Prior art

As a technical patent analyst, I have analyzed US Patent 9,001,774B2 (hereafter '774 patent) and its cited prior art references. The priority date for the '774 patent is April 21, 2005.

The '774 patent describes a system and method for channel estimation in a delay diversity wireless communication system, particularly in OFDM/OFDMA networks. Key aspects include:

• Receiving uplink signals to determine processing parameters (time delay, phase rotation, gain) for downlink transmissions from multiple antenna ports (Claim 1, 6).
• Processing data symbols based on these parameters (Claim 1).
• Transmitting pilots, which may or may not be processed by these parameters (Claim 2, 7).
• Demodulating data symbols using the processing parameters and pilots, which may involve channel estimation (Claim 6, 10).
• Determination of parameters on a user-by-user basis (Claim 3, 8).
• Time delay in time domain, phase rotation in frequency domain (Claim 4, 9).

Below is an analysis of the most relevant prior art cited within the '774 patent, focusing on those published before the '774 patent's priority date of April 21, 2005. The brief descriptions are primarily based on the titles and general context provided in the '774 patent, as full texts of the cited patents were not provided for a deeper analysis. Potential anticipation under 35 U.S.C. § 102 is indicated where conceptual overlap is apparent.

Relevant Prior Art Analysis

1. EP0807989A1

• Full Citation: EP0807989A1, "Devices for transmitter path weights and methods therefor," Motorola Ltd.
• Publication Date: November 19, 1997 (Pre-dates '774 priority date)
• Brief Description: The patent generally describes devices and methods for weighting transmitter paths. While the details of the weighting are not specified in the '774 patent's provided text, "path weights" could imply gain adjustments.
• Potential Anticipation (35 U.S.C. § 102):
  • Claims 1, 6: The concept of applying "gain" as a processing parameter (Claim 1) or receiving a processing parameter including gain (Claim 6) could potentially be anticipated, depending on the specifics of how "path weights" are determined and applied.

2. US6219334B1

• Full Citation: US6219334B1, "Receiving apparatus for receiving orthogonal frequency division multiplexing signal and receiving method thereof," Kabushiki Kaisha Toshiba.
• Publication Date: April 17, 2001 (Pre-dates '774 priority date)
• Brief Description: This patent pertains to a receiving apparatus and method for OFDM signals, suggesting a focus on receiver-side processing for OFDM communication.
• Potential Anticipation (35 U.S.C. § 102):
  • Claims 6, 10: The general concept of receiving and demodulating OFDM data, particularly with channel estimation for an OFDM system, could be broadly anticipated by a receiving apparatus for OFDM signals. However, the specific "processing parameter" aspect of the '774 patent's claims would require detailed comparison.

3. EP1185048A2

• Full Citation: EP1185048A2, "Preamble design for multicarrier transmission over channels with multiple inputs and outputs," Nortel Networks Limited.
• Publication Date: March 6, 2002 (Pre-dates '774 priority date)
• Brief Description: This patent addresses the design of preambles for multicarrier (e.g., OFDM) transmission in MIMO systems. Preambles are often used for channel estimation and synchronization.
• Potential Anticipation (35 U.S.C. § 102):
  • Claims 1, 5: If the preamble design implicitly allows for determination of channel characteristics that could lead to processing parameters like delays or gains, or if the uplink signal in claim 5 (which includes preamble) is used for similar purposes.
  • Claim 6: The reception of pilots (which can be part of preambles) for channel estimation.

4. EP1185001A2

• Full Citation: EP1185001A2, "Adaptive time diversity and spatial diversity for OFDM," Nortel Networks Limited.
• Publication Date: March 6, 2002 (Pre-dates '774 priority date)
• Brief Description: This patent covers adaptive time and spatial diversity techniques for OFDM. Spatial diversity typically involves multiple transmit antennas, and time diversity can involve delays. This strongly aligns with the core concept of "delay diversity" in the '774 patent.
• Potential Anticipation (35 U.S.C. § 102):
  • Claims 1, 2, 3, 4, 6, 7, 8, 9: The broad concepts of using time delays and spatial diversity (multiple antennas) in an OFDM system to achieve diversity. If "adaptive" implies selection based on channel conditions, it could potentially anticipate the "determining a processing parameter" (Claim 1) and "user-by-user basis" (Claim 3) aspects, as well as the use of delays and phase rotations (Claim 4). The '774 patent specifically mentions "delayed diversity wireless network was disclosed previously U.S. patent application Ser. No. 11/327,799," which itself mentions "multiple copies of the same OFDM symbol are delayed by different delay values." The EP1185001A2's title directly mentions "time diversity," strongly suggesting delay use.

