UNITED STATES PATENT AND TRADEMARK OFFICE
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`
`
`In Re:
`
`U.S. Patent No. 8,284,833:
`
`Attorney Docket No. 082944.0102
`
`Inventor:
`
`Jin, Hui, et al.
`
`Filed:
`
`March 28, 2011
`
`Issued:
`
`October 9, 2012
`
`
`
`
`
`
`
`:
`
`:
`
`:
`
`IPR No. Unassigned
`
`Assignee: California Institute of Technology
`
`Title: Serial Concatenation of Interleaved Convolutional Codes Forming
`Turbo-Like Codes
`
`
`
`Mail Stop PATENT BOARD
`Patent Trial and Appeal Board
`U.S. Patent and Trademark Office
`P.O. Box 1450
`Alexandria, Virginia 22313-1450
`
`
`Submitted Electronically via the Patent Review Processing System
`
`
`
`DECLARATION OF HENRY D. PFISTER
`
`Active 17101440.3
`
`

`
`Table of Contents
`
`
`
`I.
`
`II.
`
`III.
`
`IV.
`
`A.
`
`B.
`
`A.
`
`B.
`
`A.
`
`B.
`
`Background and Qualifications .................................................................................... 1
`
`Legal Understanding ........................................................................................................ 3
`
`Anticipation ......................................................................................................................... 3
`
`Obviousness ......................................................................................................................... 4
`
`Background on the Relevant Technology ................................................................ 8
`
`Review of Linear Error-Correcting Codes ................................................................ 8
`Background on Turbo Codes and Modern Coding Theory .............................. 12
`
`The Patents at Issue ....................................................................................................... 20
`
`The ‘833 Patent ............................................................................................................... 20
`
`Effective Date for the ‘833 Patent Claims .............................................................. 26
`
`V.
`
`The Prior Art .................................................................................................................... 26
`
`A.
`
`Prior Art Considered ..................................................................................................... 26
`
`VI.
`
`Construction of Claims ................................................................................................. 30
`
`A.
`
`B.
`
`C.
`
`D.
`
`E.
`
`Level of Ordinary Skill in the Art .............................................................................. 31
`
`“wherein two or more memory locations of the first set of memory
`locations are read by the permutation module different times from one
`another” .............................................................................................................................. 31
`
`“Permutation module” .................................................................................................. 32
`
`“Combine” Terms ............................................................................................................ 34
`
`“Index” ................................................................................................................................ 35
`
`VII.
`
`Invalidity ............................................................................................................................ 37
`
`A.
`
`Anticipation by the MacKay Software .................................................................... 37
`
`‘833 Patent Claim 1 ........................................................................................................ 37
`
`‘833 Patent Claim 2 ........................................................................................................ 52
`
`‘833 Patent Claim 4 ........................................................................................................ 55
`
`‘833 Patent Claim 6 ........................................................................................................ 57
`
`‘833 Patent Claim 8 ........................................................................................................ 60
`
`‘833 Patent Claim 9 ........................................................................................................ 72
`
`‘833 Patent Claim 10 ..................................................................................................... 74
`
`‘833 Patent Claim 11 ..................................................................................................... 77
`
`‘833 Patent Claim 13 ..................................................................................................... 79
`
`Active 17101440.3
`
`i
`
`

`
`B.
`
`Obviousness by ‘710 Patent in view of Hennessy .............................................. 81
`
`‘833 Patent Claim 1 ........................................................................................................ 82
`
`‘833 Patent Claim 2 ........................................................................................................ 93
`
`‘833 Patent Claim 4 ........................................................................................................ 94
`
`‘833 Patent Claim 6 ........................................................................................................ 96
`
`‘833 Patent Claim 8 ........................................................................................................ 97
`
`‘833 Patent Claim 9 ...................................................................................................... 107
`
`‘833 Patent Claim 10 ................................................................................................... 108
`
`‘833 Patent Claim 11 ................................................................................................... 108
`
`‘833 Patent Claim 13 ................................................................................................... 110
`
`
`
`Active 17101440.3
`
`ii
`
`

