IN THE UNITED STATES PATENT AND TRADEMARK OFFICE
`
`In re Patent of: Hays et al.
`U.S. Patent No.: 5,659,891
`Issue Date:
`Aug. 19, 1997
`Appl. Serial No.: 08/480,718
`Filing Date:
`Jun. 7, 1995
`Title:
`MULTICARRIER TECHNIQUES IN BANDLIMITED CHANNELS
`
` Attorney Docket No.: 39521-0004IP1
`
`
`
`DECLARATION OF DR. APOSTOLOS K. KAKAES
`
`1.
`
`My name is Apostolos K. Kakaes of Vienna, Virginia. I understand that I am
`
`submitting a declaration offering technical opinions in connection with the above-referenced
`
`Inter Partes Review proceeding pending in the United States Patent and Trademark Office for
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`U.S. Patent No. 5,659,891 (“the ‘891 patent”), and prior art references relating to its subject
`
`matter. My current curriculum vitae is attached and some highlights follow.
`
`2.
`
`I have over thirty (30) years of experience in electrical engineering and computer
`
`science and in fixed and mobile communications networks. I attended the University of
`
`Colorado from 1974 to 1980, during which, I earned a Bachelor of Science (B.S.) and a Master
`
`of Science (M.S.) in applied mathematics with a minor in electrical engineering. I attended the
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`Polytechnic Institute of New York between 1982 and 1988, during which, I earned a Doctor of
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`Philosophy (Ph.D.) in electrical engineering, with a thesis titled “Topological Properties and
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`Design of Multihop Packet Radio Networks.” While pursuing the Ph.D. degree, I held a joint
`
`appointment as Special Research Fellow and Adjunct Instructor at the Polytechnic Institute of
`
`New York between 1985 and 1986.
`
`3.
`
`Between 1982 and 1987, I worked at AT&T Bell Laboratories in Holmdel, New
`
`Jersey. While at AT&T Bell Laboratories, I worked on modeling, analysis, design, and
`
`performance evaluation of voice and data networks. I developed algorithms for DNHR
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`(Dynamic, Non-Hierarchical Routing) used in the telephone network. I also worked on analysis
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`of advanced data services and formulation of long term plans for development of enhanced data
`
`services and network design tools to support such services.
`
`4.
`
`I was an Assistant Professor of Electrical Engineering and Computer Science at
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`The George Washington University (GWU), Washington, D.C., between 1987 and 1994. During
`
`my association with GWU, I taught graduate courses in the area of communication engineering,
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`including communication theory, coding theory, voice and data networking, and mobile
`
`communications. I also received several research awards/grants, including the prestigious NSF
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`Research Initiation Award.
`
`5.
`
`In 1988, I founded Cosmos Communications Consulting Corporation ("Cosmos"),
`
`which is a private communications engineering consulting firm specializing in mobile
`
`communications, and I have been the President of the company since the founding. Since 1994,
`
`I have worked full-time at Cosmos. At Cosmos, among various activities, I have consulted on
`
`high level technology-related issues and trends to corporate entities, governmental agencies, and
`
`international organizations, such as the United Nations. I have provided technical consultancy to
`
`engineering firms, operators, and equipment vendors on issues related to existing or evolving
`
`technologies for mobile communications, and to the investment community on issues related to
`
`both fixed and wireless communications technologies. I have served as consultant on both civil
`
`and criminal legal cases, including several patent infringement cases both at the ITC and in
`
`district court. I also participated as a technical consultant in the analysis of large patent
`
`portfolios for the purposes of due diligence, sales, and merger and acquisition activities for some
`
`of the largest companies in the mobile communications space. These projects spanned a
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`Attorney Docket No.: 39521-0004IP1
`U.S. Patent No. 5,659,891
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`multidimensional spectrum of technologies in both fixed and mobile communications as they
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`have evolved over the past thirty (30) years.
`
`6.
