(ll) lN'l'l‘lRNA'l‘lONAL APPLlC/t'l'lUN PUBLESl—llfll) UMBER THE l’A'l'lCNl' CUGE’ERA'l‘lGN 'l‘REA'lW (PCT)
`
`(l9) World intellectual Pmpefly Organization
`International Human
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`(43) lnt‘et'natittnal I’nlfiicatisn Bate
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`17 September 2%9 {17.69.2l399) (10) ,lntnrnatlnnal Publication Number
`
`Wt) 2%9/1, lStltlS A2
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`(53)
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`Internatitm a1 l’atent Classificatlnn:
`HML 5/1?” (2006.0 l ‘)
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`(21)
`
`Internatinnal Applicatinn Number:
`
`PCT/IE3 2009/050968
`
`(22)
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`Internatittnal Filing flats:
`
`9 March 2009 (09.03.2009)
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`(25)
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`(81)
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`Filing Language:
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`Fultlicati on Langu age:
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`English
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`English
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`Yriority Ham:
`61/035 ,14-4
`61/157,23l
`
`li) March 2008 (10.032908)
`4 March 2009 (04.032009)
`
`US
`US
`
`Applicant {fijr all designated States except (£31): KONEN—
`KLEJKE PHILH’S ELECTRONICS N.'.V [ML/NE];
`(Er-:Leneit'oudéeweg 1, NL-5621 BA Eindhmen (ML).
`
`inventors; and
`lnvealtars/Applicant's; (/br US 0121);): WANG, Dong {US/
`US]; PO. BOX 3001 345 Scarbomugh RQad, Brim'cliff
`Mai/1m, Naw York 1051(}--8(}0l
`(US). YANG, Jun
`[US/US]; PO. Box 3l)0l 345 Scarbarougli Read, Brim»-
`Cliff Mat-1m", New York IOSlG-RGO! (US). BERRU, Dang—
`nacnew {US/US]; PO. Box 3001 345 Scarborough Rand,
`Btiarcliff Manor, New York 10.5 10—800}, (US).
`
`Agent: DAMIEN, Daniel, M.; Philips Intellecniztl Proper-
`W 8;, Standards, High, Tech Campus 44, PO, BOX 220,
`NDSSGO AE Eindliove ‘1 (NE).
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`EC, L:L::, LKL, Ls, F1, GB, GD, CL}, GH, GM, GT, HN,
`HR, HU, ID, IL, LN, 13 JP, KL, KG, KM, KN KP, KK,
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`(84)
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`Designated States (unless otherwise indicaled, far only
`kind Qf’rcgianal protection (amiable): ARIPO {BW, (Eli,
`GM, KE, LS MW, MZ, NA, SD, SL, SZ, TX, US, ZM,
`ZW), Eurasian (AM, AZ, BY, KG, KZ, Ml), RU, TJ,
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`NIR, NE, SN, TD, TG),
`lkijlaratiuns under Rule 4.17:
`
`as to applicant's entitlement to applyfor and be granted
`a patent (Rule 4.1 Wit,»
`
`as to the applicant’s entitlement to claim the priority of
`the writer application (Rule 4,17(iii,))
`Published:
`
`Ltd/flout international Search report and to be republished
`upsn receipt oft/mt repart (Rule 48.2(g})
`
`{54) Title: A PHYSICAL LAYER CONVERGENCE PlKO'l‘DCOL (PLCP) PACKET S’l‘llUCTURlE FOR MULTIPLE-MPH?"
`MU L'l‘lPLE-O UTPU 'l‘ (MIMO) COMM UNlCATION SYSTEMS
`
`,L m
`
`
`294*?it“: t
`
`
`l’muamitttt'
`
`Figure 1
`
`(57) Abstract: A physitxtl layer converge» ce preteen} (PLCP) data stmcture (300) transmitted in a multiple-input-multipla-mnput
`
`lagaCy hffa/(ll‘lf (3 2), wherein tin: legacy praamble (311) and lllC laga egacy portion including a legacy preamble (El 1) and a
`
`oy llffatltfl' (3l2) carry inlimnatlnn compliant with at least a
`WiMe-Llia standard; and a high tln’nughput (HT) {Lumen including a HT preamble (32l) and a HT header (322), and wharein the
`HT preamble (321) iJELFI‘ifiS infntmatinn enabling a recelva D t‘ the. MEMO cominwiiwtion system to dared: I'Efiifilflffll signals.
`
` M ”
`
`’53
`
`mc
`
`;
`as
`
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`
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`43>
`43>
`
`N $
`
`9
`5;:
`
`

