Patents by Inventor Prabhakar Chitrapu
Prabhakar 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).
-
Publication number: 20080090563Abstract: Classes of cognition models which may include: 1) Radio Environment models, 2) Mobility models and 3) Application/User Context models are utilized in a wireless communications network. Radio Environment models represent the physical aspects of the radio environment, such as shadowing losses, multi-path propagation, interference and noise levels, etc. Mobility models represent users motion, in terms of geo-coordinates and/or logical identifiers, such as street names etc. as well as speed of user terminal etc. The context model represents the present state and dynamics of each of these application processes within itself and between multiple application processes. These data are employed to optimize network performance.Type: ApplicationFiled: December 5, 2007Publication date: April 17, 2008Applicant: InterDigital Technology CorporationInventor: Prabhakar Chitrapu
-
Publication number: 20080076478Abstract: An antenna and radio frequency unit (ARFU) that is external to a wireless transmit/receive unit (WTRU) includes a radio frequency (RF) front end device and an antenna in communication with the RF front end device. The RF front end device is in communication with the WTRU.Type: ApplicationFiled: August 24, 2007Publication date: March 27, 2008Applicant: INTERDIGITAL TECHNOLOGY CORPORATIONInventors: Jeffrey Russell, Aliye Kaya, Prabhakar Chitrapu, Paul Russell
-
Publication number: 20080013486Abstract: A method and apparatus for enhancing communication services in an evolved global system for mobile communications (GSM)/enhanced data rates for GSM evolution (EDGE) radio access network (GERAN) are disclosed. At least one full rate physical channel and/or half rate physical channel are provided to support communication services that do not require higher order modulation (HOM), and at least one fractional rate physical channel is provided to support the communication services that require HOM. The fractional rate channel occupies N timeslots for every M frames of a channel, whereby N/M is less than one half. The fractional rate channel may be used when communication services are provided on a channel that uses either 16 or 32 quadrature amplitude modulation (QAM) in a dual transfer mode (DTM) session. The communications services include at least one of voice communication services, circuit switched (CS) services and supplementary services.Type: ApplicationFiled: July 5, 2007Publication date: January 17, 2008Applicant: INTERDIGITAL TECHNOLOGY CORPORATIONInventors: Prabhakar Chitrapu, Paul Russell
-
Publication number: 20070297533Abstract: The present invention relates to hierarchical modulation (HM) and demodulation for global system for mobile communications (GSM)/enhanced data rates for GSM evolution (EDGE) radio access network (GERAN) evolution. In one embodiment, HM symbols are generated by generating primary modulated symbols based on a first bit group, generating secondary modulated symbols based on a second bit group, and combining the primary modulated symbols and the secondary modulated symbols. In another embodiment, the HM symbols are demodulated. In yet another embodiment, a received GERAN signal is converted to baseband complex symbol values, which are processed to produce training symbols and data symbols that carry pilot symbols. Channel parameters of the radio channel are estimated based on the training symbols. An equalized signal is generated based on the estimated channel parameters and data symbol. Primary and secondary demodulated symbols are generated based on the equalized signal.Type: ApplicationFiled: June 20, 2007Publication date: December 27, 2007Applicant: INTERDIGITAL TECHNOLOGY CORPORATIONInventors: Prabhakar Chitrapu, Paul Russell
-
WIRELESS COMMUNICATION METHOD AND SYSTEM FOR BIT INTERLEAVED CODED MODULATION AND ITERATIVE DECODING
Publication number: 20070260958Abstract: 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: ApplicationFiled: December 28, 2006Publication date: November 8, 2007Applicant: INTERDIGITAL TECHNOLOGY CORPORATIONInventors: Yingxue Li, Prabhakar Chitrapu -
Publication number: 20070177729Abstract: A method and apparatus is used for generating a perfectly random secret key between two or more transceivers in a wireless communication network. In a point-to-point system, both transceivers produce an estimate of the channel impulse response (CIR) based on the received radio signal. The CIR estimation is synchronized and may include error correction and detection. A long secret key of bits is generated from a digitized version of the CIR estimate, from which a perfectly secret encryption key is derived by privacy amplification.Type: ApplicationFiled: January 26, 2006Publication date: August 2, 2007Applicant: InterDigital Technology CorporationInventors: Alexander Reznik, Akinlolu Kumoluyi, Guodong Zhang, Prabhakar Chitrapu, Gregory Sternberg, Yogendra Shah, Alain Charles Briancon, Chunxuan Ye
-
