UNITED STATES PATENT AND TRADEMARK OFFICE
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`LG ELECTRONICS, INC.,
`Petitioner,
`
`v.
`
`CONSTELLATION DESIGNS, LLC,
`Patent Owner.
`
`Case No. IPR2023-00228
`U.S. Patent No. 10,693,700
`
`PATENT OWNER’S PRELIMINARY RESPONSE
`PURSUANT TO 37 C.F.R. § 42.107(a)
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`TABLE OF CONTENTS
`
`B.
`
`I.
`II.
`
`III.
`
`IV.
`
`Introduction ...................................................................................................... 1
`Using “Constellations” In Digital Communications ....................................... 6
`A.
`Overview of a Digital Communications ............................................... 6
`1.
`The Transmitter ........................................................................... 7
`2.
`The Receiver ............................................................................... 9
`Constellation Mapping and Demapping .............................................. 10
`1.
`Constellation Point Locations and Labels ................................ 10
`2.
`The Mapper ............................................................................... 11
`3.
`The Demapper ........................................................................... 13
`Hierarchical Communications ............................................................. 16
`C.
`Prior Art Approaches ..................................................................................... 18
`A.
`The Shannon Channel Capacity Limit ................................................ 18
`B.
`Prior Art Approaches Failed To Achieve the Shannon Limit ............. 19
`The Challenged ’700 Patented Invention ...................................................... 20
`A.
`The Development of the Inventive Technology.................................. 21
`B.
`The Patent’s Improved Approach to Implementing Non-
`Uniform Constellations ....................................................................... 23
`1.
`Optimizing Constellation Locations and Labels ....................... 24
`2.
`Non-Uniform Constellations Optimized For Particular
`Code Rates ................................................................................ 25
`Using Multiple Optimized Constellations For a System
`Having Multiple Code Rate and SNR Operating Points .......... 26
`The Revolutionary Results .................................................................. 27
`
`3.
`
`C.
`
`i
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`V.
`
`VI.
`
`2.
`3.
`
`C.
`
`The Challenged Claims ....................................................................... 29
`D.
`Petition ........................................................................................................... 31
`A.
`Eroz ...................................................................................................... 32
`B.
`DVB-T .................................................................................................. 34
`1.
`DVB-T Was Designed For Hierarchical Broadcast
`Communications ....................................................................... 34
`Hierarchical Modulation Constellations in DVB-T ................... 36
`DVB-T Provides for a Flexible Implementation for
`Network Operators to Choose Code Rates,
`Constellations, and Alpha Values Without Limitation ............. 40
`De Gaudenzi ........................................................................................ 42
`1.
`De Gaudenzi Uses Only APSK Constellations ........................ 42
`2.
`De Gaudenzi Describes Maintaining Uniform Phase and
`Varying a Ring Ratio of an APSK ............................................ 45
`De Gaudenzi’s Teachings Are Focused on APSK
`Constellations and Not Rectangular QAM Constellations ....... 46
`De Gaudenzi Describes and is Applicable to Non-
`Hierarchical Constellations ....................................................... 48
`The Board Should Deny Institution ............................................................... 49
`A.
`Grounds 1A, 2A, 3A, 4A: The Board Should Deny Institution
`Because LG’s Petition Fails to Establish a Reasonable
`Likelihood of Success on the “Where Each … Different Non-
`Uniform Multidimensional Symbol Constellations Is Only
`Included In One Of The … Pairs” Claim Limitation .......................... 50
`1.
`Petition Admits Claim Limitation Not Found in Prior Art
`and Provides No Evidence to Support a Conclusion of
`Obviousness .............................................................................. 51
`
`3.
`
`4.
`
`ii
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`2.
`
`3.
`
`B.
`
`Petitioners Unsupported Argument Fails to Consider
`That There is No Clear Highest Efficiency Constellation
`in a Hierarchical System ........................................................... 54
`The Proposed Modification Goes Against DVB-T’s
`Teaching of Providing Flexibility to Implementers to
`Control Constellations and Code Rates Based on
`Network Requirements ............................................................. 56
`Grounds 1B, 2B, 3B, 4B: The Board Should Deny Institution
`Because De Gaudenzi Does Not Cure the Deficiencies of
`Grounds 1A, 2A, 3A, and 4A .............................................................. 57
`1.