`

`WO 2909/113005
`
`PCT/1320091059963
`
`A PHYSECAL LAYER CGNVERGENCE PRQTGCQL {PLEP} PACKET STRUCTURE
`
`FC‘R itiiiJLTiPLEIihiPUTuMULTiPLEwGUTPUT (MEMQ) QQMMUNECATiQN SYSTEMS
`
`This appiication claims the benefit of US. Provisionai Aociication No. 61/035,144
`
`tiied on March it), 2008- and us. Provisionai Appiication No. tit/1527.231 tiied on March
`
`4, 2009.
`
`The invention reiates generaiiy to muitibieninput—muitibienoutbut (Mitt/i0)
`
`communication systems, and more particuiariy to preamhie structures for Mitt/it)
`
`communication systems.
`
`The WiMedia standard defines the specifications of a media access contrei (MAC)
`
`iayer and a ohysicai (PHY) iayer based on rnuiti—band orthogonai frequency division
`
`moduiation (MB—OFDM) transmissions. The Wit/Eadie standard enahies short—range
`
`muitimedia tiie transfers at rates of up to 480Mhos with iew power consumption. The
`
`standard operates in a frequency hand between 3.1GHz and 163.6(3Hz of the uitra—
`
`wideband (UWB) spectrum. However, the highest data rate of the WiMedia standard
`
`rate cannot meet future wireiess muitimedia acpiicaiions, such as HDTV wireiess
`
`connectivity. An effort is being made to increase the data rates to thbs and above.
`
`To this end, a multicie—input—multicie—output (Mitt/i0) technique is being considered
`
`fer future Witt/testis based wireiess communication systems. The MEMO technoidgy
`
`provides better diversity gain and can signi’iicantiy increase the channei capacity under
`
`rich scattering scenarios. The Mitt/EC) techneiogy has been successfuiiy adopted in
`
`wireiess systems inciuding, for exampie, 832.1% based wireiess iocai area networks
`
`(WLANs) and WiMax. The Mitt/i0 is aiso considered to he impiemented in the next
`
`generation Witt/Eadie based systems.
`
`Figure i shows a schematic diagram at a iviiiviO based system 106 in which a
`
`transmitter 130 inciudes iVi transmit antennas ith’i threugh 110nm and a receiver 140
`
`receives signais using N receive antennas 1204 through ‘i20ui‘xi. Typicaiiy, in a singie—
`
`input—singie-dutcut (SESQ) system, the receiver estimates only a scaiar channei
`
`parameter ‘h‘. That is, the channei estimation is eertermed by a receiver using a
`
`oreambie transmitted by a transmit antenna. On the other hand, in the Mitt/it.) system
`
`

`

`‘WO 2999/113005
`
`PCT/iBEt’itiQ/GSQS‘GS
`
`{*3
`
`100 the receive antenna tQO—X (where X is an integer equai to or greater than one)
`
`shouid estimate an M by N channei matrix H:
`
`has)
`
`zeta)
`
`.
`
`.
`
`easy)
`
`ago see
`
`H:
`
`meg mes)..hoLNi
`
`Figure 2 shows a physicai iayer convergence protocoi {PLCP} packet 290, which is
`
`a physicai iayer packet utiiized in SESQ based tit/VB communication systems The PLOP
`
`packet 2th) inciudes a preamoie 210, a header 2261) and a oayioad data 230. The
`
`preamble 210 etiows a receiver to perform the tasks of packet detection, automatic gain
`
`controi (AGC) adjustment, synchronization {at}, timing acquisition and carrier
`
`frequency offset estimation), and channei estimation. With this aim) the preamhie 210
`
`inciudes two portions: synchronization (SYNC) 211 and channei estimation (CE) 212.
`
`The synchronization portion 21“: inciudes time domain random sequences of OFDM
`
`symbois with a repetition structure These sequences have a good autocorreiation
`
`property and enabie a UWB receiver to perform packet and timing synchronization
`
`detection using correiation—oased methods. The random sequences can aiso be utilized
`
`for performing AGE and frequency offset estimation: in addition, the time domain
`
`sequences are optimized to satiety FCC power soectrai density mask requirements. The
`
`channei estimation portion 2f2 inciudee training symbois enaoiing a receiver to estimate
`
`a channei parameter ‘h’ for each subcarrier.
`
`The PLCF’ packet 290 cannot be used directly for future MENHQ based UWB
`
`communication systems. This is due to the fact that a MEMO based systems require
`
`more channei estimation symoois, since more channei parameters are needed to be
`
`estimated: in addition, more than one antenna 1tQ~X transmits simuitaneousiy oaytoad
`
`data 23%, whereby the synchronization portion 211 shouid be modified to ailow fine
`
`AGC adjustment
`
`

