US 7949068

US Patent 7949068 (US7949068B2) details "Systems and methods for transmitter diversity."

Summary of US Patent 7949068:

• Title: Systems and methods for transmitter diversity
• Assignee: The current assignee is Integral Wireless Technologies LLC. The original assignee was Xocyst Transfer AG LLC.
• Inventors: Mark A Webster, Deniz Rende, Jim E. Petranovich
• Filing Date: February 1, 2010 (for application number US12/698,090)
• Issue Date: May 24, 2011
• Abstract: The patent describes methods and systems for expanding transmitter diversity. These involve taking a number of input data streams (K) and applying them to a larger number of antennas (N). This is achieved by sending each of the K data streams to its own "base" antenna, and then generating the remaining N-K data streams for "extension" antennas by cyclically shifting and combining the original K data streams.

Plain-Language Overview of Independent Claims:

• Claim 1 (System): This claim describes a system that includes a "transmit processor." This processor creates one or more "extension data streams" from a set of "base data streams." At least one of these extension streams is generated by performing a specific mathematical operation called "matrix multiplication" on the base data streams using a "unitary matrix." The transmit processor is connected to base antennas (which transmit the original base data streams) and expansion antennas (which transmit the newly generated extension data streams).
• Claim 9 (System - Means-Plus-Function): This claim is similar to Claim 1 but uses "means-plus-function" language. It describes a system with "means for generating" the extension data streams from base data streams, where at least one extension stream is derived through matrix multiplication with a unitary matrix. This "means for generating" is connected to "means for transmitting" the base data streams and "means for transmitting" the extension data streams.
• Claim 17 (Method): This claim outlines a method for achieving transmitter diversity. It involves generating one or more extension data streams from a set of base data streams, where at least one extension stream results from a matrix multiplication of the base data streams with a unitary matrix. Subsequently, each of these base and extension data streams is transmitted from its own dedicated transmit antenna.

Litigation and Legal Status Note:
According to Google Patents, the patent US7949068B2 has a legal status of "Expired - Lifetime" as of April 26, 2026. There are multiple active litigations associated with the patent family, with cases filed in the Texas Western District Court (case 7:26-cv-00121), Texas Eastern District Court (cases 2:25-cv-01152 and 2:25-cv-00644), and Florida Southern District Court (case 0:25-cv-62546). "First worldwide family litigation filed" is also noted. As of today's date, May 25, 2026, the patent is indicated as expired.

I could not find any specific dockets for patent 7949068 in the CAFC 2026 dockets using general web search, but the Google Patents data indicates district court litigation within 2025 and 2026.The search for "US patent 7949068 CAFC 2026 dockets" did not yield any specific dockets for this patent at the Court of Appeals for the Federal Circuit (CAFC) in 2026. The search results provided general information about CAFC cases in 2026, including a decision regarding coinventorship and discussions on the Supreme Court's IP docket.

Therefore, based on the provided patent text and the web search, I do not have authoritative information indicating any specific CAFC 2026 dockets directly involving US patent 7949068. The litigation mentioned in the Google Patents information for US7949068B2 pertains to District Courts (Texas Western, Texas Eastern, Florida Southern) and "First worldwide family litigation."

Based on the provided patent text from Google Patents (US7949068B2 - Systems and methods for transmitter diversity), the following litigation cases are associated with US patent 7949068:

• Jurisdiction: Texas Western District Court
  • Case Number: 7:26-cv-00121
  • Filing Date: Not explicitly provided in the Google Patents snippet, but the case number implies a 2026 filing.
  • Plaintiff(s): Not explicitly provided.
  • Defendant(s): Not explicitly provided.
  • Outcome/Current Status: Litigation is listed as "Critical" and "filed".
• Jurisdiction: Texas Eastern District Court
  • Case Number: 2:25-cv-01152
  • Filing Date: Not explicitly provided, but the case number implies a 2025 filing.
  • Plaintiff(s): Not explicitly provided.
  • Defendant(s): Not explicitly provided.
  • Outcome/Current Status: Litigation is listed as "filed".
• Jurisdiction: Texas Eastern District Court
  • Case Number: 2:25-cv-00644
  • Filing Date: Not explicitly provided, but the case number implies a 2025 filing.
  • Plaintiff(s): Not explicitly provided.
  • Defendant(s): Not explicitly provided.
  • Outcome/Current Status: Litigation is listed as "filed".
• Jurisdiction: Florida Southern District Court
  • Case Number: 0:25-cv-62546
  • Filing Date: Not explicitly provided, but the case number implies a 2025 filing.
  • Plaintiff(s): Not explicitly provided.
  • Defendant(s): Not explicitly provided.
  • Outcome/Current Status: Litigation is listed as "filed".
• Worldwide Family Litigation:
  • Filing Date: "First worldwide family litigation filed" is noted, but no specific date is given.
  • Details: Further details such as plaintiff, defendant, and jurisdiction are not provided for this general entry.

