PTAB

IPR2026-00003

Nintendo Co Ltd v. Malikie Innovations Ltd

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Combination of Space-Time Coding and Spatial Multiplexing, and the Use of Orthogonal Transformation in Space-Time Coding
  • Brief Description: The ’305 patent relates to systems and methods for performing layered space-time coding for wireless channels. The disclosed technology aims to improve signal-to-noise ratio by ensuring that each transmitted data symbol is a function of multiple input symbols and is transmitted across multiple antennas, addressing limitations of prior art systems where each symbol was transmitted by only one antenna.

3. Grounds for Unpatentability

Ground 1: Claims 1-3 and 6 are anticipated and/or obvious over Paulraj.

  • Prior Art Relied Upon: Paulraj (Patent 6,377,632).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Paulraj, which teaches a wireless communication system using space-time/frequency division multiplexing, discloses all limitations of the challenged claims. Petitioner asserted that the combination of Paulraj’s coding block, transform block, and parallel-to-serial converter block constitutes the claimed "space-time coding block." Paulraj’s teaching of unique delays in each diversity branch was argued to meet the "delay arrangement" limitation, causing space-time coded symbols to be transmitted at different times. Petitioner contended that Paulraj’s disclosure of processing N symbol substreams to generate P diversity branches renders it obvious to set N=P (e.g., N=P=2) as a known design choice for adapting to various channel conditions.
    • Motivation to Combine (for §103 grounds): While primarily an anticipation ground, Petitioner argued in the alternative that it would have been obvious for a person of ordinary skill in the art (POSITA) to implement Paulraj with the number of symbol substreams equal to the number of diversity branches. This was presented as a known design choice to balance system complexity and performance.
    • Key Aspects: A central part of Petitioner's argument was that the collective output of complex valued symbols from Paulraj’s parallel-to-serial converter block corresponds to a single "space-time coded symbol" as recited in the claims, consistent with the ’305 patent’s specification and prosecution history.

Ground 2: Claims 1-3 and 6 are obvious over Rowitch in view of Paulraj.

  • Prior Art Relied Upon: Rowitch (Patent 6,628,702) and Paulraj (Patent 6,377,632).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Rowitch teaches a transmitter for a Space-Time Spreading (STS) diversity mode that meets most limitations of claim 1, including a space-time coding block (modulators 210a/b) that processes multiple input symbol substreams (YEVEN and YODD) and transmits them over separate antennas. However, Petitioner asserted Rowitch discloses space-time diversity but not the claimed delay diversity. Paulraj was argued to supply this missing element by teaching the inclusion of unique time delays in each diversity branch to improve performance.
    • Motivation to Combine (for §103 grounds): A POSITA would combine the teachings because both references address improving diversity in wireless communications. Petitioner contended a POSITA would be motivated to add the known delay diversity technique from Paulraj to the known STS transmitter of Rowitch to achieve the predictable result of improved performance, particularly in Rayleigh fading channels, which both systems were designed to operate in. The art at the time encouraged combining different forms of diversity.
    • Expectation of Success: Petitioner argued a POSITA would have a high expectation of success because Rowitch’s receiver was already designed to account for path delays, making the addition of controlled delays at the transmitter a straightforward modification. The combination was presented as the application of a known technique to a known system to obtain predictable results.

  • Additional Grounds: Petitioner asserted additional obviousness challenges for dependent claims 2 and 3 based on combinations including Jalali (Patent 6,952,454) and Schilling (Patent 6,128,330). These references were primarily used to show it was a well-known and obvious design choice to reverse the order of operations, such as performing demultiplexing before encoding/modulation, as recited in the dependent claims.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under §314(a) and §325(d) is not warranted. The petition asserted that this is the first IPR filed against the ’305 patent, its validity has not been previously adjudicated, and the prior art references relied upon were not considered during the original prosecution. Petitioner also stated that the co-pending district court litigation is in an early stage and that it would stipulate not to pursue in district court any invalidity grounds that were raised or reasonably could have been raised in the IPR if review is instituted.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-3 and 6 of the ’305 patent as unpatentable.