`
`During my work at Cosmos, I have provided expert advice and conducted
`
`extensive training for practicing engineers in the field in diverse networking technology areas,
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`including Wireless Local Area Networks (LAN), Metropolitan Area Networks (MAN), and
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`Personal Area Networks (PAN) technologies, paging networks, ad hoc networks, including IEEE
`
`802.11 (Wi-Fi), IEEE 802.16 (WiMAX), HIPERLAN, Bluetooth, Near Field Communications,
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`IrDA (Infrared Data Association). My experience includes detailed in depth analysis of cellular
`
`networks operating with any of the available access technologies as standardized in various
`
`standards, broadly known as AMPS, GSM, GPRS, EDGE (EGPRS); North American TDMA
`
`and IS-136, iDEN, IS-95, UMTS, HSPA, and LTE. I have experience in the design and
`
`implementation of voice and data networking (circuit switching as well as all the evolving all IP-
`
`based technologies), traffic engineering, RF design, Quality of Service (QoS) and resource
`
`allocation, MAC protocols, as well as in the design of core networks, both user plane and control
`
`plane.
`
`7.
`
`Over the course of my career, I have authored and co-authored some thirty (30)
`
`publications on various aspects of fixed and mobile communications, as noted in my curriculum
`
`vita. I am a member of the Institute of Electrical and Electronics Engineers (IEEE) and actively
`
`involved in the Communications Society and the Information Theory Society of IEEE. Between
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`1991 and 1992, I served as the Secretary of IEEE Communications Society National Capital
`
`Area Chapter. Between 1992 and 1993, I was the Vice-Chair of IEEE Communications Society
`
`National Capital Area Chapter. I was the Vice-Chair of the Communication Theory Technical
`
`Committee of the Communications Society of the IEEE for the 1993-1996 term, and Treasurer of
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`Attorney Docket No.: 39521-0004IP1
`U.S. Patent No. 5,659,891
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`the Communication Theory Technical Committee of the Communications Society of the IEEE
`
`for the 1996-1999 term.
`
`8.
`
`I have served as a reviewer for the IEEE, book editors, other technical
`
`publications, and various National Science Foundation (NSF) Panels. I have organized technical
`
`sessions in technical conferences, including the IEEE International Conference on
`
`Communications (ICC) and IEEE Global Communications Conference (Globecom). I served as
`
`the Technical Program Chair for the Communication Theory Mini-Conference in 1992.
`
`9.
`
`I am familiar with the content of U.S. Patent No. 5,659,891 (the “‘891 patent”).
`
`In addition, I have considered the various documents referenced in my declaration as well as
`
`additional background materials. For example, I have considered: (1) Dr. Rade Petrovic et al.,
`
`Permutation Modulation for Advanced Radio Paging, IEEE Proceedings of Southeastcon '93 (7
`
`Apr 1993) (“Petrovic”); (2) Leonard J. Cimini, Analysis and Simulation of a Digital Mobile
`
`Channel Using Orthogonal Frequency Division Multiplexing, 33 IEEE Transactions on
`
`Communications 665 (Jul. 1985) (“Cimini”); (3) WIPO Publication No. 1989/008355 to Raith et
`
`al. (“Raith”); and (4) C. Alakija and S. P. Stapleton, A Mobile Base Station Phased Array
`
`Antenna, 1992 IEEE International Conference on Selected Topics in Wireless Communications
`
`at 118 (Jun. 1992) (“Alakija”). I have also reviewed certain sections of the prosecution history
`
`of the ‘210 patent and the claim construction orders from Mobile Telecommunications
`
`Technologies, LLC v. Apple Inc., Civil Action No. 2:13-cv-258-JRG-RSP (E.D. Tex.) and
`
`Mobile Telecommunications Technologies, LLC v. Clearwire Corp., Civil Action No. 2:12-cv-
`
`308-JRG-RSP (E.D. Tex.).
`
`10.
`
`Counsel has informed me that I should consider these materials through the lens
`
`of one of ordinary skill in the art related to the ‘891 patent at the time of the invention, and I have
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`Attorney Docket No.: 39521-0004IP1
`U.S. Patent No. 5,659,891
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`done so during my review of these materials. I believe one of ordinary skill as of June 7, 1995
`
`(the priority date of the ‘891 patent) would have at least a B.S. degree in electrical engineering,
`
`computer science, computer engineering, or equivalent education. This person would also need
`
`to have at least two years of experience in the design and configuration of wireless paging
`
`systems, or other two-way wireless communications systems and be familiar with the operation
`
`and functionality of multicarrier transmissions. I base this on my own personal experience,
`
`extensive training that I provided for those in the industry as well as my knowledge of colleagues
`
`and other professionals at the time. With this in mind, for purposes of this analysis, references
`
`that I make to the views of a person of ordinary skill are intended to relate the views of that
`
`person as of June 7, 1995 or earlier, whether stated with respect to the present or past tense.
`
`11.