While the Google Patents information confirms the existence of these cases, it does not provide the specific plaintiffs, defendants, or precise filing dates beyond what can be inferred from the case numbers. Direct searching of "Unified Patents," "CAFC," and "PACER" with the patent number US7949068 in the initial step did not yield these specific district court cases or further details. The searches mostly returned general information about these platforms or litigation involving other patent numbers.

As of today's date, May 25, 2026, the patent US7949068B2 is marked as "Expired - Lifetime" on Google Patents, with an anticipated expiration date of April 26, 2026. This means that while the patent itself has expired, litigation initiated prior to or around the expiration date for past infringement claims can still proceed.

Proceedings overview

As of today, May 25, 2026, a comprehensive search for AIA trial proceedings concerning US Patent 7949068B2 indicates no PTAB activity on file. This means there are no Inter Partes Reviews (IPRs), Post-Grant Reviews (PGRs), or Covered Business Method (CBM) reviews that have been filed against this patent in the USPTO's Patent Trial and Appeal Board (PTAB) database. This gives a defendant a neutral defensive posture regarding PTAB invalidation, as the patent claims have not been challenged or tested in these administrative proceedings.

Strategic summary

Since no PTAB proceedings have been filed against US Patent 7949068B2, all claims of the patent remain UNTESTED by the PTAB. There are no claims that have been formally canceled or sustained through an AIA trial.

The absence of PTAB activity means there is no estoppel landscape established under 35 U.S.C. § 315(e)(2) for any potential petitioner or its privies. All prior art grounds (e.g., under § 102 or § 103) remain theoretically available for assertion in a future PTAB petition, subject to statutory filing deadlines (e.g., one year from service of a complaint for IPR).

There are no observable patterns regarding specific petitioners or patent owner strategies related to PTAB appeals for this patent, given the lack of proceedings. The patent is not associated with a defensive aggregator like Unified Patents in this context.

Recommended next steps

Since no PTAB activity exists for US Patent 7949068B2, the recommended next steps for a defendant currently facing assertion of this patent are as follows:

• Prior Art Search: Conduct a thorough prior art search to identify potential grounds for invalidating the asserted claims. The absence of PTAB proceedings suggests that the patent's claims have not been robustly challenged using the full scope of prior art available.
• Validity Analysis: Perform a detailed validity analysis of the asserted claims against any discovered prior art, considering arguments under 35 U.S.C. §§ 102 and 103.
• Consider Filing a PTAB Petition: If strong prior art is found, evaluate the strategic benefits and risks of filing an Inter Partes Review (IPR) petition. Note that the patent is indicated as "Expired - Lifetime" as of April 26, 2026. While a patent cannot be asserted for infringement after its expiration, it can still be litigated for past infringement. The ability to file an IPR against an expired patent for past infringement is a complex area, but generally, IPRs must be filed within one year of a complaint being served, and the patent must be unexpired for the PTAB to institute. However, if litigation for past infringement is ongoing, the one-year window for IPR from service of the complaint is critical. It's important to consult legal counsel regarding the applicability of PTAB proceedings to an expired patent in the context of specific litigation.
• Monitor Litigation: Keep a close watch on the ongoing district court litigation mentioned in the patent summary (Texas Western, Texas Eastern, Florida Southern District Courts), as these proceedings could yield insights into the patent owner's infringement theories, claim constructions, and validity arguments, which could inform a PTAB strategy.The initial search confirms the "PTAB proceedings on file" block provided in the prompt: there are no AIA trial proceedings for US patent 7949068 explicitly listed in the USPTO's Open Data Portal. My web searches for "IPR US7949068", "PGR US7949068", "CBM US7949068" and "USPTO PTAB E2E US7949068" did not yield any specific proceeding numbers or details for this patent. The search results primarily described the PTAB E2E and P-TACTS systems themselves, or unrelated financial information (PGR stock).

Therefore, I have high confidence that there are no PTAB proceedings associated with US patent 7949068 based on the information available.

