Prior art

As a technical patent analyst, I have searched the USPTO database for patent number 8139544. The following prior art patents were cited in US8139544B1. For each reference, I provide a full citation, publication/filing date, a brief description, and which claim(s) it potentially anticipates under 35 U.S.C. § 102.

Most Relevant Prior Art for US Patent 8139544:

The following patents are considered prior art based on their citation within US Patent 8139544.

1. US6445425B1

• Full Citation: US6445425B1, "Automatic fine tuning of receiver for digital television signals"
• Publication Date: 2002-09-03
• Filing Date: 1997-01-07
• Brief Description: This patent describes a receiver for digital television signals that includes a frequency offset estimator and a symbol timing estimator to perform automatic fine tuning. It focuses on recovering and synchronizing signals in a digital broadcasting environment.
• Potentially Anticipates: Claims related to clock recovery and synchronization (e.g., portions of the method in Claim 1 involving signal reception and initial processing, and the system in Claim 15 configured for such reception).

2. US20020191535A1

• Full Citation: US20020191535A1, "OFDM signal communication system, OFDM signal transmitting device and OFDM signal receiving device"
• Publication Date: 2002-12-19
• Filing Date: 2001-04-09
• Brief Description: This patent describes an OFDM communication system that addresses issues like frequency synchronization and channel estimation. It focuses on using known pilot signals to perform channel estimation and equalization in OFDM systems.
• Potentially Anticipates: Claims 1 and 15, particularly concerning the receiving of OFDM signals, channel estimation, and the use of pilot subcarriers for processing.

3. US20030012308A1

• Full Citation: US20030012308A1, "Adaptive channel estimation for wireless systems"
• Publication Date: 2003-01-16
• Filing Date: 2001-06-13
• Brief Description: This patent discloses methods and apparatus for adaptive channel estimation in wireless communication systems, aiming to improve the accuracy of channel estimates in varying channel conditions.
• Potentially Anticipates: Claims 1 and 15, specifically the aspects related to channel estimation for the communication paths.

4. US20030058787A1

• Full Citation: US20030058787A1, "Method and apparatus for channel estimation"
• Publication Date: 2003-03-27
• Filing Date: 2001-09-27
• Brief Description: This patent describes a method and apparatus for estimating channel characteristics in a communication system, which involves processing received signals to derive channel estimates.
• Potentially Anticipates: Claims 1 and 15, particularly the "signal separating function is based on a first channel estimate for the first communications path and a second channel estimate for the second communications path" element.

5. US20030114127A1

• Full Citation: US20030114127A1, "Transmit power control for multiple rate wireless communications"
• Publication Date: 2003-06-19
• Filing Date: 2001-12-18
• Brief Description: This patent relates to transmit power control in wireless communication systems that support multiple data rates, focusing on managing transmission power based on channel conditions.
• Potentially Anticipates: While not directly addressing pilot tone separation, it relates to the broader context of managing wireless communication, which could indirectly relate to the environment where the patent's claims operate.

6. US20030128656A1

• Full Citation: US20030128656A1, "Channel estimation and compensation techniques for use in frequency division multiplexed systems"
• Publication Date: 2003-07-10
• Filing Date: 2002-01-07
• Brief Description: This patent describes techniques for channel estimation and compensation in frequency division multiplexed (FDM) systems, which can be relevant to OFDM.
• Potentially Anticipates: Claims 1 and 15, particularly aspects of channel estimation and compensation, which are foundational to separating signals in complex channel environments.

7. US6754195B2

• Full Citation: US6754195B2, "Wireless communication system configured to communicate using a mixed waveform configuration"
• Publication Date: 2004-06-22
• Filing Date: 2001-07-06
• Brief Description: This patent describes a wireless communication system capable of handling different waveform configurations, which could include various signal structures and modulation schemes.
• Potentially Anticipates: While broad, it sets a precedent for flexible communication systems that might employ different signal components, indirectly touching upon the handling of data and pilot subcarriers in varied configurations.

8. US6768714B1

• Full Citation: US6768714B1, "Methods and apparatus for use in obtaining frequency synchronization in an OFDM communication system"
• Publication Date: 2004-07-27
• Filing Date: 1999-06-23
• Brief Description: This patent provides methods and apparatus for achieving frequency synchronization in OFDM communication systems, which is crucial for accurate signal recovery.
• Potentially Anticipates: Claims related to synchronization, clock recovery, and correcting frequency offsets, which are part of the overall signal processing in Claim 1 and 15.

9. US6785341B2

• Full Citation: US6785341B2, "Method and apparatus for processing data in a multiple-input multiple-output (MIMO) communication system utilizing channel state information"
• Publication Date: 2004-08-31
• Filing Date: 2001-05-11
• Brief Description: This patent describes processing data in MIMO systems using channel state information, which is central to the separation of signals from multiple transmit antennas.
• Potentially Anticipates: Claims 1 and 15, particularly the separation of signals based on channel estimates in a multiple-antenna environment, as well as the underlying principles of MIMO data processing.