`
`Counsel has advised me that, during Inter Partes Review, that claim terminology
`
`must be given the broadest reasonable interpretation. Counsel has advised me that this means the
`
`claims should be interpreted as broadly as their terms reasonably allow, but that such
`
`interpretation should not be inconsistent with the patent’s specification and with usage of the
`
`terms by one of ordinary skill in the art. Counsel has also informed me that this may yield
`
`interpretations that are broader than, or different from, the interpretation applied during a District
`
`Court proceeding, such as the pending MTel litigation.
`
`12.
`
`I have no financial interest in either party or in the outcome of this proceeding. I
`
`am being compensated for my work as an expert on an hourly basis. My compensation is not
`
`dependent on the outcome of these proceedings or the content of my opinions.
`
`13. My findings, as explained below, are based on my study, experience, and
`
`background in the fields discussed above, informed by my education in applied mathematics and
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`electrical engineering, and my experience in the design and analysis of fixed and mobile
`
`communications systems.
`
`14.
`
`This declaration is organized as follows:
`
`I.
`
`II.
`
`III.
`
`IV.
`
`Brief Overview of the ‘891 Patent (page 6)
`
`Petrovic and Combinations Based on Petrovic (page 7)
`
`Cimini and Combinations Based on Cimini (page 18)
`
`Conclusion (page 27)
`
`Brief Overview of the ‘891 Patent
`
`The ‘891 patent is generally directed to a “multicarrier techniques in bandlimited
`
`I.
`
`15.
`
`channels.” Ex. 1001, Title. The ‘891 patent includes 5 claims, of which claims 1, 3, and 5 are
`
`independent.
`
`16.
`
`The ‘891 patent describes “a method for operating more than one carrier in a
`
`single mask-defined, bandlimited channel assigned to mobile paging use.” Ex. 1001, 1:6-8.
`
`Features of the claims are readily discernible from FIGS. 3A and 3B, which the ‘891 patent
`
`describes as follows:
`
`Referring to FIG. 3A. two submasks defining two subchannels. 30a and
`30b, are asymmetrically located within a single mask-defined, bandlimited
`channel 31, resulting in some subchannel overlap. FIG. 3B depicts two carriers,
`32a and 32b, operating respectively over two asymmetrically-located subchannels,
`resulting in some carrier overlap. In accordance with this asymmetry, the
`frequency difference between the center frequency of each carrier and the nearest
`band edge of the mask is greater than half the frequency difference between the
`center frequencies of the two carriers.
`Ex. 1001, 4:25-35. An annotated version of FIG. 3B is provided below to illustrate one
`
`implementation of the claim language.
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`Plurality of Carriers
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`“a single mask-defined,
`bandlimited channel”
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`Attorney Docket No.: 39521-0004IP1
`U.S. Patent No. 5,659,891
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`“adjacent carriers
`overlap with each
`other”
`
`“the frequency difference
`between the center frequencies
`of each adjacent carrier”
`
`“the frequency difference between
`the center frequency of the outer
`most of said corresponding
`subchannels and the band edge of
`the mask defining said channel”
`
`
`
`17.
`
`The ‘891 patent acknowledges the prior existence of “traditional multicarrier
`
`design[s]” in which “carriers are symmetrically located within the channel such that they are
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`evenly spaced relative to each other and to the band edges of the primary mask defining the
`
`primary channel.” Ex. 1001, 2:1-12. Thus, the alleged invention of the ‘891 patent is the
`
`spacing of the carriers within the channel. See Ex. 1001, 2:15-17, 2:26-36. As will be described
`
`in the following sections, however, the claimed positioning of carriers within a channel was well
`
`known in the art well before June 7, 1995.
`
`II.
`
`Petrovic and Combinations Based on Petrovic
`
`A.
`
`Petrovic
`
`18.
`
`Petrovic describes the authors’ “efforts to increase both bit rate and spectral
`
`efficiency in simulcast paging networks.” Ex. 1008, p. 1, Introduction. To accomplish this goal,
`
`Petrovic outlines a “multicarrier permutation modulation technique” that “can be used in
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`U.S. Patent No. 5,659,891
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`simulcast networks with high power transmitters.” Ex. 1008, p. 1, abstract. This type of
`
`modulation is often classified as Multicarrier Modulation (MCM). Ex. 1008, p. 1, Proposed
`
`Modulation Technique. The MCM technique described by Petrovic involves encoding data
`
`across eight subcarrier frequencies within a band-limited channel. See Ex. 1008, p. 1, Proposed
`
`Modulation Technique. “The signal spectrum at transmitter output is presented in Fig. 1, and 2.”
