Full opinion text
MEMORANDUM OPINION AND ORDER T. JOHN WARD, District Judge. I. INTRODUCTION Plaintiff Wi-LAN, Inc. (“Wi-LAN”) filed suit against numerous defendants (collectively “Defendants”) alleging infringement of U.S. Patent Nos. 5,282,222 (“the '222 patent”) and RE37,802 (“the '802 patent”). The '222 patent is entitled “Method and Apparatus for Multiple Access Between Transceivers in Wireless Communications using OFDM Spread Spectrum.” The '802 patent, entitled “Multicode Direct Sequence Spread Spectrum,” is a continuation-in-part of the application leading to the '222 patent, with the same named inventors. This order addresses the parties’ various claim construction disputes. The order will first briefly address the technology at issue in the case and then turn to the merits of the claim construction issues. II. BACKGROUND OF THE TECHNOLOGY The patents-in-suit are directed to voice and data transmission in wireless communications. The '222 patent is directed to wideband Orthogonal Frequency Domain Modulation communication systems, while the '802 patent is directed to direct sequence spread spectrum communication systems. The abstract of the '222 patent states: A method for allowing a number of wireless transceivers to exchange information (data, voice or video) with each other. A first frame of information is multiplexed over a number of wideband frequency bands at a first transceiver, and the information transmitted to a second transceiver. The information is received and processed at the second transceiver. The information is differentially encoded using phase shift keying. In addition, after a pre-selected time interval, the first transceiver may transmit again. During the preselected time interval, the second transceiver may exchange information with another transceiver in a time duplex fashion. The processing of the signal at the second transceiver may include estimating the phase differential of the transmitted signal and pre-distorting the transmitted signal. A transceiver includes an encoder for encoding information, a wideband frequency division multiplexer for multiplexing the information onto wideband frequency voice channels, and a local oscillator for upconverting the multiplexed information. The apparatus may include a processor for applying a Fourier transform to the multiplexed information to bring the information into the time domain for transmission. Claim 1 of the '222 patent is reproduced below: A transceiver including a transmitter for transmitting electromagnetic signals and a receiver for receiving electromagnetic signals having amplitude and phase differential characteristics, the transmitter comprising: an encoder for encoding information; a wideband frequency division multiplexer for multiplexing the information onto wideband frequency channels; a low pass filter; a local oscillator for upconverting the multiplexed information for transmission; a processor for applying a Fourier transform to the multiplexed information to bring the information into the time domain for transmission; further including, in the receiver of the transceiver: a bandpass filter for filtering the received electromagnetic signals; a local oscillator for downeonverting the received electromagnetic signals to produce output; a sampler for sampling the output of the local oscillator to produce sampled signals to the channel estimator; a channel estimator for estimating one or both of the amplitude and the phase differential of the received signals to produce as output one or both of an estimated amplitude and an estimated phase differential respectively; and a decoder for producing signals from the sampled signals and the output from the channel estimator. The abstract of the '802 patent states: In this patent, we present MultiCode Direct Sequence Spread Spectrum (MCDSSS) which is a modulation scheme that assigns up to N DSSS codes to an individual user where N is the number of chips per DSSS code. When viewed as DSSS, MC-DSSS requires up to N correlators (or equivalently up to N Matched Filters) at the receiver with a complexity of the order of N2 operations. In addition, a non ideal communication channel can cause InterCode Interference (ICI), i.e., interference between the N DSSS codes. In this patent, we introduce new DSSS codes, which we refer to as the “MC” codes. Such codes allow the information in a MC-DSSS signal to be decoded in a sequence of low complexity parallel operations which reduce the ICI. In addition to low complexity decoding and reduced ICI. MC-DSSS using the MC codes has the following advantages: (1) it does not require the stringent synchronization DSSS requires, (2) it does not require the stringent carrier recovery DSSS requires and (3) it is spectrally efficient. Claim 1 of the '802 patent is reproduced below: A transceiver for transmitting a first stream of data symbols, the transceiver comprising: a converter for converting the first stream of data symbols into plural sets of N data symbols each; first computing means for operating on the plural sets of N data symbols to produce modulated data symbols corresponding to an invertible randomized spreading of the first stream of data symbols; and means to combine the modulated data symbols for transmission. III. GENERAL PRINCIPLES GOVERNING CLAIM CONSTRUCTION “A claim in a patent provides the metes and bounds of the right which the patent confers on the patentee to exclude others from making, using or selling the protected invention.” Burke, Inc. v. Bruno Indep. Living Aids, Inc., 183 F.3d 1334, 1340 (Fed.Cir.1999). Claim construction is an issue of law for the court to decide. Markman v. Westview Instruments, Inc., 52 F.3d 967, 970-71 (Fed.Cir.1995) (en banc), aff'd, 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577 (1996). To ascertain the meaning of claims, the court looks to three primary sources: the claims, the specification, and the prosecution history. Markman, 52 F.3d at 979. The specification must contain a written description of the invention that enables one of ordinary skill in the art to make and use the invention. Id. A patent’s claims must be read in view of the specification, of which they are a part. Id. For claim construction purposes, the description may act as a sort of dictionary, which explains the invention and may define terms used in the claims. Id. “One purpose for examining the specification is to determine if the patentee has limited the scope of the claims.” Watts v. XL Sys., Inc., 232 F.3d 877, 882 (Fed.Cir.2000). Nonetheless, it is the function of the claims, not the specification, to set forth the limits of the patentee’s claims. Otherwise, there would be no need for claims. SRI Int’l v. Matsushita Elec. Corp., 775 F.2d 1107, 1121 (Fed.Cir.1985) (en banc). The patentee is free to be his own lexicographer, but any special definition given to a word must be clearly set forth in the specification. Intellicall, Inc. v. Phonometrics, Inc., 952 F.2d 1384, 1388 (Fed.Cir.1992). Although the specification may indicate that certain embodiments are preferred, particular embodiments appearing in the specification will not be read into the claims when the claim language is broader than the embodiments. Electro Med. Sys., S.A. v. Cooper Life Sciences, Inc., 34 F.3d 1048, 1054 (Fed.Cir.1994). This court’s claim construction decision must be informed by the Federal Circuit’s decision in Phillips v. AWH Corporation, 415 F.3d 1303 (Fed.Cir.2005) (en banc). In Phillips, the court set forth several guideposts that courts should follow when construing claims. In particular, the court reiterated that “the claims of a patent define the invention to which the patentee is entitled the right to exclude.” 