Publication number: 20070140494Abstract: A system and method for providing variable security levels in a wireless communication network. The present invention optimizes the often conflicting demands of highly secure wireless communications and high speed wireless communications. According to a preferred embodiment of the present invention, various security sensors are scanned to determine the likely presence of an intruder within a predetermined trust zone. If an intruder is likely present, the security level is changed to the highest setting, and consequently a lower data rate, while the intruder is identified. If the identified intruder is in fact a trusted node, the security level is returned to a lower setting. If the identified intruder is not a trusted node, the security level is maintained at an elevated state while the intruder is within the trust zone.Type: ApplicationFiled: September 30, 2005Publication date: June 21, 2007Applicant: InterDigital Technology CorporationInventors: Akinlolu Kumoluyi, Alexander Reznik, Guodong Zhang, Prabhakar Chitrapu, Sung-Hyuk Shin, Yingming Tsai
-
Publication number: 20070121939Abstract: In a communication system comprising a plurality of transmit/receive units (TRUs), a method for embedding a watermark into data includes modifying a carrier signal containing data to embed watermark information. The modified carrier signal is transmitted. A receiver receives the modified carrier signal and extracts the watermark information from the modified carrier signal.Type: ApplicationFiled: October 3, 2006Publication date: May 31, 2007Applicant: InterDigital Technology CorporationInventors: Robert Olesen, Prabhakar Chitrapu, John Kaewell,, Bing Chiang, Richard Herschaft, John Hoffmann, Sung-Hyuk Shin, Alexander Reznik
-
Publication number: 20070053325Abstract: A method and apparatus for securing wireless communications are disclosed. A watermark message is encoded to watermark message symbols. A cover message is encoded to cover message symbols. The watermark message symbols are then overlaid onto the cover message symbols to generate a watermark-embedded cover message in a physical layer. The watermark message symbols have a substantially lower amplitude than the cover message symbols. Thus, the watermark message introduces small perturbation around the constellation points of the cover message symbols. The watermark message symbol may span or spread over a plurality of cover message symbols and may be encrypted with a secret key. The watermark message is used for improving receiver performance by transmitting additional information or for security enhancement purposes. The watermarking function may be selectively turned on and off.Type: ApplicationFiled: April 24, 2006Publication date: March 8, 2007Applicant: InterDigital Technology CorporationInventors: Sung-Hyuk Shin, Yogendra Shah, Prabhakar Chitrapu, Alain Briancon
-
Publication number: 20070036353Abstract: The present invention relates to secret key generation and authentication methods that are based on joint randomness not shared by others (JRNSO), in which unique channel response between two communication terminals generates a secret key. Multiple network access points use a unique physical location of a receiving station to increase user data security. High data rate communication data is encrypted by generating a random key and a pseudo-random bit stream. A configurable interleaving is achieved by introduction of JRNSO bits to an encoder used for error-correction codes. Databases of user data are also protected by JRNSO-based key mechanisms. Additional random qualities are induced on the joint channel using MIMO eigen-beamforming, antenna array deflection, polarization selection, pattern deformation, and path selection by beamforming or time correlation. Gesturing induces randomness according to uniquely random patterns of a human user's arm movements inflected to the user device.Type: ApplicationFiled: May 31, 2006Publication date: February 15, 2007Applicant: InterDigital Technology CorporationInventors: Alexander Reznik, Debashish Purkayastha, Steven Goldberg, Robert Olesen, Marian Rudolf, Inhyok Cha, Alan Carlton, Yogendra Shah, Shamim Rahman, Rajat Mukherjee, Robert DiFazio, Gregory Sternberg, Leonid Kazakevich, Kazimierz Siwiak, Guodong Zhang, Tanbir Haque, Louis Guccione, Prabhakar Chitrapu, Akinlolu Kumoluyi, Alain Briancon
-
Publication number: 20070025366Abstract: A system and method for supporting mobile Internet communication is provided which employs a plurality of Routers and a plurality of Mobile Nodes (MNs). Each Router has a unique communication address. Each MN is associated with a home Router. Each Router has an associated Mobile Node Location List identifying each MN for which the Router is the home Router and the communication address of a Router corresponding to a current location of each such MN. Each MN is movable from an old location where the MN communicates with the Internet via one Router to a current location where the MN communicates with the Internet via a different Router. Communication at the current location via the different Router is established by communicating to the MN's home Router the communication address of the different Router as the communication address corresponding to the MN's current location.Type: ApplicationFiled: October 4, 2006Publication date: February 1, 2007Applicant: InterDigital Technology CorporationInventors: Sharif Shahrier, Prabhakar Chitrapu
-