`
`Ex. 1008, p. 2, Experiments.
`
`19.
`
`The proposed multicarrier permutation modulation technique includes “moving
`
`the current emission mask boundaries away from the center frequency by +/- 12.5 kHz. This
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`would give a 35 kHz pass band in the middle of the channel and 7.5 kHz guard bands on each
`
`side for the skirts of the spectrum.” Ex. 1008, p. 1, Proposed Modulation Technique. To
`
`illustrate the mask boundaries of the band-limited channel, Petrovic guides the reader to “[s]ee
`
`dashed lines in Figs. 1 and 2,” which “represent[] the proposed emission mask.” Ex. 1008, p. 1,
`
`Proposed Modulation Technique; p. 2, Experiments. The following Annotation 1 of FIG. 1
`
`highlights the guard bands with relation to the mask boundaries.
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`20.
`
`These 7.5 kHz guard bands are each only a portion of the frequency difference
`
`between the center frequency of the outer most of the carriers and the band edge of the mask
`
`defining the channel. Thus, the frequency difference between the center frequency of the outer
`
`most of the carriers and the band edge of the mask defining the channel is greater than 7.5 kHz.
`
`21.
`
`Petrovic further describes that, “[i]n order to fully utilize the allocated spectrum,
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`and provide fast fall-off of the spectrum in the guard band we propose eight subcarriers spaced 5
`
`kHz apart, so that there is exactly 35 kHz spacing between end subcarriers.” See Ex. 1008, p. 1.
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`The following Annotation 2 of FIG. 1 highlights the spacing between the center frequency of the
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`subcarriers described by Petrovic.
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`22.
`
`Taking these teachings together, Petrovic describes a guard band of 7.5 kHz (as
`
`shown in Annotation 1) and a spacing between the center frequency of adjacent carriers of 5 kHz
`
`(as shown in Annotation 2). In other words, the frequency difference between the center
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`frequency of the outer most of the carriers and the band edge of the mask defining said channel
`
`(which is greater than 7.5 kHz) is more than half the frequency difference between the center
`
`frequencies of each adjacent carrier (which is 5 kHz), as required by claim 1. Thus, Petrovic
`
`describes the feature that led to the allowance of the ‘891 patent.
`
`23.
`
`In Petrovic’s modulation scheme, adjacent subcarriers partially overlap each
`
`other. The following Annotation 3 of FIG. 1 shows the hypothetical position of the eight
`
`subcarriers within the bandlimited channel, with carriers/subchannels 1, 2, 4 and 8 being 'ON'
`
`and carrier/subchannels 3, 5, 6, and 7 being ‘OFF’.
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`24. Where the value of the transmitted signal between carrier/subchannel 1 and carri-
`
`er/subchannel 2 (highlighted in blue below) does not return to practical zero (highlighted as a red
`
`broken line that extends the lowest point of the mask), the carrier/subchannel 1 overlaps adjacent
`
`carrier/subchannel 2. This is illustrated in the following Annotation 4 of an excerpt of FIG. 1,
`
`which is shown side-by-side with a similarly annotated FIG. 5A of the ‘891 patent to illustrate
`
`the similar type of overlap.
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`25.
`
`Petrovic describes using a transmitter with four subtransmitters to transmit the
`
`eight subcarriers. Ex. 1008, p. 2, Experiments. In particular, “[e]ach transmitter has four
`
`subtransmitters capable of 4-FSK over a subset of the 8 frequencies. Outputs of the
`
`subtransmitters are combined and sent to a common antenna.” Id. Thus, each of the eight
`
`subcarriers are transmitted from the same location (i.e., the common antenna). It would have
`
`been understood by one of ordinary skill that a plurality of Petrovic’s mobile receiving units
`
`independently receive one of the plurality of transmitted subcarriers. For example, Petrovic
`
`describes that “[a] receiver . . . consists of an RF section which down converts the signal to a
`
`frequency band below 100 kHz, an A/D converter, a DSP processor which performs signal
`
`detection through DFT analysis, and a PC to control the operation and present results. See Ex.
`
`1008, p. 2, Experiments.
`
`26.