5. EP1359684A1

• Full Citation: EP1359684A1, "Wireless transmission using an adaptive transmit antenna array," Motorola Energy Systems Inc.
• Publication Date: November 5, 2003 (Pre-dates '774 priority date)
• Brief Description: This patent relates to wireless transmission using adaptive transmit antenna arrays. Adaptive arrays often adjust transmission characteristics (like gains, phases) based on channel conditions.
• Potential Anticipation (35 U.S.C. § 102):
  • Claims 1, 3, 4, 6, 8, 9: Similar to EP1185001A2, "adaptive" implies channel-dependent adjustments. The use of "transmit antenna array" directly relates to using multiple antenna ports. If "adaptive" includes adjusting gains and delays/phase rotations, it could potentially anticipate many aspects of parameter determination and application.

6. US20040086055A1

• Full Citation: US20040086055A1, "Pilot-aided channel estimation for OFDM in wireless systems," Ye Li.
• Publication Date: May 6, 2004 (Pre-dates '774 priority date)
• Brief Description: This publication focuses on channel estimation techniques using pilot signals specifically for OFDM wireless systems.
• Potential Anticipation (35 U.S.C. § 102):
  • Claims 1, 6, 10: The fundamental concept of using pilot signals for channel estimation in OFDM, which is a key part of the '774 patent's methods. The determination of "processing parameters based on the received uplink signal" (Claim 1) or "demodulating ... based on the processing parameter, the first pilot and the second pilot" (Claim 6) with "estimating a channel using the first pilot, the second pilot" (Claim 10) are directly addressed.

7. US20040110510A1

• Full Citation: US20040110510A1, "Apparatus and method for channel quality estimation and link adaptation in orthogonal frequency division multiplexing (OFDM) wireless communication system," Taehyun Jeon.
• Publication Date: June 10, 2004 (Pre-dates '774 priority date)
• Brief Description: This patent application describes methods and apparatus for channel quality estimation and link adaptation in OFDM systems. Channel quality estimation often informs transmission parameters.
• Potential Anticipation (35 U.S.C. § 102):
  • Claims 1, 6, 10: The concept of estimating channel quality (which is a form of channel estimation) and using it for link adaptation could broadly encompass determining processing parameters (like gains/delays for better link) and using channel estimates for demodulation.

8. US20040131011A1

• Full Citation: US20040131011A1, "Transmission signals, method and apparatus," Kabushiki Kaisha Toshiba.
• Publication Date: July 8, 2004 (Pre-dates '774 priority date)
• Brief Description: This reference generally discusses transmission signals, methods, and apparatus, but without further detail, it's hard to assess specific overlap.
• Potential Anticipation (35 U.S.C. § 102): A detailed analysis would require the full text. Based solely on the title, broad aspects of "transmitting a first pilot and a second pilot; and transmitting a first data symbol and a second data symbol on two antenna ports" (Claim 1) or "receiving a first pilot, a second pilot, a first data symbol and a second data symbol transmitted on the two antenna ports" (Claim 6) could be related.

9. US20040156328A1

• Full Citation: US20040156328A1, "Random access for wireless multiple-access communication systems," Walton J. Rodney.
• Publication Date: August 12, 2004 (Pre-dates '774 priority date)
• Brief Description: This patent application focuses on random access procedures in wireless multiple-access communication systems.
• Potential Anticipation (35 U.S.C. § 102): Less direct relevance to channel estimation and delay diversity processing, but uplink signals (Claim 1, 5, 6) could be related to random access. Unlikely to anticipate the core aspects of parameter determination and application.

10. EP1453223A1

• Full Citation: EP1453223A1, "Transmission diversity communication device," Fujitsu Limited.
• Publication Date: September 1, 2004 (Pre-dates '774 priority date)
• Brief Description: This patent describes a "transmission diversity communication device," which directly relates to the diversity aspects of the '774 patent, likely involving multiple antennas.
• Potential Anticipation (35 U.S.C. § 102):
  • Claims 1, 6: The fundamental concept of transmit diversity using multiple antenna ports for data transmission. The specific nature of the "processing parameters" (delays, gains, phase rotations) would require more detailed comparison with the EP patent.