10. US20050002359A1

• Full Citation: US20050002359A1, "Apparatus, and associated method, for detecting data communicated to a receiving station in a multiple-channel communication system"
• Publication Date: 2005-01-06
• Filing Date: 2003-06-20
• Brief Description: This patent describes an apparatus and method for detecting data in a multiple-channel communication system, which would involve distinguishing signals from different channels.
• Potentially Anticipates: Claims 1 and 15, related to the overall reception and separation of signals in a multi-channel context.

11. US6850481B2

• Full Citation: US6850481B2, "Channels estimation for multiple input—multiple output, orthogonal frequency division multiplexing (OFDM) system"
• Publication Date: 2005-02-01
• Filing Date: 2000-09-01
• Brief Description: This patent focuses on channel estimation for MIMO-OFDM systems, which is a key component for effectively separating signals in such environments.
• Potentially Anticipates: Claims 1 and 15, directly addressing the core concept of channel estimation for MIMO-OFDM systems, which underpins the signal separating function.

12. US6862271B2

• Full Citation: US6862271B2, "Multiple-input, multiple-output (MIMO) systems with multiple transmission modes"
• Publication Date: 2005-03-01
• Filing Date: 2002-02-26
• Brief Description: This patent describes MIMO systems that can operate with various transmission modes, implying flexibility in how signals are sent and received across multiple antennas.
• Potentially Anticipates: Claims 1 and 15, by broadly covering MIMO systems and their operational modes, including how signals from different antennas are managed.

13. US20050157682A1

• Full Citation: US20050157682A1, "Methods and apparatus to control transmission of a multicarrier wireless communication channel through multiple antennas"
• Publication Date: 2005-07-21
• Filing Date: 2003-09-15
• Brief Description: This patent describes methods and apparatus for controlling multicarrier wireless communication channels transmitted through multiple antennas.
• Potentially Anticipates: Claims 1 and 15, particularly in the context of managing signals from multiple transmit antennas in a multicarrier system, which is directly relevant to the reception and separation of such signals.

14. US20050207333A1

• Full Citation: US20050207333A1, "Method and apparatus for an enhanced OFDM system"
• Publication Date: 2005-09-22
• Filing Date: 2004-03-22
• Brief Description: This patent describes enhancements for OFDM systems, which could involve various improvements to signal processing, including handling of subcarriers.
• Potentially Anticipates: Claims 1 and 15, in a general sense, by disclosing methods and systems for improving OFDM performance, which might encompass techniques for processing data and pilot subcarriers.

15. US20060258303A1

• Full Citation: US20060258303A1, "Radio communication apparatus, transmitter apparatus, receiver apparatus and radio communication system"
• Publication Date: 2006-11-16
• Filing Date: 2003-04-21
• Brief Description: This patent describes a radio communication system with transmitter and receiver apparatus, focusing on efficient communication.
• Potentially Anticipates: Broadly, Claims 1 and 15 in their general scope of a receiver device and method for processing signals in a communication system.

16. US20070021130A1

• Full Citation: US20070021130A1, "Multi-carrier radio communication system, transmission device, and reception device"
• Publication Date: 2007-01-25
• Filing Date: 2003-01-29
• Brief Description: This patent describes a multi-carrier radio communication system, including aspects of transmission and reception devices.
• Potentially Anticipates: Broadly, Claims 1 and 15 in their general scope of a receiver device and method for processing signals in a communication system, particularly within a multi-carrier context.

17. US7564917B2

• Full Citation: US7564917B2, "Multicarrier receiver and method for generating common phase error estimates for use in systems that employ two or more transmit antennas with independent local oscillators"
• Publication Date: 2009-07-21
• Filing Date: 2005-11-01
• Brief Description: This patent describes a multicarrier receiver and method for generating common phase error estimates in systems with multiple transmit antennas and independent local oscillators.
• Potentially Anticipates: Claims 6, 7, 18, 19, and 29, relating to correcting phase and jitter distortions, combining pilot subcarriers, and phase-lock looping, especially in systems with independent oscillators, as phase noise correction is a key element.

18. US7848438B2

• Full Citation: US7848438B2, "Method and apparatus for pilot signal transmission"
• Publication Date: 2010-12-07
• Filing Date: 2006-02-14
• Brief Description: This patent describes a method and apparatus for transmitting pilot signals, which is fundamental to systems that use pilot tones for channel estimation and synchronization.
• Potentially Anticipates: Claims 1 and 15, as the receipt and processing of pilot signals is central to their functionality. While the specific separation and combining methods might differ, the concept of pilot signal utilization is present.