PTAB

IPR2016-01342

ZTE USA Inc v. Evolved Wireless LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method and Apparatus for Transmitting Preamble Sequence
  • Brief Description: The ’481 patent relates to methods and systems for transmitting data in a mobile communication system. The claimed invention specifically covers generating a preamble sequence for a Random Access Channel (RACH) by repeating a specific code sequence multiple times to form a consecutive sequence and then concatenating a single cyclic prefix (CP) to the front of it before transmission.

3. Grounds for Unpatentability

Ground 1: Claims 1-2 are invalid under 35 U.S.C. §102 or obvious under 35 U.S.C. §103 over Panasonic 700.

  • Prior Art Relied Upon: Panasonic 700 (3GPP Contribution R1-060700).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Panasonic 700, a technical contribution to the 3GPP standards body, disclosed every limitation of claims 1 and 2. The reference explicitly taught a RACH preamble structure containing multiple repetitions ("M Repetition") of a Constant Amplitude Zero Auto Correlation (CAZAC) sequence. This repeated sequence was preceded by a single cyclic prefix (CP), and the entire structure was shown to fit within a single radio frame. Petitioner asserted this structure directly mapped to the method steps of independent claim 1. Dependent claim 2, requiring the specific sequence to be a CAZAC sequence, was also expressly taught by Panasonic 700.

Ground 2: Claim 3 is obvious over Panasonic 700 in view of Panasonic 114.

  • Prior Art Relied Upon: Panasonic 700 (3GPP Contribution R1-060700) and Panasonic 114 (3GPP Contribution R1-061114).
  • Core Argument for this Ground:
    • Prior Art Mapping: Building on the preamble structure taught by Panasonic 700, Petitioner contended that Panasonic 114 provided the missing limitation of claim 3: "applying a cyclic shift to said specific sequence." Panasonic 114, another contribution from the same 3GPP working group, expressly concluded that "cyclic-shifted CAZAC sequence has superior performance" and proposed using such sequences for the RACH preamble.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine these references as they addressed the identical problem of optimizing RACH preamble design within the same standards body (3GPP WG1). Panasonic 114’s direct comparison showed the superiority of using cyclic-shifted sequences, providing a clear reason to modify the base structure of Panasonic 700 to incorporate this known improvement.
    • Expectation of Success: A POSITA would have a high expectation of success, as the combination involved substituting a known, better-performing sequence type (cyclic-shifted CAZAC) into a known preamble structure to achieve the predictable benefit of improved correlation properties.

Ground 4: Claims 8-9 are obvious over Panasonic 700 in view of Motorola 595.

  • Prior Art Relied Upon: Panasonic 700 (3GPP Contribution R1-060700) and Motorola 595 (Application # 2007/0058595).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that while Panasonic 700 taught the functional method steps of apparatus claim 8, Motorola 595 supplied the necessary structural components. Motorola 595 disclosed a generic transmitter architecture for a mobile device, including logic circuitry (e.g., a microprocessor) that would serve as the claimed "preamble generation unit" and transmit circuitry that would serve as the "transmission unit." Petitioner asserted that these hardware components were well-known and capable of performing the preamble generation and transmission functions taught by Panasonic 700. Claim 9’s requirement for generating a CAZAC sequence was met by Panasonic 700.
    • Motivation to Combine: A POSITA seeking to implement the RACH transmission method from Panasonic 700 would have been motivated to use a standard transmitter architecture, such as the one disclosed in Motorola 595. This combination represented a routine design choice of implementing known functions on a well-understood hardware platform.
    • Expectation of Success: Success would be predictable, as it involved programming known hardware (a microprocessor and transmitter) to perform the straightforward signal processing steps described in Panasonic 700.
  • Additional Grounds: Petitioner asserted further obviousness challenges against claims 4, 6, 10, 11, and 13. These grounds built upon the core combinations by adding Chu (a 1972 journal article on Zadoff-Chu sequences) to teach the fundamental mathematical properties of applying cyclic shifts via multiplication with an exponential sequence, and combined all references to address the remaining dependent claims.

4. Key Claim Construction Positions

  • "consecutive sequence having a length (N*L)" (claims 1 and 8): Petitioner argued that this term should be given its plain and ordinary meaning. Petitioner noted that while it had proposed a narrower construction in a related IPR, the Patent Owner had since advocated for the broader plain and ordinary meaning in district court, and the claims were unpatentable under either interpretation.
  • "preamble generation unit" and "transmission unit" (claim 8): Petitioner contended that these terms are not means-plus-function limitations under §112. It proposed they should be construed broadly as "hardware and/or software in the user equipment that is capable of performing the respective functions recited," which would encompass the generic microprocessor and transmitter circuitry disclosed in the prior art.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that institution was proper because the grounds presented were not redundant with those in three co-pending IPRs filed against the same patent (IPR2016-00758, IPR2016-00981, and IPR2016-01349). The petition asserted that it relied on different primary prior art references, distinct arguments, and different evidence than the other proceedings.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-4, 6, 8-11, and 13 of Patent 8,218,481 as unpatentable.