United States Patent [191
`United States Patent 1191
`Marash
`Murash
`
`
`[l1J Patent Number: 111 J Patent Number:
`[45) Date of Patent:
`145J Date of Patent:
`
`5,825,898
`5,825,898
`Oct 20, 1998
`Oct. 20, 1998
`
`
`
`111II111 111II111
`
`1541
`SYSTEM AND METHon FOR ADAIYrlV[ [54] SYSTEM ANn METHOI) I'"OR AI)AI)TIVI~
`
`INTERFER ENC I~ CANCI-: LLlNC
`INTEHFERENCt: CANCELLING
`
`Inventor:
`Inventor:
`
`JOSCllh lI,lHrllSh, Haifa. Israel
`J OSCllh I\IllnlSh, Haifa, Israel
`
`1751
`1751
`1731
`Assignee: Llll1mr Signall'roccssing Lid., Ilaifa,
`[73] Assignee: Lllrnnr Signal I'rocl'SSing Lid., Ilaifa.
`brad
`Israel
`
`121] Appl. No.: 672,899
`App!. No.: 672,899
`[21]
`
`[221
`Il2]
`1511
`151]
`[52[
`[52]
`
`[58]
`[58]
`
`1561
`1561
`
`Jun . 27, 1996
`Jun .27, 1996
`
`Filed:
`Filed:
`I.nt. CI.6
`HO·m 3/00
`... _ ......... _......
`Int. CI.6
`...... • HO·m 3/00
`U.S. CI. .......................... 381/92; 381194.1; 381/91.2;
`U.S. CI. . ........................ 3t11/92; 381/94.1 ; 381191.2;
`
`38\194.7; 3671121: 367/119 381 194.7; 367/ 121: 361/119
`Field of Search
`.......... 381{92, 94, 155,
`Field of Search ............................... 381/92.94,155,
`381/94.1,94.2-94.4,94.7,26,122. III;
`381/94.1 ,94.2-94.4,94.7,26,122, Ill;
`367/1 21- 122, [23-126, 119. 118
`367/121-122, [23-126, [19,118
`
`I{cfcrcnccs Citl-d
`References Cited
`
`U.S. PATENT DOCU MENTS
`U.S. PATENT DOCUMENTS
`
`4,239,936
`4,239.936
`4,363.007
`4.363.007
`4,409,435
`4,409, 435
`4,442,546
`4,442,546
`4,459,85 1
`4,459,85 1
`
`4,495,643 4,495,643
`4,5 17,41 5
`4,5 17,41 5
`4,559,642
`4,559,642
`4,58 1,758
`4.581,758
`4,589, 137
`4.589.137
`4,622,692
`4,622,692
`4,628,529
`4,628,529
`4,653, 102
`4,653.102
`4,653,606
`4,653.606
`4,658,426
`4,658.426
`
`12/1980 Sakoc .
`12/1980 Saka<: .
`12/1982 IInramQlo ci al.
`12/1982 Ilnmmolo c( al ..
`
`iOf1983 0 00 . 10/ 1983 000 .
`411984 Ishiga ki .
`4{1984 Ishigaki .
`7f 1984 C rQslack .
`7{1984 Croslack .
`1/ 1985 Orban.
`1/1985 Orban.
`5/1985 I.aurence.
`5{1985 Laurence.
`12/1985 Mi)"aji tt at. .
`12/1985 Miynji ~1 al. .
`4/1986 Co kN tt al.
`4/1986 C(lker el al.
`5{1986 Miller.
`5/1986 Miller.
`I lf1986 Cole .
`11/1986 C(l ie •
`12{1986 &nh CI 31.
`12/1986 &r1h et al.
`3/1987 Uan"",n.
`3/1987 Uansen .
`3/1987 Flanagan.
`.1/l987 Flanagan .
`4{1987 Chabrics CI ~I.
`411987 Cllabries et al.
`
`(Lisl continucd on nexi pagc.)
`(List continued on next pagc.)
`
`FOREIGN PATENT DOCUMENTS
`FO REIG N PATENT DOCUMENTS
`
`B 0411360
`l3(l4113QO
`0059745 HI
`0059745 III
`0411360 HI
`(}411 360 Bl
`0483 845 A2
`0 483 845 A2
`048.l845
`~s.184 S
`0721251
`0721251
`0724415
`0724415
`
`,fOOOO EurOJl'l'an 1'31. Off ..
