`
`
`
`
`
`
`
`(12) United States Patent
`US 8,416,862 B2
`(10) Patent N0.:
`
`
`
`
`
`
`
`
`(45) Date of Patent:
`Apr. 9, 2013
`Aldana et a].
`
`
`
`USOO8416862B2
`
`
`
`(54) EFFICIENT FEEDBACK 0F CHANNEL
`
`
`
`INFORMATION INA CLOSED LOOP
`
`
`
`BE AMFORMING WIRELESS
`
`
`COMMUNICATION SYSTEM
`
`
`
`
`
`(75)
`
`
`
`Inventors: Carlos Aldana, San Francisco, CA (US);
`
`
`
`
`
`Joonsuk Kim, San Jose, CA (US)
`
`
`
`
`
`
`
`
`(73) Assignee: Broadcom Corporation, Irvine, CA
`
`
`
`
`
`(US)
`
`
`
`( * ) Notice:
`
`
`
`
`
`
`
`
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`
`
`
`
`
`
`
`
`U‘S‘C‘ 1540)) by 2247 days.
`.
`,
`..
`
`
`
`
`(21) APP] NO . 11/237 341
`
`
`
`
`
`
`(22) Filed:
`
`
`
`
`
`Sep. 28, 2005
`
`
`
`2003/0139196 Al *
`............ 455/522
`7/2003 Medvedev et a1.
`
`
`
`
`
`
`
`2004/0042558 A1 *
`3/2004 Hwang et a1.
`375/267
`
`
`
`
`
`
`2005/0286663 A1 'v"
`12/2005 Poon ............................. 375/347
`
`
`
`
`
`OTHER PUBLICATIONS
`
`
`
`
`
`
`
`A unified algebraic transformation approach for parallel recursive
`
`
`
`
`
`
`
`
`and adaptive filtering and SVD algorithms Jun Ma; Parhi, K.K.;
`
`
`
`
`
`
`
`
`
`
`Deprettere, E.F.; Signal Processing, IEEE Transactions on [see also
`
`
`
`
`
`
`
`
`Acoustics, Speech, and Signal Processing, IEEE Transactions on]
`
`
`
`
`
`
`
`vol. 49, Issue 2, Feb. 2001 pp. 424—437.*
`
`
`
`
`
`
`
`
`
`* cited by examiner
`
`
`
`
`
`
`
`Primary Examiner 7 Shuwang Pin
`
`
`
`
`Assistant Examiner i Michael NEH
`(74) Attorney, Agent, or Firm 7 Garlick & Markison; Holly
`
`
`
`
`
`
`
`
`L. Rudnick
`
`
`
`
`
`
`Prior Publication Data
`
`
`
`OCt' 26’ 2006
`.
`.
`
`
`
`
`
`
`Related US Application Data
`
`
`
`
`(63) Continuation-in—part of application No. 11/168,793,
`filed on Jun. 28, 2005.
`
`
`
`
`;
`.
`.
`.
`.
`
`
`
`
`
`30238151211 app1.19am? NO'190/g73'fi31‘ figgigg 2:);
`
`
`
`
`
`J lpigvbsggga
`app iea 1011
`’
`’
`’
`fila d
`0‘
`'
`
`
`
`
`
`
`
`
`
`e on u '
`'
`’
`
`(:1)
`Int Cl
`
`
`
`v
`(2006 01)
`H0;1K 1/10
`g
`.
`.
`'
`
`
`
`
`
`
`
`........ 375/260, 375/267, 375j350
`(;2) U..S. Cl.
`......‘
`
`
`
`
`
`
`
`(”8) Fleld otiClassifiglatiaon Searclh """""lili'w 375 267
`
`
`
`
`
`
`
`See app leation
`e or comp ete searc
`istory.
`g
`.
`References Clted
`(”6)
`
`
`U.S. PATENT DOCUMENTS
`
`
`
`$541,607 A *
`7/1996 Reinhardt
`..................... 342/372
`
`
`
`2002/0187753 A1* 12/2002 Kim et a1.
`....................... 455/69
`
`
`
`
`
`
`
`
`
`
`ABSTRACT
`(57)
`
`
`
`
`
`
`
`
`
`A method for feeding back transmitter beamforming infor-
`mation from a receiving Wireless communication device to a
`
`
`
`
`
`
`
`
`
`
`
`transmitting Wireless communication device includes a
`
`
`
`
`
`
`receiving Wireless communication device receiving a pre-
`amble sequence from the transmitting Wireless device. The
`
`
`
`
`
`
`
`
`receiving Wireless device estimates a channel response based
`
`
`
`
`
`
`
`upon the preamble sequence and then determines an esti-
`
`
`
`
`
`
`
`
`mated transmitter beamforming unitary matrix based upon
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`the channel response and a receiver beamforming unitary
`
`
`
`
`
`
`
`
`matrix. The receiving Wireless device then decomposes the
`
`
`
`
`
`
`
`estimated transmitter beamforming unitary matrix to produce
`the transmitter beamforming infomiation and then Vvirelessly
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`sends the transmitter beamforming information to the trans—
`
`
`
`
`
`
`
`
`initting Wireless device. The receiving Wireless device may
`
`
`
`
`
`
`
`transform the estimated transmitter beamforming unitary
`matrix using a QR decomposition operation such as a Givens
`
`
`
`
`
`
`Rotation operation to produce the transformer beamforming
`
`
`
`
`
`
`
`mformanon'
`
`
`20 Claims, 8 Drawing Sheets
`
`
`
`
`
`
`
`
`
`
`
`(65)
`
`
`
`
`US 2006/0239374 A1
`
`
`
`(60)
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`lFFT
`coraztsgiartgon
`interleaving
`o-
`o
`
`
`
`
`
`
`
`
`
`
`
`module fl
`module fi
`module 1_3_4
`3 8
`g), 5
`
`
`
`.
