEIGHTING THE ESTIMATED
`
`
`
`
`
`
`PATH LOSS BASED ON THE EST'IMATE'S QUALITY
`
`
`
`
`
`Petitioner's Exhibit 1007
`
`Petitioner's Exhibit 1007
`
`

`
`U.S. Patent
`
`Aug. 9, 2005
`
`Sheet 4 of 7
`
`US 6,928,102 B2
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`Petitioner's Exhibit 1007
`
`Petitioner's Exhibit 1007
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`

`
`U.S. Patent
`
`Aug. 9, 2005
`
`Sheet 5 of 7
`
`US 6,928,102 B2
`
`—-— CLOSED ONLY
`
`—-— SCHEME -I
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`
`Petitioner's Exhibit 1007
`
`Petitioner's Exhibit 1007
`
`

`
`
`U.S. Patent
`
`
`
`
`
`Aug. 9, 2005
`
`
`
`Sheet 6 of 7
`
`
`
`US 6,928,102 B2
`
`
`
`
`FIG. 7
`
`A 7
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`new (smn
`
`Petitioner's Exhibit 1007
`
`1
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`
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`
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`
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`- _ — ‘ ‘ _ . ' _ _ _ - — _ _ _ _ - ' ‘ _ _ - _ ’ _ - - - ' — —L—-
`.|
`—o— scneme -II
`
`
`Petitioner's Exhibit 1007
`
`

`
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`U.S. Patent
`
`
`
`
`Aug. 9, 2005
`
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`
`Sheet 7 of 7
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`US 6,928,102 B2
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`FIG. 9
`
` STDOFESTIMATEDSNR((8)
`
`
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`2
`
`1
`
`
`
`_ _ _ _
`
`
`
`—-— CLOSED ONLY
`
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`_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ -5-
`.|
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`Petitioner's Exhibit 1007
`
`
`
`
`
`'5:‘.5.
`
`
`
`
`
`uomanuzenBusorESHIIATEDsun
`
`Petitioner's Exhibit 1007
`
`

`
`
`
`US 6,928,102 B2
`
`1
`
`USER EQUIPMENT USING COMBINED
`
`
`
`
`CLOSED LOOP/OPEN LOOP POWER
`
`
`
`
`CONTROL
`
`CROSS REFERENCE TO RELATED
`
`
`
`APPLICATION
`
`
`This application is a continuation of U.S. application Ser.
`
`
`
`
`
`
`No. 10/459,035, filed Jun. 11, 2003 now U.S. Pat. No.
`
`
`
`
`
`
`
`
`
`
`6,728,292, which is a continuation of U.S. patent application
`
`
`
`
`
`
`Ser. No. 09/531,359 filed Mar. 21, 2000 now U.S. Pat. No.
`
`
`
`
`
`
`
`
`
`
`
`6,600,772, which is incorporated by reference as if fully set
`
`
`
`
`
`
`forth.
`
`
`BACKGROUND
`
`This invention generally relates to spread spectrum time
`
`
`
`
`
`
`
`
`
`
`
`
`
`division duplex (TDD) communication systems. More
`particularly, the present invention relates to a system and
`
`
`
`
`
`
`
`
`method for controlling transmission power within TDD
`
`
`
`
`
`
`
`communication systems.
`
`
`FIG. 1 depicts a wireless spread spectrum time division
`
`
`
`
`
`
`
`duplex (TDD) communication system. The system has a
`
`
`
`
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`
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`plurality of base stations 301-307. Each base station 301
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`communicates with user equipments (UEs) 321-323 in its
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`operating area. Communications transmitted from a base
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`station 301 to a UE 321 are referred to as downlink com-
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`munications and communications transmitted from a UE
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`321 to a base station 301 are referred to as uplink commu-
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`nications.
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`In addition to communicating over different frequency
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`spectrums, spread spectrum TDD systems carry multiple
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`communications over the same spectrum. The multiple
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`signals are distinguished by their respective chip code
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`sequences (codes). Also, to more efficiently use the spread
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`spectrum, TDD systems as illustrated in FIG. 2 use repeating
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`frames 34 divided into a number of time slots 361-3611, such
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`as fifteen time slots. In such systems, a communication is
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`sent in selected time slots 361-3611 using selected codes.
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`Accordingly, one frame 34 is capable of carrying multiple
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`communications distinguished by both time slot 361-3611
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`and code. The combination of a single code in a single time
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`slot is referred to as a resource unit. Based on the bandwidth
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`required to support a communication, one or multiple
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`resource units are assigned to that communication.
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`Most TDD systems adaptively control
`transmission
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`power levels. In a TDD system, many communications may
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`share the same time slot and spectrum. When a UE 321 or
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`base station 301 is receiving a specific communication, all
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`the other communications using the same time slot and
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`spectrum cause interference to the specific communication.