`

`‘WO 2999/113005
`
`PCTi’IBEOfifii/GSQS‘GS
`
`Therefore, in order to support iViiMO in future Mitt/i0 based UWB systems, there is a
`
`need to define a new PLCP packet structure to meet at ieast the requirements above.
`
`Additionaiiy, the new PLCP packet shouid toe backward compatihie with current and/’or
`
`previous versions of the Witt/tedia standards. The PLCP packet shouid aiso guarantee
`
`that a signai transmitted from muitipie transmit antennas satisfies FCC power spectrai
`
`mask requirements. Yet, the overioad of the PLCP packet shouid he as iow as possihie
`
`in order not to degrade the systems’ performance.
`
`Certain embodiments of the invention inciude a physioai iayer convergence protocoi
`
`{PLCP} data structure transmitted in a muitiple—ihput—muitipie—output (MEMO)
`
`communication system. The PLOP data structure comprises a iegaey portion inciuding a
`
`legacy preamhie and a iegacy header, wherein the iegacy preamhie and the legacy
`
`header carry information compiiant with at ieast a Witt/tedia standard; and a high
`
`throughput (HT) portion inciuding a HT preamble and a HT header, wherein the HT
`
`preamhie carries information enabiing a receiver of the i‘i/iii‘viO communication system to
`
`decode received signais.
`
`Certain embodiments of the invention inciude a method for transmitting data in a
`
`muitipie~input—muttipie—output (MEMO) communication system having muitipie transmit
`
`antennas and having muitipie receive antennas. The method inciudes generating a
`
`PLCP data structure comprising a iegacy portion for carrying information compiiant with
`
`at ieast a Witt/iedia standard, a high throughput (HT) portion and a data portion;
`
`transmitting from a first transmit antenna the PLCP data structure; and transmitting from
`
`the multipie transmit antennas, exciuding the first transmit antenna. the HT portion and
`
`the data portion of the that}? data structure.
`
`Certain embodiments of the invention inciude a method for transmitting data in a
`
`muitipie~input—muitipie—output (Mitt/HQ) communication system having muitipie transmit
`
`antennas and having muitipie receive antennas. The method inoiudes generating a
`
`PLCP data structure (369) comprising a iegacy portion for carrying information
`
`compiiant with at ieast a Witt/tedia standard, a high throughput (HT) portion and a data
`
`portion; and transmitting the PLCP data structure from the muitipie transmit antennas,
`
`