`o 3.,
`0- 8
`('5 g
`
`
`
`
`
`
`E 2
`puncture
`encodlng
`g. a“
`: g 3.
`
`
`
`
`
`
`
`3 g.
`o g
`module m module fl
`0 <1 m
`
`H ti
`n t
`Sm
`A ‘1
`3";
`
`
`
`
`
`
`
`
`
` mapping
`interleaving
`0° 5 e 3 °”
`5
`lFFT
`g
`
`
`module 1_2§
`
`
`
`
`
`
`module m
`module @
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Page 1 of 19
`
`SAMSUNG EXHIBIT 1001
`
`Page 1 of 19
`
`SAMSUNG EXHIBIT 1001
`
`
`
`
`US. Patent
`
`
`
`
`Apr. 9, 2013
`
`
`
`Sheet 1 0f 8
`
`
`
`
`
`US 8,416,862 B2
`
`__
`
`
`
` ___asE8__38$8Awmv"_qofiflmmmmcozooccoocozflmmwmn_25u,x1111111wmm\_
`
`“__"<9.mm_on._aun_mm_,wwm._mm//mmcozumccou_/|||||||||||||\_EZ<|__Nwcozomccoookn=8_w
`532m;_//’.x850:
`
`
`
`___
`
`Page 2 of 19
`
`Page 2 of 19
`
`
`
`
`US. Patent
`
`Apr. 9, 2013
`
`Sheet 2 0f 8
`
`US 8,416,862 B2
`
`I:o_w.m>coo_EaxxMeson”EwK:6289
`
`0:69:_v239:238E963005
`
`o:08
`
`mm.23
`
`mm.936
`
`xm\x._.
`
`£235
`
`2:uoE
`
`.82
`
`8:268
`
`mEuoE
`
`Eccmco
`
`$3.6m£936ch
`
`938E
`
`“E
`
`U:209:0
`
`
`w:9:0:69:0:60.:
`
`
`_lm_."Ux:o_m_m>cooEmma:._.\mCtSE
`
`mm5%
`
`LmEEmcm:
`
`mEmmwooa
`
`0.:uoE
`
`eoeyeuu! lsoq
`
`
`
`mm_m:m_mgEmu950350
`
`onwh
`
`8IN.9".
`
`562255:5:93
`
`omEmu832:8
`
`“E9585mmEmu958E
`
`
`
` mo8omEmuwarm—:82
`
`
`
`fian>ox.Emogmx
`
`.20.9353th
`
`Sag
`
`momtmfi
`
`
`
`Sm.295me08:95
`
`
`
`Smfiwfi53:0
`
`mEmmmoEa
`
`226E
`
`aoeyemg
`OlpBJ
`
`Nmée
`
`83%“we:
`
`
`
`8389.956
`
`Page 3 of 19
`
`Page 3 of 19
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`US. Patent
`
`
`
`
`Apr. 9, 2013
`
`
`
`Sheet 3 0f 8
`
`
`
`
`US 8,416,862 B2
`
`Nmée
`
`_.mom?_M3:38.:_mm3%_9585_o:£956:30c.LENov55%
`_HE_228.:9.69:W_msuoE
`r.“Evn.HE(8:023286
`
`mcfimwooaco?m»_KPw.ncmnmmmpml...
`.I.9_wbmhU
`tNNFaWmo29850mm
`
`1.,25.23E
`
`
` ‘__Hmm____m0_5:.x:___N:m_mcm_ml.__o9:85__o_“Euczoezo__62:?I""vo.Emu__mo_.0950930_u0950930_EEEwcm:"_o
`
`._
`
`
`
`.0668:88::9555
`
`.umafix.Emon>ox59:M.J.ae
`
`
`..228Eem
`
`
`fimwmawmfimws338%m
`
`
`n.07.
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`u.o.
`
`Page 4 of 19
`
`Page 4 of 19
`
`
`
`
`
`US. Patent
`
`
`
`
`Apr. 9, 2013
`
`
`
`Sheet 4 0f 8
`
`
`
`
`US 8,416,862 B2
`
`
`outbound symbol
`
`
`streams 104
`
`
`
`._.nE_
`
`
`
`vlmlr238E
`
`Hm”:
`
`
`
`09.228E
`
`b
`
`cozm=flwcoo
`
`9399:
`
`.mbmmmmwa925.:
`
`)9:39:W2:o_um__2mcoog3n1
`
`a228E
`
`mc_>mo:mE_
`
`a9:88
`
`m5>mm=m§
`
`@MH938E
`
`
`
`230:3
`
`a2.69:
`
`mcfioocm
`
`law228E
`
`
`outbound
`data 94
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Page 5 of 19
`
`Page 5 of 19
`
`
`
`
`
`
`
`
`
`
`US. Patent
`
`
`
`
`Apr. 9, 2013
`
`
`
`Sheet 5 0f 8
`
`
`
`
`US 8,416,862 B2
`
`
`inbound
`
`data 92
`
`mcfioomu
`
`a928E
`
`
`
`9.383%
`
`
`
`vmv2.69:
`
`
`
`:00
`
`mc_>mo_.2:_
`
`
`
`09.228E
`
`corm=9mcoo
`
`mcaqumc
`
`a2.608
`
`
`
`lmu
`
`9.38225
`
`g228E
`
`832938
`
`mciamEou
`
`a232:
`
`
`beamforming (U)
`module 144
`
`
`
`
`
`FE
`
`a0:69:
`
`.Eu.
