Opinion ID: 211752
Heading Depth: 3
Heading Rank: 4

Heading: Construction of Claims 1, 2, and 33

Text: 40 Turning to the substantive claim construction issue, WMS Gaming restricts computer-implemented means-plus-function terms to the algorithm disclosed in the specification. Construing the term means for assigning a plurality of numbers representing said angular positions of said reel, said plurality of numbers exceeding said predetermined number of radial positions such that some rotational positions are represented by a plurality of numbers[,] the court in WMS Gaming rejected the argument that the corresponding structure was merely an algorithm executed by a computer, holding instead that it was limited to the specific algorithm disclosed in the specification. WMS Gaming, 184 F.3d at 1348-49. The specification's algorithm resembled the functional language assigning a plurality of numbers... in the claim itself and this court ultimately relied on that functional limitation to hold that there was no infringement. Id. at 1352. On that basis, Harris argues that this court's construction in WMS Gaming was merely a restatement of the function, not a legal holding that means-plus-function claims involving a microprocessor are always limited to the disclosed algorithm. We do not read WMS Gaming to be so limited. The WMS Gaming court could have relied on the function to limit the claim, but explicitly based the claim construction portion of its ruling on structure instead. Id. at 1348-49. A computer-implemented means-plus-function term is limited to the corresponding structure disclosed in the specification and equivalents thereof, and the corresponding structure is the algorithm. 41 Ericsson is correct that WMS Gaming applies to the means-plus-function claims in this case. Like the claim in WMS Gaming, Harris's claim 1 includes a means-plus-function limitation implemented by a microprocessor. Specifically, it recites a 42 time domain processing means for simulating the time domain effect of said dispersive medium on signals transmitted through it by deducing prescribed characteristics of said medium, and for producing estimates of said information signals in accordance with a preselected relationship between said prescribed characteristics of said simulated effect and said known and received signals. 43 The district court did not have the benefit of briefing on WMS Gaming, but this precedent establishes that corresponding structure of the time domain processing means cannot be merely a symbol processor, as the district court held. The symbol processor construction does not incorporate any disclosed algorithm. We hold that the corresponding structure for the time domain processing means is a microprocessor programmed to carry out a two-step algorithm in which the processor calculates generally nondiscrete estimates and then selects the discrete value closest to each estimate. Specifically, the patent discloses, as corresponding structure, a processor 37, advantageously comprised of a pair of processors—a support processor (SUPP) [37A] and a fast array processor (FAP) [37B,] shown in Figure 4 and described at col. 11, l. 37—col. 12, l. 32, which is programmed to carry out the disclosed data recovery algorithm illustrated in Figures 8A, 8B, and 9 and described at col. 7, l. 18—col. 8, l. 38; col. 13, l. 45—col. 14, l. 20; and col. 15, l. 2—col. 16, l. 11. Processor 37A carries out the first part of the algorithm: calculating the effect of the medium and applying it to the received symbols. '338 patent, col. 15, ll. 26. Processor 37B examines the ... estimates and compares these codes with those corresponding to the code values capable of being transmitted. Id. col. 15, ll. 13-17. Thus, each processor performs one of the steps. 44 Aspects of this algorithm can vary based on implementation, as the specification implies. For example, the algorithm need not be applied to an eight-ary PSK transmission scheme; this is an illustration of the effect of [the] thus-far described decision process as applied to such a transmission scheme. Id. col. 15, ll. 27-29. The same decision process could be applied to another type of transmission scheme. Likewise, as Ericsson concedes, the corresponding structure of the time domain processing means is not limited to Equation (7) disclosed in column 8, line 30 of the patent. However, the specification characterizes the two-step process as the invention, not merely an implementation of the invention. See id. col. 5, II. 50-55; col. 7, II. 18-27. Thus, we reject Harris's argument that the disclosed algorithm is broad enough to literally encompass one-step processes. 4 45 Figure 9 illustrates how this algorithm is implemented. In Figure 9, the point labeled A represents the received symbol value. See id. col. 15, II. 31-33. The point labeled B represents the estimate obtained from the matrix calculations performed by processor 37A. The algorithm then involves the further step of choosing the allowed value that is closest to the estimate. In Figure 9's example, this closest discrete value is 010. Id. col. 15, ll. 37-39. 46 Thus, the district court erred in holding that claims 1, 2, and 33 can cover systems that implement either a one-step or two-step process. The corresponding structure limits the time domain processing means to a two-step algorithm in which the processor calculates generally nondiscrete estimates and then selects the discrete value closest to each estimate, or structural equivalents thereof.