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: 7505431
    Abstract: Mobility management in a wireless network having a Radio Access Network Internet Protocol (RAN IP) gateway enabling connectivity to the public Internet is provided. The system may serve as a stand-alone system or be incorporated into a UMTS network with a conventional Core Network for providing concurrent wireless telecommunication services for multiple user equipments.
    Type: Grant
    Filed: December 23, 2002
    Date of Patent: March 17, 2009
    Assignee: InterDigital Technology Corporation
    Inventors: Prabhakar R. Chitrapu, Narayan Parappil Menon, Fatih M. Ozluturk, Shamim Akbar Rahman
  • Publication number: 20090052378
    Abstract: Piggybacked acknowledgement/non-acknowledgement (PAN) bits in unreliable bit positions of a modulated symbol are swapped with data bits located in more reliable bit positions. In addition, a power offset value may be applied to the symbols containing the PAN bits.
    Type: Application
    Filed: August 22, 2008
    Publication date: February 26, 2009
    Applicant: INTERDIGITAL PATENT HOLDINGS, INC.
    Inventors: Behrouz Aghili, Marian Rudolf, Prabhakar R. Chitrapu, Stephen G. Dick
  • Publication number: 20090054094
    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: Application
    Filed: October 27, 2008
    Publication date: February 26, 2009
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Alpaslan Demir, Donald M. Grieco, John W. Haim, Andrew F. Bednarz, Philip J. Pietraski, Louis J. Guccione, Prabhakar R. Chitrapu
  • Patent number: 7489672
    Abstract: Mobility management in a wireless network having a Radio Access Network Internet Protocol (RAN IP) gateway enabling voice connectivity to the public Internet is provided. The system may serve as a stand-alone system or be incorporated into a UMTS network with a conventional Core Network for providing concurrent wireless telecommunication services for multiple user equipments.
    Type: Grant
    Filed: December 23, 2002
    Date of Patent: February 10, 2009
    Assignee: InterDigital Technology Corp.
    Inventors: Prabhakar R. Chitrapu, Narayan Parappil Menon, Fatih M. Ozluturk, Leonid Kazakevich
  • Publication number: 20090022137
    Abstract: A method of operating a wireless transmit receive unit (WTRU) and a WTRU configured to receive a radio link control (RLC)/a medium access control (MAC) header. The header is coded for reduced transmission time interval (RTTI) operation. The header includes a 16-bit cyclic redundancy check (CRC) of an RLC/MAC payload associated with the RLC/MAC header.
    Type: Application
    Filed: June 20, 2008
    Publication date: January 22, 2009
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Behrouz Aghili, Stephen G. Dick, Prabhakar R. Chitrapu, Marian Rudolf
  • Publication number: 20080310388
    Abstract: A method and apparatus for operating a wireless transmit receive unit (WTRU) in basic transmission time interval (BTTI) and reduced transmission time interval (RTTI) mode includes a WTRU in RTTI mode and a WTRU in BTTI mode receiving a plurality of coded radio blocks, the WTRU in RTTI mode decoding all of the plurality of coded radio blocks and the WTRU is in BTTI mode decoding a portion of the plurality of coded radio blocks.
    Type: Application
    Filed: June 12, 2008
    Publication date: December 18, 2008
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Behrouz Aghili, Marian Rudolf, Stephen G. Dick, Prabhakar R. Chitrapu
  • Publication number: 20080307284
    Abstract: A method and apparatus for indicating a temporary block flow (TBF) to which a piggybacked acknowledgement/non-acknowledgement (PAN) field is addressed are disclosed. A sequence may be generated from a temporary flow identity (TFI) to which the PAN field is addressed and masked with a PAN check sequence (PCS). A radio block including a PAN field and a masked PCS is transmitted. The PCS may be masked with one of TFIs which is selected in accordance with a rule pre-agreed. A secondary identifier may indicate a TBF to which the PAN field is addressed. A special value may be used to represent all TBFs assigned and a secondary identifier may indicate a TBF to which the PAN field is addressed. A special value on the PAN field may be used for control purposes for indicating an action affecting a group of receiving stations listening to the radio block.