415 F.3d at 1312 (emphasis added) (quoting Innova/Pure Water, Inc. v. Safari Water Filtration Systems, Inc., 381 F.3d 1111, 1115 (Fed.Cir.2004)). To that end, the words used in a claim are generally given their ordinary and customary meaning. Id. The ordinary and customary meaning of a claim term “is the meaning that the term would have to a person of ordinary skill in the art in question at the time of the invention, i.e., as of the effective filing date of the patent application.” Id. at 1313. This principle of patent law flows naturally from the recognition that inventors are usually persons who are skilled in the field of the invention and that patents are addressed to and intended to be read by others skilled in the particular art. Id. The primacy of claim terms notwithstanding, Phillips made clear that “the person of ordinary skill in the art is deemed to read the claim term not only in the context of the particular claim in which the disputed term appears, but in the context of the entire patent, including the specification.” Id. Although the claims themselves may provide guidance as to the meaning of particular terms, those terms are part of “a fully integrated written instrument.” Id. at 1315, quoting Markman, 52 F.3d at 978. Thus, the Phillips court emphasized the specification as being the primary basis for construing the claims. Id. at 1314-17. As the Supreme Court stated long ago, “in case of doubt or ambiguity it is proper in all cases to refer back to the descriptive portions of the specification to aid in solving the doubt or in ascertaining the true intent and meaning of the language employed in the claims.” Bates v. Coe, 98 U.S. 31, 38, 25 L.Ed. 68 (1878). In addressing the role of the specification, the Phillips court quoted with approval its earlier observations from Renishaw PLC v. Marposs Societa’ per Azioni, 158 F.3d 1243, 1250 (Fed.Cir.1998): Ultimately, the interpretation to be given a term can only be determined and confirmed with a full understanding of what the inventors actually invented and intended to envelop with the claim. The construction that stays true to the claim language and most naturally aligns with the patent’s description of the invention will be, in the end, the correct construction. Phillips, 415 F.3d at 1316. Consequently, Phillips emphasized the important role the specification plays in the claim construction process. The prosecution history also continues to play an important role in claim interpretation. Like the specification, the prosecution history helps to demonstrate how the inventor and the PTO understood the patent. Id. at 1317. Because the file history, however, “represents an ongoing negotiation between the PTO and the applicant,” it may lack the clarity of the specification and thus be less useful in claim construction proceedings. Id. Nevertheless, the prosecution history is intrinsic evidence that is relevant to the determination of how the inventor understood the invention and whether the inventor limited the invention during prosecution by narrowing the scope of the claims. Id. Phillips rejected any claim construction approach that sacrificed the intrinsic record in favor of extrinsic evidence, such as dictionary definitions or expert testimony. The en banc court condemned the suggestion made by Texas Digital Systems, Inc. v. Telegenix, Inc., 308 F.3d 1193 (Fed.Cir.2002), that a court should discern the ordinary meaning of the claim terms (through dictionaries or otherwise) before resorting to the specification for certain limited purposes. Phillips, 415 F.3d at 1319-24. The approach suggested by Texas Digital — the assignment of a limited role to the specification — was rejected as inconsistent with decisions holding the specification to be the best guide to the meaning of a disputed term. Id. at 1320-21. According to Phillips, reliance on dictionary definitions at the expense of the specification had the effect of “focus[ing] the inquiry on the abstract meaning of words rather than on the meaning of claim terms within the context of the patent.” Id. at 1321. Phillips emphasized that the patent system is based on the proposition that the claims cover only the invented subject matter. Id. What is described in the claims flows from the statutory requirement imposed on the patentee to describe and particularly claim what he or she has invented. Id. The definitions found in dictionaries, however, often flow from the editors’ objective of assembling all of the possible definitions for a word. Id. at 1321-22. Phillips does not preclude all uses of dictionaries in claim construction proceedings. Instead, the court assigned dictionaries a role subordinate to the intrinsic record. In doing so, the court emphasized that claim construction issues are not resolved by any magic formula. The court did not impose any particular sequence of steps for a court to follow when it considers disputed claim language. Id. at 1323-25. Rather, Phillips held that a court must attach the appropriate weight to the intrinsic sources offered in support of a proposed claim construction, bearing in mind the general rule that the claims measure the scope of the patent grant. The patents-in-suit include claim limitations that are argued to fall within the scope of 35 U.S.C. § 112, ¶ 6. “An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure ... in support thereof, and such claim shall be construed to cover the corresponding structure ... described in the specification and equivalents thereof.” 35 U.S.C. § 112, ¶ 6. When a claim uses the term “means” to describe a limitation, a presumption inheres that the inventor used the term to invoke § 112, ¶ 6. Biomedino, LLC v. Waters Technologies Corp., 490 F.3d 946, 950 (Fed.Cir.2007). “This presumption can be rebutted when the claim, in addition to the functional language, recites structure sufficient to perform the claimed function in its entirety.” Id., citing Altiris, Inc. v. Symantec Corp., 318 F.3d 1363, 1375 (Fed.Cir.2003). By contrast, when a claim term does not use “means,” the term is presumptively not subject to § 112, ¶ 6. CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1369 (Fed.Cir.2002); MIT v. Abacus Software, 462 F.3d 1344, 1353 (Fed.Cir.2006). A limitation lacking the term “means” may overcome the presumption if it is shown that “the claim term fails to recite sufficiently definite structure or else recites function without reciting sufficient structure for performing that function.” MIT, 462 F.3d at 1353, quoting CCS Fitness, 288 F.3d. at 1369. “What is important is whether the term is one that is understood to describe structure, as opposed to a term that is simply a nonce word or a verbal construct that is not recognized as the name of structure and is simply a substitute for the term ‘means for.’ ” Lighting World, Inc. v. Birchwood Lighting, Inc., 382 F.3d 1354, 1360 (Fed.Cir.2004). Once the court has concluded the claim limitation is a means-plus-function limitation, the first step in construing a means-plus-function limitation is to identify the recited function. See Micro Chem., Inc. v. Great Plains Chem. Co., 194 F.3d 1250, 1258 (Fed.Cir.1999). The second step in the analysis is to identify in the specification the structure corresponding to the recited function. Id. The “structure disclosed in the specification is ‘corresponding’ structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim.” Medical Instrumentation and Diagnostics Corp. v. Elekta AB, 344 F.3d 1205, 1210 (Fed.Cir.2003), citing B. Braun v. Abbott Labs., 124 F.3d 1419, 1424 (Fed.Cir.1997). The patentee must clearly link or associate structure with the claimed function as part of the quid pro quo for allowing the patentee to express the claim in terms of function pursuant to § 112, ¶ 6. See id. at 1211; see also Budde v. Harley-Davidson, Inc., 250 F.3d 1369, 1377 (Fed.Cir.2001). The “price that must be paid” for use of means-plus-function claim language is the limitation of the claim to the means specified in the written description and equivalents thereof. See O.I. Corp. v. Tekmar Co., 115 F.3d 1576, 1583 (Fed.Cir.1997). “If the specification does not contain an adequate disclosure of the structure that corresponds to the claimed function, the patentee will have ‘failed to particularly point out and distinctly claim the invention as required by the second paragraph of section 112,’ which renders the claim invalid for indefiniteness.” Blackboard, Inc. v. Desire2Learn, Inc., 574 F.3d 1371, 1382 (Fed.Cir.2009), quoting In re Donaldson Co., 16 F.3d 1189, 1195 (Fed.Cir.1994) (en banc). It is important to determine whether one of skill in the art would understand the specification itself to disclose the structure, not simply whether that person would be capable of implementing the structure. See Atmel Corp. v. Info. Storage Devices, Inc., 198 F.3d 1374, 1382 (Fed.Cir.1999); Biomedino, 490 F.3d at 953. Fundamentally, it is improper to look to the knowledge of one skilled in the art separate and apart from the disclosure of the patent. See Medical Instrumentation, 344 F.3d at 1211-12. “[A] challenge to a claim containing a means-plus-function limitation as lacking structural support requires a finding, by clear and convincing evidence, that the specification lacks disclosure of structure sufficient to be understood by one skilled in the art as being adequate to perform the recited function.” Budde, 250 F.3d at 1376-77. At issue in this case is whether certain claims of the patents-in-suit are indefinite. A claim is invalid for indefiniteness if it fails to particularly point out and distinctly claim the subject matter that the applicant regards as the invention. 35 U.S.C. § 112, ¶ 2. To prevail on an indefiniteness argument, the party seeking to invalidate a claim must prove “by clear and convincing evidence that a skilled artisan could not discern the boundaries of the claim based on the claim language, the specification, and the prosecution history, as well as her knowledge of the relevant art area.” Halliburton Energy Services, Inc. v. M-I LLC, 514 F.3d 1244, 1249-50 (Fed.Cir.2008). The primary purpose of the definiteness requirement is to ensure public notice of the scope of the patentee’s legal right to exclude, such that interested members of the public can determine whether or not they infringe. Datamize, LLC v. Plumtree Software, Inc., 417 F.3d 1342, 1347 (Fed.Cir.2005); Halliburton, 514 F.3d at 1249; Honeywell Int’l Inc. v. Int’l Trade Comm’n, 341 F.3d 1332, 1338 (Fed.Cir.2003). Courts apply the general principles of claim construction in their efforts to construe allegedly indefinite claim terms. Datamize, 417 F.3d at 1348; Young v. Lumenis, Inc., 492 F.3d 1336, 1346 (Fed.Cir.2007). A claim is indefinite only when a person of ordinary skill in the art is unable to understand the bounds of the claim when read in light of the specification. Miles Labs., Inc. v. Shandon, Inc., 997 F.2d 870, 875 (Fed.Cir.1993); Star Scientific, Inc. v. R.J. Reynolds Tobacco Co., 537 F.3d 1357, 1371 (Fed.Cir.2008). A determination of claim indefiniteness is a conclusion of law. Exxon Research & Eng’g Co. v. United States, 265 F.3d 1371, 1375-76 (Fed.Cir.2001); Datamize, 417 F.3d at 1347. A claim is indefinite only if the claim is “insolubly ambiguous” or “not amenable to construction.” Exxon, 265 F.3d at 1375; Young, 492 F.3d at 1346; Halliburton, 514 F.3d at 1249; Honeywell, 341 F.3d at 1338-39. A court may find a claim indefinite “only if reasonable efforts at claim construction prove futile.” Datamize, 417 F.3d at 1347. A claim term is not indefinite solely because the term presents a difficult claim construction issue. Id.; Exxon, 265 F.3d at 1375; Honeywell, 341 F.3d at 1338. “If the meaning of the claim is discernable, even though the task may be formidable and the conclusion may be one over which reasonable persons will disagree, ... the claim [is] sufficiently clear to avoid invalidity on indefiniteness grounds.” Exxon, 265 F.3d at 1375; Halliburton, 514 F.3d at 1249. IV. AGREED CONSTRUCTIONS Based upon the joint submission of claim construction charts, the following terms of the '222 and '802 patents have been agreed to by the parties, and therefore adopted by the Court: Claim term Agreed Construction X a real value that when multiplied by the duration of one time domain sample provides the maximum expected clock error_ V. TERMS IN DISPUTE OF THE '222 PATENT 1. “transceiver” Wi-LAN’s Proposed Construction Defendants’ Proposed Construction “a two-way radio unit” “transceiver that omits clock recovery, carrier recovery, automatic gain control, passband limiter, power amplifier, an equalizer, and an interleaver-deinterleaver” Alternatively, “transmitter and receiver that omits clock recovery, carrier recovery, automatic gain control, passband limiter, power amplifier, an equalizer, and an _interleaver-deinterleaver”_ The Court finds that claim 1 of the '222 patent requires a “transceiver,” whereas claim 7 of the '222 patent requires a “wireless transceiver.” Claim 1 requires that the transceiver has both a transmitter for transmitting and a receiver for receiving. In the Background and Summary of the Invention section, the specification expressly states that a transceiver is “capable of transmitting and receiving information (voice, data or video) in the form of electromagnetic signals,” “may be fixed or portable,” and in personal communications networks may be a “portable radio unit.” '222 patent, 1:33-36, 1:43-45. The Court finds that the ordinary definition of the term “transceiver” is a device that both transmits and receives data. While the Court finds that a two-way radio unit may be a transceiver, the Court rejects Wi-LAN’s argument that the transceiver must necessarily be limited to a radio unit. The Court finds that the primary dispute between the parties is whether certain advantages or benefits of the disclosed system are merely optional or are mandatory omissions from the definition of a “transceiver.” Defendants argue that the specification makes repeated disclaimers of prior art transceiver components throughout the specification and distinguishes the “present invention” from the prior art on the basis that it omits a number of components found in prior art transceivers. Defendants argue that the Federal Circuit is clear that when the specification makes clear that the alleged invention does not include particular items those items are outside the scope of the claims. The Court disagrees with Defendants’ arguments. While there is language in the specification indicating that the present invention distinguishes prior art as requiring certain attributes