`of 0000
`European I'al. Off ..
`9/1982
`EUrQJl'I'3n I'al. Off ..
`9/t982
`European I'al. Off ..
`2{t!l91
`2/1991 EuroJl'l'a n Pal. Off ..
`EuroJX'an I'at Off ..
`5{1992 EuroJl'l'a n 1'a1- Off ..
`5{1!l92
`European 1':11. Off ..
`1/1993 European l'al. Off ..
`1/1993
`Europ"an I'al. Off ..
`European !'at orr . .
`711996 European )'al. Off ..
`7/ 1996
`European I'a!. orr ..
`11/ 1996 European I'at. Off ..
`1111996
`
`4/ 1997 European I~JI. Off.
`4/1997
`European l'at Off.
`Japan.
`bjlQ89
`6/1989
`Japan.
`1/1992
`Japan.
`Japan.
`1{1992
`7/1991
`7{1991 United Kingdom.
`United Kingdom.
`
`889089()3.3
`88908903.3
`1-149695
`1· 149695
`4-16900
`4-16900
`223997 1 H
`2239971 B
`WO-A-97/
`WO-A-971
`WlPO .
`,fOOOO
`
`23068 2J068 of 0000 WlPO .
`WO 88fl)9512
`WlPO.
`WO 88fl)9512 12{1988 W1PO .
`12/1988
`WlPO .
`711994 WlPO .
`WO 94/16517
`7/1994
`WO 94/ 16517
`WlPO.
`6{1997 WIPO.
`WO 97/230S8
`6/1997
`WO 97!23068
`
`O'mER PUBucxn ONS
`OTI-IER PUBU C"XTlONS
`
`"Bcamfonning, a versatile approach 10 spacial fJl1ering,"
`'"Beamfonning, a versatile approach 10 spacial fillering,"
`IEEE ASSN Magazine, Apr. 1988, vol. 5, No.2, pp. 4-24.
`IEEE ASSN Magazine, Apr. 1988, vol. 5, No.2, pp. 4-24.
`Sewald el aI., "Application of ... 13eamfonning 10 Reject Sewald el aI., "Applicalion of ... Bcamfonning 10 Rejecl
`
`Turbulence Noise in Airduc1S," 1996 IEEE Inlernalional
`Turbulence Noil>e in Airducls," 1996 IEEE Inlernational
`Conference on Acouslics. Spcech and Signal Processing
`Confercnce on Aoouslics. Speech and Signal Proc'Cssing
`Proceedings ( ICASSP). May 7-16, 1996, vol. 5, No.
`Proceedings ( ICASSP), May 7-]6, 1996, vol. 5, No.
`CONF-2 1. May 7, 1996, IEEE Pl'. 2734-2737.
`CONF-2 1, May 7. 1996, IEEE pp. 2734-2737.
`Widrow et aI., Adapativc Noise Cancclling: Principles alld
`Widrowet aI., Adapalive Noise Cancelling: Principles and
`Applicalions, Proc. IEEE 63: 1692- 1716,1975.
`Applicalions, !'roc. IEEE 63: 1692- 1716, 1975.
`Vall Veen and Buckley, Beamforming: A Vcrsali lc Approach
`Van Veen and Buckley, Bearnfomling: A Vers:lli lc Approach
`
`10 Spatial Filtering, IEEE ASSP Mag. 5(2),4-24,1988. 10 Spalial Fillering, IEEE ASSI' Mag. 5(2),4-24, 1988.
`
`Griffiths and Jim, An Allernative Approach to Linearly Gritliths and Jim, An Ailernative Approach to Linearly
`Conslrained Adaptive l3eamforming, IE.EE Trans. Anl. l'rop. Conslraincd Adapliv.:: Be amforming, I£EE Trans. Anl. l'rop.
`
`AI'-30:27-34, 1982.
`A I'- 30:27- 34, !982.
`
`AHSTIMc r
`AHSTRACT
`
`Primary Extllililler-Curtis A . Kuntz
`"rilllary E.l"lllIIiller-Curtis A . Kunl~.