    Type: Application
    Filed: June 5, 2008
    Publication date: December 11, 2008
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Behrouz Aghili, Stephen G. Dick, Marian Rudolf, Prabhakar R. Chitrapu
  • Publication number: 20080285506
    Abstract: A method and apparatus for indicating a temporary block flow (TBF) to which a piggybacked acknowledgement/non-acknowledgement (PAN) field is addressed. A PAN check sequence (PCS) is created, for example using a cyclic redundancy check (CRC) encoding. The PCS is masked with a temporary flow identity (TFI) assigned to a TBF or a mask generated based on the TFI. A data block including the PAN field and the masked PCS is then processed for transmission. The mask may be generated by converting the TFI using an (M, N) code, M being not greater than the number of bits of the PCS and N being the number of bits of the TFI. With this scheme, a TFI may be transmitted in a PAN field without using explicit bits to identify the TBF.
    Type: Application
    Filed: March 27, 2008
    Publication date: November 20, 2008
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Marian Rudolf, Behrouz Aghili, Prabhakar R. Chitrapu, Stephen G. Dick, Philip J. Pietraski, Yan Li
  • Publication number: 20080279211
    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: May 7, 2008
    Publication date: November 13, 2008
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Prabhakar R. Chitrapu, Aghili Behrouz, Marian Rudolf, Stephen G. Dick
  • Publication number: 20080274698
    Abstract: A method and an apparatus for indicating a temporary block flow (TBF) to which a piggybacked acknowledgement/non-acknowledgement (PAN) field is addressed. A method and apparatus of performing receive processing to reduce the probability of false acceptance of erroneous PANs are also disclosed. A transmit station generates a PAN check sequence (PCS) and performs a channel coding on a PAN field and the PCS. The transmit station scrambles the encoded bits of the PAN field and the PCS with a TBF-specific scrambling code. Because of the scrambling, the PCS decoding at a receive station will pass if the data block is received by an intended receive station, while the PCS decoding will fail if received by a non-intended receive station. Alternatively, the scrambling may be performed before the channel coding. Alternatively, the transmit station may combine the PAN field and a temporary flow identity (TFI) to generate a PCS.
    Type: Application
    Filed: April 18, 2008
    Publication date: November 6, 2008
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Yan Li, Stephen G. Dick, Prabhakar R. Chitrapu, Marian Rudolf, Behrouz Aghili, Khushali N. Manseta
  • Publication number: 20080267114
    Abstract: A wireless communication device is configured as an in-home node-B (H(e)NB). The H(e)NB is configured to perform a locking function to control modification of carrier and user controlled parameters, and also configured to detect a change in location.
    Type: Application
    Filed: April 29, 2008
    Publication date: October 30, 2008
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Rajat P. Mukherjee, Shankar Somasudaram, Ulises Olvera-Hernandez, Yogendra C. Shah, Prabhakar R. Chitrapu, Inhyok Cha
  • Patent number: 7444144
    Abstract: A method and system for performing initial cell search is disclosed. Step 1 processing is preformed to detect a peak primary synchronization code (PSC) location (i.e. chip offset or chip location). Step 2 processing is performed to obtain the toffset and code group. Step 3 processing is performed to identify the midamble of a base station with which the WTRU performing the initial cell search may synchronize with.
    Type: Grant
    Filed: February 5, 2004
    Date of Patent: October 28, 2008
    Assignee: InterDigital Technology Corporation
    Inventors: Alpaslan Demir, Donald M. Grieco, John W. Haim, Andrew F. Bednarz, Philip J. Pietraski, Louis J. Guccione, Prabhakar R. Chitrapu
  • Publication number: 20080240151
    Abstract: A method and apparatus for power control in a wireless communication involves establishing at least two orthogonal sub-channels within a channel for communication and controlling transmitted power in each sub-channel independently.
    Type: Application
    Filed: March 28, 2008
    Publication date: October 2, 2008
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Prabhakar R. Chitrapu, Behrouz Aghili, Stephen G. Dick
  • Patent number: 7415043
    Abstract: A spread spectrum method and apparatus for protecting and authenticating wirelessly transmitted digital information using numerous techniques. The apparatus may be a wireless code division multiple access (CDMA) communication system, a base station, a wireless transmit/receive unit (WTRU), a transmitter, a receiver and/or an integrated circuit (IC). The wireless CDMA communication system includes a transmitter which steganographically embeds digital information in a CDMA communication signal and wirelessly transmits the CDMA communication signal. The system further includes a receiver which receives the CDMA communication signal and extracts the steganographically embedded digital information from the received CDMA communication signal.