`
`I, Henry D. Pfister, declare as follows:
`
`1.
`
`I make this declaration based upon my own personal knowledge
`
`and, if called upon to testify, would testify competently to the matters
`
`contained herein.
`
`2.
`
`I have been asked to provide technical assistance in the inter
`
`partes review of U.S. Patent No. 8,284,833 ("the ’833 Patent").1 I have also
`
`reviewed and analyzed U.S. Patent Nos. 7,116,710 ("the ’710 Patent”)2;
`
`7,421,032 (“’032 patent”);3 and 7,916,781(“’781 patent”).4
`
`3.
`
`This declaration is a statement of my opinions on issues related
`
`to the patentability of claims 1, 2, 4, 6, 8, 9, 10, 11, and 13 of the ‘833
`
`Patent.
`
`I.
`
`Background and Qualifications
`
`4. My qualifications are stated more fully in my curriculum vitae.
`
`Here I provide a brief summary of my qualifications. I was an active
`
`contributor and collaborator in the community that included the inventors
`
`
`
` Ex. 1007.
`
` 1
`
`2 Ex. 1001.
`
`3 Ex. 1004.
`
`4 Ex. 1006.
`
`Active 17101440.3
`
`1
`
`

`
`and subject matter of the ‘710; ‘032; ‘781; and ‘833 patents before and after
`
`May 2000. From 1997-2003, I was a graduate student at the University of
`
`California, San Diego (UCSD) studying electrical engineering. During
`
`1998-1999, I took my first sequence of courses on error-correcting codes
`
`and my course project for the 1999 winter quarter was on repeat-accumulate
`
`codes. This work led to my first conference paper, which was entitled “The
`
`serial concatenation of rate-1 codes through uniform random interleavers,”
`
`was presented at the Allerton conference in 1999 and may be referred to
`
`herein as “Pfister & Siegel.”5 This paper generalized the idea of repeat-
`
`accumulate codes to include arbitrary outer codes and multiple inner
`
`accumulate codes. I continued my studies and eventually became a
`
`professor. Now, I am an associate professor in the Department of Electrical
`
`and Computer Engineering at Duke University. Before this appointment, I
`
`taught in the Department of Electrical and Computer Engineering of Texas
`
`A&M University, College Station from 2006-2014. I received my Ph.D. in
`
`electrical engineering from the University of California, San Diego (UCSD)
`
`in 2003 and then spent two years in R&D at Qualcomm, Inc., and one year
`
`as a post-doctoral researcher at the Swiss Federal Institute of Technology,
`
`Lausanne (EPFL). I am a co-author on more than 60 peer-reviewed
`
`
`
` Ex. 1057.
`
` 5
`
`Active 17101440.3
`
`2
`
`

`
`publications on information theory, error-correcting codes, and wireless
`
`communication including the IEEE Communications Society 2007 best
`
`paper in Signal Processing and Coding for Data Storage. During my career,
`
`I have been the principal investigator (or co-PI) on seven funded research
`
`grants receiving, in total, more than two million dollars in funding. Five of
`
`these grants have come from the National Science Foundation (NSF)
`
`including the NSF Career Award in 2008. Finally, I am currently an
`
`associate editor for the IEEE Transactions on Information Theory and I
`
`regularly serve as a reviewer of grant proposals submitted to the National
`
`Science Foundation.
`
`II.
`
`Legal Understanding
`
`5. My opinions are also informed by my understanding of the
`
`relevant law. I understand that the patentability analysis is conducted on a
`
`claim-by-claim basis and that there are several possible reasons that a patent
`
`claim may be found to be unpatentable.
`
`6.
`
`I understand that earlier publications and patents may act to
`
`render a patent unpatentable for one of two reasons: (1) anticipation, and (2)
`
`obviousness.
`
`A.
`
`Anticipation
`
`Active 17101440.3
`
`3
`
`

`
`7.
`
`First, I understand that a single prior art reference, article,
`
`patent, or publication “anticipates” a claim if each and every element of the
`
`claim is disclosed in that prior art. I further understand that, where a claim
`
`element is not explicitly disclosed in a prior art reference, the reference may
`
`nonetheless anticipate a claim if the missing claim element is necessarily
`
`present in the apparatus or a natural result of the method disclosed—i.e. the
`
`missing element is “inherent.”
`
`B.
`
`8.
`
`Obviousness
`
`Second, I understand that the prior art may render a patent
`
`claim "obvious." I understand that two or more prior art references, articles,
`
`patents, or publications that each disclose fewer than all elements of a patent
`
`claim may nevertheless be combined to render a patent claim obvious if the
`
`combination of the prior art collectively discloses all elements of the claim
`
`and one of ordinary skill in the art at the time would have been motivated to
`
`combine the prior art. I understand that this motivation to combine need not
`
`be explicit in any of the prior art, but may be inferred from the knowledge of
`
`one of ordinary skill in the art at the time the patent was filed. I also
`
`understand that one of ordinary skill in the art is not an automaton, but is a
`
`person having ordinary creativity. I further understand that one or more
`
`prior art references, articles, patents, or publications that disclose fewer than
`
`Active 17101440.3
`
`4
`
`