`Assis/a111 Examil/er-Duc Nguyen
`Ass;s/(III/ Examiller- Duc Nguyen
`AI/orney, Agem, or Firm--Frommcr, Lawrence & I'!aug,
`AI/orne), Agefl/, or Firm- Frommer, Lawrence & l-bug,
`LLP; "IOOmas J. Kowalski; I. Muc Asperas
`LLP; Thomas J. Kowalski; I. Marc Asperas
`1571
`1571
`An adaptivc system and melhod for reducing illlcrfcrencc in
`An adaptive systcm and method for reducing i11lerferencc in
`a signal received (rom an array of sensors. Adaptive Hilers
`a signal received from an array of sensors. Adaptive fillcrs
`are used to generalc cancelling signals Ihal closely approxi.
`arc used to gcnl'ralC cancelling signals Ih:1l closely approxi(cid:173)
`male the intcrference prescnt in Ihc received signal. lnc
`male Ihe interference pr.::sent in lhe received signal. The
`adaptive fillcr wcighls are converted into 100 frequency
`adaptive Hiler weights arc converted inlo too frequency
`domain where tbe frequency representalion values in a
`domain where the frequency rcprClSCnl31ion values in a
`selectcd frequency range are truncated to avoid signal leak· selected frequency range arc truncated 10 avoid signallcak(cid:173)
`
`age involving narrow band signals. Decolorizing filters arc
`age involving narrow band signals. Decnlori:dng Hhers arl!
`used 10 produce the cance!ling signals having a llal fre (cid:173)
`used to produce too cancciling signals having a tlal fre(cid:173)
`qucncy spectrum. Normalized power differcncc is used limit
`quency spectrum . Normalized power difference is used limit
`lhc opera tion of the adaptive IilteTS to Ihc case where therc
`Ihe operalion of the adaptive fillers to Ihe case where there
`is some directional interference 10 be elimi nated.
`is somc direclional inlerference 10 be elimillaled.
`
`28 Claims, 15 I)rawlng ShN!ls
`28 C laims, 1.5 ]}ruwlng S heets
`
`RTL898_1001-0001
`
`Realtek 898 Ex. 1001
`
`

`
`5,825,898 5,825,898
`
`I'age 2
`Page 2
`
`U.S. PATENT DOCUMENTS
`U.S. PATENT DOCUMENTS
`
`9/1987 [wahara d 31.
`4,696,043
`9/ 1987 Iwaha ra CI 31.
`4,6%,043
`1/1988 M~ise l .
`4,718,096
`1/1988 Me i~ l
`4,718,096
`.
`3/ 1988 Levin d al. .
`4,731,850
`3/l988 Lev in cl al. •
`4.73 1,850
`4/ 1988 J:lkQ et 31.
`4,741,038
`4/ 1988 Elko el 31.
`4,741 .OJ8
`6/ 1988 Gebert el al.
`4.750,207
`6/ 1988 Gcbc rl tl al ..
`4,750,207
`9/ 1988 Taguchi .
`4.769,847
`9/ 1988 'n'Suchi .
`4.769,847
`1/1989 ElkQ Cl 31.
`4,802,227
`111 989 El ko eI al.
`4,802,227
`3/ 1989 V,lmur Cl al.
`4,811,404
`3/ 1989 Vilmur CI al.
`4,81 1,404
`3/ 1990 [lorn .
`4,910,718
`3f 19?O !lorn .
`4,910,7 18
`3/ 1990 'llIubcrt .
`3/ 1990 TllUb~rt .
`4,910,719
`4,910,719
`6/ 1990 Naimnlur ...
`4,932,063
`6/ 1990 Nakamura .
`4,932,063
`6/ 1990 lIallor; .
`4,937,871
`6/ 1990 lIall or; •
`4,937,871
`9/1990 7..arek el 31.
`4,956,867
`911990 Za,ek cl 31.
`4,956,867
`4,965,834 10/ 1990 Miller .
`4,965,834 10/ 1990 Mill er .
`5,075,694 12/199 1 Donnangclo CI al. .
`5.075.694 12!199 1 Donnangclo cl al. •
`2/1992 Takahashi el at. .
`2/1992 Takahash i Cl al.
`5,086,415
`5,086.415
`5, 142,585
`8/1992 Ta ylor .
`8/1992 1',,)'10' .
`5,14 2,585
`3/ 1993 Sugiya ma.
`3/ 1993 Sugiyama.
`5, 192,918
`5, 192.9 18
`5,208,864
`5/ 1993 Kaneda.
`5.208.864
`5/ 1993
`I\"neda .
`5/ 1993 Ariyoshi.
`5,212,764
`5.212,764
`5/1993 Ari)'oshi .