`

`‘WO 2999/113005
`
`PCTi’IBEtitifii/GSQS‘GS
`
`wherein each transmit antenna transmits a cyciicaiiy shifted version of the iegacy
`
`portion.
`
`Certain embodiments of the invention inciude a physicai iayer convergence protocoi
`
`(PLOP) data structure to be transmitted in a muitipiedhput—muitipieoutput (Mitt/i0)
`
`communication system. The PLOP comprises a iegacy portion inciuding a iegacy
`
`preamhie and a iegacy headers wherein the iegacy preamoie and the iegacy header
`
`carry information compiiant with at ieast a Witviedia standard; and a high throughput
`
`(HT) portion inciuding a HT channei estimation (CE) preamhie and a HT header,
`
`wherein the HT CE preambie carries frequency domain sequences for estimating
`
`channei effects of signais transmitted by aii multipie transmit antennae.
`
`Certain embodiments of the invention inciude a method tor transmitting data in a
`
`muitipieuinputumuitipie—output (MEMG) communication system having muitipie transmit
`
`antennas and having muitipie receive antennas. The method comprises generating a
`
`PLCP data structure comprising a iegacy portion for carrying information compiiant with
`
`at ieast a Wii‘viedia standard, a high throughput (HT) channei estimation (CE) preambie
`
`and a HT header portion and a payioad data portion; and transmitting the FLOP data
`
`structure from the muitipie transmit antennas.
`
`The subject matter that is regarded as the invention is particuiariy pointed out and
`
`distinctiy ciaimed in the ciaims at the conciusion of the specification. The foregoing and
`
`other features and advantages of the invention wiii be apparent from the toiiowing
`
`detaiied description taken in conjunction with the accompanying drawings.
`
`Figure 1
`
`is a schematic diagram of a ivtiiviQ based system;
`
`Figure 2 is a diagram of a physicai iayer convergence protecoi (FLCF’) packet
`
`constructed according to the WiMedia standard;
`
`Figure 3 is a diagram of a PUSF’ packet data structure constructed in accordance
`
`with an embodiment or” the invention;
`
`Figure 4 is a flowchart describing a tone distributing process impiemented in
`
`accordance with an embodiment or” the invention;
`
`Figure 5 iiiustrates AGO preamhies generated using the tone distributing process;
`
`

`

`‘WO 2999/113005
`
`PCT/IBEOQQ/GSQS‘GS
`
`'Ji
`
`Figure 6 illustrates autocorreiation and crossucorrelation simulation graphs of AGE;
`
`preambles;
`
`Figure '2’ illustrates CE preambles generated using the tone distributing process;
`
`and
`
`Figure 8 is a PLCP packet constructed in accordance with another embodiment: of
`
`theinvendon.
`
`it is important to note that the embodiments disclosed by the invention are only
`
`examples of the many advantageous uses of the innovative teachings herein.
`
`in
`
`general, statements made in the specification of the present application do not
`
`necessarily limit any of the various claimed inventions. Moreover, some statements
`
`may apply to some inventive features but not to others.
`
`in general, unless otherwise
`
`indicated, singular elements may be in plural and vice versa with no loss of generality.
`
`in the drawings, like numerals refer to like parts through several views.
`
`Figure 3 shows an exemplary and nonnlimiting diagram of a physical layer
`
`convergence protocol (PLCF’) packet 30% constructed in accordance with an
`
`embodiment of the invention. The PLCP packet 300 is a data structure including a
`
`legacy preamble 311 and a legacy header 3f 2, a high~throughput (HT) preamble 321
`
`and a l-lT header 322, as well as a payload data portion 330. in comparison to the
`
`PLOP packet 200 a new preamble (32t) and header (322) are added in the PLCP
`
`packet 300. The structure of the PLOP 300 will be described with reference to a Milt/i0
`
`based communication system shown in Figure 1.
`
`in a preferred embodiment, the legacy preamble 3tt and header 312 are
`
`transmitted only through the first transmit antenna itQ-i to carry information as
`
`included in a standard PLCF’ preamble 210 and header 220, respectively.
`
`in a
`
`preferred embodiment, the legacy preamble 3ft and legacy header 312 are as defined
`
`in the Wilt/ledia standard version 1.0. This allows iVllMO—‘nased UWB systems to perform
`
`the tasits of packet detection, AGC control, timing synchronization, frequency offset
`
`estimation, and channel estimation to decode header information. The AGE control and
`
`the channel estimation are performed only for the channel transmitting the legacy
`
`