    Type: Grant
    Filed: January 13, 2005
    Date of Patent: August 19, 2008
    Assignee: InterDigital Technology Corporation
    Inventors: John David Kaewell, Jr., Prabhakar R. Chitrapu, Robert Lind Olesen, Sung-Hyuk Shin, John Erich Hoffmann, Alexander Reznik
  • Publication number: 20080181097
    Abstract: The invention enhances channel correction techniques for orthogonal frequency division multiplexing (OFDM) systems so that higher effective data rates can be achieved with a minimal processing load. OFDM channel values determined due to known sequences in one domain can be used to seed solution matrices for channel value determination in other domains. This method can be applied to multiple-input multiple-output (MIMO) systems in order to deal with signal distortion while maintaining a reasonable processor loading profile. In another embodiment, a method to optimize channel partitioning during channel estimation processing in an ultra-wide band (UWB) OFDM wireless communications network includes creating a plurality of windows across a time-frequency channel plane, adaptively sizing the plurality of windows, and merging the plurality of windows.
    Type: Application
    Filed: November 12, 2007
    Publication date: July 31, 2008
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Steven J. Goldberg, Inhyok Cha, Prabhakar R. Chitrapu
  • Patent number: 7406068
    Abstract: A Radio Local Area Network (RLAN) includes a Radio Access Network Internet Protocol (RAN IP) gateway that enables connectivity to the public Internet. The system may serve as a stand-alone system or be incorporated into a UMTS used with conventional Core Network, particularly for tracking and implementing AAA functions in the Core Network.
    Type: Grant
    Filed: December 23, 2002
    Date of Patent: July 29, 2008
    Assignee: InterDigital Technology Corporation
    Inventors: Prabhakar R. Chitrapu, Narayan Parappil Menon, Yi-Ju Chao, Shamim Akbar Rahman
  • Patent number: 7395055
    Abstract: A method for controlling the communications of a wireless transmit/receive unit (WTRU) in a wireless network using presence and situation information begins by generating presence and situation information pertaining to the WTRU. The presence and situation data is stored and, subsequently, retrieved upon receipt of a communication at the WTRU. The communication settings of the WTRU are adjusted by using the presence and situation information.
    Type: Grant
    Filed: August 29, 2005
    Date of Patent: July 1, 2008
    Assignee: InterDigital Technology Corporation
    Inventors: Prabhakar R. Chitrapu, John David Kaewell, Jr.
  • Patent number: 7394795
    Abstract: The present invention provides a Radio Local Area Network (RLAN) that includes a Radio Access Network Internet Protocol (RAN IP) gateway that enables connectivity to the Internet. The RAN IP gateway is configured to use predetermined interfaces to couple with Radio Network Controllers (RNCs) and base stations to provide an IP connection to the Internet for user equipment.
    Type: Grant
    Filed: December 23, 2002
    Date of Patent: July 1, 2008
    Assignee: InterDigital Technology Corporation
    Inventors: Prabhakar R. Chitrapu, Narayan Parappil Menon, Fatih M. Ozluturk, Brian Gregory Kiernan, Shamim Akbar Rahman, Yi-Ju Chao
  • Publication number: 20080137718
    Abstract: Techniques of channel correction and demodulation for orthogonal frequency division multiplexing (OFDM) systems are enhanced so that higher effective data rates and/or lower error rates can be achieved with a minimal processing load. Pilots are adaptively moved and/or removed, and their positions are changed, to enhance the channel estimation, decoding, and demodulation processes at the receiver. Reception is also enhanced by adding, removing, or changing the positions, of information-carrying data bits.
    Type: Application
    Filed: December 5, 2007
    Publication date: June 12, 2008
    Applicant: INTERDIGITAL TECHNOLOGY CORPORATION
    Inventors: Inhyok Cha, Prabhakar R. Chitrapu
  • Patent number: 7386009
    Abstract: In one aspect of the invention signal/control messages are embedded as packets in the payloads of SMS messages. The SMS messages are transmitted in a cellular network employing SMPP protocol. SMS messages intended to traverse an TCP/IP network are introduced to the TCP/IP network employing ICMP protocol. The protocol conversions are performed by a message center (MC), such as a SMS center or an SGSN in a cellular network or a WLAN Access Router when the SMS message is forwarded to a WLAN. The SMS messages are typically created by a mobile user, which is also capable of receiving the SMS messages having a signal/control message in the SMS message payload.
    Type: Grant
    Filed: May 28, 2003
    Date of Patent: June 10, 2008
    Assignee: InterDigital Technology Corporation
    Inventors: Gautam G. Reddy, Prabhakar R. Chitrapu