CSR Technology, Inc. ("CSR") filed a patent infringement action against Bandspeed, Inc. ("Bandspeed") for infringement of its signal processing patents. After the district court issued its claim construction ruling, Bandspeed moved for summary judgment.
As the district court explained, "[t]he '771 and '886 patents relate to signal detection and acquisition respectively. Signal detection involves checking an incoming signal for its fit with reference signals, so as to detect the signal's identity. Signal acquisition involves sampling an incoming signal so as to acquire it."
Bandspeed made two arguments on summary judgment: "that its products do not infringe the asserted patents because they neither: (1) 'multiply the [signal] data with data representative of at least one hypothesis' as required by Claim 1 of the '771 patent; nor (2) 'obtain data bit information that indicates which portions of said modulated signal have a sign change' as required by Claim 1 of the '886 patent.' With respect to the first point, Bandspeed argues that summary judgment of noninfringement is warranted for Claim 1 of the '771 patent because its products do not, as the claim requires, 'multiply the [signal] data with data representative of at least one hypothesis.' The Court must therefore determine if there is any genuine issue about whether the BSP2500 and BSP1000 devices multiply signal and hypothesis data."
On the first point, the district court then proceeded to disagree with Bandspeed: "Indeed, several implementations for multiplication abound; it is a matter of design choice. For example, one could code a functions, called multiply.py (in Python) or multiply.m (in MATLAB). In such a function one could hard-code numerous multiplication tables for a subset of inputs relevant to an application, merely using a chain of successive if-then statements. Or one could code a multiplication module using iterative loops or binary shifts and additions. Or one could simply use the built-in star operator, if the language provided such operator. To multiply very large numbers, one could perform logarithmic addition of the operands followed by an inverse logarithm of the result. The happenstance that many programming languages (including Verilog) provide a built-in star operator for certain numerical data types does not elevate such a language 'feature' to the status of the only way to implement multiplication."
With respect to the second point, as explained by the district court, "Bandspeed argues that summary judgment of noninfringement is warranted for Claim 1 of the '886 patent because its products do not, as the claim requires, 'obtain data bit information that indicates which portions of said modulated signal have a sign change.'"
In addressing this point, the district court first construed the claim: "In light of the claim language and the specification, the Court construes 'obtaining data bit information that indicates which potions of said modulated signal have a sign change' as covering methods which obtain data bit information from a source other than the actual data in the received RF signal, such as a local source. By construing the language as such, the Court has construed the claim in light of the claim language and the specification. The Court has taken care not to import a claim limitation from the specification into the claim."
Based on this claim construction, the district court determined that the summary judgment motion should be denied. "That Bandspeed's products do not obtain data bit information from the actual data in the received RF signal, therefore, does not remove its products from the scope of Claim 1 of the '886 patent given the Court's present construction. Thus, notwithstanding the absence of a genuine issue of material fact, the Court's claim construction negates Bandspeed's claim of an entitlement to summary judgment of noninfringement as a matter of law."
Accordingly, the district court denied Bandspeed's motion for summary judgment of non-infringement.
CSR Technology, Inc. v. Bandspeed, Inc., Case No. 8:11-cv-00494-MRP-MLG (C.D. Cal. Oct. 15, 2012)