`The Petition Fails to Explain How the Optimization
`Approach of De Gaudenzi Could Be Applied to the Eroz-
`DVB-T Combination ................................................................. 58
`All Grounds: The Board Should Deny Institution Because LG’s
`Petition Fails to Establish a Reasonable Likelihood of Success
`That A Person of Skill In The Art Would Want to Combine
`Eroz and DVB-T .................................................................................. 65
`1.
`Many Unexplained Substantial Functional Changes
`Would be Required By the Combination, Which Would
`lead Person of Skill in the Art Away From the
`Combination .............................................................................. 65
`VII. CONCLUSION .............................................................................................. 67
`
`C.
`
`iii
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`TABLE OF AUTHORITIES
`
`Cases
`
` Page(s)
`In re Kahn, 441 F.3d 977 (Fed. Cir. 2006) .......................................................passim
`Other Authorities
`35 U.S.C. § 103 ........................................................................................................ 31
`
`iv
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`TABLE OF EXHIBITS
`Description
`Declaration of Dr. Giuseppe Caire
`Declaration of Dr. Guillen i. Fabregas
`U. Madhow, Fundamentals of Digital Communication, Cambridge
`University Press 2008
`R.G. Gallager, Principles of Digital Communication, Cambridge University
`Press 2008
`Eroz et al., New DVB-S2X constellations for improved performance
`on the satellite channel, Int. J. Satell. Commun. Network 2016;
`34:351–360, Published online 14 September 2015 in Wiley Online
`Library (wileyonlinelibrary.com)
`RESERVED
`N.S. Login et al., Non-Uniform Constellations for ATSC 3.0, IEEE
`Transactions on Broadcasting, Vol. 62, No. 1, March 2016
`P. Gill, W. Murry, M. Wright, Practical Optimization, Emerald
`Group Publishing Limited (1982)
`RESERVED
`RESERVED
`RESERVED
`Curriculum Vitae and Publication List of Dr. Giuseppe Caire
`Curriculum Vitae and Publication List of Dr. Guillen i. Fabregas
`RESERVED
`Giuseppe Caire, Giorgio Taricco, and Ezio Biglieri, Bit-Interleaved Coded
`Modulation, IEEE Transactions of Information Theory, vol. 44, no. 3, May
`1998 (“Caire”)
`Alexander Schretz, and Chris Weck, Hierarchical modulation – the
`transmission of two independent DVB-T multiplexes on a single frequency,
`European Broadcasting Union Technical Review, April 2003, pages 1-13.
`RESERVED
`
`Exhibit
`2001
`2002
`2003
`
`2004
`
`2005
`
`2006
`2007
`
`2008
`
`2009
`2010
`2011
`2012
`2013
`2014
`2015
`
`2016
`
`2017
`
`v
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`I.
`
`Introduction
`The challenged claims and subject matter are not merely patentable over the
`
`prior art, they are revolutionary. For over 60 years prior to the ʼ700 Patent’s
`
`inventions, experts strove to design digital communication systems that could
`
`perform near the ultimate limit for reliable transmission of information, known as
`
`the Shannon channel capacity limit. They all failed.
`
`But where others failed for 60 years, the ‘700 Patent inventors succeeded,
`
`developing a system and approach that did the unthinkable and finally achieved
`
`capacity near or equal to the Shannon limit. They did so by going against all
`
`conventional wisdom in digital communications design. Instead of trying to
`
`improve error-correcting methods used to transmit constellations, they tried to
`
`improve the constellations themselves. Instead of keeping constellation points
`
`uniformly spaced, they experimented with changing both the locations and labels
`
`of the constellations.
`
`The result was revolutionary. The inventors of the ʼ700 Patent developed
`
`techniques for optimizing signal constellations for capacity. The resulting
`
`communication systems were astronomical improvements over the prior art,
`
`providing never before seen levels of performance that finally achieved the holy
`
`grail sought for 60 years, the Shannon channel capacity limit.
`
`1
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`And Petitioner LG took notice. It previously marveled that the inventive
`
`constellations yielded performance gains “well above the famous [Shannon]
`
`shaping gain limit of 1.53 dB.” (EX2007 at 202). Petitioner LG also previously
`
`conceded that the inventors were the first to describe the use of optimizing a
`
`constellation for capacity. (EX2007 at 197).