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`Increasing the transmission power level of one communi-
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`cation degrades the signal quality of all other communica-
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`tions within that time slot and spectrum. However, reducing
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`the transmission power level too far results in undesirable
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`signal to noise ratios (SNRs) and bit error rates (BERs) at the
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`receivers. To maintain both the signal quality of communi-
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`cations and low transmission power levels,
`transmission
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`power control is used.
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`One approach to control transmission power levels is
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`open loop power control.
`In open loop power control,
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`typically a base station 301 transmits to a UE 321 a reference
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`downlink communication and the transmission power level
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`of that communication. The UE 321 receives the reference
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`communication and measures its received power level. By
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`subtracting the received power level from the transmission
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`power level, a pathloss for the reference communication is
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`determined. To determine a transmission power level for the
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`10
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`15
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`20
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`25
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`30
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`35
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`40
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`45
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`50
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`55
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`60
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`65
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`2
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`uplink, the downlink pathloss is added to a desired received
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`power level at the base station 301. The UE’s transmission
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`power level is set to the determined uplink transmission
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`power level.
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`Another approach to control transmission power level is
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`closed loop power control. In closed loop power control,
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`typically the base station 301 determines the signal
`to
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`interference ratio (SIR) of a communication received from
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`the UE 321. The determined SIR is compared to a target SIR
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`(SIRTARGET). Based on the comparison, the base station
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`301 transmits a power command, bTPC. After receiving the
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`power command,
`the UE 321 increases or decreases its
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`transmission power level based on the received power
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`command.
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`Both closed loop and open loop power control have
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`disadvantages. Under certain conditions, the performance of
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`closed loop systems degrades. For instance, if communica-
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`tions sent between a UE and a base station are in a highly
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`dynamic environment, such as due to the UE moving, such
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`systems may not be able to adapt fast enough to compensate
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`for the changes. The update rate of closed loop power
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`control
`in TDD is 100 cycles per second which is not
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`sufficient for fast fading channels. Open loop power control
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`is sensitive to uncertainties in the uplink and downlink gain
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`chains and interference levels.
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`One approach to combining closed loop and open loop
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`power control was proposed by the Association of Radio
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`Industries and Business (ARIB) and uses Equations 1, 2, and
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`3.
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`TUE=PBS(11)+L
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`PB5(11)=PB5(11—1)+bTPCA,-PC
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`b
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`1: if SIRE; < SIRTARGET
`:
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`TPC {-1: if SIRBS > SIRTARGET
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`Equation 1
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`Equation 2
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`Equamn 3
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`TUE is the determined transmission power level of the UE
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`321. L is the estimated downlink pathloss. PBS(n) is the
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`desired received power level of the base station 301 as
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`adjusted by Equation 2. For each received power command,
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`the desired received power level
`is increased or
`bTPC,
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`decreased by ATPC. ATPC is typically one decibel (dB). The
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`power command, bTPC, is one, when the SIR of the UE’s
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`uplink communication as measured at the base station 30,
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`SIRB5, is less than a target SIR, SIRTARGET. Conversely, the
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`power command is minus one, when SIRB5 is larger than
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`SIRTARGET’
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`Under certain conditions, the performance of these sys-
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`tems degrades. For
`instance,
`if communications sent
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`between a UE 32 and a base station 30 are in a highly
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`dynamic environment, such as due to the UE 32 moving, the
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`path loss estimate for open loop severely degrades the
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`overall system’s performance. Accordingly, there is a need
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`for alternate approaches to maintain signal quality and low
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`transmission power levels for all environments and sce-
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`narios.
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`SUMMARY
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`A spread spectrum time division duplex user equipment
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`uses frames with time slots for communication. It receives
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`power commands and receives a first communication having
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`a transmission power level in a first time slot. It measures a
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`power level of the first communication as received and
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`determines a pathloss estimate based on in part the measured
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`received first communication power level and the first
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`Petitioner's Exhibit 1007
`
`Petitioner's Exhibit 1007
`
`

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`US 6,928,102 B2
`
`4
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`The closed loop power command generator 88 uses the
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`measured communication’s received power level and the
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`interference level, IRS, to determine the Signal to Interfer-
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`ence Ratio (SIR) of the received communication. Based on
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`a comparison of the determined SIR with a target SIR
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`(SIRTARGET), a closed loop power command is generated,
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`bTRC, such as a power command bit, bTRC, step 38.
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`Alternately,
`the power command may be based on any
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`quality measurement of the received signal.