Publication number: 20060274641Abstract: In a wireless communication system comprising at least one wireless transmit/receive unit (WTRU), a base station, and a radio network controller (RNC), a method for constant envelope orthogonal frequency division multiplexing (CE-OFDM) modulation comprises the WTRU performing an inverse transform on the data. The WTRU next performs constant envelope (CE) modulation on the data and transmits the CE-OFDM data to the base station. The base station receives the data and CE demodulates the data. The base station performs a transform on the demodulated data.Type: ApplicationFiled: March 31, 2006Publication date: December 7, 2006Applicant: InterDigital Technology CorporationInventors: Donald Grieco, Sung-Hyuk Shin, Yingming Tsai, Guodong Zhang, Prabhakar Chitrapu, Alain Briancon, Paul Marinier, TieJun Shan, Yogendra Shah
-
Publication number: 20060258347Abstract: Classes of cognition models which may include: 1) Radio Environment models, 2) Mobility models and 3) Application/User Context models are utilized in a wireless communications network. Radio Environment models represent the physical aspects of the radio environment, such as shadowing losses, multi-path propagation, interference and noise levels, etc. Mobility models represent users motion, in terms of geo-coordinates and/or logical identifiers, such as street names etc. as well as speed of user terminal etc. The context model represents the present state and dynamics of each of these application processes within itself and between multiple application processes. These data are employed to optimize network performance.Type: ApplicationFiled: July 7, 2006Publication date: November 16, 2006Applicant: InterDigital Technology CorporationInventor: Prabhakar Chitrapu
-
Publication number: 20060199579Abstract: 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: ApplicationFiled: May 3, 2006Publication date: September 7, 2006Applicant: InterDigital Technology CorporationInventor: Prabhakar Chitrapu
-
Publication number: 20060200673Abstract: 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: ApplicationFiled: April 26, 2005Publication date: September 7, 2006Applicant: InterDigital Technology CorporationInventors: Guodong Zhang, Prabhakar Chitrapu
-
Publication number: 20060183464Abstract: A wireless communication system includes a base station that receives information regarding neighboring wireless systems and updates and stores this information for use in handover of user equipments (UEs).Type: ApplicationFiled: April 17, 2006Publication date: August 17, 2006Applicant: InterDigital Technology CorporationInventors: Arty Chandra, Prabhakar Chitrapu, Narayan Menon
-
Publication number: 20060156009Abstract: 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: ApplicationFiled: July 29, 2005Publication date: July 13, 2006Applicant: InterDigital Technology CorporationInventors: Sung-Hyuk Shin, Alexander Reznik, Guodong Zhang, Prabhakar Chitrapu
-
Publication number: 20060148516Abstract: A wireless network provides controlled wireless communications with multi-mode wireless WTRUs. The wireless network has at least one base station having a transceiver operating in an infrastructure communication mode with multi mode WTRUs and a controller that transmits control signals via infrastructure communications with a WTRU that control peer-to-peer mode communications of that WTRU with other WTRUs. A WTRU has transceiver components configured for selective operation in an infrastructure communication mode with a network base station and in a peer-to-peer communication mode with other WTRUs. The WTRU also has a transceiver controller configured to selectively control peer-to-peer mode communications with other WTRUs based on communication signals received in infrastructure communications with a network base station.Type: ApplicationFiled: March 2, 2006Publication date: July 6, 2006Applicant: InterDigital Technology CorporationInventors: Gautam Reddy, Prabhakar Chitrapu, Leonid Kazakevich, Teresa Hunkeler, Arty Chandra
-
Publication number: 20060133338Abstract: A method and system for securing wireless communications is disclosed. In one embodiment, different security policies are used based on the distance between a receiver and a transmitter, whereby data in the wireless communications can only be demodulated if received in particular trust zones. In another embodiment, a plurality of bit stream fragments are transmitted by a plurality of transmitters to a receiver located in an area where transmission patterns radiated by the transmitters intersect. Alternatively, the receiver performs a function on packet data units (PDUs) transmitted by the transmitters. In yet another embodiment, primary modulation points of a modulation constellation are split into clusters of proximate secondary modulation points which can be demodulated only by a receiver that is within range of the transmitter. In yet another embodiment, a main waveform is transmitted which overlays a QPSK signal with hierarchical modulation (HM) having encoded descrambling information.Type: ApplicationFiled: November 18, 2005Publication date: June 22, 2006Applicant: InterDigital Technology CorporationInventors: Alexander Reznik, Alan Carlton, Alain Briancon, Yogendra Shah, Prabhakar Chitrapu, Rajat Mukherjee, Marian Rudolf
-
Publication number: 20060111149Abstract: The present invention relates to a method and system using dynamic beam forming for wireless communication signals in a wireless network. Base stations and/or UEs are provided with antenna systems having a range of beam forming selections. Relative base station and UE locations are one type of criteria used to make beam forming decisions.Type: ApplicationFiled: December 22, 2005Publication date: May 25, 2006Applicant: InterDigital Technology CorporationInventors: Prabhakar Chitrapu, Steven Goldberg