PTAB

IPR2025-00888

OnePlus Technology Shenzhen Co Ltd v. Pantech Corp

Key Events

Petition

petition

Title: Method and Apparatus for Muting in Wireless Communication System
Brief Description: The ’251 patent relates to a wireless communication system for performing muting on a Physical Downlink Shared Channel (PDSCH) to avoid interference from neighboring cells. The technology involves generating and transmitting muting information that specifies a muting cycle, offset, and pattern for Channel State Information-Reference Signal (CSI-RS) measurements.

Prior Art Relied Upon: Chandrasekhar-I (Application # 2012/0264441).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Chandrasekhar-I discloses all limitations of the challenged claims. For independent claims 7 and 12, Chandrasekhar-I allegedly teaches a method/user equipment for receiving CSI-RS muting information that includes both a "first data field" and a "second data field."
  - The "first data field," indicating a cycle and offset of muting subframes, was mapped to Chandrasekhar-I's disclosure of a PDSCHmutingdutycycle parameter and a CSIRSoffset parameter, from which the muting subframe offset is known.
  - The "second data field," an n-bit bitmap where n is an integer from 12 to 28, was mapped to Chandrasekhar-I’s PDSCHmutingenabled parameter. This parameter is a bitmap of length N (the reuse factor), and Chandrasekhar-I explicitly discloses reuse factors of 16, 20, and 28, which fall within the claimed range. Each bit of this bitmap indicates whether to apply muting for a corresponding CSI-RS pattern.
- Key Aspects: Petitioner contended that Chandrasekhar-I anticipates the claims. Alternatively, if any minor difference is found, combining the disclosed elements to arrive at the claimed invention would have been obvious to a Person of Ordinary Skill in the Art (POSITA).

Prior Art Relied Upon: Chandrasekhar-I (Application # 2012/0264441) and Chandrasekhar-II (Patent 8,514,738).
Core Argument for this Ground:
- Prior Art Mapping: This ground was presented to the extent the "first data field" limitation is interpreted to require a single, jointly encoded signal for the muting cycle and offset. Petitioner argued that Chandrasekhar-I provides the base system for PDSCH muting. Chandrasekhar-II, which addresses the same technical problem, explicitly taught jointly encoding the muting duty cycle and subframe offset into a single signal to be transmitted.
- Motivation to Combine: A POSITA would combine these references to reduce signaling overhead. Chandrasekhar-I itself discussed the goal of minimizing overhead, and Chandrasekhar-II provided a known technique to achieve it. The fact that both references share the same inventor and assignee (Texas Instruments) and address similar problems in CoMP environments would have prompted a POSITA to consider their teachings together.
- Expectation of Success: A POSITA would have a high expectation of success because combining the references involved applying a known optimization technique (joint encoding) to a similar system to achieve the predictable result of improved signaling efficiency.

Prior Art Relied Upon: Chandrasekhar-I (Application # 2012/0264441) and TI (a 3GPP proposal R1-103696).
Core Argument for this Ground:
- Prior Art Mapping: This ground focused on fully satisfying the claimed range for the n-bit bitmap ("an integer among 12 to 28"). While Chandrasekhar-I disclosed values of 16, 20, and 28, the TI reference explicitly taught additional reuse factors of 12 and 16 for similar antenna port configurations. Combined, the references disclose all four specific bitmap values mentioned in the ’251 patent's specification (12, 16, 20, and 28).
- Motivation to Combine: A POSITA would combine the references because they are analogous art from the same party (Texas Instruments), were submitted around the same time, and address the same technical considerations for determining CSI-RS pattern reuse factors. The TI proposal would have been seen as a natural source to supplement Chandrasekhar-I's teachings on achievable reuse factors.
- Expectation of Success: There would be a high expectation of success in applying the reuse factors from TI to the system of Chandrasekhar-I, as both documents are based on the same underlying LTE standards and antenna configurations.
Additional Grounds: Petitioner asserted an additional obviousness challenge (Ground 5) based on the combination of Chandrasekhar-I, Chandrasekhar-II, and TI, relying on similar motivations to combine.

"a first data field": Petitioner argued this term should be interpreted to mean "one or more data fields" based on the indefinite article "a" and the patent's disclosure of separate signaling regions. This interpretation supports the anticipation argument under Ground 1. The obviousness argument in Ground 2 (combining with Chandrasekhar-II) was presented as an alternative for a narrower construction requiring a single field.

Priority Date Challenge: Petitioner argued the ’251 patent is not entitled to its claimed foreign priority date of August 11, 2010. The petition contended that the Korean priority applications lacked sufficient written description for key claim limitations, including the "second data field having n-bit bitmap, the n being an integer among 12 to 28." If this argument prevails, the ’251 patent's effective priority date would be no earlier than August 11, 2011, making Chandrasekhar-I and Chandrasekhar-II prior art under §102(e) without needing to rely on their own provisional application dates.

To streamline the analysis under 35 U.S.C. §314(a) and the Fintiv factors, Petitioner stipulated that if the inter partes review (IPR) is instituted, it will not pursue any ground in the parallel district court litigation that it raised or reasonably could have raised in the IPR. This stipulation follows the precedential guidance in Sotera Wireless, Inc. v. Masimo Corp.

Petitioner requests institution of IPR and cancellation of claims 7, 9-12, and 14-16 of the ’251 patent as unpatentable.