Patents by Inventor Prabhakar R. Chitrapu

Prabhakar R. Chitrapu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8116773
    Abstract: Method and apparatus for facilitating high level handoff decisions performed by a gateway device of a personal area network (PAN) which examines criteria regarding both the devices making up the PAN as well as the enterprise networks which are the subject of the potential handoff.
    Type: Grant
    Filed: May 12, 2005
    Date of Patent: February 14, 2012
    Assignee: InterDigital Technology Corporation
    Inventors: Prabhakar R. Chitrapu, Steven Jeffery Goldberg
  • Patent number: 8086228
    Abstract: A method and apparatus for identifying a code group representative of a predetermined number of base stations is disclosed. A chip offset within a frame is input into a first correlator. A plurality of samples of chips at which a primary synchronization code (PSC) has been detected are input into the first correlator. Output of the first correlator is multiplied by the complex conjugate of the PSC to obtain a magnitude for the signals being transmitted at the chips inputted into the first correlator. The magnitude is summed over four frames. The summed signals view of a predetermined set of decision variables is evaluated. A case number, a code group, a timeslot location, and a system frame number are determined based on the evaluation and noise estimation.
    Type: Grant
    Filed: October 27, 2008
    Date of Patent: December 27, 2011
    Assignee: InterDigital Technology Corporation
    Inventors: Alpaslan Demir, Donald M. Grieco, John W. Haim, Andrew F. Bednarz, Phillip J. Pietraski, Louis J. Guccione, Prabhakar R. Chitrapu
  • Publication number: 20110252111
    Abstract: A device and method for registering devices on advanced networks as well as providing operative communications between a legacy device and a advanced network. The legacy device may contain data, such as sensor data, which is being collected on a network outside the communication range/abilities of the legacy device. An intermediary device may receive the data via a first communication scheme and send the device to a server collecting the data via a second communication scheme.
    Type: Application
    Filed: January 7, 2011
    Publication date: October 13, 2011
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Joseph M. Murray, Jean-Louis Gauvreau, Rocco DiGirolamo, Kenneth F. Lynch, Prabhakar R. Chitrapu, Scott C. Hergenhan, Robert A. DiFazio
  • Publication number: 20110252241
    Abstract: A method for reducing overhead when transmitting and receiving an Internet Protocol (IP) packet by a device begins with receiving of the IP packet by the device. In the packet, an IP address of the packet has been removed and replaced with a watermarking signature based on the IP address. The IP address is obtained using the watermarking signature. The IP address is attached to the packet and the packet is forwarded by the device to a destination over a network using the IP address.
    Type: Application
    Filed: June 23, 2011
    Publication date: October 13, 2011
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Guodong Zhang, Prabhakar R. Chitrapu
  • Patent number: 8036325
    Abstract: A method and apparatus for cancelling interference in received signals are disclosed. A receiver includes a knowledge-based interference cancellation unit, a blind interference cancellation unit and a trade-off management unit. The knowledge-based interference cancellation unit cancels interference in the received signals based on pre-known knowledge and the blind interference cancellation unit cancels interference in the received signals without the pre-known knowledge. The trade-off management unit determines a trade-off between knowledge-based interference cancellation and blind interference cancellation, whereby at least one of the knowledge-based interference cancellation and the blind interference cancellation is selectively preformed based on the trade-off. The interference cancellation may be performed by implementing at least one of a successive interference cancellation (SIC), a principal component analysis (PCA) and an independent component analysis (ICA).
    Type: Grant
    Filed: September 13, 2006
    Date of Patent: October 11, 2011
    Assignee: Interdigital Technology Corporation
    Inventors: Prabhakar R. Chitrapu, Steven Jeffrey Goldberg
  • Publication number: 20110228750
    Abstract: The implementation of Local IP Access (LIPA), “Extended” LIPA (ELIPA), and Selected IP Traffic Offload (SIPTO) for the design of a “Converged Gateway” (CGW) are disclosed. The gateway system may provide various features such as femtocell access to local networks, public Internet, and private service provider networks.
