Apple Inc v. Optis Cellular Technology LLC

1. Case Identification

• Case #: IPR2020-00465
• Patent #: 8,102,833
• Filed: February 28, 2020
• Petitioner(s): Apple Inc.
• Patent Owner(s): Optis Cellular Technology, LLC
• Challenged Claims: 1-14

2. Patent Overview

• Title: Method and Apparatus for Transmitting Uplink Signal in Wireless Communication System
• Brief Description: The ’833 patent discloses a method for transmitting uplink signals in a wireless communication system. The invention focuses on a specific arrangement of data, control, and ACK/NACK signals within a two-dimensional time-frequency resource matrix and the three-step process (multiplexing, mapping, and overwriting) used to create this arrangement.

3. Grounds for Unpatentability

Ground 1: Claims 1-14 are obvious over Qualcomm, Cho, Qualcomm-269, and Samsung.

• Prior Art Relied Upon: Qualcomm (3GPP Document R1-075037), Cho (Application # 2006/0262871), Qualcomm-269 (3GPP Document R1-073269), and Samsung (3GPP Document R1-073094).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that the combination of these four references, all related to uplink signal formatting in 3GPP LTE systems, rendered the claimed invention obvious. The mapping was presented as a layered combination:
    • Qualcomm was asserted to teach the foundational method of multiplexing control and data signals and mapping them into a two-dimensional resource matrix for transmission. It disclosed a channel interleaver that maps a stream of multiplexed bits row-by-row into a matrix, which is then read out column-by-column, with columns corresponding to SC-FDMA symbols.
    • Cho was combined with Qualcomm to teach the specific arrangement of placing control signals at the "front" of the multiplexed stream. Cho disclosed that mapping control information across the first sub-carriers (the top rows of the matrix) provides time diversity and improves the performance of control information detection. This addressed the claimed limitation of placing control signals at a "front part" of the multiplexed signals.
    • Samsung was added to teach placing high-priority ACK/NACK signals in specific, reliable locations. Samsung disclosed that placing ACK/NACK signals directly adjacent to reference signal (RS) symbols minimizes channel estimation losses and addresses low signal-to-noise ratio issues, thereby teaching the placement of ACK/NACK signals in columns adjacent to those used for reference signals.
    • Qualcomm-269 was introduced to provide the mechanism for placing the ACK/NACK signals as taught by Samsung. It disclosed that ACK/NACK transmission "punctures" (i.e., overwrites) data signals. Petitioner argued a POSITA would apply this puncturing to the data portions of the matrix, not the higher-priority control signals, and would do so starting from the last row (farthest from the control signals) to avoid corrupting the control information.
  • Motivation to Combine: Petitioner contended a POSITA would combine these references because they all address known problems in the same field of 3GPP LTE uplink design. A POSITA would have been motivated to modify Qualcomm's general multiplexing scheme with Cho's technique to gain the explicit benefit of improved time diversity for control signals. To further enhance reliability for critical ACK/NACK signals, a POSITA would have incorporated Samsung's teaching of placing them adjacent to reference symbols. Finally, to implement this placement, a POSITA would have used the known and simple technique of puncturing taught by Qualcomm-269, a method that avoids altering the overall signal structure.
  • Expectation of Success: Petitioner asserted a POSITA would have had a reasonable expectation of success because combining these known techniques from the same technical field would predictably result in an operational system exhibiting the known benefits of each element. The modifications were presented as straightforward implementations within the capabilities of a POSITA.

4. Key Claim Construction Positions

• Petitioner noted that the parties in the related district court case agreed to several constructions, which it applied in the petition. These constructions clarified the sequence of the claimed steps for independent claims 1 and 8:
  • "serially multiplexing first control signals and data signals...": This was construed to mean the signals are mapped in a sequence where one is directly after the other, with control signals at the front and data signals at the rear.
  • "mapping the multiplexed signals to": Construed as occurring after the multiplexing step.
  • "mapping ACK/NACK control signals to": Construed as occurring after the multiplexed signals are mapped.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that the Board should not exercise its discretion to deny institution under §314(a) or §325(d). The core arguments were:
  • The petition was not a follow-on filing by the same petitioner, and Petitioner had no relationship to a previously filed IPR by another party (Huawei) on the same patent.
  • The parallel district court litigation was in an early stage. No claim construction ruling had been issued, fact and expert discovery were not scheduled to close for several months, and the trial date was still distant and subject to change given the number of patents and claims asserted.
  • The technical subject matter was complex and well-suited for the PTAB's expertise, making an IPR a more efficient and effective forum for resolving the validity dispute compared to a jury trial.

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-14 of the ’833 patent as unpatentable.