`
`a939:
`
`o o o
`
`
`inbound symbol
`
`
`streams 124
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Page 6 of 19
`
`Page 6 of 19
`
`
`
`
`
`
`
`
`
`US. Patent
`
`
`
`
`Apr. 9, 2013
`
`
`
`Sheet 6 0f 8
`
`
`
`
`US 8,416,862 B2
`
`V
`
`>
`
`A.lllllllllllllll
`
`
`
`
`
`
`
`----fl..owflwmmmwmmw......
`
`
`
`Page 7 of 19
`
`Page 7 of 19
`
`
`
`
`
`
`US. Patent
`
`
`
`
`Apr. 9, 2013
`
`
`
`Sheet 7 0f 8
`
`
`
`
`US 8,416,862 B2
`
`VON
`
`
`
`eon
`
`con
`
`
`
`o:
`
`
`
`NE
`
`
`
`
`
`EEEmcgvmecanooxomaooflv659:5:m8qu29v
`
`
`
`3029585m5§2Emmn
`
`
` .mEEmcm:25289E0::Emcmfi
`LmEEmcmbm:.28235:09:0068va$3BEEmcmfi
`
`
`
`mucwcoQEooxomnnmmh
`
`
`
`xEmEmEEBtcmon
`
`
`
`«EM
`
`\-.0."—
`
`
`
`5mem:_E.2EmmnV6225399.658:289:38:5me
`
`
`
`
`
`we.
`
`
`
`
`$59.5080:9VxEmE@5882:meho«$25me$280
`
`
`
`
`woumEEoooion9385208
`
`
`
`3VxEmEbEE:mEE§Emmn
`
`
`
`
`
`
`
`5282man$5me65chcon:$2335590853950
`
`
`
`
`
`
`
`c_$282anA3xEmEESE:m:_E.£Ewmn.wEEmcmz99.:sz
`
`
`
`New
`
`memomm
`$289E8:83.3:520mfiEzmwBEEmma
`
`
`
`
`
`
`
`
`
`
`
`
`
`Page 8 of 19
`
`Page 8 of 19
`
`
`
`
`
`
`US. Patent
`
`
`
`
`Apr. 9, 2013
`
`
`
`Sheet 8 0f 8
`
`
`
`
`US 8,416,862 B2
`
`vow
`
`
`
`mom
`
`
`
`
`
`
`
`
`
`6289com:893SD:nI@223965.20wmanoowo
`
`
`
`
`
`.wEEmcmbQmEcmm22>95VxEmEESE:mEEBDPEmmn
`
`
`
`5289“mA>VxEmEESE:mEgeEmwn
`
`oom
`
`
`
`o5
`
`
`
`wow
`
`xomnumfi22>9cosfiommcmzo me:9vxEmEESE:
`
`
`@558?meumHmEzmwomanoomo
`.wEEmcmiwEmcanoo
`
`
`
`
`EosmEBE@586?me
`
`
` 53::ng98289E0:gEmcmfi
`.wEEmcmbm:8%935:09:00xomnumfi8w:55885:.
`
`
`
`wEmcanooxomnumfi
`
`
`
`xEmEmEFEQEmmn
`
`Now
`
`
`
`
`
`magma
`5289E9.:8:0396:520BmEzQOEEmma
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`Page 9 of 19
`
`Page 9 of 19
`
`
`
`
`
`
`
`US 8,416,862 B2
`
`1
`
`EFFICIENT FEEDBACK 0F CHANNEL
`
`
`INFORMATION IN A CLOSED IJOOP
`
`
`BEAMFORMING WIRELESS
`
`
`COMMUNICATION SYSTEM
`
`
`CROSS REFERENCES TO RELATED
`
`
`APPLICATIONS
`
`
`
`
`
`
`
`2
`
`The low noise amplifier receives inbotmd RF signals via the
`
`
`
`
`
`
`
`
`
`antenna and amplifies then. The one or more intermediate
`
`
`
`
`
`
`
`
`frequency stages mix the amplified RF signals with one or
`
`
`
`
`
`
`
`
`more local oscillations to convert the amplified RF signal into
`
`
`
`
`
`
`
`
`baseband signals or intermediate frequency (IF) signals. The
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`filtering stage filters the baseband signals or the IF signals to
`attenuate unwanted out of band signals to produce filtered
`
`
`
`
`
`
`
`signals. The data recovery stage recovers raw data from the
`
`
`
`
`
`
`
`
`
`
`filtered signals in accordance with the particular wireless
`
`
`
`
`
`
`
`
`communication standard.
`
`
`As is also known, the transmitter includes a data modula-
`
`
`
`
`
`
`
`
`tion stage, one or more intermediate frequency stages, and a
`
`
`
`
`
`
`
`
`power amplifier. 'lhe data modulation stage converts raw data
`
`
`
`
`
`
`
`
`
`into bascband signals in accordance with a particular wirclcss
`
`
`
`
`
`
`
`communication standard. The one or more intermediate fre-
`
`
`
`
`
`
`
`quency stages mix the baseband signals with one or more
`
`
`
`
`
`
`
`
`
`local oscillations to produce RF signals. The power amplifier
`
`
`
`
`
`
`
`amplifies the RF signals prior to transmission via an antenna.