    Type: Application
    Filed: December 3, 2010
    Publication date: September 22, 2011
    Applicant: InterDigital Patent Holdings, Inc.
    Inventors: John L. Tomici, John Cartmell, Prabhakar R. Chitrapu, Rocco Di Girolamo, Jean-Louis Gauvreau, Aravind Kamarajugadda, Chunxuan Ye, Kushanava Laha, Reeteshkumar Varshney, Nicholas J. Podias, Arty Chandra, Alpaslan Y. Demir, Martino Freda, Scott C. Hergenhan, Dale N. Seed, Michael F. Starsinic, Anthmane Touaq, Onkarnath Upadhyay, Paul Russell
  • Publication number: 20110216727
    Abstract: A method for using orthogonal sub-channels (OSCs) in a wireless transmit/receive unit (WTRU). A capability report is received from the WTRU, including an indication whether the WTRU supports OSCs. A determination is made whether to use OSCs for the WTRU and the result of the determination is signaled to the WTRU. If OSCs are used with the WTRU, the signaling includes an OSC assignment for the WTRU. In one embodiment, two resources are assigned to the WTRU and each resource is assigned to a different OSC.
    Type: Application
    Filed: May 16, 2011
    Publication date: September 8, 2011
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Prabhakar R. Chitrapu, Behrouz Aghili, Marian Rudolf, Stephen G. Dick
  • Patent number: 7987369
    Abstract: A method for reducing overhead when transmitting an Internet Protocol (IP) packet begins by selecting a watermarking signature based on the IP address of the packet. The watermarking signature is applied to the packet and the IP address is removed from the packet. The packet is sent to a receiver, which looks up the IP address of the packet by using the watermarking signature. The watermarking signature can be a radio frequency watermarking signature or a digital watermarking signature. A similar method employing watermarking can be used to reduce medium access control header overhead.
    Type: Grant
    Filed: April 26, 2005
    Date of Patent: July 26, 2011
    Assignee: InterDigital Technology Corporation
    Inventors: Guodong Zhang, Prabhakar R. Chitrapu
  • Publication number: 20110170488
    Abstract: A method and apparatus of providing a piggybacked positive acknowledgement/negative acknowledgement (ACK/NACK) (PAN) field indicator (PANI) and a polling indicator are disclosed. A combined field of a PANI bit, a relative reserved block period (RRBP) bit and an EGPRS supplementary polling (ES/P) field may indicate a polling scheme and a presence of a PAN field. Alternatively, the presence of the PAN field in the data block may be indicated by using a specific training sequence. Alternatively, a forward error correction (FEC) coding may be performed on the data block including the header, and the presence of the PAN field may be indicated by scrambling the encoded bits corresponding the header with a specific scrambling sequence. Alternatively, a header check sequence (HCS) may be generated and the presence of the PAN field is indicated by mixing a predetermined sequence with the HCS.
    Type: Application
    Filed: March 21, 2011
    Publication date: July 14, 2011
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Prabhakar R. Chitrapu, Behrouz Aghili, Marian Rudolf, Stephen G. Dick
  • Publication number: 20110161673
    Abstract: The present invention is related to a method and apparatus for enhancing security of communications. The apparatus comprises a security processing unit, a data processing unit, a cross-layer watermarking unit, and optionally a smart antenna processor. The security processing unit generates a token/key to be used in watermarking and sends a node security policy to other components. The data processing unit generates user data. The cross-layer watermarking unit includes at least one of Layer-2/3, Layer-1 and Layer-0. Each layer performs a different scheme or degree of watermarking. The cross-layer watermarking unit embeds the token/key into the user data transmission on at least one of the layers selectively in accordance with a security policy.
