TQ Delta, LLC v. Cisco Systems, Inc., No. 18-1766 (Fed. Cir. 2019)Annotate this Case
The challenged patents relate to certain improvements to electronic communications systems that lower the peak-to-average power ratio (PAR) of the transmitted signals. Lowering the PAR of a communications system is desirable because it reduces power consumption and the likelihood of transmission errors. The challenged patents specifically address a PAR problem that arises in the transmission of digital data using multicarrier communications systems, such as digital subscriber line (DSL) systems. In inter partes review proceedings, the Patent Trial and Appeal Board invalidated all claims of the two related patents as obvious in view of prior art, 35 U.S.C. 103. The Federal Circuit reversed. The fact findings underlying the Board’s obviousness determinations are not supported by substantial evidence. The Board based its findings on the assertions in Cisco’s petition, which the Board expressly adopted as its own findings and conclusions. No reasonable factfinder could find, based on Cisco’s petition and supporting expert declaration, that a person of ordinary skill would have recognized prior art’s disclosure of phase scrambling as a solution to reduce the PAR of other prior art.