`
`
`
`
`
`
`
`In many systems, the transmitter will include one antenna
`
`
`
`
`
`
`
`
`
`for transmitting the RF signals, which are received by a single
`
`
`
`
`
`
`
`antenna, or multiple antennas, of a receiver. When the
`
`
`
`
`
`
`
`
`receiver includes two or more antennas, the receiver will
`
`
`
`
`
`
`
`
`select one ofthem to receive the incoming RF signals. In this
`
`
`
`
`
`
`
`
`instance, the wireless communication between the transmit-
`
`
`
`
`
`
`
`
`
`
`
`
`
`tcr and rcccivcr is a singlc-output-singlc-input (SISO) com-
`munication, even if the receiver includes multiple antennas
`
`
`
`
`
`
`
`that are used as diversity antennas (i.e., selecting one of them
`
`
`
`
`
`
`
`
`
`to receive the incoming RF signals). For SISO wireless com-
`
`
`
`
`
`
`
`
`
`munications, a transceiver includes one transmitter and one
`
`
`
`
`
`
`
`receiver. Currently, most wireless local area networks
`
`
`
`
`
`
`
`
`(WLAN) that are IEEE 802.11, 802.1 la, 802,11b, or 802.11g
`
`
`
`
`
`
`
`employ SISO wireless communications.
`
`
`
`
`Other types of wireless communications include single-
`
`
`
`
`
`
`
`
`
`input-multiple-output (SIMO), multiple-input-single-output
`(MISO), and multip1e-input-multiple-output (MIMO). In a
`
`
`
`
`SIMO wireless communication, a single transmitter pro—
`
`
`
`
`
`
`ces ses data into radio frequency signals that are transmitted to
`
`
`
`
`
`
`
`
`
`a receiver. The receiver includes two or more antennas and
`
`
`
`
`
`
`
`
`
`two or more receiver paths. Each of the antennas receives the
`
`
`
`
`
`
`
`
`RF signals and provides them to a corresponding receiver
`
`
`
`
`
`
`
`path (e.g., LNA, down conversion module, filters, and ADCs).
`
`
`
`
`
`
`
`
`
`Each of the receiver paths processes the received RF signals
`
`
`
`
`
`
`
`to produce digital signals, which are combined and then pro-
`
`
`
`
`
`
`
`
`
`
`ces sed to recapture the transmitted data.
`
`
`
`
`
`For a multiple-input-single-output (MISO) wireless com-
`
`
`
`
`
`munication, the transmitter includes two or more transmis-
`
`
`
`
`
`
`
`sion paths (e.g., digital to analog converter, filters, up—conver—
`
`
`
`
`
`
`
`
`sion module, and a power amplifier) that each converts a
`
`
`
`
`
`
`
`
`corresponding portion of baseband signals into RF signals,
`
`
`
`
`
`
`
`which are transmitted via corresponding antennas to a
`
`
`
`
`
`
`
`receiver. The receiver includes a single receiver path that
`
`
`
`
`
`
`
`
`receives the multiple RF signals from the transmitter. In this
`
`
`
`
`
`
`
`
`instance, the receiver uses beam forming to combine the
`
`
`
`
`
`
`
`
`multiple RF signals into one signal for processing.
`
`
`
`
`
`
`
`For a multiplc-input-multiplc-output (MIMO) wirclcss
`
`
`
`
`communication, the transmitter and receiver each include
`
`
`
`
`
`
`
`multiple paths. In such a communication, the transmitter par-
`
`
`
`
`
`
`
`allel processes data using a spatial and time encoding func—
`
`
`
`
`
`
`
`
`
`tion to produce two or more streams of data. The transmitter
`
`
`
`
`
`
`
`
`includes multiple transmission paths to convert each stream
`
`
`
`
`
`
`
`of data into multiple RF signals. The receiver receives the
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`multiple RF signals via multiple receiver paths that recapture
`the streams of data utilizing a spatial and time decoding
`
`
`
`
`
`
`
`
`
`function. The recaptured streams of data are combined and
`
`
`
`
`
`
`
`
`subsequently processed to recover the original data.
`
`
`
`
`
`
`To further improve wireless communications, transceivers
`
`
`
`
`
`
`may incorporate beamfonning. In general, beamforming is a
`
`
`
`
`
`
`
`
`
`
`
`
`
`BACKGROUND OF THE INVENTION
`
`
`
`
`
`
`This application is a continuation—in—part of US. Utility
`application Ser. No. 11/168,793, filed Jun. 28, 2005 which
`
`
`
`
`
`
`
`
`
`claims priority to II.S. Provisional Patent Application Ser.
`
`
`
`
`
`
`
`
`No. 60/673,451, filedApr. 21, 2005, and this application also
`
`
`
`
`
`
`
`
`
`
`claims priority to US. Provisional Patcnt Application Scr.
`
`
`
`
`
`
`
`
`No. 60/698,686, filed Jul. 13, 2005, all ofwhich are incorpo-
`
`
`
`
`
`
`
`
`
`rated herein by reference for all purposes.
`
`
`
`
`
`
`
`
`1. Technical Field of the Invention
`
`
`
`This invention relates generally to wireless communica-
`
`
`
`
`
`tion systems and more particularly to wireless communica—
`
`
`
`
`
`
`tions using beamfonning.