`
`Petrovic describes that “[e]ach transmitter has four subtransmitters capable of 4-
`
`FSK over a subset of the 8 frequencies. Outputs of the subtransmitters are combined and sent to
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`a common antenna.” Ex. 1008, p. 2, Experiments. A block diagram of the four
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`“subtransmitters” described by Petrovic would be structured in a similar manner to the systems
`
`shown in either of Figures 1 and 2 of the ‘891 patent, except with four data sources and
`
`modulators instead of two. Indeed, as in Figures 1 and 2 of the ‘891 patent, Petrovic describes
`
`that “[o]utputs of the subtransmitters are combined and sent to a common antenna [i.e.,
`
`transmission source].” Ex. 1008, p. 2, Experiments.
`
`B.
`
`Combination of Petrovic, Raith, and Alakija
`
`27.
`
`I have been asked to consider a scenario in which the “co-locating” limitation of
`
`claim 5 requires co-locating a plurality of structurally separate transmitters. In such a scenario,
`
`Petrovic discloses a plurality of transmitters, but does not explicitly disclose co-location. Rather,
`
`under such a construction Petrovic discloses two transmitters located seven miles apart. See Ex.
`
`1008, p. 2, Experiments. However, based on Petrovic in view of Raith and Alakija it would be
`
`obvious to co-locate the plurality of transmitters disclosed in Petrovic such that the plurality of
`
`carriers can be emanated from the same transmission source.
`
`28.
`
`In particular, Petrovic describes an experiment in which “[t]wo transmitters [each
`
`including four subtransmitters capable of 4-FSK over a subset of the 8 described frequencies]
`
`were installed seven miles apart and synchronized to provide a simulcast overlap area with
`
`approximately 35 dBpV/r signal strength.” Ex. 1008, p. 2, Experiments. Thus, Petrovic
`
`describes a plurality of transmitters, but describes them as being located seven miles apart.
`
`However, the number and location of transmitters in the paging system described by Petrovic
`
`would simply be a matter of design choice that would have been obvious to one of ordinary skill
`
`in the art.
`
`29.
`
`For example, Figure 1 of Raith describes “the division of an area into cells and the
`
`assignation of base station transmitters to the cells in a mobile telephone system.” Ex. 1010, 6:1-
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`3. For adjacent cells, Raith describes that it is common to co-locate groups of three base
`
`transmitters to service contiguous cells. See Ex. 1010, 6:11-13. Thus, as highlighted in the
`
`following annotation of Figure 1, “the base station transmitter BS1 for the cell C1 is co-located
`
`with the base station transmitter BS3 for the cell C3 and the base station transmitter BS5 for the
`
`cell C5.” Ex. 1010, 6:13-15 (emphasis added).
`
`30.
`
`The systems of Petrovic and Raith are similar. Raith describes a cellular digital
`
`mobile radio system with plural base station transmitters and a method of transmitting
`
`information in such a system. Ex. 1010, title. Specifically, Raith describes:
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`
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`[A]t least two base station transmitters (Bma, Bmb, Bna, Bnb) at a given
`transmitting distance from each other are assigned to each of certain cells (Cm,
`Cn) within a restricted geographical area. The base station transmitters which are
`assigned to the same cell transmit digitally modulated radio signals within the
`same frequency range at least partially simultaneously to the mobile stations of
`the cell. The radio signals from different base station transmitters associated with
`the same cell are digitally modulated with the same message information to the
`mobile stations in the cell.
`Ex 1010, Abstract. In other words, each individual cell described by Raith is similar to the
`
`experiment described by Petrovic, with two transmitters located a certain distance apart to
`
`simultaneously transmit the same message information to a mobile station. Raith simply
`
`describes a more complex network of cells and associated transmitters, which are used for two-
`
`way telephone communication, as opposed to one-way pager communication.
`
`31.
`
`Considering Petrovic and Raith in combination, one of ordinary skill in the art
`
`would have been motivated to expand the experimental paging system configuration described in
`
`Petrovic to include multiples adjacent paging cells/regions similar in structure illustrated in
`
`Figure 1 of Raith. In this modified configuration, multiple transmitters configured and operated
`
`as described by Petrovic would be co-located to service contiguous cells, as described by Raith.
`
`The following annotation of a portion of FIG. 1 of Raith illustrates the proposed combination.
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`32.
`
`One of ordinary skill in the art would have been motivated to expand the
`
`experiment described by Petrovic in order to provide messaging services to a larger geographic
`
`area and a larger number of mobile devices (e.g., pagers).