`
`all of the elements of a patent claim may render a patent claim obvious if
`
`including the missing element would have been obvious to one of skill in the
`
`art (e.g., the missing element represents only an insubstantial difference over
`
`the prior art or a reconfiguration of a known system).
`
`9.
`
`Under the doctrine of obviousness, a claim may be invalid if the
`
`differences between the invention and the prior art are such that the subject
`
`matter as a whole would have been obvious at the time the invention was
`
`made to a person having ordinary skill in the art to which the subject matter
`
`pertains.
`
`10.
`
`I understand that obviousness is based on the scope and content
`
`of the prior art, the differences between the prior art and the claim, the level
`
`of ordinary skill in the art, and secondary indicia of obviousness and non-
`
`obviousness to the extent they exist.
`
`11.
`
`I understand that secondary indicia of both obviousness and
`
`non-obviousness should be considered when evaluating whether a claimed
`
`invention would have been obvious to one of ordinary skill at the time of
`
`invention. These secondary indicia of non-obviousness may include, for
`
`example:
`
`Active 17101440.3
`
`5
`
`

`
`• a long felt but unmet need in the prior art that was satisfied by the
`
`claimed invention;
`
`• commercial success of processes claimed by the patent;
`
`• unexpected results achieved by the invention;
`
`• praise of the invention by others skilled in the art;
`
`• the taking of licenses under the patent by others; and
`
`• deliberate copying of the invention.
`
`12.
`
`I also understand that there are second indicia of the
`
`obviousness of an alleged invention.
`
`13.
`
`I understand that there must be a relationship between any such
`
`secondary indicia and the claimed invention. I further understand that if the
`
`claimed invention produced expected results that this is also a secondary
`
`consideration supporting an obviousness determination.
`
`14.
`
`It
`
`is also my understanding
`
`that
`
`there are additional
`
`considerations that may be used as further guidance as to when the above
`
`factors will result in a finding that a claim is obvious, including the
`
`following:
`
`• the claimed invention is simply a combination of prior art elements
`
`according to known methods to yield predictable results;
`
`Active 17101440.3
`
`6
`
`

`
`• the claimed invention is a simple substitution of one known element
`
`for another to obtain predictable results;
`
`• the claimed invention uses known techniques to improve similar
`
`devices or methods in the same way;
`
`• the claimed invention applies a known technique to a known device or
`
`method that is ready for improvement to yield predictable results;
`
`• the claimed invention would have been "obvious to try" choosing
`
`from a finite number of identified, predictable solutions, with a
`
`reasonable expectation of success;
`
`• there is known work in one field of endeavor that may prompt
`
`variations of it for use in either the same field or a different one based
`
`on design incentives or other market forces if the variations would
`
`have been predictable to one of ordinary skill in the art;
`
`• there existed at the time of invention a known problem for which there
`
`was an obvious solution encompassed by the patent's claims; and
`
`• there is some teaching, suggestion, or motivation in the prior art that
`
`would have led one of ordinary skill to modify the prior art reference
`
`or to combine prior art reference teachings to arrive at the claimed
`
`invention.
`
`Active 17101440.3
`
`7
`
`

`
`15. Finally, I understand that a claim may be deemed invalid for
`
`obviousness in light of a single prior art reference, without the need to
`
`combine references, if the elements of the claim that are not found in the
`
`reference can be supplied by the knowledge or common sense of one of
`
`ordinary skill in the relevant art.
`
`III. Background on the Relevant Technology
`
`A.
`
`Review of Linear Error-Correcting Codes
`
`16. Channel coding is the practice of adding redundancy to a
`
`message or repeating it in order to make it more robust against noise. It is
`
`used because noise and errors are essentially unavoidable in many systems
`
`(e.g., wireless communications and magnetic storage). Coding allows one to
`
`reduce the rate of information transfer in exchange for increased reliability
`
`and usually provides large gains in overall system efficiency. Channel
`
`coding works by first designing a set of codewords that can be reliably
`
`transmitted over a noisy channel and then associating each codeword with a
`
`message.6
`
`
`
` In the District Court Action (identified below), the Judge construed
`
` 6
`
`“codeword” to mean “a discrete encoded sequence of data elements.”
`
`Active 17101440.3
`
`8
`
`