`

`‘WO 2999/113005
`
`PCT/IBEMM/GSQS‘GS
`
`preamhie 311 and iegacy header 312. Furthermore, since oniy ene transmit antenna
`
`1104 transmits this information, the FCC sewer spectrai mask is satisfied.
`
`To aiiew A66 and channei estimation of other channels, the HT preamhie 321
`
`inciudes an AGC nreambie 321 "1 and a channei estimation (CE) preambie 321% (see
`
`Figure 3). Each transmit antenna 110% (where X is an integer greater than or euuai to
`
`one) transmits a ditierent AGE preamhie 321—1, and aii transmit antennas 119-1
`
`through itu—ivi transmit their ewn AGO preamhies 321—1 at the same time. in order to
`
`acquire a precise AGC adjustment, the AGC preambies 321-1 from different transmit
`
`antennas ttfi—X shouid he uncorreiated. With this aim, the content of the AGC
`
`preamhies 321—1 is determined using a “tone distributing” process. in a preferred
`
`embodiment, the AGC creambie 3214 inciudes a short preambie having six OFDi‘i/i
`
`symhois.
`
`Figure 4 shows an exempiary and nonwiimiting flowchart 400 describing the tone
`
`distributing process imeiernented in accordance with an emhediment er” the invention. At
`
`$410 a frequency domain sequence that inciudes a number of New symbois is defined,
`
`which can he the same as the corresccnding frequency dcmain sequence at one at the
`
`preambie sequences defined in the Witviedia standard version v1.0. The parameter Nap-r-
`
`is the number at subcarriers in an OFDi‘i/i symhoi. Non—zero symbeis from a QPSK
`
`consteiiation can he eiected for this purpcse to guarantee a fiat power spectrum. At
`
`Sit-2t), the frequency demain sequence is distributed to transmit antennas 11G~1 through
`
`110~iVi. At $43G, for each transmit antenna ttd—X its time—domain sequence to be
`
`inciuded in the respective AGC preamhie 321—1 is generated. Sceciticaiiy, a time
`
`domain AGO preambie (TX) to be transmitted by a transmit antenna “HO—X is generated
`
`as 'idiiows:
`
`rt = were
`
`{Stilt}
`_
`V
`PX (k) : <
`K
`
`(i
`
`J; 2:: XVM + X,2.M + X‘s... NWT — 1M + X
`A A A
`
`,orherwise
`
`<1 )
`
`

`

`‘WO 2999/113005
`
`PCT/IBEOtffii/GSQS‘GS
`
`where, S(k) is the vaiue ef the frequency demain at subcarrier k, ink) is a
`
`respective frequency domain preambie of the transmit antenna f'iO—X, and iFFTiFX) is
`
`an inverse fast Fourier transform”
`
`A nen—iimiting exampie iiiustrating the eeeratien cf the tone distributing process is
`
`prdvided in Figure 5. Preambies 510 and 520 are generated using the frequency
`
`domain sequence 530. As can he noticed, the vaiues of the eubcarriers aiternate
`
`between zero and Sik).
`
`in this examcie. the transmit antennas tftiwt and 110—2
`
`transmit the preambies 51 O and 520 through different subcarriers. Thus, the respective
`
`time demain AGO preambles 510 and 520 are uncorrelated. This is further iiiustrated in
`
`Figure 6, which shows autecerreiatien simuietien resuits of the time domain AGC
`
`preamhies 510 and 520 in graphs 610 and 62D, respectiveiy, and their cress—cerrectidn
`
`in graph 630‘ As can be noticed, the cross—correction signei (i.e., the measure cf
`
`simiiarity ef the two signais) is zero.
`
`The CE preamhie 321—2 is censtructed in such way that the preamhies generated
`
`by different transmit entennes’i ’1 OuX are Orthogenei. This ensures that the different
`
`chenneis can be separateiy estimated. Specificaiiy, each transmit antenna ’ifO—X
`
`transmits M different CE preambies 321—2 during fy’i different time periods, The fvt
`
`different CE preamhies 321—2 are generated using the tone distributing processing,
`
`wherein the time domain preamhie BL} transmitted by a transmit antenna f'iO-i during a
`
`time period i is determined as feiiows:
`
`is r:
`
`,t:n
`
`B;,,;ikii=<; () f f’
`0
`,them'irer
`
`.
`
`(2‘
`
`c2;
`
`JHHD)
`
`’
`(
`Whare, “10,41
`
`r‘
`1:::’
`1,4,...1751
`
`are index sets, each cf which has M eiements and
`
`
`NFFZ'
`
`9;- flflj
`
`and n1 i-ir22...i_ir2M =t1’2”""MFFT}, Chi is the respective frequency domain
`
`