`
`
`
`
`2. Description of Related Art
`
`
`
`
`Communication systems are known to support wireless
`
`
`
`
`
`
`and wire lincd communications bctwccn wirclcss and/or wire
`
`
`
`
`
`
`
`
`lined communication devices. Such communication systems
`
`
`
`
`
`
`range from national and/or international cellular telephone
`
`
`
`
`
`
`
`systems to the Internet to point-to-point in-home wireless
`
`
`
`
`
`
`
`networks. Each type of communication system is con-
`
`
`
`
`
`
`
`structed, and hence operates, in accordance with one or more
`
`
`
`
`
`
`
`
`communication standards. For instance, wireless communi-
`
`
`
`
`
`
`cation systems may operate in accordance with one or more
`
`
`
`
`
`
`
`
`standards including, but not limited to, IEEE 802.11, Blue-
`
`
`
`
`
`
`
`
`
`tooth, advanced mobile phone services (AMPS), digital
`
`
`
`
`
`
`
`AMPS, global system for mobile communications (GSM),
`
`
`
`
`
`
`
`code division multiple access (CDMA),
`local multi—point
`
`
`
`
`
`
`
`distribution systems (LMDS), multi-chaimel-multi-point dis-
`
`
`
`
`
`tribution systems (MMDS), and/or variations thereof.
`
`
`
`
`
`
`Depending on the type ofwireless communication system,
`
`
`
`
`
`
`a wireless communication device, such as a cellular tele—
`
`
`
`
`
`
`
`phone, two-way radio, personal digital assistant (PDA), per-
`
`
`
`
`
`
`
`
`sonal computer (PC), laptop computer, home entertainment
`
`
`
`
`
`
`
`equipment, et cetera communicates directly or indirectly with
`
`
`
`
`
`
`other wireless communication devices. For direct communi-
`
`
`
`
`
`
`
`cations (also known as point-to-point communications), the
`
`
`
`
`
`
`participating wireless commtmication devices tune their
`
`
`
`
`
`
`receivers and transmitters to the same channel or channels
`
`
`
`
`
`
`
`(e. g., one of the plurality of radio frequency (RF) carriers of
`
`
`
`
`
`
`
`the wireless communication system) and communicate over
`
`
`
`
`
`
`
`that channe1(s). For indirect wireless communications, each
`
`
`
`
`
`
`
`wireless communication device communicates directly with
`
`
`
`
`
`
`an associated base station (e.g., for cellular services) and/or
`
`
`
`
`
`
`
`
`
`an associated access point (e.g., for an in-home or in-building
`
`
`
`
`
`
`
`
`wireless network) via an assigned channel. To complete a
`
`
`
`
`
`
`communication conncction bctwccn thc wirclcss communi-
`
`
`
`
`
`
`cation devices, the associated base stations and/or associated
`
`
`
`
`
`
`
`
`access points communicate with each other directly, via a
`
`
`
`
`
`
`
`
`system controller, via the public switch telephone network,
`
`
`
`
`
`
`
`
`Via the Internet, and’or Via some other wide area network.
`
`
`
`
`
`
`
`
`
`
`For each wireless communication device to participate in
`
`
`
`
`
`
`wireless communications, it includes a built-in radio trans-
`
`
`
`
`
`
`ceiver (i.e., receiver and transmitter) or is coupled to an asso—
`
`
`
`
`
`
`
`ciated radio transceiver (e.g., a station for in-home and/or
`
`
`
`
`
`
`
`
`in-building wireless communication networks, RF modem,
`
`
`
`
`
`etc.). As is known, the receiver is coupled to the antenna and
`
`
`
`
`
`
`
`includes a low noise amplifier, one or more intermediate
`
`
`
`
`
`
`
`frequency stages, a filtering stage, and a data recovery stage.
`
`
`
`
`
`
`
`
`
`10
`
`
`
`15
`
`
`
`20
`
`
`
`30
`
`
`
`35
`
`
`
`40
`
`
`
`45
`
`
`
`
`
`
`
`60
`
`
`
`65
`
`
`
`Page 10 of 19
`
`Page 10 of 19
`
`
`
`
`
`US 8,416,862 B2
`
`10
`
`15
`
`20
`
`30
`
`40
`
`45
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`3
`
`processing technique to create a focused antenna beam by
`
`
`
`
`
`
`
`
`
`
`
`
`
`shifting a signal in time or in phase to provide gain of the
`signal in a desired direction and to attenuate the signal in other
`
`
`
`
`
`
`
`
`directions. Prior art papers (1) Digital beamforming basics
`
`
`
`
`
`
`
`
`
`(antelmas) by Steyskal, Hans, Journal of Electronic Defense,
`
`
`
`
`
`
`Jul. 1, 1996; (2) Utilizing Digital Down converters for E11]-
`
`
`
`
`
`
`
`
`
`cient Digital Beamforming, by Clint Schreiner, Red River
`
`
`
`
`
`
`
`
`
`
`
`
`
`Engineering, no publication date; and (3) Interpolation Based
`Transmit Beamfonning for MIMO-OFMD with Partial Feed-
`
`
`
`
`
`back, by Jihoon Choi and Robert W. Heath, University of
`
`
`
`
`
`
`
`Texas, Department of Electrical and Computer Engineering,
`
`
`
`
`
`
`Wireless Networking and Communications Group, Sep. 13,
`
`
`
`
`
`
`
`2003 discuss beamfonning concepts.