of the transceiver that are not required in the applicants’ invention, the Court finds that the language is not a clear limitation that the term transceiver is to be so limited. Rather, the Court finds that certain omissions of the present invention, compared to the prior art, are merely advantageous and not necessary. The Court finds that the “not required” language in the specification does not necessarily mean “omitted” or “excluded.” For example, in the Detailed Description of the Preferred Embodiments section, the language only states that some of the prior art components of a transceiver are “not required” or “not used” and briefly describes how the “omissions” of these components can be done without impairing the quality and capacity of the system. '222 patent, 4:55-63; 12:45-50. The Court finds that there is no express requirement that the present invention necessarily excludes the optional components nor is there any express disavowal that the term “transceiver” excludes the optional components. The Court finds that not a single claim in the '222 patent includes the requirement that these optional components must be omitted from the transceiver. Further, because claim 7 provides certain limitations of the width of the frequency band so that “neither carrier nor clock recovery is required at the second transceiver,” such a limitation would be meaningless if the transceiver had already expressly omitted clock recovery and carrier recovery. The Court finds that, in the entirety of the specification and the claims and considering the ordinary meaning of the term, the omission of the disputed elements is merely optional, i.e. “not required,” and is not a necessary exclusion. Thus, the Court construes the term “transceiver” as “a device that transmits and receives data.” 2. “amplitude and phase differential characteristics” Claim Language Wi-LAN’s Proposed Construction Defendants’ Proposed Construction “amplitude and phase differential characteristics’: “amplitude and phase distortions” Alternative: “amplitude and phase differences in the received signal caused by the wireless channel” “amplitude and phase characteristics resulting from differential modulation” “amplitude and phase differential” “amplitude and phase distortions” Same alternative “difference in amplitude and phase” “differential characteristics “amplitude and phase distortions” “characteristics resulting from differential modulation” Same alternative “estimated amplitude and an “amplitude and phase estimated phase differential” distortions” Same alternative “estimated difference in amplitude or phase between received data symbols” The Court rejects Wi-LAN’s proposal that “differential” in the claims is equal to “distortions.” The claims of the '222 patent never mention “distortion.” While much of the '222 patent references “phase differential,” the patent also references “distortion” in various instances. However, the patent never refers to a “differential” as a “distortion” and never equates those terms. The Court finds that Wi-LAN is seeking to improperly remove the word “differential” from the claims and substitute an entirely different word. The Court finds that “differential” and “distortion” have different meanings. Claim 1 of the '222 patent requires “amplitude and phase differential characteristics,” “the amplitude,” “the phase differential,” “an estimated amplitude,” and “an estimated phase differential.” Further, dependent claim 4 recites “the estimated amplitude” or “the estimated phase differential,” dependent claim 6 recites “estimated amplitude and phase differential,” dependent claim 11 recites “an estimated phase differential,” and dependent claim 12 recites “the phase differential.” The claims recite only two terms: “amplitude” and “phase differential.” In other words, the words “differential” and “phase” must be construed together as “phase differential.” Thus, the Court rejects the parties’ arguments that the term “differential” applies to both “phase” and “amplitude.” Accordingly, based on the claim language, the Court rejects Wi-LAN’s argument that the “differential” term implies that it is distortions to both the amplitude and phase of the signal or differences in both the amplitude and phase caused by the channel. Similarly, based on the claim language, the Court rejects Defendants’ argument that the “differential” term implies that it is the result of differential modulation to both the amplitude and phase of the signal, as compared to just the phase of the signal. If the Court were to require differential modulation to both the amplitude and the phase of the transmitted signal, it would impermissibly eliminate the preferred embodiment of multilevel differential phase shift keying (MDPSK), a technique that changes the phase of a signal and not the amplitude of the signal. This interpretation is consistent with the specification. The Abstract and the Background and Summary of the Invention sections provide that “[t]he processing of the signal at the second transceiver may include estimating the phase differential of the transmitted signal ...” '222 patent, Abstract, 3:4-6. The Detailed Description also has numerous references to “phase differential.” See id. at 9:43-61; 10:58-11:2; 11:18-12:13; 18:1-9. While the focus of the patent is on differential phase modulation, hence the repeated use of the term “phase differential,” there are at least two references in the specification to the potential use of amplitude modulation by the technique of quadrature amplitude modulation (“QAM”). See id. at 5:34-35; 7:24-27. However, the '222 patent suggests that QAM should not be used because “amplitude modulation makes it difficult to equalize the distorting effects of the channel on the signal.” Id. at 7:24-27. Based upon the claim language chosen by the patentee, the Court finds that the claimed language does not necessarily require the alternative disclosed technique of amplitude modulation. In the claims, the term “differential” applies specifically only to the phase of the signal, and does not reference or relate to the term amplitude in the claim language. While the transmitted and received signals will necessarily have an amplitude (and phase), and there will likely be distortions to the amplitude (and phase) caused by the channel, the Court finds that the express claim language indicates that the term differential, and hence differential modulation, only applies to the phase of the signal and not the amplitude. In the patent, the claimed channel estimator estimates the phase differential of the transmitted signals by sampling the amplitude envelope of the signals. See '222 patent, 11:1-28. The specification expressly describes a “phase estimator” in the channel estimator. See '222 patent, 10:58-60; 18:48-50. The Court agrees with the Defendants that estimates of the “amplitude” and the “phase differential” are used to correct for distortion over the channel, and accordingly, the “phase differential” of the received signal is supplied to the “pre-distorter” to correct for “phase distortion over the channel.” See '222 patent, 9:43-61. The channel estimator uses the differences in amplitude of the signals by sampling the amplitude envelope to estimate the phase differential of the transmitted signal, see '222 patent, 11:3-12:22, and the estimated “amplitude” and the “phase differential” are then used to correct for distortion over the channel. See claim 4; see