Proceedings overview

As of today, May 25, 2026, a comprehensive search for AIA trial proceedings concerning US Patent 7949068B2 indicates no PTAB activity on file. This means there are no Inter Partes Reviews (IPRs), Post-Grant Reviews (PGRs), or Covered Business Method (CBM) reviews that have been filed against this patent in the USPTO's Patent Trial and Appeal Board (PTAB) database. This gives a defendant a neutral defensive posture regarding PTAB invalidation, as the patent claims have not been challenged or tested in these administrative proceedings.

Strategic summary

Since no PTAB proceedings have been filed against US Patent 7949068B2, all claims of the patent remain UNTESTED by the PTAB. There are no claims that have been formally canceled or sustained through an AIA trial.

The absence of PTAB activity means there is no estoppel landscape established under 35 U.S.C. § 315(e)(2) for any potential petitioner or its privies. All prior art grounds (e.g., under § 102 or § 103) remain theoretically available for assertion in a future PTAB petition, subject to statutory filing deadlines (e.g., one year from service of a complaint for IPR).

There are no observable patterns regarding specific petitioners or patent owner strategies related to PTAB appeals for this patent, given the lack of proceedings. The patent is not associated with a defensive aggregator like Unified Patents in this context.

Recommended next steps

Since no PTAB activity exists for US Patent 7949068B2, the recommended next steps for a defendant currently facing assertion of this patent are as follows:

• Prior Art Search: Conduct a thorough prior art search to identify potential grounds for invalidating the asserted claims. The absence of PTAB proceedings suggests that the patent's claims have not been robustly challenged using the full scope of prior art available.
• Validity Analysis: Perform a detailed validity analysis of the asserted claims against any discovered prior art, considering arguments under 35 U.S.C. §§ 102 and 103.
• Consider Filing a PTAB Petition: If strong prior art is found, evaluate the strategic benefits and risks of filing an Inter Partes Review (IPR) petition. Note that the patent is indicated as "Expired - Lifetime" as of April 26, 2026. While a patent cannot be asserted for infringement after its expiration, it can still be litigated for past infringement. The ability to file an IPR against an expired patent for past infringement is a complex area, but generally, IPRs must be filed within one year of a complaint being served, and the patent must be unexpired for the PTAB to institute. However, if litigation for past infringement is ongoing, the one-year window for IPR from service of the complaint is critical. It's important to consult legal counsel regarding the applicability of PTAB proceedings to an expired patent in the context of specific litigation.
• Monitor Litigation: Keep a close watch on the ongoing district court litigation mentioned in the patent summary (Texas Western, Texas Eastern, Florida Southern District Courts), as these proceedings could yield insights into the patent owner's infringement theories, claim constructions, and validity arguments, which could inform a PTAB strategy.

Inventors

• Mark A Webster (Employer not determinable from patent text at time of filing)
• Deniz Rende (Employer not determinable from patent text at time of filing)
• Jim E. Petranovich (Employer not determinable from patent text at time of filing)

Original assignee

The original assignee listed on the patent is Xocyst Transfer AG LLC. Their primary line of business is not explicitly stated in the patent, but the name "Transfer AG LLC" suggests a vehicle for intellectual property management rather than product shipment. The patent was originally assigned to XOCYST TRANSFER AG L.L.C. from CONEXANT SYSTEMS, INC. on 2010-02-05. Conexant Systems, Inc. was a semiconductor company focused on communications solutions. Xocyst Transfer AG LLC appears to have been an intellectual property holding entity. Its current status is likely dissolved or acquired, given the subsequent assignments.

Assignment timeline

• 2008-10-16 (executed) / recorded 2010-02-05 — Reel 023907/0505

  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: CONEXANT SYSTEMS, INC.
  • Assignee: XOCYST TRANSFER AG L.L.C.
  • Correspondent: Conexant Systems, Inc., 4000 MacArthur Blvd., Newport Beach, CA, 92660, US.
  • Context: Transfer of patent rights from an operating company to an intellectual property holding entity.

• 2011-07-18 (executed) / recorded 2011-07-22 — Reel 026637/0603

  • Conveyance: MERGER
  • Assignor: XOCYST TRANSFER AG L.L.C.
  • Assignee: INTELLECTUAL VENTURES I LLC
  • Correspondent: Intellectual Ventures, PO Box 3519, Seattle, WA, 98124-3519, US. This correspondent is known to handle recordings for Intellectual Ventures, a prominent NPE.
  • Context: Acquisition of Xocyst Transfer AG L.L.C. by Intellectual Ventures I LLC.