`
`17. A length-
`
` binary code is simply a subset of the
`
` binary-
`
`vectors of length-
`
`. Each vector in this subset of called a codeword. A
`
`binary linear code is a binary code where the modulo-2 sum of any two
`
`codewords is also a codeword. In practice, most systems use linear codes
`
`for two reasons: simplicity and performance. First, linear codes are much
`
`simpler to describe, encode, and analyze. Second, there are very few cases
`
`where non-linear codes are better than linear codes. So, there is no real price
`
`to be paid for this simplicity.
`
`18. Linear codes can be described using linear algebra. In
`
`particular, they are defined by matrices and vectors of elements that can be
`
`added, subtracted, multiplied, and divided. A set of numbers, which obey all
`
`the standard rules of arithmetic, is an algebraic object known as a field. For
`
`example, real and complex numbers are both fields. The binary alphabet
`
` with standard multiplication and modulo-2 addition is also a field
`
`(more specifically, a finite field). Either a generator matrix or parity-check
`
`matrix can be used to define a linear code.
`
`
`
`Corrected Claim Construction Order (D.I. 105), Ex 1024, at 9-10.
`
`Statements about “codewords” herein are made in view of that construction.
`
`Active 17101440.3
`
`9
`
`

`
`19. The generator matrix
`
` of a binary linear code is a
`
` binary
`
`matrix whose row space equals the code. In particular, any codeword can be
`
`written as the modulo-2 sum of some rows in
`
` and each row of
`
` is a
`
`codeword. If
`
` has full-rank, then it naturally defines an encoder from
`
`
`
`information bits to
`
` code bits. In this case, we say that the code has length
`
`, dimension
`
`, and rate
`
`.
`
` For an information vector
`
`, the codeword
`
` is defined by the modulo-2
`
`sum
`
`.
`
`20. The parity-check matrix
`
` of a binary linear code is an
`
`
`
`binary matrix where each row defines a parity-check equation satisfied by all
`
`codewords. For example, let
`
` be the -th bit of a codeword and assume
`
`that the first row of
`
` is all-zero except for ones in positions
`
`.
`
`Then,
`
`the
`
`first
`
`row
`
`represents
`
`a
`
`parity-check
`
`equation,
`
` modulo 2, that all codewords must satisfy. In fact,
`
`all codewords in the code must satisfy all of the parity-check equations
`
`defined by the parity-check matrix. If the code has dimension
`
` and
`
` is
`
`full rank, then
`
` and
`
`.
`
`21.
`
`In general, the ideal decoding process for a code consists of
`
`finding the most-likely codeword given the observed channel outputs.
`
`Suppose the noisy channel has binary outputs and, during transmission, it
`
`Active 17101440.3
`
`10
`
`

`
`introduces an error in each position independently with probability
`
`.
`
`Then, the ideal decoding process consists of finding the codeword that most
`
`closely matches the received sequence.
`
`22. A rate-
`
` binary convolutional encoder is a finite-state
`
`mapping (or transducer) that, during each time step, accepts
`
` input bits and
`
`produces
`
` output bits. The internal state of the encoder is also updated
`
`during each step. If
`
`, then the encoder can introduce structured
`
`redundancy in the output stream and a suitably designed decoder (e.g., a
`
`Viterbi decoder) can exploit this redundancy to correct errors in that bit
`
`stream.
`
`23. Since a convolutional encoder continuously receives inputs and
`
`generates outputs, it defines a code whose codewords are infinitely long. In
`
`practice, convolutional codes are truncated or terminated to generate
`
`codewords of finite length. If the sum of any two input sequences is
`
`encoded into the sum of their associated output sequences and the zero-
`
`padded right shift by
`
` of an input sequence generates the zero-padded right
`
`shift by
`
` of its associated output sequence, then the convolutional code is
`
`linear. Also, the block code formed by truncating (or terminating) a linear
`
`convolutional code is also linear.
`
`Active 17101440.3
`
`11
`
`