`
`But now that LG is accused of infringing these acknowledged inventions, it
`
`is singing a different tune. The Board should deny institution, however, because
`
`LG’s Petition fails to establish the required reasonable likelihood of success under
`
`any of the asserted grounds for at least the following reasons:
`
` Petition fails to provide any evidence that the combination of Eroz
`
`and DVB-T meets the “where each … different non-uniform
`
`multidimensional symbol constellation is only included in one of the
`
`… code rate constellation pairs” limitation recited in each challenged
`
`claim, much less enough evidence to meet Petitioner LG’s burden;
`
`and
`
` Petition attempts to cure this deficiency by relying on De Gaudenzi,
`
`but the Petition fails to explain how the proposed combination could
`
`be made or why a person of ordinary skill in the art would have a
`
`reasonable expectation of success in making the proposed
`
`combination.
`
`2
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`No Reasonable Likelihood of Success with Respect to Eroz and DVB-T
`
`Combination: As explained below, each challenged claim of the Patent Owner
`
`Constellation Design’s ‘700 Patent is directed to a data communication system and
`
`requires that “each … different non-uniform multidimensional symbol
`
`constellation is only included in one of the … code rate constellation pairs.” But
`
`the Petition fails to even attempt to identify this limitation in either Eroz or DVB-T.
`
`Instead of providing this necessary evidence, the Petition provides a number of
`
`conclusory statements that it would be obvious to optimize each constellation. But
`
`the Petition (1) fails to recognize that there is no clear highest efficiency
`
`constellation in a hierarchical constellation, which represents two data streams,
`
`because increasing spectral efficiency and/or improving SNR performance for one
`
`data stream necessarily reduces spectral efficiency and/or reduces SNR
`
`performance for the other data stream; and (2) the proposed modification goes
`
`against DVB-T’s teaching of providing flexibility to control constellations and code
`
`rates based on different transmission requirements.
`
`No Reasonable Likelihood of Success with Respect to Eroz, DVB-T, and
`
`De Gaudenzi Combination: Acknowledging the weakness of the Eroz-DVB-T
`
`combination, the Petition relies upon De Gaudenzi as allegedly teaching the “each
`
`… different non-uniform multidimensional symbol constellation is only included
`
`in one of the … code rate constellation pairs.” But the author of De Gaudenzi has
`
`3
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`submitted a declaration confirming that his work and article could not be
`
`easily applied to DVB-T’s hierarchical QAM constellations. For example,
`
`author Dr. Guillén i Fàbregas, has confirmed:
`
` Recognizing that configuring constellation and code rate pairs that
`
`have been optimized for SNR or spectral efficiency would have been
`
`desirable is one thing. Finding the system to achieve this goal is a very
`
`different thing. Indeed, in my opinion it is not straightforward how
`
`someone could modify the combination of references cited in the
`
`Petition to optimize for SNR or spectral efficiency. (Fabregas
`
`Declaration at 2, 13).
`
` “My co-authors and I did not develop nor did we describe optimizing
`
`rectangular QAM constellations. We only worked on multi-ring
`
`APSK constellations. Moreover, the techniques we did describe in De
`
`Gaudenzi could not be easily applied to a rectangular QAM
`
`constellation.” (Fabregas Declaration at 10).
`
` “My co-authors and I did not develop and did not describe optimizing
`
`hierarchical constellations. Instead, our optimization process only
`
`considered non-hierarchical APSK constellations in which a single
`
`data stream is represented and which only has one code rate
`
`associated with it at any one time. In my opinion, it is not clear or
`
`4
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`straightforward how anyone could apply the techniques I disclosed in
`
`De Gaudenzi to a hierarchical system. For instance, my techniques
`
`were directed towards improving capacity for a constellation
`
`representing a single data stream that could only be used with a single
`
`code rate at any one time. A hierarchical constellation, such as those
`
`described in DVB-T, represent two data streams and can used with two
`
`different code rates at any given time.” (Fabregas Declaration at 12).
`
` “I recall, during that symposium in Nice France, thinking that the
`
`presentation of the work by Barsoum, Jones and Fitz was genuinely
`
`original and interesting. I was impressed by the scope of the work:
`
`embarking into a full constellation optimization to result in non-
`
`uniform (in all degrees of freedom) constellations is a challenging and
`
`commendable project. I recall speaking to a colleague regarding the
`
`concepts described during the presentation. Despite having worked on
`
`the subject for a number of years, I did not make a connection
`
`between the materials presented in Nice France and my own work as
`
`described in De Gaudenzi.” (Fabregas Declaration at 6).
