Qualcomm Inc v. UNM Rainforest Innovations

1. Case Identification

• Case #: IPR2021-00582
• Patent #: 8,565,326
• Filed: February 23, 2021
• Petitioner(s): QUALCOMM Incorporated
• Patent Owner(s): UNM Rainforest Innovations
• Challenged Claims: 1-5

2. Patent Overview

• Title: Techniques for Circularly Shifting Coded Bits in a Wireless Communication System
• Brief Description: The ’326 patent describes a method for rearranging coded data bits for retransmission in a Hybrid Automatic Repeat Request (HARQ) wireless communication system. The technique involves performing a circular shift on a plurality of coded bits, where the length of the shift is variable and depends on both the modulation order being used and the number of transmission attempts.

3. Grounds for Unpatentability

Ground 1: Claims 1-2 and 4-5 are anticipated or obvious over Yoon

• Prior Art Relied Upon: Yoon (Application # 2003/0072292).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Yoon disclosed every limitation of the challenged claims. Yoon taught a transmitter in a HARQ system that used a "bit rearranger" to perform a "right rotation" on coded bits during retransmission to improve error probability. This "right rotation" was argued to be a circular shift. Critically, Yoon disclosed that the length of this rotation was variable, depending on both the "number of transmissions" attempted and the "modulation order" of the scheme in use. For example, Yoon described a 2-bit rotation for a first retransmission and a 4-bit rotation for a second retransmission when using 64QAM (modulation order 6), but a 1-bit rotation for a first retransmission when using 8PSK (modulation order 3). This directly maps to the core limitation of claim 1, which requires "performing a circular shift, with a variable length related to a modulation order and a number of transmissions."
  • Key Aspects: Petitioner contended that Yoon's disclosure was so complete that it anticipated the claims under 35 U.S.C. §102, or at a minimum, rendered them obvious under §103.

Ground 2: Claims 4 and 5 are obvious over Yoon in view of Wengerter

• Prior Art Relied Upon: Yoon (Application # 2003/0072292) and Wengerter (WO 2006/119794).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground specifically addressed the "processor included in the transmitter" limitation of apparatus claims 4 and 5. While Petitioner argued Yoon’s "bit rearranger" and "modulator" inherently met this limitation, this combination was presented as an alternative. Wengerter, which addressed similar problems of bit-to-symbol mapping in HARQ systems, explicitly taught that transmitter components like an encoder and mapper could be implemented in a "digital signal processor."
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) implementing the functionality of Yoon’s transmitter would have been motivated to look to known transmitter implementations, such as those in Wengerter, for guidance. Since both references operate in the same technical field, a POSITA would combine Yoon’s circular shift method with Wengerter’s teaching of a processor-based implementation as a predictable and well-known design choice.
  • Expectation of Success: A POSITA would have a reasonable expectation of success, as using digital signal processors to implement modulator and bit arrangement functions was a common and well-understood practice in wireless communications at the time.

Ground 3: Claim 3 is obvious over Yoon in view of Naka

• Prior Art Relied Upon: Yoon (Application # 2003/0072292) and Naka (EP 1 819 079).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground addressed the additional limitations of dependent claim 3, which required "generating a reordered index sequence" of the coded bits and "allocating the ones of the plurality of coded bits based on the reordered index sequence." Yoon taught an interleaver that reordered bits but did not explicitly disclose using an index-based method. Naka disclosed an interleaver apparatus that explicitly generated a reordered index sequence using several calculation steps and then read out (i.e., allocated) the coded bits according to this final reordered index.
  • Motivation to Combine: A POSITA implementing the interleaver in Yoon’s transmitter would have recognized that using a reordered index sequence, as taught by Naka, was one of a finite number of known and predictable ways to perform the bit reordering function. Both references address interleaving for retransmissions, making the combination logical for achieving a more detailed implementation of Yoon's higher-level disclosure.
  • Expectation of Success: Success would be expected because implementing an interleaver by generating and using a reordered index sequence was a standard technique within a POSITA's technical grasp.

4. Key Claim Construction Positions

• "circular shift": Petitioner argued this term should be construed as "an operation that moves a sequence of bits from one end of an ordered group of bits to the other end." This construction was adopted in a parallel district court litigation involving the ’326 patent. Petitioner contended this construction is consistent with the patent’s figures and correctly distinguishes the claimed "circular shift" from the broader concept of "interleaving," which Patent Owner had unsuccessfully proposed as the construction in the parallel case.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §314(a) based on the Fintiv factors would be inappropriate. The core arguments were:
  • The parallel district court proceedings were in early stages with minimal investment from the court and parties.
  • The trial dates in the parallel litigation were uncertain and likely to be delayed beyond the potential Final Written Decision (FWD) date for this inter partes review (IPR).
  • The invalidity grounds presented in the petition differ from those in the litigation, and the petition challenges claim 3, which was not asserted in the litigation.
  • Petitioner (Qualcomm) is not a defendant in the parallel litigation, weighing against denial.
  • The merits of the petition are particularly strong, relying on prior art that was not before the Examiner during prosecution.

6. Relief Requested

• Petitioner requested the institution of an IPR and the cancellation of claims 1-5 of the ’326 patent as unpatentable.