`

`‘WO 2999/113005
`
`PCT/TBEOQQ/GSQS‘GS
`
`preamhie and S is the frequency domain sequence. The index sets can be generated
`
`randomiy. in one embodiment the index sets may be:
`
`Sta 2 {also + M,a + 2M; 62 + NW. , M}
`
`in a preferred embodiment, the number of OFDM symbois in a GE preamoie 321-1
`
`is six for the case where ivi squats 2.
`
`Figure 7 iiiustrates 4 CE preambies 1’10, 1’26, 739 and T40 generated from a
`
`frequency domain sequence 750 using the tone distributing process. in this exampie, an
`
`OFDM symboi inciudes 128 subcarriers. As can be noticed, every transmit antenna
`
`110~X transmits a signai on aii subcarriers oniy once during tVi time periods. in addition,
`
`during each time period oniy one transmit antenna 110-X transmits signais on a sub—
`
`carrier. This enabies estimation of the channei.
`
`in accordance with another embodiment of the invention, the iegaoy preambie 311
`
`and iegacy header 312 can be transmitted by ail transmit antennas ttdmt through 110—
`
`M using a cyclic deiay diversity (EDD) scheme. Specificaiiy, the transmit antenna 11Gn1
`
`transmits the originai content of the iegacy preambie 311 and iegacy header 312, white
`
`the transmit antennas 110-2 through 11i3~ivi send cyclicaiiy shifted version of the iegacy
`
`preambie 311 and iegacy header 312. it shouid be noted that the GFDivt symbois (time
`
`domain sequences) inciuded in the HT preamble 321 are generated using the tone
`
`distributing process. These sequences can he further utiiized for packet detection and
`
`timing synchronization using conventionai correiation based methods. such that the
`
`legacy preambie 311 is backward compatipie.
`
`Figure 8 shows an exempiary and non—iimiting diagram of a physicai iayer
`
`convergence protocoi (PLOP) packet 8G0 constructed in accordance with an
`
`embodiment of the invention. The PLCP packet and is a data structure inciuding a
`
`legacy breambie 811 and a iegacy header $12, a HT channei estimate (Ct-2) preambie
`
`821 and a HT header 822, as weii as a payioad data portion 830. in comparison to the
`
`PLCP packet 300. the PLCP packet 890 does not include the AGC oreambie 3211
`
`The PLCF’ packet 800 is transmitted by aii transmit antennas 1104 through tifl—ivi,
`
`where the iegacy preamble 811 and iegacy header 8-12 are generated using the tone
`
`

`

`‘WO 2999/113095
`
`PCT/IBEOQQ/GSQS‘GS
`
`9
`
`distributing process, wherein the time domain sequences of the preambie are defined
`
`using equation (2), with i=1. This guarantees that the transmitted time domain
`
`sequences are not correiated, Furthermore, a precise iviiiviO AGC adjustment can be
`
`achieved based on the tegacy preambie 811.
`
`The i—i'f CE preamhie 821 inciudes frequency domain sequences for estimating oniy
`
`channeis 2 through M. The first channel is estimated using the legacy preamhie 811.
`
`Therefore, the totai extra preamble overioad is reduced to Edi/id) OFDivt symhois. For
`
`exampie, the totai extra overhead for a f‘viiiViO based UWB system, inciuding two
`
`transmit antennas, is oniy 6 OFDM symooist The HT CE preambie 821 is transmitted
`
`during Pvt—t time periods, and the channei estimation preambie Di,i as defined in
`
`equation (2) is transmitted within the imth (i:2,..,i\/i) period via thej~th antenna. Stir) is the
`
`frequency domain channei estimation sequence, which can be same as the channei
`
`estimation sequence defined, for exampie, in the Witv’iedia standard version v1.6. it
`
`shouid he noted that different design of the index sets 9
`
`” 212‘” can resuit in
`
`different timing synchronization performance and can be Optimized to improve the
`
`synchronization performance of iegacy devices.
`
`The foregoing detaiied description has set forth a few of the many forms that the
`
`invention can take. it is intended that the foregoing detaiied description be understood
`
`as an iiius ration of seiected forms that the invention can take and not as a iimitation to
`
`the definition of the invention. it is oniy the ciaims, inciuding aii equivaients that are
`
`intended to define the scope of this invention,
`
`Most preferahiy, the principies of the invention are impiemented as a combination of
`
`hardware, firmware and software, Moreover, the software is preferahiy impiemented as
`
`an application program tangihiy embodied on a program storage unit or computer
`
`readabie medium. The appiication program may he upioaded to, and executed by, a
`
`machine comprising any suitahie architecture. Preferably, the machine is impiemented
`
`on a computer piattorm having hardware such as one or more centrai processing units
`
`("CPU"), a memory, and input/output interfaces. The computer piatform may aiso
`
`inciude an operating system and microinstruction code. The various processes and
`
`functions described herein may be either part of the microinstruction code or part of the
`
`