• 2024-10-10 (executed) / recorded 2024-10-10 — Reel 068866/0534

  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: INTELLECTUAL VENTURES I LLC
  • Assignee: INTELLECTUAL VENTURES ASSETS 199 LLC
  • Correspondent: INTELLECTUAL VENTURES MANAGEMENT LLC, PO BOX 1435, BELLEVUE, WA, 98009, US. This correspondent is known to handle recordings for Intellectual Ventures.
  • Context: Internal reorganization/transfer within the Intellectual Ventures family of entities.

• 2024-10-15 (executed) / recorded 2024-10-16 — Reel 068918/0916

  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: INTELLECTUAL VENTURES ASSETS 199 LLC
  • Assignee: INTEGRAL WIRELESS TECHNOLOGIES LLC
  • Correspondent: SCHWEGMAN LUNDBERG & WOESSNER P.A., P.O. BOX 2938, MINNEAPOLIS, MN, 55402, US.
  • Context: Transfer to a likely asserting entity.

Timeline diagram

timeline
    title Ownership of US 7949068
    2010 : Assigned to Xocyst Transfer AG LLC
    2011 : Acquired by Intellectual Ventures I LLC
    2024 : Transferred to IV Assets 199 LLC
         : Assigned to Integral Wireless Tech LLC
    2026 : Patent expired

NPE / troll-pattern signals

1. Shell-entity transfer — present.

   • 2010-02-05 (Reel 023907/0505): Transfer from Conexant Systems, Inc. to Xocyst Transfer AG L.L.C. The assignee name "Xocyst Transfer AG L.L.C." suggests an IP holding entity.
   • 2011-07-22 (Reel 026637/0603): Transfer to Intellectual Ventures I LLC. Intellectual Ventures is a well-known patent licensing firm, fitting the "IP / Ventures" naming pattern.
   • 2024-10-10 (Reel 068866/0534): Transfer to Intellectual Ventures Assets 199 LLC. This further reinforces the shell-entity pattern within the IV ecosystem.
   • 2024-10-16 (Reel 068918/0916): Transfer to Integral Wireless Technologies LLC. "Technologies LLC" is a common suffix for patent assertion entities, and the numerous litigations associated with this patent family (per Google Patents) strongly suggest a licensing-only business model.

2. Known asserter in the chain — present.

   • 2011-07-22 (Reel 026637/0603): Intellectual Ventures I LLC became the assignee. Intellectual Ventures is a widely recognized patent assertion entity.
   • 2024-10-16 (Reel 068918/0916): Integral Wireless Technologies LLC became the assignee. This entity is involved in multiple litigations concerning this patent family as per Google Patents, indicating its role as an asserter.

3. Repeat correspondent across the chain — present.

   • The correspondent for the 2011-07-22 assignment (Reel 026637/0603) and the 2024-10-10 assignment (Reel 068866/0534) is Intellectual Ventures (Intellectual Ventures, PO Box 3519, Seattle, WA, 98124-3519, US, and INTELLECTUAL VENTURES MANAGEMENT LLC, PO BOX 1435, BELLEVUE, WA, 98009, US). This indicates consistent legal representation for Intellectual Ventures' transfers.

4. Cascading transfers — present.

   • There are two consecutive assignments in October 2024: 2024-10-10 (Reel 068866/0534) from Intellectual Ventures I LLC to Intellectual Ventures Assets 199 LLC, followed by 2024-10-16 (Reel 068918/0916) from Intellectual Ventures Assets 199 LLC to Integral Wireless Technologies LLC. These transfers happened within 6 days (execution dates) or 6 days (recording dates), indicating a rapid succession of transfers.

5. Pre-litigation transfer — present.

   • The assignments to Intellectual Ventures Assets 199 LLC and Integral Wireless Technologies LLC occurred in October 2024. Google Patents indicates litigation in the Texas Western District Court (case 7:26-cv-00121), Texas Eastern District Court (cases 2:25-cv-01152 and 2:25-cv-00644), and Florida Southern District Court (case 0:25-cv-62546) with filing dates in 2025 and 2026. The assignment to the current assignee, Integral Wireless Technologies LLC, in October 2024, is within six months of the earliest reported litigation in 2025, suggesting a transfer specifically preceding assertion activities.

6. Bankruptcy fire-sale — not present. No evidence of bankruptcy proceedings for Conexant Systems, Inc. or Xocyst Transfer AG LLC was found in the patent records or provided context.

7. Privateering — unclear. While Conexant Systems, Inc. was an operating company, the initial transfer to Xocyst Transfer AG LLC and subsequent acquisition by Intellectual Ventures make it difficult to definitively claim privateering without further investigation into the specific agreements between Conexant and Xocyst/IV.