`
`For at least these reasons, the Petition should be denied.
`
`5
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`II.
`
`Using “Constellations” In Digital Communications
`The challenged patent concerns an improved method and system for using
`
`“constellations” in a digital communication system. A digital communication
`
`system is used to transmit digital bits (sequences of 0s and 1s) from one device (a
`
`transmitter) to another (a receiver). As explained below in more detail, a
`
`“constellation” point is a carrier signal value (such as amplitude and/or phase) that
`
`can be used to represent a longer sequence of bits. Transmitting information using
`
`an appropriate constellation point signal value can make a data communication
`
`system faster and more efficient.
`
`Overview of a Digital Communications
`A.
`A digital communication system typically includes a transmitter that sends
`
`information to a receiver over a wireless or wired channel. (EX2001 at 5; EX2003
`
`at 2-4; EX2004 at 1-5, 95, 181-183, 208-209).
`
`As illustrated in the above overview, information in the form of user bits
`
`(sequences of 0s and 1s) is input to the transmitter, which first converts those bits
`
`into an electromagnetic signal and then transmits that electromagnetic signal over
`
`the channel to the receiver. (EX2001 at 5; EX2003 at 2-4; EX2004 at 1-5, 95, 181-
`
`6
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`183, 208-209). As the electromagnetic signal passes through the channel, bits and
`
`data can be lost or corrupted; in this manner, the channel introduces “noise” (signal
`
`loss) to the transmission. (EX2001 at 5; EX2003 at 2-4; EX2004 at 1-5, 95, 181-
`
`183, 208-209). The receiver receives the electromagnetic signal (along with any
`
`noise introduced by its passage through the channel) and converts the received
`
`signal back into bits. (EX2001 at 5-6; EX2003 at 2-4; EX2004 at 1-5, 95, 181-183,
`
`208-209).
`
`Each digital communication system has a measurable “capacity,” which is the
`
`maximum amount of information that the system can reliably send over the channel.
`
`(EX2001 at 6; EX2003 at 252; EX2004 at 253-254, 311-312).
`
`The Transmitter
`1.
`In a digital communication system, the transmitter typically includes three
`
`main components: a coder, a mapper, and a modulator. (EX2001 at 6; EX2003 at
`
`2-4; EX2004 at 1-5, 95, 181-183, 208-209).
`
`The coder is used to transform the input user bits into a longer sequence of
`
`output bits according to error-correcting codes to enable later error correction by
`
`the receiver. (EX2001 at 6; EX2003 at 2-3; EX2004 at 11, 298). For example, the
`
`7
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`coder may add additional redundant bits to the input user bits that would later
`
`enable the receiver’s decoder to use error-correcting codes (such as turbo codes or
`
`Low Density Parity Check (LDPC) codes) to help detect or recover user bits lost to
`
`noise during transmission. (EX2001 at 6; EX2003 at 2-3; EX2004 at 11, 298).
`
`The code rate is a ratio of the relative length of the input user bits to the length of
`
`the output bits. For example, a code rate of 1/2 indicates that for every bit in the
`
`sequence of input user bits, there are 2 bits in the sequence of output bits.
`
`Similarly, a code rate of 3/5 indicates that for every 3 bits in the sequence of input
`
`user bits, there are 5 bits in the sequence of output bits.
`
`The resulting new bit sequence is input to the mapper, which maps this new
`
`sequence to constellation points, which are one or more carrier signal values (such
`
`as amplitude and/or phase) that can be used to represent a longer sequence of bits.
`
`(EX2001 at 7; EX2003 at 7; EX2004 at 181-209). Such mapping and constellations
`
`are a focal point of the challenged claims and are discussed in more detail in the
`
`following “Constellation Mapping and Demapping” section. (EX2001 at 7).
`
`Next, the mapper provides these constellation values to the modulator, which
`
`creates a signal to be modulated to reflect the constellation values provide by the
`
`mapper and then be sent through the channel. (EX2001 at 19; EX2003 at 2-3;
`
`EX2004 at 181-209). There are numerous different ways for a modulator to apply
`
`such information to a carrier signal. (EX2001 at 7; EX2003 at 2-3; EX2004 at 181-
`
`8
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`209). For example, in a Pulse Amplitude Modulation (PAM), the modulator can
`
`modify (modulate) the amplitude of the carrier signal so that the signal’s different
`
`amplitudes will represent different bit sequences. (EX2001 at 7-8; EX2003 at 45;
`
`EX2004 at 184-196).