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`For use in estimating the path loss between the receiving
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`the
`and transmitting stations 50, 52 and sending data,
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`receiving station 50 sends a communication to the transmit-
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`ting station 58, step 40. The communication may be sent on
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`any one of various channels. Typically, in a TDD system, the
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`channels used for estimating path loss are referred to as
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`reference channels, although other channels may be used. If
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`the receiving station 50 is a base station 301, the commu-
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`nication is preferably sent over a downlink common channel
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`or a common control physical channel (CCPCH). Data to be
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`communicated to the transmitting station 52 over the refer-
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`ence channel is referred to as reference channel data. The
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`reference data may include, as shown, the interference level,
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`IRS, multiplexed with other reference data, such as the
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`transmission power level of the reference channel, TRS. The
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`interference level, IRS, and reference channel power level,
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`TRS, may be sent in other channels, such as a signaling
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`channel. The closed loop power control command, bTRC, is
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`typically sent in a dedicated channel. The dedicated channel
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`is dedicated to the communication between the receiving
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`station 50 and transmitting station 52, step 40.
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`The reference channel data is generated by a reference
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`channel data generator 86. The reference data is assigned
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`one or multiple resource units based on the communication’s
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`bandwidth requirements. A spreading and training sequence
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`insertion device 82 spreads the reference channel data and
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`makes the spread reference data time-multiplexed with a
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`training sequence in the appropriate time slots and codes of
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`the assigned resource units. The resulting sequence is
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`referred to as a communication burst. The communication
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`burst is subsequently amplified by an amplifier 78. The
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`amplified communication burst may be summed by a sum
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`device 72 with any other communication burst created
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`through devices, such as a data generator 84, spreading and
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`training sequence insertion device 80 and amplifier 76.
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`The summed communication bursts are modulated by a
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`modulator 64. The modulated signal is passed through an
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`isolator 60 and radiated by an antenna 56 as shown or,
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`alternately, through an antenna array. The radiated signal is
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`passed through a wireless radio channel 54 to an antenna 58
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`of the transmitting station 52. The type of modulation used
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`for the transmitted communication can be any of the those
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`known to those skilled in the art, such as direct phase shift
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`keying (DPSK) or quadrature phase shift keying (QPSK).
`The antenna 58 or, alternately, antenna array of the
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`transmitting station 52 receives various radio frequency
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`signals. The received signals are passed through an isolator
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`62 to a demodulator 66 to produce a baseband signal. The
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`baseband signal is processed, such as by a channel estima-
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`
`tion device 100 and a data estimation device 102, in the time
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`slots and with the appropriate codes assigned to the com-
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`munication burst of the receiving station 50. The channel
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`estimation device 100 commonly uses the training sequence
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`component
`in the baseband signal
`to provide channel
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`information, such as channel impulse responses. The chan-
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`nel information is used by the data estimation device 102, a
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`power measurement device 110 and a quality measurement
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`device 114.
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`10
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`15
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`20
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`25
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`30
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`35
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`40
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`45
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`50
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`55
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`60
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`65
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`
`
`Petitioner's Exhibit 1007
`
`
`3
`communication transmission power level. The user equip-
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`
`ment sets a transmission power level for a second commu-
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`nication in a second time slot from the user equipment based
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`on in part the pathloss estimate weighted by a quality factor
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`and adjusted by the power commands.
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`BRIEF DESCRIPTION OF THE DRAWINGS
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`FIG. 1 illustrates a prior art TDD system.
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`FIG. 2 illustrates time slots in repeating frames of a TDD
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`system.
`FIG. 3 is a flow chart of combined closed loop/open loop
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`power control.
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`FIG. 4 is a diagram of components of two communication
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`stations using combined closed loop/open loop power con-
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`trol.
`
`FIGS. 5-10 depict graphs of the performance of a closed
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`loop, ARIB’s proposal and two (2) schemes of combined
`closed loop/open loop power control.
`
`
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`
`
`DETAILED DESCRIPTION OF THE
`
`
`
`PREFERRED EMBODIMENTS
`
`
`The preferred embodiments will be described with refer-
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`
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`ence to the drawing figures where like numerals represent
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`like elements throughout. Combined closed loop/open loop
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`power control will be explained using the flow chart of FIG.
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`3 and the components of two simplified communication
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`stations 50, 52 as shown in FIG. 4. For the following
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`discussion, the communication station having its transmit-
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`ter’s power controlled is referred to as the transmitting
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`station 52 and the communication station receiving power
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`controlled communications is referred to as the receiving
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`station 50. Since combined closed loop/open loop power
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`control may be used for uplink, downlink or both types of
`
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`communications, the transmitter having its power controlled
`
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`
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`may be located at a base station 301, UE 321 or both.
`
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`
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`Accordingly, if both uplink and downlink power control are
`
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`
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`used, the receiving and transmitting station’s components
`
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`are located at both the base station 301 and UE 321.