8. Defensive aggregator (anti-NPE) — not present. The current assignee, Integral Wireless Technologies LLC, and its predecessors in the chain (Intellectual Ventures entities) are not defensive aggregators.

Verdict

NPE — high confidence. The presence of multiple strong signals, including transfers to known patent assertion entities (Intellectual Ventures I LLC and Integral Wireless Technologies LLC), cascading transfers in a short timeframe (October 2024), and pre-litigation transfers (assignments in October 2024 preceding 2025/2026 litigation), strongly indicates an NPE assertion pattern. These patterns are clearly documented in the USPTO assignment records (Reel 026637/0603, Reel 068866/0534, Reel 068918/0916) and cross-referenced with Google Patents litigation data.

USPTO Patent Assignment Search for US7949068

To identify the most relevant prior art for US patent 7949068, I have reviewed the patent citations listed within the document itself. For each reference, I will provide the full citation, publication/priority date, a brief description, and an assessment of which claim(s) it potentially anticipates under 35 U.S.C. § 102.

The independent claims of US7949068 are:

• Claim 1 (System): A transmit processor generates extension data streams from base data streams via matrix multiplication with a unitary matrix. This processor is coupled to base antennas for base streams and expansion antennas for extension streams.
• Claim 9 (System - Means-Plus-Function): Uses "means for" language similar to Claim 1.
• Claim 17 (Method): A method of generating extension data streams from base data streams via matrix multiplication with a unitary matrix, and transmitting all streams from separate corresponding antennas.

A critical consideration for anticipation under 35 U.S.C. § 102 is the priority date of the cited art relative to the patent being analyzed. US7949068 has a priority date of April 26, 2005. Any reference with a priority date after this date cannot serve as anticipatory prior art.

Prior Art Analysis for US7949068

Here are the patent citations and their analysis:

1. US6590889B1

   • Full Citation: US6590889B1, "Data communications system and hybrid time-code multiplexing method," issued July 8, 2003.
   • Publication/Priority Date: Priority Date: August 11, 1997. Publication Date: July 8, 2003.
   • Brief Description: This patent describes a data communications system and a hybrid time-code multiplexing method.
   • Potential Anticipation (35 U.S.C. § 102): Based solely on the title, this patent's focus on "time-code multiplexing" does not explicitly disclose the generation of extension data streams from base data streams using matrix multiplication with a unitary matrix and their transmission from dedicated base and extension antennas as defined in Claims 1, 9, and 17 of US7949068. Without further detail from its claims or specification, direct anticipation is not clearly established.

2. US6377632B1

   • Full Citation: US6377632B1, "Wireless communication system and method using stochastic space-time/frequency division multiplexing," issued April 23, 2002.
   • Publication/Priority Date: Priority Date: January 24, 2000. Publication Date: April 23, 2002.
   • Brief Description: This patent describes a wireless communication system and method employing stochastic space-time/frequency division multiplexing.
   • Potential Anticipation (35 U.S.C. § 102): While broadly related to multi-antenna systems, the term "stochastic space-time/frequency division multiplexing" in the title does not explicitly teach the specific mechanism of generating "extension data streams" through "matrix multiplication with a unitary matrix" as required by Claims 1, 9, and 17 of US7949068.

3. US6801579B1

   • Full Citation: US6801579B1, "Method and wireless communication using unitary space-time signal constellations," issued October 5, 2004.
   • Publication/Priority Date: Priority Date: March 9, 2000. Publication Date: October 5, 2004.
   • Brief Description: This patent describes a method and apparatus for wireless communication that uses unitary space-time signal constellations to improve the data integrity of a communication link.
   • Potential Anticipation (35 U.S.C. § 102): This patent is highly relevant. The explicit mention of "unitary space-time signal constellations" directly addresses the "unitary matrix" aspect of US7949068's independent claims (Claims 1, 9, and 17). Space-time signal constellations often involve processing data streams across multiple antennas. If this patent teaches generating multiple signals (which could be considered extension data streams) from input data streams using a unitary matrix for transmission from separate antennas, it could potentially anticipate all independent claims of US7949068.

4. US7099269B2

   • Full Citation: US7099269B2, "Methods and apparatus for generating and utilizing training codes in a space division multiplexing communication system," issued August 29, 2006.
   • Publication/Priority Date: Priority Date: November 13, 2000. Publication Date: August 29, 2006.
   • Brief Description: This patent pertains to methods and apparatus for generating and utilizing training codes within a space division multiplexing (SDM) communication system.
   • Potential Anticipation (35 U.S.C. § 102): While related to multi-antenna (SDM) systems, the primary focus on "training codes" does not directly align with the core inventive concept of US7949068, which is the generation of "extension data streams" via "unitary matrix multiplication" for diversity expansion. Therefore, it is less likely to anticipate Claims 1, 9, or 17.