also '222 patent, 9:43-61. This interpretation is further reinforced by the patentee’s co-pending application, now U.S. Patent No. 5,369,670 (“the '670 patent”), that was referenced in the prosecution history of the '222 patent as being “relevant to the extent that it includes a description of the phase estimation technique disclosed in the present application.” See Applicants’ April 19, 1993 Information Disclosure Statement. The '670 patent expressly states that “[a] differential of a sequence of symbols or data points is a measure of the time rate of change of a sequence of symbols or data points .... it may be estimated as a difference between symbols or data points.” '670 patent, 4:3-11. “The information in the carrier signal may be carried in the phase differential of a number of consecutive time instants, or as differential phase shifts of a number of frequency components of the transmitted signal.” '670 patent, 4:27-31. Further, the '670 patent states that “the estimation of the phase differential may be made from sampling the amplitude of the transmitted signal” and that the estimated phase differential can be used to “produce a corrected signal.” '670 patent, 2:46-48, 63-68. Thus, the specification of the '670 patent is consistent with this Court’s interpretation of the claims in the '222 patent. In an alternative construction, Wi-LAN proposes that the amplitude and phase differences in the received signal are “caused by the wireless channel.” Defendants take a contrary position and contend that the differences result solely from “differential modulation.” Neither position is entirely correct. The wireless channel can cause differences or distortions to the amplitude or phase of the transmitted signal by numerous affects, such as Doppler shifts, multipath interference, fading, and clock error. Thus, while there will likely be distortions to the amplitude and phase of the transmitted signal caused by the channel, the claim language, as interpreted in light of the specification, indicates that the terms “amplitude” and “phase differential” as claimed are not the distortions or differences to the signal as a result of the channel. Further, the Court finds that the claimed phrase, because the term “differential” applies to “phase” and not “amplitude,” cannot be referencing the differences or distortions of the channel on both the amplitude and phase of the received signal. Rather, the term “phase differential,” based upon the specification, the claims, and one of ordinary skill in the art, implies that the transmitted information is carried in the phase differential of the transmitted signals, i.e., the phase differential is the result of differential modulation and not the effects of the wireless channel. As described further in the analysis section for the term “channel estimator,” the channel estimator computes the effects of the distortions from the differences in the amplitude and phase differential, but it does not directly measure or compute the distortions. Rather, the channel estimator supplies the estimated phase differential to correct for or equalize the phase distortions over the channel. This construction for the term channel estimator confirms the Court’s construction for the term “amplitude” and “phase differential” of the signal as not being distortions or mere differences as a result of the channel effects. For the above reasons, the Court construes the term “phase differential” to mean “difference in phase resulting from differential modulation. ” The term “characteristic” is not used in the specification of the '222 patent. The Court finds that the term applies to both “amplitude” and “phase differential” in claim 1. Thus, the Court construes the term “amplitude and phase differential characteristics” to mean “characteristics of both the amplitude and the difference in phase resulting from differential modulation of the received data signals.” The Court construes the term “amplitude and phase differential” to mean “amplitude and difference in phase resulting from differential modulation.” The Court construes the term “an estimated amplitude and an estimated phase differential” to mean “an estimated amplitude and an estimated difference in phase resulting from differential modulation. ” 3. “channel estimator” Wi-LAN’s Proposed Construction Defendants’ Proposed Construction “a device for computing the amplitude and/or phase distortions of a received signal” “a device for estimating one or both of the amplitude and the phase differential of the received signals to produce as output one or both of the difference in amplitude or phase between received data symbols” Alternative: “a device for computing amplitude and/or phase differences in the received signal caused by the wireless channel”_ The construction for this term is largely related to the construction for the terms relating to “amplitude and phase differential.” In light of the Court’s prior constructions, the only term to be construed is the “channel estimator” term itself. As previously stated, the claimed channel estimator estimates the phase differential of the transmitted signals by sampling the amplitude envelope of the signals. See '222 patent, 11:1-28. There may be distortions to the amplitude and phase of the transmitted signal caused by the channel. However, the Court finds that estimates of the “amplitude” and the “phase differential” are used to correct for distortions over the channel, not that the channel estimator itself directly computes or measures the distortions. See '222 patent, 9:43-61. Accordingly, the “phase differential” of the received signal is supplied to the “pre-distorter” to correct for “phase distortion over the channel.” Id. The Defendants’ construction largely recites most of the subsequent language following the term to be construed, and therefore the Court rejects Defendants’ construction as being unhelpful. Again, the Court rejects Wi-LAN’s proposal to equate the term differential to distortion. The Court finds that the language of the claims and specification are clear that the channel estimator may compute an estimated phase differential and estimated amplitude, but it is not necessarily a device for computing distortions. See '222 patent, 9:43-61. The channel estimator of the '222 patent first obtains an estimated amplitude of the received signal by sampling the amplitude envelope, which is then used to obtain an estimated “phase differential” to correct for the channel’s effects on the received signal. '222 patent, 11:10-19. The specification provides that the channel estimator is for “estimating the channel.” See '222 patent, 10:67-11:1. Further, the plain language of the term “channel estimator” implies that it is a device that estimates the channel. Wi-LAN’s expert confirms that the goal of the channel estimator is to estimate the channel, and more particularly to estimate the effect of the channel on information symbols. Thus, the Court construes the term “channel estimator” to mean “a device that estimates the effect of the channel on the transmitted signals.” 