`
`
`
`
`
`In order for a transmitter to properly implement beamform-
`
`
`
`
`
`
`
`
`ing (i.e., determine the beamforming matrix [V]), it needs to
`
`
`
`
`
`
`
`
`
`know properties of the channel over which the wireless com-
`
`
`
`
`
`
`
`
`munication is conveyed. Accordingly, the receiver must pro-
`
`
`
`
`
`
`
`vide feedback information for the transmitter to determine the
`
`
`
`
`
`
`
`
`properties ofthe channel. One approach for sending feedback
`
`
`
`
`
`
`
`from the receiver to the transmitter is for the receiver to
`
`
`
`
`
`
`
`
`determine the channel response (H) and to provide it as the
`
`
`
`
`
`
`
`
`feedback information. An issue with this approach is the size
`
`
`
`
`
`
`
`
`ofthe feedback packet, which may be so large that, during the
`
`
`
`
`
`
`
`
`
`time it takes to send it to the transmitter, the response of the
`
`
`
`
`
`
`
`channel has changed.
`
`
`
`To reduce the size of the feedback,
`the receiver may
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`decompose the channel using singular value decomposition
`(SVD) and send information relating only to a calculated
`
`
`
`
`
`
`
`value of the transmitter’s beamforming matrix (V) as the
`
`
`
`
`
`
`
`
`feedback information. In this approach, the receiver calcu-
`
`
`
`
`
`
`
`lates (V) based on H:UDV*, where H is the channel
`
`
`
`
`
`
`
`
`response, D is a diagonal matrix, and U is a receiver unitary
`
`
`
`
`
`
`matrix. While this approach reduces the size of the feedback
`
`
`
`
`
`
`
`
`information, its size is still an issue for a MIMO wireless
`
`
`
`
`
`
`
`
`
`35
`communication. For instance, in a 2><2 MIMO wireless com-
`
`
`
`
`
`
`
`munication,
`the feedback needs four elements that are all
`
`
`
`
`
`
`
`
`
`complex Cartesian coordinate values [VI 1 V12;V21 V22]. In
`
`
`
`
`
`
`
`general, Vik:aik+j *bik, where aik and bik are values between
`
`
`
`
`
`
`
`
`[—1 , 1]. Thus, with 1 bit express per each element for each of
`
`
`
`
`
`
`
`
`
`
`the real and imaginary components, aik and bik can be either
`
`
`
`
`
`
`
`
`
`
`—V2 or 1/2, which requires 4><2><1:8 bits per tone. With 4 bit
`
`
`
`
`
`
`
`
`
`expressions per each element of V(f) in an orthogonal fre-
`
`
`
`
`
`
`
`quency division multiplexing (OFDM) 2><2 MIMO wireless
`
`
`
`
`
`
`
`communication, the number of bits required is 1728 per tone
`
`
`
`
`
`
`
`
`(e.g., 4*2*54*4:1728, 4 elements pertone, 2 bits forreal and
`
`
`
`
`
`
`
`
`imaginary components per tone, 54 data tones per frame, and
`
`
`
`
`
`
`
`
`
`4 bits per element), which requires overhead for a packet
`
`
`
`
`
`
`
`
`
`exchange that is too large for practical applications.
`
`
`
`
`
`
`
`Therefore, a need exists for a method and apparatus for
`
`
`
`
`
`
`
`
`reducing beamforming feedback information for wireless
`
`
`
`
`
`
`
`communications.
`
`BRIEF SUMMARY OF THE INVENTION
`
`
`
`
`The present invention is directed to apparatus and methods
`
`
`
`
`
`
`
`of operation that are further described in the following Brief
`
`
`
`
`
`
`
`
`
`Description of the Drawings, the Detailed Description of the
`
`
`
`
`
`Invention, and the claims. Other features and advantages of
`
`
`
`
`
`
`
`
`the present invention will become apparent from the follow-
`
`
`
`
`
`
`
`
`
`ing detailed description ofthe invention made with reference
`
`
`
`
`
`
`
`
`
`
`
`to the accompanying drawings.
`BRIEF DESCRIPTION OF TIIE SEVERAL
`
`
`
`VIEWS OF THE DRAWINGS
`
`
`
`
`
`
`
`55
`
`
`
`60
`
`
`
`65
`
`
`
`FIG. 1 is a schematic block diagram of a wireless commu—
`
`
`
`
`
`nication system in accordance with the present invention;
`
`
`
`
`
`
`
`
`
`
`Page 11 of19
`
`4
`
`FIG. 2 is a schematic block diagram illustrating an embodi-
`
`
`
`
`
`ment of a wireless communication device in accordance with
`
`
`
`
`
`the present invention;
`
`
`
`FIG. 3 is a schematic block diagram illustrating another
`
`
`
`
`
`
`embodiment of another wireless communication device in
`
`
`
`
`
`accordance with the present invention;
`
`
`
`
`
`FIG. 4 is a schematic block diagram ofbaseband transmit
`
`
`
`
`
`processing in accordance with the present invention;
`
`
`
`
`
`
`FIG. 5 is a schematic block diagram of baseband receive
`
`
`
`
`
`processing in accordance with the present invention;
`
`
`
`
`
`
`FIG. 6 is a schematic block diagram of a beamforming
`
`
`
`
`
`wireless communication in accordance with the present
`
`
`
`
`
`invention;
`
`FIG. 7 is a flow chart illustrating another embodiment of
`
`
`
`
`
`
`the present invention for providing beamforming feedback
`
`
`
`
`
`
`
`
`information from a receiver to a transmitter; and
`
`
`
`
`
`FIG. 8 is a flow chart illustrating another embodiment of
`
`
`
`
`
`
`the present invention for providing beamforming feedback
`
`
`
`
`
`
`
`
`information from a receiver to a transmitter
`
`
`
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`FIG. 1 is a schematic block diagram illustrating a commu-
`
`
`
`
`
`
`nication system 10 that includes a plurality of base stations
`
`
`
`
`
`
`
`and/or access points 12, 16, a plurality ofwireless communi-
`
`
`
`
`
`
`
`
`cation devices 18-32 and a network hardware component 34.