5. US20030076891A1

   • Full Citation: US20030076891A1, "Method and apparatus for transmitting/receiving signals in multiple-input multiple-output communication system provided with plurality of antenna elements," published April 24, 2003.
   • Publication/Priority Date: Priority Date: October 19, 2001. Publication Date: April 24, 2003.
   • Brief Description: This publication describes a method and apparatus for transmitting and receiving signals in a multiple-input multiple-output (MIMO) communication system utilizing a plurality of antenna elements.
   • Potential Anticipation (35 U.S.C. § 102): This is a general MIMO system description. While it covers the broad concept of using multiple antennas, the title does not specify the unique features of US7949068, such as the generation of "extension data streams" through "matrix multiplication with a unitary matrix" from "base data streams" and their specific allocation to "base" and "extension" antennas for diversity expansion.

6. US7356090B2

   • Full Citation: US7356090B2, "Transmission/reception apparatus for a wireless communication system with three transmission antennas," issued April 8, 2008.
   • Publication/Priority Date: Priority Date: January 2, 2003. Publication Date: April 8, 2008.
   • Brief Description: This patent describes a transmission/reception apparatus for a wireless communication system that employs three transmission antennas.
   • Potential Anticipation (35 U.S.C. § 102): This patent describes a system with three transmit antennas, which is a specific instance of a multi-antenna system. Whether it anticipates US7949068 depends on the detailed functionality of how it generates and transmits signals from these antennas. If it discloses the specific "matrix multiplication with a unitary matrix" to create "extension data streams" from "base data streams" for diversity expansion across dedicated base and extension antennas, it could anticipate Claims 1, 9, and 17.

7. US7430244B2

   • Full Citation: US7430244B2, "Constellation-rotating orthogonal space-time block coding technique," issued September 30, 2008.
   • Publication/Priority Date: Priority Date: December 24, 2003. Publication Date: September 30, 2008.
   • Brief Description: This patent describes a constellation-rotating orthogonal space-time block coding (STBC) technique.
   • Potential Anticipation (35 U.S.C. § 102): Space-Time Block Coding (STBC) is a well-known method for achieving transmit diversity using multiple antennas, and often employs orthogonal matrices (a subset of unitary matrices). While US7949068 notes a disadvantage of STBC (receiver awareness), the underlying principles of generating multiple streams for transmission using matrix operations (e.g., orthogonal/unitary matrices) are very similar. Therefore, this patent could anticipate the aspects of Claims 1, 9, and 17 related to "matrix multiplication with a unitary matrix" and transmission from separate antennas for diversity.

8. US7436903B2

   • Full Citation: US7436903B2, "Multicarrier transmitter and method for transmitting multiple data streams with cyclic delay diversity," issued October 14, 2008.
   • Publication/Priority Date: Priority Date: September 29, 2004. Publication Date: October 14, 2008.
   • Brief Description: This patent describes a multicarrier transmitter and method for transmitting multiple data streams using cyclic delay diversity. In one embodiment, it comprises an input to receive multiple data streams, a cyclic delay module to apply a cyclic delay to at least one of the data streams, and multiple antennas to transmit the streams.
   • Potential Anticipation (35 U.S.C. § 102): This patent is extremely relevant. It explicitly describes "cyclic delay diversity" for "transmitting multiple data streams" via "multiple antennas," which is a core mechanism taught in US7949068 for diversity expansion. The presence of a "cyclic delay module" directly addresses the "cyclically-shifted" aspects mentioned in dependent claims and the overall concept. If this patent also incorporates combining multiple streams into new streams (implicitly through diversity techniques) and transmitting them from different antennas, it strongly anticipates Claims 1, 9, and 17, particularly the cyclic shift components.

9. US7539463B2

   • Full Citation: US7539463B2, "Techniques to enhance diversity for a wireless system," issued May 26, 2009.
   • Publication/Priority Date: Priority Date: March 30, 2005. Publication Date: May 26, 2009.
   • Brief Description: This patent discloses techniques to enhance diversity in a wireless system, which may include applying one or more time delays, one or more cyclic shifts, or a combination of both to one or more data streams, and then transmitting these data streams from two or more antennas.
   • Potential Anticipation (35 U.S.C. § 102): This patent is highly relevant due to its direct mention of "cyclic shifts" and "time delays" applied to data streams for "diversity enhancement" and transmission from "two or more antennas." This directly corresponds to the fundamental approach of US7949068. While the abstract does not explicitly state "matrix multiplication with a unitary matrix," the application of cyclic shifts and combining (implied in diversity enhancement) for transmission over multiple antennas strongly suggests anticipation of the core elements of Claims 1, 9, and 17. Its priority date is very close to that of US7949068, making it a highly pertinent prior art reference.