4. “a wideband frequency division multiplexer for multiplexing the information onto wideband frequency channels” Wi-LAN’s Proposed Construction Entire disputed phrase: “a device for placing information onto a number of frequencies (K) having a frequency range between the frequencies (Af), both large enough to be able to achieve a specific throughput and large enough to be able to avoid using either a clock or a carrier recovery device without substantially affecting the BER” ivideband frequency division multiplexer: “a device for placing information onto wide-band frequency channels” Defendants’ Proposed Construction Entire disputed phrase: “a multiplexer for multiplexing the information onto frequency channels with a K and a Af large enough to be able to achieve a specific throughput and large enough to be able to avoid using either a clock or a carrier recovery device without substantially affecting the BER” wideband frequency division multiplexer: “a multiplexer for multiplexing the information onto [wideband] frequency channels” wideband frequency channels: “a number of frequencies (K) having a frequency range between the frequencies (Af), both large enough to be able to achieve a specific throughput and large enough to be able to avoid using either a clock or a carrier recovery device without substantially affecting the bit error rate (BER)” wideband frequency channels: “frequency channels with a K and a Af large enough to be able to achieve a specific throughput and large enough to be able to avoid using either a clock or a carrier recovery device without substantially affecting the BER” The. phrase to be construed is “a wideband frequency division multiplexer for multiplexing the information onto wide-band frequency channels.” “Wideband in this patent document is described in the context of Wideband-Orthogonal Frequency Domain Modulation (W-OFDM or wideband OFDM).” '222 patent, 5:24-26. The specification defines Wideband-OFDM as “OFDM with a K and Af large enough to be able to achieve a specific throughput and large enough to be able to avoid using either a clock or a carrier recovery device without substantially affecting the BER.” '222 patent, 6:30-34. The specification of the '222 patent repeatedly states that a “first frame of information is multiplexed over a number of wideband frequency bands at a first transceiver, and the information transmitted to a second transceiver. See '222 patent, Abstract; 2:54-57. The transceiver includes “a wideband frequency division multiplexer for multiplexing the information onto wideband frequency channels.” See '222 patent, Abstract; 3:25-28. “To implement wideband modulation, Orthogonal Frequency Division Multiplexing (OFDM) is preferred in which the information, for example encoded speech, is multiplexed over a number of contiguous frequency bands.” '222 patent, 7:12-15. Wi-LAN argues that the term “frequency division multiplexer” means “a device for placing information onto a number of frequencies. Further, Wi-LAN argues that “frequency division multiplexing” is a method for transmitting information simultaneously in the frequency domain by placing information onto a number of frequencies. Thus, Wi-LAN contends that the term multiplexing means “placing.” The Court disagrees with Wi-LAN. However, the Defendants do not provide a helpful construction for the term and merely argue that it is “a multiplexer for multiplexing the information” onto wideband frequency channels. The Court finds that the terms “multiplexer” and “multiplexing” are well known in the art. The Court finds that the term “multiplexer” means a device that multiplexes, e.g., combines or merges two or more signals or input channels into a single output signal or single output channel. Likewise, the Court finds that the term “multiplexing” means combining two or more signals into a single output signal. There is nothing in the specification or claim language that dictates straying away from these well known-meanings. The Court finds that one of ordinary skill in the art would understand, in general, frequency division multiplexing as a type of multiplexing where different frequencies are used to combine multiple streams of data for transmission, wherein each signal is assigned a different carrier frequency. The Court finds that one of ordinary skill in the art would understand, in general, orthogonal frequency-division multiplexing as a type of frequency division multiplexing where a number of sub-carriers are used to carry data, wherein the data is divided into several parallel data streams or channels, one for each sub-carrier. These meanings are consistent with the specification of the '222 patent. Wi-LAN’s proposed construction conflicts with the well-known meaning of the term multiplexer by redefining “multiplexing” as “placing.” The Court finds that “multiplexing” involves more than merely “placing information onto.” The Court notes that the term “multiplexing” is used in claim 7 and the parties do not attempt to define the word “multiplexing.” Thus, the Court construes the disputed term “wide-band frequency division multiplexer” and not the undisputed “multiplexing” term. The Court construes the term “wideband frequency division multiplexer for multiplexing the information onto wideband frequency channels” to mean “a device that combines the information from multiple inputs into a single output for multiplexing the information onto wideband frequency channels. ” In regards to the term “-wideband frequency channels,” the parties essentially adopt the same construction that is supported by the specification, see '222 patent, 6:30-34, with a few notable differences. The Court finds that “wideband frequency channels” means “frequency channels with” certain characteristics, and that the Defendants’ proposed construction follows the specification more closely than Wi-LAN’s proposal. However, the Court agrees with Wi-LAN that K, Af, and BER should be described with more than just symbols or acronyms. In the specification K is defined as a “number of points,” Af is defined as “frequency band,” and BER is defined as “bit error probability” or “bit error rate.” '222 patent, 1:64-66; 5:26-29; 7:44-46. Thus, the Court construes the term “wideband frequency channels” to mean “frequency channels with a K (number of points) and a Af (frequency band) large enough to be able to achieve a specific throughput and large enough to be able to avoid using either a clock or a carrier recovery device without substantially affecting the BER (bit error rate). ” 5. “points” Wi-LAN’s Proposed “frequencies” Proposed Construction “divisions within a frame corresponding to one information symbol each” The relevant language in claim 7 of the '222 patent is as follows: “the frequency band is formed from a first set of K1 points and a pair of tail slots each having K2 points, each of the points being separated by a frequency range of Af.” Claim 7 also states that “the frequency band” is that upon which information is multiplexed. The specification expressly defines that the entire available bandwidth B is divided into a number of points K, where adjacent points are separated by a frequency band, Af. See '222 patent, 5:26-31; 17:17-22. The available bandwidth B is the product of a number of points K multiplied by a frequency band Af, that is B=KAf. Id. The K points are grouped into a frame of K1 points and two tail slots of K2 points each, so that K = K1 + K2. Id. Thus, based upon Figure 2 and the corresponding specification, it is clear that the points are located within the bandwidth, that there can be K1 points or K2 points, and that K1 points are located in the frame and K2 points are located outside the frame but still in the available bandwidth. See id. and FIG. 2. The Court finds that “points” does not equate