`
`B.
`
`Background on Turbo Codes and Modern Coding Theory
`
`24. The introduction of turbo codes in 1993 by Berrou, Glavieux,
`
`and Thitimajshima started a revolution in coding theory that initiated great
`
`advances in error-correcting codes. 7 Turbo codes were a new class of error-
`
`correcting codes formed by a parallel concatenation of two convolutional
`
`encoders through a pseudo-random interleaver (or permutation).
`
`25. The main drawback of convolutional codes is that they only
`
`produce local redundancy in the output stream. Thus, they cannot handle
`
`error patterns with a small number of errors that fall very close together in
`
`the data stream. Turbo codes overcome this deficiency by encoding the
`
`input bits twice. First, the input bits are feed to a convolutional encoder in
`
`their normal order. Then, the input bits are reordered by pseudo-random
`
`interleaver and encoded again by a convolutional encoder. With this setup, a
`
`small number of errors will cause a decoding error only if they are close
`
`together in both the original data stream and the permuted data stream.
`
`Since this is much less likely, the performance is improved.
`
`
`
` C. Berrou, A. Glavieux, and P. Thitimajshima, “Near Shannon Limit Error
`
` 7
`
`Correcting Coding and Decoding.” (1993), Ex. 1061.
`
`Active 17101440.3
`
`12
`
`

`
`26.
`
`In 1995, David J. C. MacKay rediscovered Robert Gallager’s
`
`long-forgotten, 1963
`
`low-density parity-check
`
`(LDPC) codes and
`
`demonstrated their outstanding performance.8 He also observed that turbo
`
`codes have much in common with LDPC codes. Like turbo codes, the
`
`construction of LDPC codes is based on pseudo-random permutations and
`
`the decoding is based on an iterative process. In fact, it was shown by
`
`McEliece, MacKay, and Cheng in 1998 that turbo decoding and LDPC
`
`decoding can both be seen as an instance of the same unified principle.9
`
`27. LDPC codes are most easily understood in terms of their parity-
`
`check matrix and its associated Tanner graph. The parity-check matrix
`
`
`
`was described earlier and the Tanner graph associated with an
`
` parity-
`
`check matrix is a bipartite graph with
`
` variable nodes,
`
` check nodes, and
`
`an edge connecting the -th variable node to the -th check node if and only
`
`
`
` MacKay and Neal, “Near Shannon Limit Performance of Low Density
`
` 8
`
`Parity Check Codes”, Ex. 1062
`
`9 McElice, MacKay, and Cheng, “Turbo Decoding as an Instance of Pearl’s
`
`‘Belief Propagation’ Algorithm”, IEEE Journal on Selected Areas in
`
`Communication, Vol 16, No. 2, Feb. 1998 Ex. 1033.
`
`Active 17101440.3
`
`13
`
`

`
`if
`
`. The standard iterative decoder for LDPC codes works by passing
`
`messages along these edges.
`
`28.
`
`In 1997, Gallager’s LDPC codes were modified to have Tanner
`
`graphs with an irregular degree structure and were shown to achieve near-
`
`Shannon performance on the binary erasure channel (BEC) by Luby,
`
`Mitzenmacher, Shokrollahi, Spielman, and Stemann. 10 This work also
`
`showed that irregular low-density generator-matrix (LDGM) codes benefit
`
`from irregularity on the BEC. A little later, MacKay and others (e.g.,
`
`Richardson and Urbanke) were also experimenting with irregular LDPC
`
`codes on general binary channels. Their results showed that irregularity
`
`provided valuable performance gains in practice.
`
`29. Richardson, Urbanke,
`
`and Shokrollahi
`
`extended
`
`the
`
`optimization of irregular LDPC codes in Luby, Mitzenmacher, Shokrollahi,
`
`Spielman, and Stemann’s to general channels in a paper that was released on
`
`the Internet on April 5th 1999 and submitted to the IEEE Transactions on
`
`
`
`10 Luby, Mitzenmacher, Shokrollahi, Spielman, and Stemann, “Practical
`
`loss-resilient codes”, Ex. 1028,
`
`Active 17101440.3
`
`14
`
`