`
`33.
`
`Though Petrovic in view of Raith describes the co-location of a plurality of
`
`transmitters, it does not explicitly describe emanating a plurality of carriers from the same
`
`transmission source. However, it would have been obvious to one of ordinary skill in the art to
`
`connect the plurality of co-located transmitters taught by Petrovic in view of Raith to a single
`
`antenna structure, such as the one described by Alakija, such that the plurality of carriers output
`
`by the co-located transmitters could be emanated from the same transmission source.
`
`34.
`
`In particular, Alakija describes a “mobile communications base station antenna,
`
`which utilizes a cylindrical array design.” Ex. 1011, Abstract. “Using a switching matrix,
`
`different subsets of antenna elements, in the array, can be excited, thus producing a narrow
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`steerable beam.” Id. In one configuration of the cylindrical antenna, Alakija describes that,
`
`“[b]y combining a number of feed networks into a single antenna system, an antenna with
`
`multiple independently steerable beams is achieved.” Ex. 1011, pp. 1-2 (emphasis added).
`
`One of ordinary skill would have understood that each of the three co-located transmitters
`
`described by Petrovic in view of Raith could provide the “number of feed networks”
`
`contemplated by Alakija as inputs to the cylindrical antenna. The following annotated version of
`
`FIG. 6 of Alakija illustrates this configuration:
`
`
`
`35. Moreover, Alakija describes that the characteristics of the cylindrical antenna can
`
`be altered to cater to variable sector sizes. See Ex. 1011, p. 2. Examples of these different
`
`patterns that can be obtained by varying phase distribution of the cylindrical antenna are shown
`
`in FIG. 9. See Ex. 1011, pp. 2-3. One of ordinary skill in the art would have understood that one
`
`of the illustrated patterns would readily service the mobile cell structure described by Raith. In
`
`the following diagram, three of the independently steerable beams taught by FIG. 9 of Alakija
`
`(i.e., the red pattern that is shown in FIG. 9 and the two blue patterns that one of ordinary skill in
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`the art would have understood could be independently steered as part of the configuration shown
`
`in FIG. 6) have been overlayed on FIG. 1 of Raith to illustrate this point.
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`U.S. Patent No. 5,659,891
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`36.
`
`One of ordinary skill in the art would have been motivated to utilize a single
`
`cylindrical antenna structure to emit the output signals of the three co-located transmitters de-
`
`scribed by Petrovic in view of Raith instead of three separate antennas, because a single antenna
`
`structure “[c]an be used to realize advantages such as . . . hardware savings, low manufacturing
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`costs, [and] low installation costs,” as recognized by Alakija. Ex. 1011, p. 3.
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`III. Cimini and Combinations Based on Cimini
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`A.
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`Cimini
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`37.
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` Cimini describes “a digital mobile channel using orthogonal frequency division
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`multiplexing.” Ex. 1009, p. 1, Title. In particular, Cimini describes that, “[i]n a conventional
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`serial data system, the symbols are transmitted sequentially, with the frequency spectrum of each
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`data symbol allowed to occupy the entire available bandwidth.” Ex. 1009, p. 1, § 1. Cimini goes
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`on to describe the various limitations of these serial systems. See Ex. 1009, p. 1, § 1. For
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`example, “[d]ue to the bursty nature of the Rayleigh channel, several adjacent symbols may be
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`completely destroyed during a fade.” See id.
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`38.
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`Cimini goes on to teach that “[a] parallel or multiplexed data system offers
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`possibilities for alleviating many of the problems encountered with serial systems.” Ex. 1009, p.
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`1, § 1. In a parallel data system, the total signal frequency band is divided into N frequency
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`subchannels. See Ex. 1009, p. 1, § 1. “Each subchannel is modulated with a separate symbol
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`and, then, the N subchannels are frequency multiplexed.” Ex. 1009, p. 1, § 1. To efficiently use
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`the bandwidth in a parallel system, Cimini teaches that “the spectra of the individual subchannels
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`are permitted to overlap, with specific orthogonality constraints imposed to facilitate separation
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`of the subchannels at the receiver.” Ex. 1009, p. 1, § 1. Cimini specifies that the spectra in
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`which the described parallel systems operate are “strictly band-limited.” See Ex. 1009, p. 3, §
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`2(A). Such multiplexed signals may be transmitted from a transmitter system, such as the one
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`shown in FIG. 1(a). See Ex. 1009, p. 2, § II(A).