`

`‘WO 2999/113095
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`PCTi’IBEOfifii/GSQS‘GS
`
`iii
`
`appiicatien program, or any cembinatien iheree‘i, which may be executed by a CPU,
`
`whether or met such computer er precessor is expiieitiy shown. in addition, verieue ether
`
`peripherai units may be connected to the computer piet‘i‘erm such as an eddiiienai data
`
`storage unit and a printing unit.
`
`

`

`‘WO 2099/”3065
`
`PCT/’132099/956963
`
`ti
`
`
`Ciaims
`
`What we ciaim is:
`
`t.
`
`A physicai iayer convergence protocoi (PLOP) data structure (300)
`
`transmitted in a muitipie—input-muitipie-dutput (Mitt/HQ) communication system,
`
`comprising:
`
`a iegacy portion inciuding a iegacy oreamhie (3M) and a iegacy header
`
`(312), wherein the iegacy preambie (311} and the iegacy header i312) carry
`
`information compiiant with at ieast a Wiiviedia standard; and
`
`a high throughput (HT) portion inciuo‘ing a HT preamhie (32i) and a HT
`
`header {321), wherein the HT preamble (321} carries information enabiing a
`
`receiver of the iii/iiiviQ communication system to decode received slgnais.
`
`2.
`
`The PLCP data structure at ciaim 1, wherein the iegacy portion is
`
`ransmitted from a first transmit antenna of the it/iii‘viti) system.
`
`3.
`
`The PLCP data structure of ciairn ’5, wherein the HT preambie further
`
`comprises an automatic gain controi (AGO) oreambie (SZi—i) and a channei
`
`estimation (CE) preambie ("32”: Q).
`
`4.
`
`The PLCP data structure of ciaim 3, wherein content oi the AGC
`
`preamble is determined by a tone distributing process, the tone distributing
`
`process comprising:
`
`determining a frequency domain sequence (S410);
`
`distributing the frequency domain sequence to muitipie transmit
`
`antennas of the MEMO system (3420}; and
`
`for each transmit antenna, generating a time domain sequence to be
`
`inciuded in the respective AGC preamble.
`
`5.
`
`The PLCP data structure of ciairn 4, wherein content of the CE preamhie
`
`is determined by the tone distributing process.
`
`