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`The receiving station 50 receives various radio frequency
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`signals including communications from the transmitting
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`station 52 using an antenna 56, or alternately, an antenna
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`array. The received signals are passed through an isolator 60
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`to a demodulator 68 to produce a baseband signal. The
`
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`
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`baseband signal is processed, such as by a channel estima-
`
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`
`
`
`tion device 96 and a data estimation device 98, in the time
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`slots and with the appropriate codes assigned to the trans-
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`mitting station’s communication. The channel estimation
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`device 96 commonly uses the training sequence component
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`as channel impulse responses. The channel information is
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`used by the data estimation device 98,
`the interference
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`measurement device 90,
`the signal power measurement
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`device 92 and the transmit power calculation device 94. The
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`data estimation device 98 recovers data from the channel by
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`estimating soft symbols using the channel
`information.
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`Using the soft symbols and channel information, the trans-
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`mit power calculation device 94 controls the receiving
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`station’s transmission power level by controlling the gain of
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`an amplifier 76.
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`The signal power measurement device 92 uses either the
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`soft symbols or the channel information, or both, to deter-
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`mine the received signal power of the communication in
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`decibels (dB). The interference measurement device 90
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`determines the interference level
`IRS, within the
`in dB,
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`channel, based on either the channel information, or the soft
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`symbols generated by the data estimation device 98, or both.
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`Petitioner's Exhibit 1007
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`US 6,928,102 B2
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`5
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`The power level of the processed communication corre-
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`sponding to the reference channel, RTS, is measured by the
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`power measurement device 110 and sent
`to a pathloss
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`estimation device 112, step 42. Both the channel estimation
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`device 100 and the data estimation device 102 are capable of
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`separating the reference channel from all other channels. If
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`an automatic gain control device or amplifier is used for
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`processing the received signals, the measured power level is
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`adjusted to correct for the gain of these devices at either the
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`power measurement device 110 or the pathloss estimation
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`device 112. The power measurement device 110 is a com-
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`ponent of the combined closed loop/open loop controller
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`108. As illustrated in FIG. 4, the combined closed loop/open
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`loop power controller 108 comprises the power measure-
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`ment device 110, pathloss estimation device 112, quality
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`measurement device 114, and transmit power calculation
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`device 116.
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`To determine the path loss, L, the transmitting station 52
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`also requires the communication’s transmitted power level,
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`TRS. The transmitted power level, TRS, may be sent along
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`with the communication’s data or in a signaling channel. If
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`the power level, TRS, is sent along with the communication’s
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`data, the data estimation device 102 interprets the power
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`level and sends the interpreted power level to the pathloss
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`estimation device 112. If the receiving station 50 is a base
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`station 301, preferably the transmitted power level, TR5, is
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`sent via the broadcast channel (BCH) from the base station
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`301. By subtracting the received communication’s power
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`level, RTS in dB, from the sent communication’s transmitted
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`power level, TR5 in dB, the pathloss estimation device 112
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`estimates the path loss, L, between the two stations 50, 52,
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`step 44. In certain situations, instead of transmitting the
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`transmitted power level, TR5, the receiving station 50 may
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`transmit a reference for the transmitted power level. In that
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`case, the pathloss estimation device 112 provides reference
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`levels for the path loss, L.
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`If a time delay exists between the estimated path loss and
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`the transmitted communication, the path loss experienced by
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`the transmitted communication may differ from the calcu-
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`lated loss. In TDD systems where communications are sent
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`in differing time slots 361-336”, the time slot delay between
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`received and transmitted communications may degrade the
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`performance of an open loop power control system. Com-
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`bined closed loop/open loop power control utilizes both
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`closed loop and open loop power control aspects. If the
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`quality of the path loss measurement is high, the system
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`primarily acts as an open loop system. If the quality of the
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`path loss measurement is low, the system primarily acts as
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`a closed loop system. To combine the two power control
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`aspects, the system weights the open loop aspect based on
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`the quality of the path loss measurement.
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`A quality measurement device 114 in a weighted open
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`loop power controller 108 determines the quality of the
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`estimated path loss, step 46. The quality may be determined
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`using the channel information generated by the channel
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`estimation device 100, the soft symbols generated by the
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`data estimation device 102 or other quality measurement
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`techniques. The estimated path loss quality is used to weight
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`the path loss estimate by the transmit power calculation
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`device 116. If the power command, bTPC, was sent in the
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`communication’s data, the data estimation device 102 inter-
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`prets the closed loop power command, bTPC. Using the
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`closed loop power command, bTPC, and the weighted path
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`the transmit power calculation device 116 sets the
`loss,
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`transmit power level of the receiving station 50, step 48.
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`The following is one of the preferred combined closed
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`loop/open loop power control algorithms. The transmitting
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`10
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`15
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`25
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`45
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`50
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`55
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`60
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`65
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`6
`station’s power level in decibels, PT5, is determined using
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