`5,241,692
`8/1993
`llarrison et al.
`8/1993 "lartisan ('( al.
`5,24 1,692
`5/ 1994 Kami )"a.
`5/1994 Kamiya .
`5,313,555
`5,313,555
`6/ 1994 lIum .
`5,319.7)6
`6/ 1994 Ilunl.
`5,319.736
`811994 Alld co ct al. ,
`5,335,011
`8/ 1994 Aoklco et al •.
`5,335,0 11
`5,353,376 10/ 1994 Oh Cl al ••
`5,353,376 10/ 1994 Oh et al.
`1/1995 Andrea et al ..
`5.381,473
`111995 A",lIea e1 al ..
`5,38 1,473
`5,41 2,735
`5/ 1995 Engebretson ct 31.
`5/1995 Engebretsoo C1 31.
`5,41 2,735
`5,41 6,845
`5/ 1995 Shen.
`5fl 995 S hen .
`5,41 6,845
`
`5/1995 B,ne.
`5,41 6,847
`5/1995 B.ne .
`5,41 6,847
`5/1995 Shimada.
`5,41 6,887
`511995 Shimada.
`5,4 16,887
`7/1995 Yang et 31.
`7/1995 Yans CI 31.
`5,432,859
`5,432,859
`5,473,701 12/1995 Ce7.anne N a1.
`5.473,70 1 12/1995 CC7.a nne cl 81.
`5,473,702 12/1995 Yos hida el 31.
`5.473,702 12/1995 Yoshida t l 31.
`1/1996 Allen Cl al.
`1/ 1Q96 Allen cl al.
`5,485,5 15
`5,485,5 15
`5,5 11, 128
`4/1996 Li ndemann.
`5,5 11, 128
`4/1996 Li ndemann .
`5/ 1996 RQy, III el al.
`5,5 15,378
`5/1996 Roy, ill ct al.
`5,5 15,378
`6/1996 1\;lIion c1 al .•
`5,524,056
`6/1996 KilliQ" cl al.
`5,524,056
`5,524,057
`6/1996 Akiho el al.
`5,524,057
`6/1996 Akiho el al ..
`5.546,090
`8/1996 RQY, J1[ et al.
`5,546,090
`8/19% Roy. III Cl al. .
`5,581,620 1]/19% Bmndst~in Cl 31.
`5,581,620 1111996 Bra ndslcin CI 31. .
`1/1997 Cni et al.
`5,592,181
`1/1997 Cai CI . 1. .
`5,592,18 1
`1/1997 Barratt et BI.
`5,592,49(1
`1/1997 Barratt cl 31.
`5,592.490
`3/1997 Cale, el al. .
`5,615,175
`3/1997 CatN et 31.
`5,615,175
`5,625,697
`4/1997
`l30wen ct al ..
`5,62.5,697
`4/1997
`'lowen c1 al .•
`4/1997 (}Qldburg ~t 31.
`4/1997 GQJdbll rg eI al.
`5,625,880
`5.625,880
`5,627,799
`5/1997 Iloshu)'am a .
`5,627,799
`5/1997 Ilos huyama .
`5/1997 IIQshu)'ama .............................. 381192
`5/1<)fj7
`5,627,999
`Ilos hu )'a ma .............................. 381192
`5,627,999
`5,642,353
`6/1997 Roy, lit Cl al.
`6/1997 Roy, ill Ci 31.
`5,642,.153
`5,644,641
`7/ 1997 Ikeda .
`5,644.1>41
`7/1997
`Ik~..:I a .
`5,657,393
`8/1997 Crow .
`5,657,393
`8/1997 Crow.
`9/1997 Chu cl al.
`5,664,021
`9/1997 Chu ei al. .
`5.664,021
`5,668,747
`9/1997 Ohashi.
`5,668,747
`9/ 1997 Oh""hi.
`9f1997 Andrea ct al.
`9{1997 Andrea cl ai, ,
`5,673,325
`5,673,325
`5,68<),572 1111997 Ohki el al ..
`5,689,572 11/1997 Ohki Cl al. .
`5,70 1,344 12/1997 Wakui .
`5,701,344 12/1997 Wakui ,
`5,7 15,3 19
`2/1998 Chu .
`2f1998 Chu .
`5,715,3 19
`311998 Ikeda,
`3/1998 Ikeda .