`
`Information Theory in the same year.11 I received an invitation to download
`
`a copy of the submitted paper by email from a publically-accessible website
`
`on April 5, 1999.12 I downloaded a copy of the paper on the same day.13 I
`
`was aware that the authors sent emails to others in the field to distribute the
`
`“Design of Provably Good Low-Density Parity Check Codes” paper.
`
`Around the time of this email, this was a conventional way to make others in
`
`the field aware of new publications. The authors stated that “[i]n the present
`
`paper we present result indicating the remarkable performance that can be
`
`achieved by properly chosen irregular codes.” 14 This led to codes that
`
`approach capacity in practice. 15 Thus, it was well known by 1999 that
`
`making LDPC code structures “irregular” was beneficial. In 1999, this
`
`
`
`11 Richardson, Shokrollahi, and Urbanke, “Design of Provably Good Low-
`
`Density Parity Check Codes,” EX 1029, at 4.
`
`12 Ex. 1066 (Email from Paul Siegel to me an others forwarding April 5,
`
`1999 email from Tom Richardson, Amin Shokrollahi, and Ruediger Urbanke
`
`inviting download of “Design of provably good low-density party check
`
`codes.”)
`
`13 A copy of the paper that I downloaded on April 5, 1999 is Ex. 1029.
`
`14 Ex. 1029, at 4.
`
`15 Ex. 1029, at 5 and Fig. 2.
`
`Active 17101440.3
`
`15
`
`

`
`irregular structure was extended and generalized to all turbo codes in
`
`“Irregular Turbocodes” by Frey and MacKay (“Frey & MacKay”), by
`
`encoding irregularly repeated symbols.16 This paper was generally presented
`
`at the 1999 Allerton Conference on Communications, Control and
`
`Computing. The Allerton Conference is generally regarded as one of the
`
`main conferences in the field of information theory and communications and
`
`generally occurs in September. In 1999, the conference occurred from
`
`September 22-24, 1999 with the paper being published on the authors’
`
`websites in October of 1999. The proceedings were published later.
`
`30.
`
`In 1996, Benedetto and Montorsi provided one explanation for
`
`the excellent performance of turbo codes by showing that, on average, turbo
`
`codes have good distance properties.17 In particular, they computed the
`
`average weight enumerator (averaged over all possible interleavers) of a
`
`turbo code and showed that the bit-error rate due to low-weight codewords
`
`decreases as the block length increases. This led them to introduce the
`
`interleaver gain as a way to estimate the performance of parallel
`
`concatenated codes. Later, with Divsalar and Pollara, this approach was
`
`
`
`16 Frey & MacKay, Ex 1012.
`
`17 Ex. 1063.
`
`Active 17101440.3
`
`16
`
`

`
`extended to serial concatenated codes.18 Together, these two works define
`
`the interleaver gain exponent (IGE), which is numerical parameter that
`
`estimates the rate at which the bit (or block) error rate decreases as the block
`
`length increases. The IGE conjecture, which was defined formally in
`
`“Coding Theorems for Turbo-like Codes” by Divsalar, Jin, and McEliece
`
`(“the Divsalar reference”)19, asserts that these estimates are mathematically
`
`correct.20
`
`31.
`
`It is worth noting that in Section VI of Benedetto & Montorsi,
`
`one example focuses on turbo codes constructed with rate-1 accumulators.21
`
`While this predates the introduction of repeat-accumulate codes, it is not
`
`particularly surprising. This is because the rate-1 accumulator is actually a
`
`standard element in the simplest non-trivial rate-1/2 recursive systematic
`
`
`
`18 S. Benedetto , D. Divsalar , G. Montorsi , F. Pollara, “Serial
`
`Concatenation of Interleaved Codes: Performance Analysis, Design, and
`
`Iterative Decoding” (1996), Ex. 1032.
`
`19 Divsalar, Ex. 1011
`
`20 Divsalar, Ex. 1011, at 3-5.
`
`21 Benedetto & Montorsi, Ex. 1063, at 422-426.
`
`Active 17101440.3
`
`17
`
`