`
`
`
`
`
`
`
`Note that the network hardware 34, which may be a router,
`
`
`
`
`
`
`
`
`
`switch, bridge, modem, system controller, et cetera provides
`
`
`
`
`
`
`
`a wide area network connection 42 for the communication
`
`
`
`
`
`
`
`
`system 10. Further note that the wireless communication
`
`
`
`
`
`
`
`
`devices 18-32 may be laptop host computers 18 and 26,
`
`
`
`
`
`
`
`
`
`personal digital assistant hosts 20 and 30, personal computer
`
`
`
`
`
`
`
`hosts 24 and 32 and/or cellulartelephone hosts 22 and 28. The
`
`
`
`
`
`
`
`
`details of the wireless communication devices will be
`
`
`
`
`
`
`
`
`described in greater detail with reference to FIG. 2.
`
`
`
`
`
`
`Wireless communication devices 22, 23, and 24 are located
`
`
`
`
`
`
`
`within an independent basic service set (IBSS) area and com—
`
`
`
`
`
`
`
`
`
`municate directly (i.e., point to point). In this configuration,
`
`
`
`
`
`
`
`these devices 22, 23 , and 24 may only communicate with each
`
`
`
`
`
`
`
`
`
`
`other. To communicate with other wireless communication
`
`
`
`
`
`
`devices within the system 10 or to communicate outside ofthe
`
`
`
`
`
`
`system 10, the devices 22, 23, and/or 24 need to affiliate with
`
`
`
`
`
`
`
`
`
`
`one of the base stations or access points 12 or 16.
`
`
`
`
`
`
`The base stations or access points 12, 16 are located within
`
`
`
`
`
`
`
`
`
`basic service set (BSS) areas 11 and 13, respectively, and are
`
`
`
`
`
`
`
`
`
`operably coupled to the network hardware 34 via local area
`
`
`
`
`
`
`
`network connections 36, 38. Such a connection provides the
`
`
`
`
`
`
`
`
`base station or access point 12, 16 with connectivity to other
`
`
`
`
`
`
`
`
`devices within the system 10 and provides connectivity to
`
`
`
`
`
`
`
`other networks via the WAN connection 42. To communicate
`
`
`
`
`
`
`
`
`with the wireless communication devices within its BSS 11 or
`
`
`
`
`
`
`
`13, each of the base stations or access points 12-16 has an
`
`
`
`
`
`
`
`
`
`associated antenna or antenna array. For instance, base station
`
`
`
`
`
`
`
`
`or access point 12 wirelessly communicates with wireless
`
`
`
`
`
`
`
`
`communication devices 18 and 20 while base station or
`
`
`
`
`
`
`
`
`access point 16 wirelessly communicates with wireless com—
`
`
`
`
`
`
`
`munication devices 26-32. Typically, the wireless communi-
`
`
`
`
`
`
`
`cation devices register with a particular base station or access
`
`
`
`
`
`
`
`
`point 12, 16 to receive services from the communication
`
`
`
`
`
`
`
`
`system 10.
`
`
`Typically, base stations are used for cellular telephone
`
`
`
`
`
`
`
`
`systems and like-type systems, while access points are used
`
`
`
`
`
`
`
`
`
`for in—home or in-building wireless networks (e.g., IEEE
`
`
`
`
`
`
`
`802.1 1 and versions thereof, Bluetooth, and/or any other type
`
`
`
`
`
`
`
`
`
`ofradio frequency based network protocol). Regardless ofthe
`
`
`
`
`
`
`
`Page 11 of 19
`
`
`
`5
`
`particular type ofcommunication system, each Wireless com-
`
`
`
`
`
`
`
`munication device includes a built-in radio and/or is coupled
`
`
`
`
`
`
`
`to a radio.
`
`
`FIG. 2 is a schematic block diagram illustrating an embodi-
`
`
`
`
`
`
`ment of a wireless communication device that includes the
`
`
`
`
`
`
`
`host device 18—32 and an associated radio 60. For cellular
`
`
`
`
`
`
`
`
`
`telephone hosts, the radio 60 is a built-in component. For
`
`
`
`
`
`
`
`personal digital assistants hosts, laptop hosts, and/or personal
`
`
`
`
`
`
`
`
`computer hosts, the radio 60 may be built-in or an externally
`
`
`
`
`
`
`
`
`
`coupled component.
`As illustrated, the 110st device 18-32 includes a processing
`
`
`
`
`
`
`
`
`module 50, memory 52, a radio interface 54, an input inter-
`
`
`
`
`
`
`
`face 58, and an output interface 56. The processing module 50
`
`
`
`
`
`
`
`
`and memory 52 execute the corresponding instructions that
`
`
`
`
`
`
`
`are typically done by the host device. For example, for a
`
`
`
`
`
`
`
`
`
`cellular telephone host device, the processing module 50
`
`
`
`
`
`
`
`performs the corresponding communication functions in
`
`
`
`
`
`
`accordance with a particular cellular telephone standard.