    Type: Application
    Filed: March 8, 2011
    Publication date: June 30, 2011
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Sung-Hyuk Shin, Alexander Reznik, Guodong Zhang, Prabhakar R. Chitrapu
  • Patent number: 7944884
    Abstract: A method for using orthogonal sub-channels (OSCs) in a wireless transmit/receive unit (WTRU). A capability report is received from the WTRU, including an indication whether the WTRU supports OSCs. A determination is made whether to use OSCs for the WTRU and the result of the determination is signaled to the WTRU. If OSCs are used with the WTRU, the signaling includes an OSC assignment for the WTRU. In one embodiment, two resources are assigned to the WTRU and each resource is assigned to a different OSC.
    Type: Grant
    Filed: October 24, 2008
    Date of Patent: May 17, 2011
    Assignee: InterDigital Patent Holdings, Inc.
    Inventors: Prabhakar R. Chitrapu, Behrouz Aghili, Marian Rudolf, Stephen G. Dick
  • Patent number: 7929409
    Abstract: A method and apparatus for protecting and authenticating wirelessly transmitted digital information using numerous techniques. The apparatus may be a wireless orthogonal frequency division multiplexing (OFDM) communication system, a base station, a wireless transmit/receive unit (WTRU), a transmitter, a receiver and/or an integrated circuit (IC). The wireless OFDM communication system includes a transmitter which steganographically embeds digital information in an OFDM communication signal and wirelessly transmits the OFDM communication signal. The system further includes a receiver which receives the OFDM communication signal and extracts the steganographically embedded digital information from the received OFDM communication signal.
    Type: Grant
    Filed: January 13, 2005
    Date of Patent: April 19, 2011
    Assignee: InterDigital Technology Corporation
    Inventors: Prabhakar R. Chitrapu, John David Kaewell, Jr., Robert Lind Olesen, Sung-Hyuk Shin, John Erich Hoffmann, Richard Dan Herschaft
  • Patent number: 7912093
    Abstract: A method and apparatus of providing a piggybacked positive acknowledgement/negative acknowledgement (ACK/NACK) (PAN) field indicator (PANI) and a polling indicator are disclosed. A combined field of a PANI bit, a relative reserved block period (RRBP) bit and an EGPRS supplementary polling (ES/P) field may indicate a polling scheme and a presence of a PAN field. Alternatively, the presence of the PAN field in the data block may be indicated by using a specific training sequence. Alternatively, a forward error correction (FEC) coding may be performed on the data block including the header, and the presence of the PAN field may be indicated by scrambling the encoded bits corresponding the header with a specific scrambling sequence. Alternatively, a header check sequence (HCS) may be generated and the presence of the PAN field is indicated by mixing a predetermined sequence with the HCS.
    Type: Grant
    Filed: May 7, 2008
    Date of Patent: March 22, 2011
    Assignee: InterDigital Technology Corporation
    Inventors: Prabhakar R. Chitrapu, Aghili Behrouz, Marian Rudolf, Stephen G. Dick
  • Patent number: 7904723
    Abstract: The present invention is related to a method and apparatus for enhancing security of communications. The apparatus comprises a security processing unit, a data processing unit, a cross-layer watermarking unit, and optionally a smart antenna processor. The security processing unit generates a token/key to be used in watermarking and sends a node security policy to other components. The data processing unit generates user data. The cross-layer watermarking unit includes at least one of Layer-2/3, Layer-1 and Layer-0. Each layer performs a different scheme or degree of watermarking. The cross-layer watermarking unit embeds the token/key into the user data transmission on at least one of the layers selectively in accordance with a security policy.
    Type: Grant
    Filed: July 29, 2005
    Date of Patent: March 8, 2011
    Assignee: InterDigital Technology Corporation
    Inventors: Sung-Hyuk Shin, Alexander Reznik, Guodong Zhang, Prabhakar R. Chitrapu
  • Publication number: 20100318796
    Abstract: A method for transmitting an encrypted signal to a wireless transmit/receive unit (WTRU) such that decryption of the encrypted signal depends on a trust zone associated with the WTRU is disclosed. The encryption may be performed using hierarchical modulation, scrambling, authentication, location validation, or a combination thereof. The size of a trust zone may also be adjusted.