to merely “frequencies” as Wi-LAN suggests. However, the Court finds that points can exist in the frame and outside the frame in the tail slots, and thus disagrees with Defendants’ proposed construction that points means “divisions within a frame.” The specification also expressly states that “each point in the frame corresponds to one information symbol.” '222 patent, 5:35-36. However, because the Court finds that the “tail slots” of K2 points are outside of the frame of information, then those K2 points would not necessarily correspond to “an information symbol” based upon the specification. Thus, Defendants’ proposed construction including “corresponding to one information symbol each” is incorrect. The Court construes the term “points” to mean “divisions within the frequency band.” Wi-LAN’s Proposed “groups of frequencies that act as guard bands to reduce power outside of the frequency 6. “tail slots” Proposed Construction “divisions within a frame that act as a guard band” The construction of this term relates to the construction for the term “points.” Claim 7 of the '222 patent expressly states that “the frequency band is formed from ... a pair of tail slots each having K2 points.” The specification states that the “two tail slots act as guard bands to ensure that the out-of-band signal is below a certain power level.” '222 patent, 5:36-38. Both parties agree that the tail slots act as a guard band, but disagree as to the remainder of the proposed constructions. Based upon Figure 2 and the corresponding specification, it is clear that K1 points are located in the frame and K2 points, corresponding to the two tail slots, are located outside the frame but still in the available bandwidth or frequency band. See '222 patent, 5:26-40, FIG. 2. Thus, the Court rejects Defendants’ proposed construction that tail slots are necessarily “divisions within a frame.” The Court does not find that Wi-LAN’s proposal to include the phrase “reduce power outside of the frequency band” is necessary or is entirely based upon the specification. Thus, the Court construes the term “tail slots” as “divisions within the frequency band that act as guard bands. ” 7. “Where T is the duration of one time domain sample, the information is multiplexed over a number M of levels, and K1 selected such that 211 X/Kl < n/M” Wi-LAN’s Proposed Construction “T is the duration of one time domain sample, the information is multiplexed over a number of distinct phases, and K1 selected such that 211 X/Kl < II/M” Proposed Construction “T is the duration of one time domain sample equal to l/(KiAf), using multilevel dijferential phase shift keying with M levels to multiplex the information, where K1 is selected such that 2n X/Kl < n/M” No construction necessary for “T is the duration of one time domain sample” number M of levels: “a number of distinct phases” number M of levels: “multilevel differential phase shift keying M levels” The specification states that when “t [clock error] is equal to X T where T is duration of one time domain sample and X is any real value, the shift [in phase difference] is equal to 2nAfXT.” '222 patent, 5:68-6:2. The parties agreed that the term “X’ means “a real value that when multiplied by the duration of one time domain sample provides the maximum expected clock error.” “Hence, t causes a shift in the phase difference between adjacent symbols of value 211 X/Kl since T is equal to l/(KlAf).” Id. at 6:2-4. Claim 7 expressly requires that K1 is selected such that 2IIX/K1 < n/M. The Court finds that the connection between “maximum expected clock error” and 211 X/Kl in claim 7 is based upon T being equal to l/(KlAf). The Court rejects Wi-LAN’s argument that no construction is necessary for this phrase. Thus, the Court construes the term “T is the duration of one time domain sample” to mean “T is the duration of one time domain sample equal to l/(KlLj).” The term “M” is referenced twice in claim 7: “the information is multiplexed over a number M of levels” and “K1 selected such that 211 X/Kl < II/M.” The specification provides that “M is the number of levels each symbol can take.” '222 patent, 5:44-46. The specification further provides that “let us assume that MDPSK is used in an OFDM system with the number M of levels.” Id. at 6:34-36. Still further, the specification provides that it is a “necessary condition for wideband OFDM” that K1 is selected so that 211 X/Kl < II/M. Id. at 7:3-7. The Court finds that the specification expressly defines 2n X/Kl as the “phase difference between adjacent symbols.” The Court finds that this is a well-known reference to “phase differential” used in differential modulation and the phrase “2nX/Kl” as understood by the specification and claims would only be relevant in a system using differential modulation. The Court finds that the number of “levels” does not necessarily equal the number of “phases.” Thus, the Court rejects Wi-LAN’s proposed construction that equates “number M of levels” with merely “number of distinct phases.” While the specification provides an example that uses “a number M of levels” in the context of multilevel differential phase shift keying (MDPSK), such a use is only a preferred embodiment and is not a necessary limitation to the term. See '222 patent, 5:31-35, 6:34-46. One of ordinary skill in the art would understand that the “number of M levels” can apply to various types of differential modulation techniques, such as QAM or MDPSK. The Court construes the term “the information is multiplexed over a number M of levels” to mean “the information is multiplexed over a number M of levels, where M is the member of levels each symbol can take using differential modulation. ” 8. “carrier [recovery]” and “clock recovery” Wi-LAN’s Proposed Construction carrier [recovery]: “synchronizing the local oscillator to the carrier frequency of the received signal” clock recovery: “synchronizing the sampling clock to the timing of the received signal”_ Defendants’ Proposed Construction carrier [recovery]: “recovery of the carrier signal” clock recovery: “recovery of the clock” Claim 7 requires that “the width of the frequency band is chosen so that neither carrier nor clock recovery is required at the second transceiver.” The terms “carrier” and “clock recovery” are also used in the construction of the term “wideband frequency channels” in claim 1. Defendants argue that the claim language uses carrier and clock recovery generally and does not limit those terms to any particular known technique. Wi-LAN argues that the terms are limited to a particular technique that is implicitly defined in the context of the prior art receiver shown in FIG. lb. There are numerous references to clock and carrier recovery in the specification and not one instance restricts the types of clock or carrier recovery that should be avoided. See '222 patent, 2:19-24; 4:55-63; 6:30-33; 6:46-50; 12:45-50; 13:5-7; 13:17-19; Figure lb. The specification provides only that the use, in general, of “clock recovery” and “carrier recovery” is not required by the present invention. It does not provide that certain specific techniques or methods of “clock recovery” or “carrier recovery” are not required. The Court finds that the terms should not be limited to a particular embodiment or method, particularly when the claims and specification do not support such a limited interpretation. Thus, the Court rejects Wi-LAN’s proposed constructions and finds