11. US20040248527A1

• Full Citation: US20040248527A1, "Device and method for compensating for phase distortion in base station of OFDMA-based cellular system," Youn-Ok Park.
• Publication Date: December 9, 2004 (Pre-dates '774 priority date)
• Brief Description: This patent application focuses on compensating for phase distortion in OFDMA base stations. "Phase rotation" is explicitly mentioned as a processing parameter in the '774 patent (Claims 1, 6).
• Potential Anticipation (35 U.S.C. § 102):
  • Claims 1, 4, 6, 9: The use of "phase rotation" as a processing parameter, especially if determined based on channel characteristics. This seems highly relevant to claims 4 and 9 of the '774 patent.

12. US6842487B1

• Full Citation: US6842487B1, "Cyclic delay diversity for mitigating intersymbol interference in OFDM systems," Telefonaktiebolaget Lm Ericsson (Publ).
• Publication Date: January 11, 2005 (Pre-dates '774 priority date)
• Brief Description: This patent explicitly teaches "cyclic delay diversity for mitigating intersymbol interference in OFDM systems." This is highly relevant as the '774 patent states, "In an advantageous embodiment, the delays introduced by OFDM symbol processing block 230 are cyclic delays, as disclosed in U.S. patent application Ser. No. 11/327,799."
• Potential Anticipation (35 U.S.C. § 102):
  • Claims 1, 4, 6, 9: The core concept of introducing time delays (specifically cyclic delays) for diversity in OFDM systems using multiple antennas (implied by diversity). This directly addresses the "time delay" and potentially "phase rotation" aspects (as time delay translates to phase rotation in frequency domain per the '774 patent).

13. US20050163263A1

• Full Citation: US20050163263A1, "Systems and methods for frequency acquisition in a wireless communication network," Gupta Alok K.
• Publication Date: July 28, 2005 (Post-dates '774 priority date, not prior art for 102(a))
• Brief Description: This patent relates to frequency acquisition.
• Prior Art Status: Not prior art under 35 U.S.C. § 102 for the '774 patent's priority date.

14. US20050176436A1

• Full Citation: US20050176436A1, "Channel estimation for a wireless communication system with multiple parallel data streams," Ashok Mantravadi.
• Publication Date: August 11, 2005 (Post-dates '774 priority date, not prior art for 102(a))
• Brief Description: This patent describes channel estimation in systems with multiple parallel data streams, common in MIMO.
• Prior Art Status: Not prior art under 35 U.S.C. § 102 for the '774 patent's priority date.

15. US20050201268A1

• Full Citation: US20050201268A1, "OFDM signal transmission method and apparatus," Tsuguhide Aoki.
• Publication Date: September 15, 2005 (Post-dates '774 priority date, not prior art for 102(a))
• Brief Description: This relates to OFDM signal transmission methods and apparatus.
• Prior Art Status: Not prior art under 35 U.S.C. § 102 for the '774 patent's priority date.

16. US20050265477A1

• Full Citation: US20050265477A1, "Wireless transmission method and wireless transmitter having a plurality of antennas," Kabushiki Kaisha Toshiba.
• Publication Date: December 1, 2005 (Post-dates '774 priority date, not prior art for 102(a))
• Brief Description: This describes a wireless transmission method and transmitter with multiple antennas.
• Prior Art Status: Not prior art under 35 U.S.C. § 102 for the '774 patent's priority date.

17. US6982670B2

• Full Citation: US6982670B2, "Phase management for beam-forming applications," Farrokh Mohamadi.
• Publication Date: January 3, 2006 (Post-dates '774 priority date, not prior art for 102(a))
• Brief Description: This patent discusses phase management in beamforming.
• Prior Art Status: Not prior art under 35 U.S.C. § 102 for the '774 patent's priority date.

18. US20060034163A1

• Full Citation: US20060034163A1, "Pilot transmission schemes for a multi-antenna system," Gore Dhananjay A.
• Publication Date: February 16, 2006 (Post-dates '774 priority date, not prior art for 102(a))
• Brief Description: This describes pilot transmission schemes for multi-antenna systems.
• Prior Art Status: Not prior art under 35 U.S.C. § 102 for the '774 patent's priority date.

19. US7003415B2

• Full Citation: US7003415B2, "Delay profile estimation apparatus and a correlating unit," Fujitsu Limited.
• Publication Date: February 21, 2006 (Post-dates '774 priority date, not prior art for 102(a))
• Brief Description: This patent relates to delay profile estimation, which is relevant for understanding multipath channels.
• Prior Art Status: Not prior art under 35 U.S.C. § 102 for the '774 patent's priority date.