    Type: Application
    Filed: December 29, 2009
    Publication date: December 16, 2010
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Alexander Reznik, Alan Gerald Carlton, Alain Charles Louis Briancon, Yogendra Shah, Prabhakar R. Chitrapu
  • Publication number: 20100315989
    Abstract: A method and apparatus for cooperative relaying in wireless communications is provided. An efficient and simplified relay scheme is disclosed that transitions between different modes on a per packet basis using scheduling information or switching information included in the packet, without requiring link reconfiguration. The cooperative relay scheme benefits further from the use of cooperative relaying protocols that emphasize centralized scheduling. One protocol emphasizes physical layer cooperation via synchronized transmissions and distributed space-time coding and the other protocol emphasizes medium access control (MAC) layer cooperation using different MAC flows or messages.
    Type: Application
    Filed: July 7, 2009
    Publication date: December 16, 2010
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Alexander Reznik, Eldad M. Zeira, Mihaela C. Beluri, Sana Sfar, Zinan Lin, Mohammed Sammour, Prabhakar R. Chitrapu
  • Publication number: 20100296431
    Abstract: Methods and apparatus are described for performing automatic repeat request (ARQ) and hybrid-ARQ (HARQ) assisted ARQ procedures in a relay-based wireless communication system. Triggers for radio link control (RLC)/ARQ retransmissions and RLC/ARQ status reporting are also described.
    Type: Application
    Filed: August 10, 2009
    Publication date: November 25, 2010
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Stephen E. Terry, Prabhakar R. Chitrapu, Mohammed Sammour
  • Patent number: 7802171
    Abstract: A wireless communication method and system for performing bit-interleaved coded modulation and iterative decoding. The system includes a transmitter and a receiver. The transmitter encodes incoming bits to generate coded bits, punctures the coded bits in accordance with a predetermined puncturing pattern to generate surviving channel bits and stolen bits and interleaves the surviving bits into interleaved surviving bits. The interleaved surviving bits are mapped to channel symbols and the stolen bits are interleaved to generate interleaved stolen bits. At least one of a plurality of antennas is selected to transmit the channel symbols based on the value of the interleaved stolen bits. The receiver receives the transmitted channel symbols, estimates a posteriori probability for both the channel symbols and the stolen bits, and retrieves information of the stolen bits by determining the selected antenna used to transmit the channel symbols.
    Type: Grant
    Filed: December 28, 2006
    Date of Patent: September 21, 2010
    Assignee: InterDigital Technology Corporation
    Inventors: Yingxue Li, Prabhakar R. Chitrapu
  • Patent number: 7782834
    Abstract: Internet protocol version 6 (IPv6) is substantially utilized throughout the entire cellular network and employs routing headers of the packets to ensure that the packets are routed via the gateway router (GR) to the end destination which is accomplished by a user equipment (UE) specifying the IP address of the gateway router as the IP address of an intermediate router in the routing header. Packets may also be routed to UEs from the GR through an intermediate router.
    Type: Grant
    Filed: May 3, 2006
    Date of Patent: August 24, 2010
    Assignee: InterDigital Technology Corporation
    Inventor: Prabhakar R. Chitrapu
  • Publication number: 20100162379
    Abstract: A method and apparatus for mitigating unwanted communication are disclosed. A request to establish communications is received at a first Protection Against Unsolicited Communications in Internet Protocol Multimedia Subsystem (PUC) server. The PUC server determines whether to block the communication. If the communication is blocked, the sender is informed and a record of the blocked communication may be stored. Alternatively, the communication may be delivered to a subsequent PUC server (along with appended information about the sender), the receiver or sent to storage.
    Type: Application
    Filed: November 30, 2009
    Publication date: June 24, 2010
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Steven J. Goldberg, Kamel M. Shaheen, Prabhakar R. Chitrapu