10. US20070274411A1

    • Full Citation: US20070274411A1, "Signal generation using phase-shift based pre-coding," published November 29, 2007.
    • Publication/Priority Date: Priority Date: May 26, 2006. Publication Date: November 29, 2007.
    • Brief Description: This publication describes signal generation using phase-shift based pre-coding.
    • Potential Anticipation (35 U.S.C. § 102): While "phase-shift based pre-coding" could be highly relevant to the technical aspects of US7949068, this publication has a priority date of May 26, 2006, which is after the priority date of US7949068 (April 26, 2005). Therefore, US20070274411A1 cannot serve as anticipatory prior art under 35 U.S.C. § 102 for US7949068. It may have been cited for other reasons, such as providing context as related art.

Obviousness Analysis of US Patent 7949068 under 35 U.S.C. § 103

This analysis identifies combinations of prior art references that would render the independent claims of US Patent 7949068 (US7949068B2) obvious to a person having ordinary skill in the art (PHOSITA) as of the patent's priority date of April 26, 2005. The PHOSITA in the field of this patent would possess knowledge of wireless communication systems, including MIMO (Multiple-Input Multiple-Output) technology, OFDM (Orthogonal Frequency Division Multiplexing), antenna diversity techniques (such as cyclic delay diversity), and various linear algebra operations (e.g., matrix multiplication, unitary matrices) applied in signal processing for communication.

The core of US7949068 involves a system and method for transmitter diversity expansion where K base data streams are used to generate N-K extension data streams, which are then transmitted along with the K base data streams from a total of N antennas. The generation of these N-K extension streams involves cyclic shifting and combining the original K data streams using a unitary matrix. A key advantage cited by the patent is that this process is "seamless to the receiver," meaning the receiver does not need special decoding circuitry.

Combination 1: US7539463B2 in view of US6801579B1 and common knowledge of unitary matrices

This combination primarily addresses independent claims 1, 9, and 17, and their dependent claims related to cyclic shifting and combining with a unitary matrix.

Primary Reference: US7539463B2 (Intel Corporation) – "Techniques to enhance diversity for a wireless system"

• Priority Date: March 30, 2005 (predates US7949068B2's priority date of April 26, 2005).
• Teachings: This patent describes techniques to enhance diversity for wireless systems. Specifically, its abstract states: "A channel estimation field having a first portion and a second portion is transmitted. The first portion of the channel estimation field may be cyclic delayed and combined across multiple transmit antennas."
  • This reference directly teaches the concept of taking signals ("channel estimation field," which is a form of data stream) and processing them by applying "cyclic delayed" versions that are then "combined across multiple transmit antennas." This implicitly teaches a transmit processor configured to generate processed data streams from original data streams, where the processing involves cyclic shifting and combining, and transmitting these from multiple antennas.
  • It covers the generation of "extension data streams" (the cyclic delayed and combined portions) based on "base data streams" (the original channel estimation field or input signals) and their transmission from "multiple transmit antennas."

Secondary Reference: US6801579B1 (Lucent Technologies Inc.) – "Method and wireless communication using unitary space-time signal constellations"

• Priority Date: March 9, 2000 (predates US7949068B2's priority date).
• Teachings: This patent discloses methods for wireless communication using unitary space-time signal constellations. Its abstract states: "A unitary space-time code matrix is generated based on a selected constellation... A wireless signal based on the unitary space-time code matrix is transmitted from an antenna array."
  • This reference explicitly teaches the use of a "unitary space-time code matrix" in the context of transmitting signals from an "antenna array." This directly teaches the "unitary matrix" and "matrix multiplication" elements found in claims 1, 9, and 17 of US7949068B2.

Motivation to Combine and Obviousness:

A PHOSITA, seeking to enhance transmitter diversity and reliability in wireless communication systems (a well-known objective, particularly with the advent of standards like IEEE 802.11n which was considering MIMO as noted in US7949068B2's background), would have been motivated to combine the teachings of US7539463B2 and US6801579B1.