`
`convolutional code. Thus, the “accumulate” code is really a new name for
`
`an well-known mapping.
`
`32. The Divsalar reference had both theoretical and practical
`
`relevance here. Theoretically, the Divsalar reference showed the IGE
`
`conjecture applied to the special case of repeat-accumulate codes. This gave
`
`researchers confidence that the performance of turbo codes was now
`
`understood and it also suggests that the more general performance estimates
`
`based on the IGE are also corrects. Practically, the Divsalar reference
`
`demonstrated that the recursive rate-1 “accumulate” convolutional encoder
`
`could be used to construct useful codes with very simple decoders. Very
`
`soon afterwards, multiple researchers began experimenting with codes based
`
`on accumulators.22 In August 1999, Dr. David MacKay presented a talk at
`
`
`
`22 L. Ping, W. K. Leung, N. Phamdo, “Low Density Parity Check Codes
`
`with Semi-random Parity Check Matrix.” Electron. Letters, Vol. 35, No. 1,
`
`pp. 38-39, Jan. 7th, 1999 (“Ping”), Ex 1014; H. D. Pfister and P. H. Siegel,
`
`“The serial concatenation of rate-1 codes through uniform random
`
`interleavers.” Proc. 37th Allerton Conf. on Comm., Control and Computing,
`
`Monticello, Illinois, pp. 260-269, Sep. 1999 (“Pfister”), Ex. 1057; Viterbi
`
`and Viterbi, “New results on serial concatenated and accumulated-
`
`Active 17101440.3
`
`18
`
`

`
`the IMA academic conference on sparse graph codes, in the speaking slot
`
`directly before one of the named inventors of the ‘833 patent (McEliece).23
`
`In his slides presented at that talk, Dr. MacKay showed on one page a graph
`
`of a Gallager code, a Repeat-accumulate code, a turbo code, and a recursive
`
`convolutional code. 24 On the very next slide, the suggestion “make
`
`irregular” appears as the second bullet under the heading “Where to go from
`
`Regular Gallagher Codes.”25 The immediate juxtaposition of these sparse
`
`graph codes, which includes a repeat-accumulate code, with a suggestion to
`
`“make irregular,” demonstrates that a person of ordinary skill in the art
`
`would recognize that irregularity would improve a repeat-accumulate code.
`
`33. By the end of 1999, it was commonly known within the field
`
`that adding irregularity to any code structure could improve its iterative-
`
`decoding performance. In the same year, it was also shown in "Low density
`
`parity check codes with semi-random parity check matrix" by Ping, Leung,
`
`
`
`convolutional turbo code performance” in Annales Des Télécommunications
`
`1999, Ex. 1031.
`
`23 Ex. 1037 at p. 3.
`
`24 Ex. 1037 at p. 42.
`
`25 Ex. 1037 at p.43.
`
`Active 17101440.3
`
`19
`
`

`
`and Phamdo ("Ping") 26 that the accumulate structure could be used to
`
`construct LDPC codes with linear-time encoders. A very similar structure
`
`with linear-time encoding was also proposed in “Constructing Low-Density
`
`Parity-Check Codes with Circulant Matrices” by Bond, Hui, and Schmidt. 27
`
`Combining these constructions with irregular LDPC codes naturally leads to
`
`codes that are expected to perform well and have low-complexity encoding.
`
`IV. The Patents at Issue
`
`A.
`
`34.
`
`The ‘833 Patent
`
`I have reviewed the ‘833 patent, which is entitled “Serial
`
`Concatenation of Interleaved Convolutional Codes Forming Turbo-Like
`
`Codes.” I understand that the application that later issued as the ‘833 patent
`
`was filed on March 28, 2011. I understand that the ‘833 patent claims
`
`priority to U.S. Patent No. 7,916,781 (the ‘781 patent) that was filed on May
`
`18, 2008. I understand that the ‘781 patent claims priority to U.S. Patent No.
`
`7,421,032 (the ‘032 patent), which, was filed on October 3, 2006. The ‘032
`
`patent, in turn, claims priority to U.S. Patent No. 7,116,710 (the ‘710
`
`patent), which was filed on May 18, 2001. I understand that the application
`
`
`
`26 Ex. 1014.
`
`27 Ex. 1030.
`
`Active 17101440.3
`
`20
`
`

`
`that later issued as the ‘710 patent was filed on May 18, 2001 and then
`
`issued on October 3, 2006. The ‘710 patent claims priority to a provisional
`
`application filed on May 18, 2000. I further understand that the ‘710 patent
`
`is a continuation-in part of U.S. Patent No. 7,089,477 (the ‘477 patent) that
`
`was filed on August 18, 2000
`
`35. The ‘833 patent is directed to Irregular Repeat Accumulate
`
`codes. I have discussed the Divsalar reference above. The coder used by
`
`the aut