`5,727fj73
`5,727fj73
`
`RTL898_1001-0002
`
`

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`
`RTL898_1001-0005
`
`

`
`U.S. Patent
`U.S. Patent
`
`
`
`Oet. 20, 1998 Oct. 20, 1998
`
`Sheet 4 of 15
`Sheet 4 of 15
`
`5,825,898
`5,825,898
`
`41
`41
`440
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`FIG.4
`FIG.4
`
`RTL898_1001-0006
`
`

`
`
`
`U.S. Patent U.S. Patent
`
`Oct. 20, 1998
`OCI. 20, 1998
`
`Shce( 5 of 15
`Sheet 5 of 15
`
`5,825,898
`5,825,898
`
`51d
`51d
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`
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`->....-j T.APPED DElAY UNE
`
`52d
`52d
`
`
`
`FIG.S FIG.S
`
`RTL898_1001-0007
`
`

`
`U.S. Patent
`U.S. Patent
`
`Oct. 20, 1998
`Oct. 20, 1998
`
`
`
`Sheet 6 of 15 Sheet 6 of 15
`
`5,825,898
`5,825,898
`
`W11
`
`670
`
`67b
`
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`
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`
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`
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`
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`
`-1..": TAPPED DElAY UNE
`
`FIG.6
`FlG.6
`
`RTL898_1001-0008
`
`

`
`U.S. Patent
`U.S. Patent
`
`Oct. 20, 1998
`Oct. 20, 1998
`
`Sheet 7 of 15
`Sheet 7 of IS
`
`5,825,898
`5,825,898
`
`<1
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`RTL898_1001-0009
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`
`84
`84
`
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`
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`FIG.8
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`
`FREQUENCY-
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`
`,------'--c-l""-MS:c-'---,
`
`UPDATE
`UPDATE
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`
`103
`103
`
`107
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`RTL898_1001-0011
`
`IX>
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`FIG.9
`FIG.9
`
`•••
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`
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`
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`FIG.10
`
`•
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`
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`115h
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`
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`
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`
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`
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`
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`
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`
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`
`RTL898_1001-0012
`
`

`
`u.s. Patent
`U.S. Patent
`
`Oct. 20, 1998
`Oct. 20, 1998
`
`Sheet II of 15
`Sheet II of 15
`
`5,825,898
`5,825,898
`
`100
`).--...../)00
`START PR~ J\----..,J
`START PROGRAM
`
`(
`
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`.--_.........,) 1D
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`
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`REGISTERS, POINTERS,
`& BUFfERS
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`I
`I
`120
`I WAIf FOR INTERRUPT ~ 131 " I WAIf FOR INTERRUPT ~ 131 h
`
`120
`I
`I
`
`(
`
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`READ SENSOR
`SAMPlES
`SAMPLES
`
`130
`130
`
`141
`14h
`
`I INPlITS T.D.L
`I INPUTS T.D.L I
`
`I INPUTS T.D.L 1
`I INPlITS T.D.L
`I
`
`SAMPLES READY
`SAMPlES READY
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`
`140
`140
`
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`
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`
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`
`I
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`
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`I
`I
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`
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`
`171
`171 "\
`(
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`I INPUTS lD.L L
`
`170
`170
`
`RTL898_1001-0013
`
`MULTIPLY VECTORS
`MULTIPLY VECTORS
`
`STORE REF. CH.
`STORE REF. CH.
`RESULTS
`RESULTS
`
`
`
`I I
`
`FIG.11 A
`FIG.11 A
`
`

`
`U.S. Patent
`U.S. Patent
`
`Oct. 20, 1998
`Oct. 20, 1998
`
`Sheet 12 of 15
`ShCCl12ofl5
`
`5,825,898
`5,825,898
`
`r - - - - L - - 1
`r--- -L--1
`I REPEAT 170-180 I
`190
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`190
`L----r--J
`I FOR All 01HER r----j
`I FOR All OTHER r--~j
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`I
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`MULTIPLY VECTORS ~ DECOLORIZATION
`FlLTER COEFF.
`. FILTER COEFF.
`I
`
`202
`l-
`
`210
`,210
`
`STORE DECOLORIZEO
`STORE DECOLORIZEO
`RESULT
`RESULT
`
`01 ,
`2
`201-
`(
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`I REF.CH. l
`l
`
`200
`200
`
`I
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`r
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`220
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`220
`I FOR All OTHER r-----..'