that they are an attempt to improperly restrict those terms to only one of the many ways of performing the clock or carrier recovery that were well-known at the time the application leading to the '222 patent was filed. The Court finds, however, that Defendants merely rephrase and rearrange the terms to be construed, and such a construction is not helpful in this instance. One of skill in the art would understand the term “carrier recovery” to generally mean the process of extracting a phase-coherent reference carrier from a received carrier waveform or providing an estimate of the carrier phase from the received signal. One of skill in the art would understand the term “clock recovery” to generally mean the process of determining the clock of the received signal or recovering clocking information from the received data. Thus, both clock and carrier recovery derive the carrier phase and clock, respectively, from the information-bearing signal. The Court construes the term “carrier recovery” to mean “process of determining the carrier phase of the received signal.” The Court construes the term “clock recovery” to mean “process of determining the clock of the received signal. ” 9. “out of band signal” Dependent claim 9 provides that “K2 is selected so that the out of band signal is less than a given level.” Subsequent to the parties’ briefing and argument on this term, the parties have agreed by letter to the Court, dated April 7, 2010, that the term “out of band signal” means “power outside the frequency band.” However, Defendants still argue that claim 9 is invalid for failing to meet 35 U.S.C. § 112. The Defendants do not argue that “out of band signal” is indefinite, but that the subsequent phrase “less than a given level” is indefinite. It appears that Defendants did not contend that “less than a given level” needed to be construed, or that the specific phrase was indefinite, until the Defendants’ responsive claim construction brief. Thus, Wi-LAN did not provide any proposed construction for the term and instead argued that the term “out of band signal” was not indefinite and had a particular meaning. The Court finds that the phrase “less than a given level” is not indefinite. A claim is indefinite only if the “claim is insolubly ambiguous, and no narrowing construction can properly be adopted.” Exxon, 265 F.3d at 1375; Honeywell, 341 F.3d at 1338-39. This term is not “insolubly ambiguous” so as to prevent construction. See Young, 492 F.3d at 1346 (claims are considered indefinite when they are “not amenable to construction or are insolubly ambiguous”). The specification contains examples from which one of ordinary skill in the art could determine the scope of the claim. For example, the “two tail slots act as guard bands to ensure that the out-of-band signal is below a certain power level” and “to ensure that the out-of-band signal is ydB or less relative to the in-band signal ...” '222 patent, 5:36-44; 6:46-48. The specification then provides an explicit example of what, in a particular instance, the “less than a given level” should be: “[t]he two tail slots of 195.3 KHz each (i.e. 8 points each) ensure that the signal outside the entire band of 100.39 MHz is below-50 dB.” '222 patent, 7:57-60. In addition, the specification teaches that “to allow use of the radio frequency spectrum ... the system must satisfy federal regulations ... [that] impose limits on the power and the frequency spread of the signals exchanged ...” '222 patent, 1:50-54. The Court finds that there is sufficient guidance in the specification as to the meaning of “less than a given level” to one of ordinary skill in the art. See Exxon, 265 F.3d at 1375 (“If the meaning of the claim is discernible, even though the task may be formidable and the conclusion may be one over which reasonable persons will disagree, we have held the claim sufficiently clear to avoid invalidity on indefiniteness grounds.”) The Court rejects Defendants’ argument that because the “level” in the claim is unspecified, no meaningful bound is placed on the patent claim. Consistent with the parties’ agreement, the Court construes the term “out of band signal” to mean “power outside the frequency band. ” The Court finds that the term “less than a given level” is not indefinite. The Court construes the term “less than a given level” to mean “less than a given power level to satisfy federal regulations.” VI. TERMS IN DISPUTE OF THE '802 PATENT 1. “transceiver” Wi-LAN’s Proposed Construction “a two-way radio unit” Defendants’ Proposed Construction “link” Wi-LAN’s construction for the term “transceiver” in the '802 patent is the same as its construction for “transceiver” in the '222 patent, while Defendants propose a construction that is different from their construction for the '222 patent. The '802 patent references a “transceiver” only a few times in the specification. In one instance, the specification provides that “we allow a single link (i.e., a single transceiver) to use more than one code at the time same.” '802 patent, 2:3-5. The Court rejects Defendants’ argument that this reference unequivocally limits the term “transceiver” to a “link.” Rather, the Court finds that this portion of the specification provides that a transceiver can be an example of a link. The Court finds that there is nothing in the specification or claims that would limit the term “transceiver” to anything other than its ordinary meaning to one of skill in the art. Thus, consistent with its construction for the term “transceiver” in the '222 patent, the Court construes the term “transceiver” as “a device that transmits and receives data. ” 2. “invertible randomized spreading” Wi-LAN’s Proposed InveHible randomized spreading: “spreading and applying complex constants chosen randomly, in a manner that is invertible” Proposed Construction InveHible randomized spreading: Defendants' proposal spreading: “modulating data symbols by codes of larger bandwidth” Alternative for spreading: “modulating data symbols by codes having multiple chips”_ “spreading using an invertible randomized transform” LG Electronics’ proposal: “spreading using an invertible randomizer transform” spreading: “distributing information bits over code chips thereby reducing the effective bandwidth” A. Spreading The independent claims of the '802 patent, in general, require operating on the plural sets of N data symbols to produce modulated data symbols corresponding to a spreading or an invertible randomized spreading of each set of N data symbols. The specification has numerous references to “spread” or “spreading.” “The invention deals with the field of multiple access communications using Spread Spectrum modulation.” '802 patent, 1:14-15. “Spread Spectrum can be classified as Direct Sequence, Frequency-Hopping or a combination of the two.” Id. at 1:18-19. “Commonly used spread spectrum techniques are Direct Sequence Spread Spectrum (DSSS) and Code Division Multiple Access (CDMA) ...” Id. at 1:21-28. In the Background section, the specification provides that “DSSS is a communication scheme in which information bits are spread over code bits (generally called chips),” and then provides certain advantages of this “information spreading.” Id. at 1:25-45. “In this patent, we present Multi-Code Direct Sequence Spread Spectrum (MC-DSSS) which is a modulation scheme that assigns up to N DSSS codes to an individual transceiver where N is the number of chips per D