`
`The Receiver
`2.
`In a digital communication system, the receiver typically mirrors the
`
`transmitter and includes: a de-modulator, a demapper, and a decoder. (EX2001 at
`
`8; EX2003 at 2-4; EX2004 at 1-5, 11, 95, 181-183, 208-209).
`
`The extracted signal values are then input to the demapper, which is used to
`
`help identify which bit sequence corresponds to the extracted constellation signal
`
`values. (EX2001 at 22; EX2003 at 3-4; EX2004 at 181-209). Such demapping is
`
`discussed in more detail in the following “Constellation Mapping and Demapping”
`
`section. (EX2001 at 8).
`
`Next, the decoder uses information from the demapper and the structure of
`
`the error-correcting code to try to identify the appropriate bit sequence and recover
`
`any of the user bits lost or corrupted due to noise during transmission. (EX2001 at
`
`8; EX2003 at 3-4, EX2004 at 11).
`
`9
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`B.
`
`Constellation Mapping and Demapping
`1.
`Constellation Point Locations and Labels
`As discussed above, the transmitter’s coder provides sequences of bits (such
`
`as the original user bits plus error correcting bits) to the mapper. The mapper then
`
`maps each sequence to constellation points. (EX2001 at 9).
`
`A constellation point has at least two characteristics: (1) it is a value
`
`associated with a variable characteristic of the signal transmitted over the channel;
`
`and (2) it represents a unique bit sequence. (EX2001 at 9). As explained below,
`
`the former is a constellation point’s “location,” and the latter is its “label.”
`
`(EX2001 at 9).
`
`Signal characteristics that may be used as constellation point locations
`
`include amplitude, phase, and frequency. (EX2001 at 9; EX2003 at 2-3, 45;
`
`EX2004 at 181-209). The particular signal characteristic (or characteristics) used
`
`as constellation point locations can depend on the type of modulation performed by
`
`the modulator. (EX2001 at 9; EX2003 at 2-3, 45; EX2004 at 181-209). For
`
`example, recall that if a modulator uses pulse amplitude modulation (PAM) to
`
`apply information to the carrier signal, the resulting signal’s different amplitudes
`
`are used to represent different bit sequences. (EX2001 at 9; EX2003 at 45;
`
`EX2004 at 184-196). In such a system, the signal’s different amplitudes may serve
`
`as constellation point locations.
`
`10
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`To illustrate, if the transmitter can send a high frequency signal having
`
`pulses of any amplitude between 0 and 1.0 volts, then any amplitude between 0
`
`and 1.0 volts can be chosen and used as a constellation point. (EX2001 at 9-10).
`
`For example, if four constellation points are needed, each of 0, .33, .66, and 1.0
`
`volts could be used as an individual constellation point. (EX2001 at 10). Where a
`
`particular constellation point falls on the spectrum of available values is called its
`
`“location.” (EX2001 at 10).
`
`To continue this simplified illustration, if each sequence of bits to be
`
`communicated from the transmitter to the receiver comprises a series of shorter 2-
`
`bit sequences (00, 01, 10, and 11), then each of those 2-bit sequences can be
`
`assigned to a corresponding constellation point. (EX2001 at 10). For example,
`
`using the constellation points identified above, the 01 sequence could be assigned
`
`any one of the 0, .33, .66, and 1.0 volt constellation points. (EX2001 at 10). The
`
`sequence to which a constellation point is assigned is its “label.” (EX2001 at 10).
`
`The Mapper
`2.
`The transmitter’s mapper uses these constellation labels and locations to
`
`map a bit sequence to a corresponding sequence of constellation points. (EX2001
`
`at 11; EX2003 at 7; EX2004 at 181-209). For example, to send sequence
`
`“10000111”, the mapper would take each 2-bit sequence, and map it to its
`
`corresponding constellation point. (EX2001 at 11). Applying the locations and
`
`11
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`labels from the below table using the PAM example, the sequence “10000111”
`
`would be broken into its composite bit sequences 10, 00, 01, and 11, which would
`
`be mapped to the voltages .66, 0.0, .33, and 1.0 respectively. (EX2001 at 11).