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`I 230
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`
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`
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`
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`
`
`
`FIG.11 B FIG.11B
`
`RTL898_1001-0014
`
`

`
`U.S. Patent
`U.S. Patent
`
`OCI. 20, 1998
`Oct. 20. 1998
`
`Sheet 13 of 15
`Shcel 13 of 15
`
`5,825,898
`5,825,898
`
`;r
`
`)60
`
`264,
`264, '
`
`SUMMATION
`SUMMATION
`
`-
`,-
`
`( OUTPUT TO O/A ~
`( OUTPUT TO O/A )
`
`26 1
`261
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`: ~263
`
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`
`28h
`281-
`
`280
`280
`
`REf CH.
`REf CH.
`SAMPLE
`SAMPLE
`POWER
`POWER
`
`STORE OllTPUT
`STORE OUlPUT
`RESULT
`RESULT
`
`270
`}70
`
`282
`282,
`
`STORE POWER X a
`STORE POW£R x a
`+ POWER AVG. x (1- a )
`+ POWER AVG. x (1- a )
`
`OLD REf CH.
`OLD REF CH.
`POWER AVG.
`POWER AVG.
`
`STORE NEW
`STORE NEW
`REf. CH. POWER AVG.
`REf. CH. POWER AVG.
`
`290
`~ }90
`
`____ I
`I
`,---------,
`------,
`I
`: REPEAT zao-290
`: REPFAT 2BO-290
`:
`FOR ALL 01liER
`,----
`fOR /IlL OTHER
`~----.. 300
`I
`I
`~
`I REf. CHANNELS
`I
`1 REf. CHANNELS
`I
`L----r ----1
`L----r---.J
`I
`FIG.11C
`FIG.11C
`
`STORE TOTAL REf.
`STORE TOTAl.. REf.
`CH. POWER AVG.
`CH. POWER AVG.
`
`~ 1 0
`310
`
`RTL898_1001-0015
`
`

`
`U.S. Patent
`U.S. Patent
`
`
`
`Oct. 20. 1998 Ocl. 20, 1998
`
`Sheet 14 of 15
`Shcel 14 of 15
`
`5,825,898
`5,825,898
`
`
`
`321 " 321
`
`320
`320
`
`MAIN CH.
`MAIN CH.
`SAMPLE
`SAMPLE
`POWER
`POWER
`
`I I
`
`STORE POWER x a
`STORE POWER X a
`
`+ POWER AVG. x (1- a ) + POWER AVG. x (1- a )
`
`322 ,
`322
`
`OLD MAIN CH.
`OLD MAIN CH.
`POWER AVG.
`POWER AVG.
`
`STORE NEW
`STORE NEW
`MAIN CH. POWER AVG .
`MAIN CH. POWER AVG .
`
`330
`~30
`
`
`. .
`MAIN CH. POWER AVG.
`MAIN CH. POWER AVG.
`x THRESHOLD
`x THRESHOLD
`
`340
`~40
`
`+~ 352,
`
`350
`
`352
`
`~
`YES
`/
`
`YES ( GO BACK TO 120) GO BACK TO 120
`
`
`
`351, 351
`
`-
`-
`
`TOTAl REf. CH.
`TOTAL REf. CH.
`
`POWER AVG. POWER AVG.
`361,
`361
`
`+
`
`> 0
`> 0
`
`NO
`NO
`
`
`
`36( 36;
`
`363 ,
`363,
`
`NEW WElGHT=
`NEW WElGHT=
`OLD WEIGHT + H OLD WEIGHTS I
`-j OLD WEIGHTS I
`OLD WEIGHT +
`2 x p. x REf. CH. x OUTPUT
`2 x I" x REf. CH. X OUTPUT
`
`STORE - )70
`
`STORE
`NEW WEIGHTS
`NEW WEIGHTS
`
`370
`
`m
`m
`
`380
`,380
`
`OMDE INTO FREQ. - ,390
`
`DMOE INTO FREQ.
`
`SINS BINS
`
`\ \
`
`,390
`
`FIG.11D
`FI G .11 0
`
`
`FlAT FREQ. _ FlAT FR£Q.
`REf. CH.
`REf. CH.
