PTAB

IPR2018-01326

Intel Corp v. Qualcomm Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Power Tracking for Multiple Transmit Signals
  • Brief Description: The ’675 patent discloses techniques for simultaneously transmitting multiple carrier-aggregated radio frequency (RF) signals using a single power amplifier (PA) and a single power tracking supply generator. The purported invention aims to reduce circuit complexity, power consumption, and cost compared to prior art systems that allegedly required separate PAs and power tracking circuits for each transmit signal.

3. Grounds for Unpatentability

Ground 1: Claims 1-6 and 18-22 are obvious over Yu in view of Wang.

  • Prior Art Relied Upon: Yu (European Application # EP 2 442 440 A1) and Wang (“Design of Wide-Bandwidth Envelope-Tracking Power Amplifiers for OFDM Applications,” IEEE Transactions on Microwave Theory and Techniques (Apr. 2005)).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Yu, a reference not considered during prosecution, discloses the core invention of the ’675 patent: a system that uses a single PA and a single power tracking supply to amplify multiple, simultaneously transmitted input signals. Petitioner mapped Yu’s control unit, which receives multiple input signals (S1, S2) and generates a single control signal (CTRL) to modulate the supply voltage for a single PA, to the claimed "power tracker" and related components. Petitioner asserted that while Yu does not explicitly detail the use of inphase (I) and quadrature (Q) components or Orthogonal Frequency Division Multiplexing (OFDM) signals, these were well-known elements in the art. To supply these missing details, Petitioner relied on Wang. Wang was presented as teaching a wide-bandwidth envelope-tracking power amplifier that expressly processes a "complex baseband signal" comprising I and Q components. Wang also explicitly discloses the use of OFDM signals in such a system. The combination of Yu's single-PA architecture with Wang's standard I/Q and OFDM signal processing allegedly renders all limitations of the challenged claims obvious.
    • Motivation to Combine: Petitioner contended a person of ordinary skill in the art (POSITA) would combine Yu and Wang as both address the same technical problem: efficient power amplification for wide-bandwidth RF signals using envelope tracking. A POSITA implementing Yu’s architecture would have naturally looked to well-established techniques for signal representation, such as the I/Q component processing taught by Wang, to ensure efficient and robust data transmission. The use of I/Q signals was described as prolific and practically implicit in modern cellular communications. Furthermore, a POSITA would be motivated to use OFDM modulation (from Wang) in Yu's system to achieve the known benefits of high data rates. Envelope tracking systems like Yu's were a known solution for mitigating the high peak-to-average power ratio (PAPR) that is a characteristic drawback of OFDM signals, making the combination particularly logical.
    • Expectation of Success: Petitioner argued a POSITA would have had a reasonable expectation of success. The integration of standard I/Q signal processing and OFDM modulation, as taught by Wang, into the envelope-tracking architecture of Yu was a combination of known elements according to known methods. Given that I/Q processing and OFDM were standard in 3G and 4G cellular systems, their implementation would have been straightforward and yielded the predictable result of an efficient, multi-signal, single-PA transmitter.

4. Key Claim Construction Positions

Petitioner stated it would rely on constructions adopted by an administrative law judge (ALJ) in a parallel International Trade Commission (ITC) investigation to demonstrate invalidity, noting that these constructions are based on the Phillips standard and that a broader construction would only strengthen its arguments.

  • "plurality of carrier aggregated transmit signals": Construed as "signals for transmission on multiple carriers at the same time to increase the bandwidth for a user." Petitioner argued Yu's simultaneous transmission of signals S1 and S2 on different carrier frequencies met this limitation.
  • "power tracker": Construed as "component in a voltage generator that computes the power requirement." Petitioner argued Yu’s control unit (100), which determines the control signal based on input signals S1 and S2, met this construction.
  • "single power tracking signal": Construed as "one (single-ended) power tracking signal." Petitioner argued Yu’s single CTRL signal, depicted as a single line, met this construction.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-6 and 18-22 of the ’675 patent as unpatentable.