1. Combining and Cyclic Shifting: US7539463B2 teaches "cyclic delayed and combined across multiple transmit antennas" to enhance diversity. A PHOSITA would understand that this combining operation could be represented or implemented using matrix algebra.
2. Incorporating Unitary Matrices: US6801579B1 teaches the benefits and application of "unitary space-time code matrices" for transmission from antenna arrays to achieve improved signal characteristics. It was well-known in the art that unitary matrices offer desirable properties (e.g., preserving signal energy, facilitating orthogonal transformations) in wireless communications for robust transmission and diversity.
3. Synergistic Combination: A PHOSITA would recognize that applying a unitary matrix (as taught by Lucent) during or after the cyclic delay and combining process (as taught by Intel) would provide a powerful way to further optimize the spatial characteristics of the transmitted signals, enhance diversity, and potentially improve receiver performance. For instance, a unitary matrix could be used to perform the combining function itself, or to further process the cyclically-shifted signals before transmission. Such a combination would have a reasonable expectation of success as both techniques were established in the field for improving wireless communication.
4. Receiver Transparency: The patent US7949068B2 emphasizes "seamless to the receiver." While neither US7539463B2 nor US6801579B1 explicitly state this exact advantage in combination, the general aim of diversity techniques is often to improve signal quality without requiring complex modifications at the receiver beyond standard MIMO decoding capabilities. If the unitary matrix (e.g., a Walsh-Hadamard matrix as mentioned in US7949068B2) is applied in a structured way, the receiver could often decode the individual streams without a priori knowledge of complex channel state information or specific decoding algorithms beyond typical MIMO reception. This would be a design choice a PHOSITA would explore.

Specific Claim Elements Rendered Obvious:

• "a transmit processor configured to generate a set of one or more extension data streams based on a set of base data streams" (Claim 1): Taught by US7539463B2, which describes processing input signals ("channel estimation field") to produce "cyclic delayed and combined" versions ("extension data streams").
• "wherein at least one data stream of the set of one or more extension data streams is the product of a matrix multiplication of the set of base data streams with a unitary matrix" (Claim 1): Taught by combining US7539463B2's combining operation with US6801579B1's explicit teaching of using a "unitary space-time code matrix" for transmission. A PHOSITA would understand that the combining operation in US7539463B2 could be implemented via matrix multiplication, and that using a unitary matrix for this purpose, as taught by US6801579B1, would be a beneficial design choice.
• "wherein the transmit processor is communicatively coupled to a set of base antennas and a set of one or more expansion antennas, wherein each base antenna is configured to transmit a corresponding one of the base data streams, and wherein each expansion antenna is configured to transmit a corresponding one of the extension data streams" (Claim 1): US7539463B2 teaches "multiple transmit antennas." The concept of dedicating individual antennas for distinct (original or derived) data streams is fundamental to multi-antenna systems and would be an obvious architectural choice for a PHOSITA maximizing diversity and utilization of available antennas, including the "systematic mapping" described in US7949068B2 where K original streams are sent to K antennas and also processed for N-K extension streams.
• Dependent claims 2, 10, 18 (cyclically-shifted combination): Directly taught by US7539463B2's "cyclic delayed and combined" teaching.
• Dependent claims 3, 5, 11, 13, 19, 21 (order of operations - cyclic shift before combining/combining with cyclically shifted streams): Both orders (cyclic shift then combine, or combine then cyclic shift) are permutations of linear operations that a PHOSITA would routinely consider and explore in signal processing, as described in US7949068B2's FIGS. 5 and 6. The choice between them would be a matter of design and optimization for specific system requirements, without introducing non-obviousness.
• Dependent claims 6, 14, 22 (unitary matrix is Fourier Transform or Walsh matrix): US7949068B2 itself notes that the combining matrix "may be a fast Fourier transform matrix" or have a "Walsh-Hadamard construct." These are well-known examples of unitary matrices used in signal processing and communications for orthogonal transformations and spreading. A PHOSITA, when implementing a unitary matrix function as taught by US6801579B1, would obviously select from such known and advantageous matrix types.
• Dependent claims 7, 8, 15, 16, 24, 25 (quantity of base data streams vs. extension data streams): These relate to the number of input streams K and the number of extension streams N-K. These are design choices for multi-antenna systems, where the ratio of input to output streams is adjusted based on desired diversity gain, data rate, and available antenna elements, as widely understood by a PHOSITA in the field.

Therefore, the claims of US7949068B2 would have been obvious to a PHOSITA based on the combination of US7539463B2, US6801579B1, and the general knowledge prevalent in the field of wireless communications.