`
`Constellation
`Label
`“00”
`“01”
`“10”
`“11”
`
`Constellation
`Location
`0
`.33
`.66
`1.0
`
`The resulting output of the example mapper is the sequence 0.66, 0.0, 0.33.
`
`and 1.0 shown in the following figure, in which the y-axis represents voltage and
`
`the x-axis represents time. (EX2001 at 11-12). For reference, the transmitted bit
`
`sequence is shown for each time slot below the figure.
`
`12
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`The Demapper
`3.
`On the receiver side, the demodulator receives and demodulates the received
`
`signal, which is a noisy version of the transmitted signal, in an attempt to extract the
`
`transmitted constellation point signal values. (EX2001 at 12; EX2003 at 3-4;
`
`EX2004 at 181-209). But because noise results from the transmission, the
`
`demodulated signal may not be identical to the constellation points output from the
`
`mapper (as shown above) but might include errors. (EX2001 at 12 EX2003 at 3-4;
`
`EX2004 at 181-209). An example output of the demodulator is shown below, in
`
`which a time-dependent continuous waveform is shown in black including noise, the
`
`average of the time-dependent continuous waveform is shown in red, the output of
`
`the demodulator is shown as discrete time values in black, and the figure is again
`
`annotated with the corresponding bit sequence:
`
`13
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`This demodulated signal is then sent to the demapper so that the demapper
`
`can convert the demodulated signal values back to bits based on the constellation
`
`points. (EX2001 at 13; EX2003 at 3-4; EX2004 at 181-209). But because of the
`
`noise introduced during transmission, the signal characteristic (e.g., amplitude,
`
`phase, frequency) values of received pulses may not exactly match the assigned
`
`constellation point locations. (EX2001 at 13; EX2003 at 3-4; EX2004 at 181-209).
`
`Accordingly, in some implementations, the demapper uses a predetermined set of
`
`14
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`signal characteristic (e.g., amplitude, phase, frequency) ranges to attempt to
`
`determine the corresponding bit sequence1. (EX2001 at 13-14; EX2003 at 127).
`
`Continuing the ongoing example, the demapper could use the following
`
`amplitude ranges to map the received signal to a corresponding bit sequence:
`
`Output of
`Demodulator
`(y)
`y <= .25
`.25 < y <= .5
`.5 < y <= .75
`.75 <= y
`
`Bit
`Sequence
`
`“00”
`“01”
`“10”
`“11”
`
`Applying this demapping scheme:
`
` if the output of the demodulator is less than or equal to .25 volts, then
`
`the bit sequence is “00”;
`
` if the output of the demodulator is greater than .25 but less than or
`
`equal to .5, then the bit sequence is “01”;
`
` if the output of the demodulator is greater than .5 but less than .75,
`
`then the bit sequence is “10”; and
`
`1 For the purpose of illustrating the basic operation of a demapper, the described
`example illustrates a demapper that performs “hard” decisions, that is, outputs
`actual decisions on which bit sequence corresponds to the input signal. (EX2001 at
`14). In many implementations, the demapper performs “soft” decisions, that is,
`outputs probabilities on which bit sequence corresponds to the input signal.
`(EX2001 at 14).
`
`15
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
` if the output of the demodulator is greater than .75, then the bit
`
`sequence is “11”. (EX2001 at 15).
`
`Using this mapping, the example output from the demodulator (shown in the
`
`figure above) would be demapped to “10” for the first pulse, demapped to “00” for
`
`the second pulse, demapped to “01” for the third pulse, and demapped to “11” for
`
`the fourth pulse. (EX2001 at 15). Put together, these component bits result in the
`
`sequence “10000111.”2 (EX2001 at 15).
`
`Hierarchical Communications
`C.
`The digital communication systems and techniques discussed so far have all
`
`related to typical non-hierarchical systems in which the communication system
`
`transmits a single stream of bits. However, one class of communication systems
`
`multiplex two data streams into a single channel, effectively creating two separate
`
`data streams. (EX2001 at 15; EX2016 at 2-3). This approach is referred to as
`
`hierarchical modulation and finds applicability in digital television broadcast where
`
`television broadcasters can enable improved capabilities to adapt the network to
`
`changing requirements. (EX2001 at 15; EX2016 at 2-3). Hierarchical systems can
`
`also provide a lower-quality fallback signal in the case of weak signals that allows
`
`2 To simplify the illustrative example, it does not include any error correction
`coding.
