Samsung Electronics Co Ltd v. Red Rock Analytics LLC

1. Case Identification

• Case #: IPR2018-00555
• Patent #: 7,346,313
• Filed: February 5, 2018
• Petitioner(s): Samsung Electronics Co., Ltd.
• Patent Owner(s): Red Rock Analytics, LLC
• Challenged Claims: 1-6, 38-43

2. Patent Overview

• Title: System for Calibrating a Transceiver
• Brief Description: The ’313 patent discloses a system and method for balancing gain between the in-phase (I) and quadrature (Q) channels in a wireless transceiver. The invention uses a loopback calibration method where a calibration RF signal, generated by the transmit chain, is injected into the receive chain to independently calibrate the I-Q gain balance of both the transmit and receive chains.

3. Grounds for Unpatentability

Ground 1: Claims 1-6 and 38-43 are obvious over Yellin in view of Su.

• Prior Art Relied Upon: Yellin (Patent 6,898,252) and Su (Patent 6,272,322).
• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that Yellin discloses all major elements of the challenged claims. Yellin teaches a communication device for correcting I-Q mismatch (both gain and phase imbalance) using a "mismatch trainer." This system comprises a transmit path (including an IQ modulator) and a receive path (including an IQ demodulator). To perform calibration, a signal is passed from the transmit path output, through a signal path, and injected into the receive path input. Yellin’s mismatch trainer then iteratively adjusts correction parameters for the transmit and receive paths to cancel out distortions. Critically, Yellin discloses adjusting the transmit path parameters while holding the receive path parameters constant, and vice-versa, which Petitioner asserted directly maps to the independent calibration limitation of claim 1. This iterative adjustment constitutes the claimed "calibration cycle" that determines transmitter and receiver I-Q gain settings to minimize an observable indicator (a cost function in Yellin).

  • Petitioner contended that while Yellin discloses the complete calibration methodology, Su provides the context of a conventional transceiver architecture. Su discloses typical direct-conversion and heterodyne transceivers with distinct I and Q channels, which are the types of devices known to suffer from the I-Q mismatch problem that Yellin solves. To the extent Yellin’s apparatus is not explicitly labeled a "transceiver," Petitioner argued it would have been obvious to implement Yellin’s advanced correction technique in a standard transceiver like that shown in Su. Dependent claims were also argued to be obvious, as implementing the system as a direct-conversion (claim 3) or heterodyne (claim 4) transceiver were known design choices taught by Su, and the calibration signal originating and being observed at baseband (claim 2) is inherent to Yellin's system. The "channel gain adjuster" of claim 5 was mapped to Yellin's mismatch trainer.

  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Yellin's teachings with Su's because both references address improving the performance of wireless communication devices. A POSITA would have been motivated to apply Yellin's sophisticated I-Q mismatch correction technique to a known device, such as the standard transceivers disclosed in Su, to achieve the predictable result of a transceiver with improved I-Q balance. Applying a known solution to a known problem in a standard device was presented as a clear motivation. Furthermore, Yellin itself suggests its applicability to devices like handsets, which are the subject of Su.

  • Expectation of Success: A POSITA would have had a high expectation of success in this combination. The integration involved applying a known calibration method (Yellin) to a standard electronic architecture (Su's transceiver) to solve a well-understood problem (I-Q mismatch). The result—a transceiver with reduced gain imbalance—was predictable and achievable using conventional design techniques.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that institution should not be denied under 35 U.S.C. § 325(d) despite a previously denied IPR petition on the same patent (IPR2017-01490). Petitioner contended that the prior petition was filed by a different petitioner (Unified Patents Inc.) and, more importantly, relied on different primary prior art (a patent to Warner). Because the instant petition relies on Yellin as the primary reference, it did not present the "same or substantially the same prior art or arguments" as the previously denied petition, making discretionary denial inappropriate.

5. Relief Requested

• Petitioner requests institution of an inter partes review (IPR) and cancellation of claims 1-6 and 38-43 of the ’313 patent as unpatentable.