20. US20060045200A1

• Full Citation: US20060045200A1, "Signal receiving method in MIMO system and device therefor," Wladimir Bocquet.
• Publication Date: March 2, 2006 (Post-dates '774 priority date, not prior art for 102(a))
• Brief Description: This describes a signal receiving method in MIMO systems.
• Prior Art Status: Not prior art under 35 U.S.C. § 102 for the '774 patent's priority date.

21. US7082159B2

• Full Citation: US7082159B2, "Methods and arrangements in a telecommunications system," Telefonaktiebolaget Lm Ericsson (Publ).
• Publication Date: July 25, 2006 (Post-dates '774 priority date, not prior art for 102(a))
• Brief Description: General methods and arrangements in telecommunication systems.
• Prior Art Status: Not prior art under 35 U.S.C. § 102 for the '774 patent's priority date.

22. US7206554B1

• Full Citation: US7206554B1, "Transmit diversity with formed beams in a wireless communications system using a common pilot channel," Arraycomm Llc.
• Publication Date: April 17, 2007 (Post-dates '774 priority date, not prior art for 102(a))
• Brief Description: This patent relates to transmit diversity with formed beams using a common pilot channel.
• Prior Art Status: Not prior art under 35 U.S.C. § 102 for the '774 patent's priority date.

23. US7251291B1

• Full Citation: US7251291B1, "System and method for I/Q imbalance compensation," Nortel Networks Limited.
• Publication Date: July 31, 2007 (Post-dates '774 priority date, not prior art for 102(a))
• Brief Description: This patent addresses I/Q imbalance compensation.
• Prior Art Status: Not prior art under 35 U.S.C. § 102 for the '774 patent's priority date.

24. US20070281624A1

• Full Citation: US20070281624A1, "Method and apparatus for channel feedback," Motorola, Inc.
• Publication Date: December 6, 2007 (Post-dates '774 priority date, not prior art for 102(a))
• Brief Description: This describes methods and apparatus for channel feedback, which could relate to transmitting processing parameters back to the base station.
• Prior Art Status: Not prior art under 35 U.S.C. § 102 for the '774 patent's priority date.

25. US7428267B2

• Full Citation: US7428267B2, "Uplink channel estimation system for orthogonal frequency division multiple access system and method thereof," Electronics And Telecommunications Research Institute.
• Publication Date: September 23, 2008 (Post-dates '774 priority date, not prior art for 102(a))
• Brief Description: This patent covers uplink channel estimation in OFDMA systems.
• Prior Art Status: Not prior art under 35 U.S.C. § 102 for the '774 patent's priority date.

26. US7453793B1

• Full Citation: US7453793B1, "Channel estimation for OFDM communication systems including IEEE 802.11A and extended rate systems," Qualcomm Incorporated.
• Publication Date: November 18, 2008 (Post-dates '774 priority date, not prior art for 102(a))
• Brief Description: This patent addresses channel estimation for OFDM communication systems, including IEEE 802.11A.
• Prior Art Status: Not prior art under 35 U.S.C. § 102 for the '774 patent's priority date.

Most Relevant Prior Art Summary

Based on the titles and their direct relevance to the claims of US9001774B2 and its disclosed "delay diversity" and "channel estimation" concepts, the following references appear to be most relevant for potential anticipation under 35 U.S.C. § 102:

• EP1185001A2 ("Adaptive time diversity and spatial diversity for OFDM"): Directly addresses "time diversity" and "spatial diversity" in OFDM, which are foundational to the '774 patent's delay diversity approach.
• US6842487B1 ("Cyclic delay diversity for mitigating intersymbol interference in OFDM systems"): Explicitly mentions "cyclic delay diversity" in OFDM, a specific implementation detailed in the '774 patent. This is highly relevant to claims involving time delays and phase rotations.
• US20040086055A1 ("Pilot-aided channel estimation for OFDM in wireless systems"): Directly focuses on using pilots for channel estimation in OFDM, a central theme of the '774 patent's claims for both determining processing parameters and demodulation.
• EP1359684A1 ("Wireless transmission using an adaptive transmit antenna array"): Discusses adaptive transmission from antenna arrays, potentially covering the determination and application of gains and phase/delay adjustments from multiple antennas.
• US20040248527A1 ("Device and method for compensating for phase distortion in base station of OFDMA-based cellular system"): Addresses phase distortion compensation, which aligns with the "phase rotation" processing parameter in the '774 patent.

These references collectively touch upon multiple antennas, diversity through delays, adaptive transmission, and pilot-aided channel estimation in OFDM/OFDMA systems, which are key elements of the '774 patent's claims. A definitive determination of anticipation would require a full review of the specifications and claims of each cited patent.