`

`‘WO 2099,"'t13titifi
`
`PCT/EEEQGEL’QStNGS
`
`12
`
`6.
`
`The PLCP data structure of ciaim 5, wherein different time domain
`
`sequences and frequency domain sequences are utilized to generate the CE
`
`preamble and the AGC preambieu
`
`"i.
`
`A method for transmitting data in a muitipie—inputnmuitipie—output (Mitt/i0)
`
`communication system having muitioie transmit antennas and having muitiple
`
`receive antennas, comprising:
`
`generating a PLOP data structure (300) comprising a iegacy portion for
`
`carrying information compiiant with at ieast a WiMedia standard, a high
`
`throughput (HT) portion and a payioad data portion;
`
`transmitting the PLCP data structure from a first transmit antenna; and
`
`transmitting the HT portion and the data portion of the PLCP data
`
`structure from the multipie transmit antennas, exciuding the first transmit
`
`antenna.
`
`8.
`
`The method or” ciaim 7, wherein the iegacy portion inciudes a iegacy
`
`preamble (311i and a legacy header (312), and wherein the HT portion inciudes
`
`a HT oreambie (321) and a HT header (322), the HT preambie carrying
`
`information enabiing the receiver of the Mitt/EC» communication system to
`
`decode received signais.
`
`9.
`
`The method or' ciaim 2’, wherein the HT preambie comprises an
`
`automatic gain controi (AGE) preambie (3213i) and a channei estimation (CE)
`
`preamble (321—2), and wherein contents of the AGC preambie and CE
`
`preamble are generated using a tone distributing process.
`
`ti).
`
`A method for transmitting data in a muitipie-input—muitipie-output (Mitt/i0)
`
`communication system having muitipie transmit antennas and having muitiple
`
`receive antennas, comprising:
`
`generating a PLCF‘ data structure (306) comprising a iegacy portion for
`
`carrying information compiiant with at ieast a Witvieciia standard, a high
`
`throughput (HT) portion and a payioad data portion; and
`
`

`

`‘WO Etiiitil'ilfititifi
`
`PC T/’13209§)I’95€i968
`
`13
`
`transmitting the PLCP data structure from the muitipie transmit antennas,
`
`wherein each transmit antenna transmits a cyciioaiiy shifted version of the
`
`iegaoy portion,
`
`it.
`
`A physioai iayer convergence protocoi (PLOP) data structure (800) to be
`
`transmitted in a muitipie-input~muitiple-output (Mitt/EC) communication system,
`
`cemprising:
`
`a iegacy portion inoiuding a iegacy oreamhie (Bti) and a iegaoy header
`
`(812), wherein the iegaey preamoie (811} and the iegaey header (81:21) carry
`
`information compiiant with at ieast a Wih’iedia standard; and
`
`a high throughput (HT) portion ineiuding a HT channei estimation (CE)
`
`preamble (821) and a HT header (822), wherein the HT CE preambie (821)
`
`carries frequency domain sequences for estimating ohannei effects of signais
`
`transmitted by ali muitipie transmit antennas:
`
`12.
`
`The PLCP data structure of oiaim ’ii, wherein the iegaoy preamble is
`
`utiiized for estimating channei effects of signais transmitted by aii muitiple
`
`transmit antennas, and wherein each transmit antenna oniy transmits on a
`
`subset of suboarriers and different transmit antennas transmit on different
`
`subsets of suhcarriers.
`
`13K
`
`The PLOP data structure of oiaim 12, wherein the iegaoy preamble and
`
`the iegaey header are generated using a tone distributing process.
`
`14.
`
`A method for transmitting data in a muitlpie—input~muitipie—output (MEMO)
`
`communication system having muitipie transmit antennas and having muitiple
`
`receive antennas, comprising:
`
`generating a PLCP data structure (800) comprising a iegaoy portion for
`
`carrying information eompiiant with at ieast a WiiViedia standard, a high
`
`throughput (HT) ohannei estimation (CE) preambie (82f) and a HT header
`
`portion and a payioad data portion (83(3); and
`
`transmitting the PLCP data structure (800) from the muitiple transmit
`
`antennas.
`
`

`

`‘WO 2099/i13065
`
`PCT/’132099/i‘ififl968
`
`14
`
`’35.
`
`The method et eieim 14, wherein channei effects of signais transmitted
`
`en different subsets of subearriers by aii muitipie transmit antennas are
`
`estimated using the iegaey preambie, and wherein the HT CE preambie carries
`
`frequency domain sequences for estimating Channei effects at signais
`
`transmitted en aii subcarriers exeiuding the subsarriers estimated by the iegacy
`
`preamble.
`
`

`

`‘WO 2999/113095
`
`PCT/IBEGQQ/GSQS‘GS
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`PCT/IBEGQQ/GSQS‘GS
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`‘WO 2999/113095
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`PCTi’IBEGfifli/GSQS‘GS
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`3/5
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`‘WO 2639/113095
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`PCT/IBEOQQ/GSQS‘GS
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