`
`
`
`r-r-
`
`OUTPUT I-
`OUTPUT -
`
`RESULT RESULT
`
`'-362
`362
`
`RTL898_1001-0016
`
`

`
`U.S. Patent
`U.S. Patent
`
`OCL. 20, 1998
`Oct. 20, 19')8
`
`Sheet 150115
`Sheet IS of IS
`
`5,825,898
`5,825,898
`
`I 400
`
`m>
`m>
`NO
`NO
`THRESHOLD? >-----~
`THRESHOLD? >-----~
`
`YES
`YES
`
`410
`410
`
`mUNCAIT m VAlUE
`lRUNCATE m VALUE
`
`1m
`
`STORE NEW
`STORE NEW
`mUNCAlID W£lGHTS
`lRUNCATED WElGfITS
`
`420
`420
`
`
`
`430 430
`
`,------ --------,
`r- ----- -------,
`
`REPEAT 360-430 REPEAT 360-430
`I
`I
`I
`I
`FOR ALL OTHER REf.
`:
`:
`FOR All. OTHER REF.
`:
`:
`I CHANNElS AND ADAPTIVE
`.,_ 440
`I CHANNElS AND ADAPTlVE
`,....
`440
`L______ _ _____ ..J
`L______ _ _____ -l
`I
`F1LITRS
`I
`.... ~
`I
`FILTERS
`I'~
`
`450
`450
`GO BACK TO 120 .---..J
`GO BACK TO 120 ...--.. . ./
`
`FIG.11E
`FIG.11 E
`
`RTL898_1001-0017
`
`

`
`5,825,898
`5,825,898
`
`"
`
`2
`2
`s v sn :l\ 1 ANI> M ETHo n FOR A I)Af"Tl VE
`S VS'rEt\', ANI> METHOI) FOR AI)AI"T1VE
`Adapti\'e noise cance ll ing can be combined with
`Adaptive noise cancell ing ca n be combined with
`INTfo: RI' fo: RENO: CANCELLI NG
`INTfo: Rn : llfo: NC E CANCELLING
`bc:amforming, a known technique of using an array of
`bc.amforming, a known technique of using an anay of
`sensors to improve reception of si£llals coming from a
`sensors 10 improve reception of signals coming from a
`BACKGROUND OF Til E INVEN'nON
`BACKGROUNI) OF 111E INVEN'"1l0N
`specific direl.1ion. A bumformer is a spatial filter that
`specific din.:C1ion. A beamformer is a spatial filter that
`Tht present invention relates generally to signal
`The present invention relates generally 10 signal
`s generates a single channel from multiple channels rccei\'cd
`S generales a single chanOtI from multiple channels received
`processing. and more specifically to an adaplive signal
`pl'Ol'<!SSing •• ocI more sllel:ifically 10 aD adaptive signal
`through multiple sensors by filtering the ioclividual multiple
`through mUltiple sensors by filtering the individual multiple
`processing sySlem and method for redul;ng inlerfererK'W: in
`processing system and method for reducing interfcrence in
`cll:innels and combining Ihem in such a way as 10 extract
`channeL<; and combining Ihem in such a way as to eXlract
`a recdved signal.
`a received signal.
`signals coming from a specific direction. 'I'hus, a beam(cid:173)
`signals coming from a specifIC directioo. Thus. a beam(cid:173)
`There arc many instances where it is desirable to have a
`There arc many instances where it is desirable to have a
`former can change the direclion of rct-eiving sensitivity
`former can change the din.:ction of re<.'Civing sensilivity
`sensor capable of receiving an information signal from a
`sensor capable of receiving an information signal from a
`to without physically moving the array o( scnsors. For de tails
`10 without physically moving thl! array of scnsors. For delails
`panicular signal SOUI\."e where the environment inclucks
`particular signal souree where the environment includes
`on heamforming, see B. I). Van Veen and K. M. Buckley,
`on beamformins, see IJ. I). Van 'Wen and K. M. Buckley,
`sources of inh:rfcrence signals al locations dim;rent froll1
`sour<.'Cs of interference signals at locations different from
`Ilcamforming:
`Beamforming:
`that of the signal SOUI\."e. One such instance is the use of
`that of lhe signal source. One such instancc is the use of
`mil'fOpbones to rel'Oro a particular par1Y's speech in a room
`A Versatile Approach to Spatial Filtering, IEEE ASSP
`A Versatile Approach to Spatial Filtering, IEEE ASSP
`microphones to record a particular pany's speech in a room
`wher.;: there arc mher parties speaking simultaneously, caus(cid:173)
`Mas, 5(2), 4- 24.
`Mag. 5(2). 4-24.