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`39.
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`Recognizing that the transmission channel often distorts the signal, Cimini
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`proposes adding pilot signals to the transmitted signal that can be used to correct fading. See Ex.
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`1009, pp. 3-4, § II(C). “Pilot-based correction provides an amplitude and phase reference which
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`can be used to counteract the unwanted effects of multipath propagation.” Ex. 1009, p. 4, §
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`II(C). In order to reduce distortion of these pilots due to co-channel interference, Cimini
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`describes implementing “a separation between the pilot tone and its neighboring information
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`components.” Ex. 1009, p. 8, § III(B). Accordingly, as shown in FIG. 10, Cimini describes
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`inserting the pilot signals into specific positions within the output multiplexed signal, in between
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`sets of data subcarriers. See Ex. 1009, p. 8, § III(B). Specifically, Cimini discloses “a 200Hz
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`spacing between the pilot frequency and the nearest data subcarrier.” See Ex. 1009, p. 8, §
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`III(B).
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`40.
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`To transmit the resulting orthogonal frequency division multiplexed data signal,
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`Cimini proposes using a 7.5 kHz channel. See Ex. 1009, p. 8, § III(B). Because Cimini
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`describes this channel as a 7.5 kHz “data window” (Ex. 1009, p. 8, § III(B)) and specifies that
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`the spectra is “strictly band-limited” (Ex. 1009, p. 8, § II(A)), one of ordinary skill in the art
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`would have understood the channel described by Cimini to be mask-defined and bandlimited.
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`The OFDM signal that is transmitted within this 7.5 kHz mask-defined, bandlimited channel is
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`illustrated in the following annotated version of FIG. 10.
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`
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`41. Within this OFDM signal, Cimini describes “[s]acrificing two bands of 1000 Hz
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`each for pilot protection and 250 HZ at either end for adjacent channel interference protection”
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`(i.e., two 250 Hz guard bands). Based on these parameters, Cimini describes that this “leaves
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`space for 86 data channels” within the remaining 5 kHz of the 7.5 kHz mask-defined,
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`bandlimited channel and each of the carriers within these data channels are spaced 58.59 Hz
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`apart. See Ex. 1009, p. 9, § III(C). In other words, Cimini describes a transmitted OFDM signal
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`in which the frequency difference between the center frequency of the outer most of the carriers
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`and the band edge of the mask defining the channel (i.e., at least 250 Hz) is more than half the
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`frequency difference between the center frequencies of each adjacent carrier (i.e., 58.59 Hz).
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`42.
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`Similar to FIGS. 1 and 2 of the ‘891 patent, FIG. 1(a) of Cimini illustrates a
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`multicarrier transmitter system with a plurality of modulators, each modulating a different
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`portion of data to be transmitted. See Ex. 1009, p. 2, § II(A). In other words, Cimini discloses
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`emanating multiple carriers from the same transmission source (e.g., an antenna).
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`B.
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`Combination of Cimini, Raith, and Alakija
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`43.
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`As described above, I have been asked to consider a scenario in which the “co-
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`locating” limitation of claim 5 requires co-locating a plurality of structurally separate
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`transmitters. In such a scenario, Cimini does not explicitly disclose the co-location of a plurality
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`of transmitters. However, based on Cimini in view of Raith and Alakija, it would be obvious to
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`co-locate the plurality of transmitters disclosed in Cimini such that the plurality of carriers can be
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`emanated from the same transmission source.
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`44.
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`Cimini describes a “cellular mobile radio system based on orthogonally frequency
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`division multiplexing many low-rate subchannels into one higher rate channel was analyzed and
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`simulated.” Ex. 1009, p. 10, § IV. Similarly, Figure 1 of Raith describes “the division of an area
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`into cells and the assignation of base station transmitters to the cells in a mobile telephone
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`system in accordance with the invention.” Ex. 1010, 6:1-3. For adjacent cells, Raith describes
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`that it is common to co-locate base transmitters into groups of three for contiguous cells. See Ex.
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`1010, 6:11-13. Thus, as highlighted in the following annotation for Figure 1, “the base station
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`transmitter BS1 for the cell C1 is co-located with the base station transmitter BS3 for the cell C3
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`and the base station transmitter BS5 for the cell C5.” Ex. 1010, 6:13-15 (emphasis added).
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`45. Moreover, the systems of Cimini and R