`
`
`
`
`
`
`The radio interface 54 allows data to be received from and
`
`
`
`
`
`
`
`
`sent to the radio 60. For data received from the radio 60 (e.g.,
`
`
`
`
`
`
`
`
`
`
`
`inbound data), the radio interface 54 provides the data to the
`
`
`
`
`
`
`
`
`
`processing module 50 for further processing and/or routing to
`
`
`
`
`
`
`the output interface 56. The output interface 56 provides
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`connectivity to an output display device such as a display,
`monitor, speakers, et cctcra such that the received data may be
`
`
`
`
`
`
`
`
`
`displayed. The radio interface 54 also provides data from the
`
`
`
`
`
`
`
`
`
`processing module 50 to the radio 60. The processing module
`
`
`
`
`
`
`
`
`50 may receive the outbound data from an input device such
`
`
`
`
`
`
`
`
`
`
`as a keyboard, keypad, microphone, et cetera via the input
`
`
`
`
`
`
`
`
`interface 58 or generate the data itself. For data received via
`
`
`
`
`
`
`
`
`
`the input interface 58, the processing module 50 may perform
`
`
`
`
`
`
`
`
`
`a corresponding host function on the data and/or route it to the
`
`
`
`
`
`
`
`
`radio 60 via the radio interface 54.
`
`
`
`
`
`
`Radio 60 includes a host interface 62, digital receiver pro-
`
`
`
`
`
`
`
`
`cessing module 64, an analog-to-digital converter 66, a high
`
`
`
`
`
`
`
`pass and low pass filter module 68, an IF mixing down con—
`
`
`
`
`
`
`
`
`
`
`version stage 70, a receiver filter 71, a low noise amplifier 72,
`
`
`
`
`
`
`
`
`
`
`a transmitter/receiver switch 73, a local oscillation module
`
`
`
`
`
`
`
`74, memory 75, a digital transmitter processing module 76, a
`
`
`
`
`
`
`digital—to—analog converter 78, a filtering/gain module 80, an
`
`
`
`
`
`IF mixing up conversion stage 82, a power amplifier 84, a
`
`
`
`
`
`
`
`transmitter filter module 85, a channel bandwidth adjust mod-
`
`
`
`
`
`
`
`ule 87, and an antenna 86. The antenna 86 may be a single
`
`
`
`
`
`
`
`
`
`antenna that is shared by transmit and receive paths as regu-
`
`
`
`
`
`
`
`
`lated by the TxRx switch 73, or may include separate anten-
`
`
`
`
`
`
`
`
`
`nas for the transmit path and receive path. The antenna imple-
`
`
`
`
`
`
`
`
`
`
`
`mentation will depend on the particular standard to which the
`
`
`
`
`
`
`Wireless communication device is compliant.
`
`
`
`
`The digital receiver processing module 64 and the digital
`
`
`
`
`
`
`
`
`transmitter processing module 76,
`in combination with
`
`
`
`
`
`
`
`operational instructions stored in memory 75, execute digital
`
`
`
`
`
`
`receiver functions and digital transmitter functions, respec-
`
`
`
`
`
`
`
`tively. The digital receiver functions include, but are not lim-
`
`
`
`
`
`
`
`
`
`
`ited to, digital intermediate frequency to baseband conver-
`
`
`
`
`
`
`
`sion, demodulation, constellation demapping, descrambling,
`
`
`
`
`
`and/or decoding. The digital transmitter functions include,
`
`
`
`
`
`
`
`but are not limited to, encoding, scrambling, constellation
`
`
`
`
`
`
`
`
`mapping, modulation, and/or digital baseband to IF conver—
`
`
`
`
`
`
`sion. The digital receiver and transmitter processing modules
`
`
`
`
`
`
`
`
`64 and 76 may be implemented using a shared processing
`
`
`
`
`
`
`
`device, individual processing devices, or a plurality of pro-
`
`
`
`
`
`
`cessing devices. Such a processing device may be a micro—
`
`
`
`
`
`
`
`processor, micro-controller. digital signal processor, micro-
`
`
`
`
`
`
`computer, central processing unit, field programmable gate
`
`
`
`
`
`
`
`array, programmable logic device, state machine, logic cir-
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`cuitry, analog circuitry, digital circuitry, and/or any device
`that manipulates signals (analog and/or digital) based 011
`
`
`
`
`
`
`
`
`
`6
`
`operational instructions. The memory 75 may be a single
`
`
`
`
`
`
`memory device or a plurality of memory devices. Such a
`
`
`
`
`
`
`
`memory device may be a read-only memory, random access
`
`
`
`
`
`
`
`memory, volatile memory, non-volatile memory,
`static
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`memory, dynamic memory, flash memory, and/or any device
`that stores digital information. Note that when the processing
`
`
`
`
`
`
`
`
`module 64 and/or 76 implements one or more of its functions
`
`
`
`
`
`
`via a state machine, analog circuitry, digital circuitry, and/or
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`logic circuitry, the memory storing the corresponding opera-
`tional instructions is embedded with the circuitry comprising
`
`
`
`
`
`
`
`the state machine, analog circuitry, digital circuitry, and/or
`
`
`
`
`
`
`
`
`
`
`logic circuitry.
`In operation, the radio 60 receives outbound data 94 from
`
`
`
`
`
`
`
`
`the host device via the host interface 62. The host interface 62
`
`
`
`
`
`
`
`
`
`
`
`routes the outbound data 94 to the digital transmitter process-
`
`
`
`
`
`
`
`
`ing module 76, which processes the outbound data 94 in
`
`
`
`
`
`
`
`
`accordance With a particular wireless commtmication stan—
`
`
`
`
`
`
`dard (e.g., IEEE 802.11, Bluetooth, et cetera) to