`
`16
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`for a graceful degradation instead of a complete signal loss. (EX2001 at 15; EX2016
`
`at 2-3).
`
`Hierarchical modulation also allows for varying levels of quality of service.
`
`(EX2016 at 2-4). For example, a hierarchical system provides higher data rates (e.g.,
`
`higher resolution video, additional channels) for a smaller coverage area closer to
`
`the transmitter, while providing lower data rates (e.g., basic service) to a larger
`
`coverage area. (EX2001 at 16; EX2016 at 2-4).
`
`In hierarchical modulation, different bits are provided with varying levels of
`
`reliability or error protection. (EX2001 at 16; EX2016 at 2-4). This can include
`
`creating a high priority data stream, which is more robust, and a low priority data
`
`stream, which is less robust. (EX2001 at 16; EX2016 at 2-4). Fundamental to
`
`hierarchical systems is that in order to provide the increased robustness for the high
`
`priority data stream, the robustness of the lower priority data stream must be
`
`decreased. (EX2001 at 16; EX2016 at 2-4). That is to say, that a hierarchical system
`
`does not provide for more reliable communication for all bits being transmitted,
`
`rather, hierarchical systems increase the robustness of some data at the cost of
`
`reducing the robustness of other data, as compared to an equivalent non-hierarchical
`
`system. (EX2001 at 16; EX2016 at 2-4).
`
`Hierarchical modulation also does not increase the overall data transmission
`
`rate of a communication system. (EX2001 at 16). To the contrary, the net data rate
`
`17
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`of the low priority and the high priority data streams will actually be less than an
`
`equivalent non-hierarchical system due to the overhead required in implementing
`
`the hierarchical communications. (EX2001 at 16; EX2016 at 3).
`
`III. Prior Art Approaches
`Digital communications systems and constellations as described above were
`
`generally known in the art. A primary—and wholly unrealized—goal in designing
`
`such systems was to design systems able to perform very close to the ultimate limit
`
`for reliable transmission of information, which is established by Shannon channel
`
`coding theorem and is known as the Shannon channel capacity limit. (EX2001 at
`
`17).
`
`In designing these prior art systems, conventional wisdom dictated that
`
`constellation locations must be equally spaced apart so that that each constellation
`
`point is as far as possible from its neighboring points. (EX2001 at 17). But this
`
`and all other prior art approaches fell far short of their “holy grail,” the Shannon
`
`limit. (EX2001 at 17).
`
`The Shannon Channel Capacity Limit
`A.
`Each digital communication system has a measurable “capacity,” which is
`
`the maximum amount of information that the system can reliably send over the
`
`channel. (EX2001 at 17; EX2003 at 252; EX2004 at 253-254, 311-312). As
`
`detailed in the challenged ʼ700 Patent, two different ways of measuring capacity
`
`18
`
`

`

`Case No. IPR2023-00228
`Patent No. 10,693,700
`
`are “joint capacity” and “parallel decode capacity.” (EX1001 at 5:6-8; 6:42-7:30;
`
`See also, e.g., EX2001 at 17).
`
`Regardless of which measure is used, each communication channel’s
`
`capacity is constrained by the Shannon channel capacity limit, which represents the
`
`theoretically best capacity a channel could possibly achieve in light of physically
`
`unsurmountable limits on error correction methods. (EX2001 at 20-21; EX2003 at
`
`252-255, 263-264; EX2004 at 1,184-187, 253). Just as nothing can move faster
`
`than the speed of light, no channel’s capacity can exceed the Shannon capacity
`
`limit. (EX2001 at 21; EX2003 at 252-255, 263-264; EX2004 at 1).
`
`Shannon calculated this capacity limit by determining the maximum possible
`
`efficiency of error correcting methods. (EX2001 at 21; EX2003 at 252-255, 263-
`
`264; EX2004 at 1,184-187, 253). This maximum amount of error correction is then
`
`compared to the levels of noise and data corruption to determine the Shannon limit,
`
`which is the maximum amount of data that can reliably transmitted over a given
`
`communication channel using error correcting methods of the maximum possible
`
`efficiency. (EX2001 at 21; EX2003 at 252-255, 263-264; EX2004 at 1,184-187,
`
`253).
`
`Prior Art Approaches Failed To Achieve the Shannon Limit
`B.
`C