`where there arc other parties speaking simultaneously. caus(cid:173)
`ing interferenl'e in the received signals.
`ing interfefCncc in the received signals.
`Since the bcamformer can effectively be pointed in many
`Since the beamformer can errc~1ively be pointed in many
`If one knows the exact characteristics of the interferencc,
`If one knows the exact characteristics of the interference,
`direClions without physically moving its sensors, the bcam(cid:173)
`directions without physically moving ilS sensors, the beam(cid:173)
`one can use a li)(ed.weight filter tosupprcss it. But it is often
`one can use a fixed-weight filtcr to suppress it. But it isoflen
`former can be combined with adaptive noise cancelling to
`former can be combined with adaptive noise cancelling to
`diflicult to prcdict the exact charach:ristics of the irnerfcr_
`diflicult to predict the exael characteristics of the illlerfer(cid:173)
`form an IIdnplivc bcamfor!l1er thlll carl sup pres.~ specific
`form an ad~p tive beamformer that can suppress specific
`eocc because they may vary aCl'Oroing 10 changes in the
`eoce because they may vary according to changes in Ihe
`directional interference ralher than general background
`directiona l interference rather th3n general background
`interference sources, the backsround noise, acoustic 2()
`interference sou rces, the background noise, acoustic 20
`noise. '111e bcamfor!l1er CDrI provide the primary input by
`noise. The beamformer can provide the primary input by
`environment, orientation of the sensor with respect to Ihe
`environment. orientation of the scnsor with rcspeet to the
`spatially filtering input signals from an array of .sensors so
`spalially tiltering input signals from an array of sensors so
`signal source, the transmission paths from the signal source
`signal source. the transmission paths from the signal sour<.'C
`that its output repfCSCntS a Signal received in the dirto'etion of
`that its output represents a signal received in the direction of
`10 IhI! sensor, and many other factors. Therefore, in ordcr to
`10 the sensor. and many other factors. Therefore, in order to
`a signal saurce. Similarly. the bcamfomlCr can provide the
`a signal source. Similarly. the beamfomler can provide the
`suppress such irnerference, an adaptive system that can
`suppress such interference, an adaptive system that can
`reference input by spatially liltering the sensor signals so
`refe rence input by spatially filtering the sensor signals so
`change ilS own parameters in response to a changing envi- :s
`change its own I'aramelers in response to a changing envi- 25
`thai the Outpul represents a signal rece ived in lhe d irection
`Ihat the out put reprc.scnts a s ignal rece ived in the direction
`rOllllle01 is needed.
`ronment is needed.
`of interference sources. I:or a seminal article on adaptive
`of interference sourcc.~. For a seminal article on adaptivc
`An adapti\'e filler is an adaptive system that can change its
`An adapti\'\: filter is an adaptive system that can change its
`beamformers. sce L. J. Griffiths & C. W. Jim, An Alternative
`beamformers. see L. J. Griffiths & C. W. Jim, An Alternative
`owo filtering chu.1deristics. in ordc:r to produce a desired
`own fillering characleristics in order to produce a desired
`Approach to Ijnearly Constrained Adaptive Ikamforming.
`Approach to Linearly Constrained Adaptive Heamforming.
`response. Typically. the filter weights defining tbe chanc(cid:173)
`response. Typically. the filter weights defining the chllue(cid:173)
`IEEE Trans. Ant . Prop. AP-30:27-34, 1982.
`IEEE Trans. Ani . Prop. AP-3O;27-34, 1982.
`teristicsof an adaptive filter l rc oontinuQUsly updated so that
`teristicsof an adaptive filter arc continuously updated so that
`One problem wilh a l'On\'entional adaplive bcamformer is
`One problem with a com:enlional adaplivc beamformer is
`tbe differcno: bet~n a signal representing a desircd
`the diffcrence betwecn a signal representing a desired
`that ilS OUlput charaderistics change depeoding on input
`thai its output characteristics change depending on input
`response and an oUlplU signal of the adaptive lilter is
`respollS<! and an output signal of the adaplive filler is
`frequeneies and SCO.'iOr dir~ion.<; with respect to interfer·
`frequencies and sensor directions wilh respect 10 interfer·
`minimi1.cd.
`minimil.cd.
`ence sources. This is due 10 the sensilivity of a beamformcr
`ence sources. l bis is due 10 the sensitivity of a beamformer
`'l'lle