Patents by Inventor Ashok Mantravadi
Ashok Mantravadi 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: 7660275Abstract: To broadcast different types of transmission having different tiers of coverage in a wireless broadcast network, each base station processes data for a wide-area transmission in accordance with a first mode (or coding and modulation scheme) to generate data symbols for the wide-area transmission and processes data for a local transmission in accordance with a second mode to generate data symbols for the local transmission. The first and second modes are selected based on the desired coverage for wide-area and local transmissions, respectively. The base station also generates pilots and overhead information for local and wide-area transmissions. The data, pilots, and overhead information for local and wide-area transmissions are multiplexed onto their transmission spans, which may be different sets of frequency subbands, different time segments, or different groups of subbands in different time segments. More than two different types of transmission may also be multiplexed and broadcast.Type: GrantFiled: October 18, 2004Date of Patent: February 9, 2010Assignee: QUALCOMM IncorporatedInventors: Rajiv Vijayan, Fuyun Ling, Gordon Kent Walker, Ramaswamy Murali, Ashok Mantravadi, Anand Subramaniam, Krishnamurthy Viswanathan, legal representative
-
Publication number: 20100002785Abstract: An adaptive thresholding technique eliminates suboptimum threshold values by adjusting for varying channel conditions to eliminate interference where no channel energy is present, without discarding viable taps having useful channel energy. The adaptive thresholding technique adaptively optimizes receive threshold values for both wide and local area channels based only on measured C/I ratios 300. Thresholds are calculated based on instantaneous C/I estimates and/or weighted average C/I estimates calculated from WID/LID energies obtained from the current superframe WIC/LIC symbols respectively. In alternate embodiments, thresholds are calculated based on instantaneous C/I estimates and/or weighted average C/I estimates calculated from WTPC and LTPC symbols for the wide and local area channels, respectively The present adaptive thresholding technique dynamically reduces the threshold as the C/I estimate increases to mitigate performance degradation due to removal of weak signal taps.Type: ApplicationFiled: October 13, 2008Publication date: January 7, 2010Applicant: QUALCOMM IncorporatedInventors: Ashok Mantravadi, Krishna Kiran Mukkavilli, Raghuraman Krishnamoorthi, Rajeev Krishnamurthi
-
Publication number: 20090304120Abstract: Techniques to transmit data with cyclic delay diversity and pilot staggering are described. For cyclic delay diversity, OFDM symbols having different cyclic delay durations are generated. The cyclic delay durations for the OFDM symbols may be selected to be time varying with respect to the cyclic delay durations for OFDM symbols transmitted by a neighboring base station. An FDM pilot is generated and multiplexed on multiple sets of subbands in different symbol periods. Waveforms for a second radio technology (e.g., W-CDMA) may be generated for data to be transmitted with this radio technology. The OFDM symbols are multiplexed onto time slots used for OFDM, and the waveforms for the second radio technology are multiplexed onto time slots used for this radio technology. One or multiple modulated signals may be generated based on the multiplexed OFDM symbols and waveforms. Each modulated signal is transmitted from a respective antenna.Type: ApplicationFiled: June 9, 2009Publication date: December 10, 2009Applicant: QUALCOMM IncorporationInventors: Avneesh Agrawal, Durga Prasad Malladi, Anastasios Stamoulis, Ashok Mantravadi, Ramaswamy Murali
-
Publication number: 20090279471Abstract: To broadcast different types of transmission having different tiers of coverage in a wireless broadcast network, each base station processes data for a wide-area transmission in accordance with a first mode (or coding and modulation scheme) to generate data symbols for the wide-area transmission and processes data for a local transmission in accordance with a second mode to generate data symbols for the local transmission. The first and second modes are selected based on the desired coverage for wide-area and local transmissions, respectively. The base station also generates pilots and overhead information for local and wide-area transmissions. The data, pilots, and overhead information for local and wide-area transmissions are multiplexed onto their transmission spans, which may be different sets of frequency subbands, different time segments, or different groups of subbands in different time segments. More than two different types of transmission may also be multiplexed and broadcast.Type: ApplicationFiled: July 20, 2009Publication date: November 12, 2009Applicant: QUALCOMM INCORPORATEDInventors: Rajiv Vijayan, Fuyun Ling, Gordon Kent Walker, Ramaaswamy Murali, Ashok Mantravadi, Anand Subramaniam, Krishnamurthy Viswanathan
-
Publication number: 20090274119Abstract: Methods and apparatus for RF handoff in a multi-frequency network. A method includes detecting a mobility event associated with a detection of a new wide area operating infrastructure (WOI), updating a current WOI identifier to a new WOI identifier, acquiring control channel information associated with the new WOI identifier, determining if an active registered flow list has been updated based on the control channel information, and performing an acquisition procedure to acquire one or more registered flows if it is determined that the active registered flow list has been updated. Another method includes detecting a mobility event associated with a detection of a new local area operating infrastructure (LOI), updating a current LOI identifier to a new LOI identifier, acquiring control channel information, determining if an active registered flow list has been updated, and performing an acquisition procedure to acquire one or more registered flows.Type: ApplicationFiled: March 5, 2009Publication date: November 5, 2009Applicant: QUALCOMM IncorporatedInventors: BINITA GUPTA, Ashok Mantravadi
-
Publication number: 20090274099Abstract: Methods and apparatus for communicating transmitter information in a communication network are disclosed. The methods and apparatus communicate transmitter specific information, in particular, which includes location information about network transmitters for use in location or positioning type services. The disclosed methods and apparatus include inserting such transmitter specific information within either a data flow of at least one transmission frame or a control channel in the at least one transmission frame. In addition, a transmitter identifier is encoded in a positioning pilot channel (PPC) within the at least one transmission frame, and the configured transmission frame transmitted to a user device. The user device may use the transmitter specific information of numerous transmitters along with the transmitter identifiers to measure how far it is from the transmitters, and then triangulate to determine position.Type: ApplicationFiled: April 30, 2009Publication date: November 5, 2009Applicant: QUALCOMM IncorporatedInventors: Qiang Gao, An Mei Chen, Ashok Mantravadi, Krishna Kiran Mukkavilli, Murali Ramaswamy Chari
-
Publication number: 20090245333Abstract: Methods and apparatus for adapting a channel estimation scheme in a transceiver in a communication system are disclosed to adapt channel estimation to the transceiver environment, particularly for high Doppler environments. The disclosed methods and apparatus effect determination of an estimate of a power delay profile of a channel or a time correlation of the channel, or both. A channel estimation scheme is then determined based on at least one of the determined power delay profile and time correlation of the channel. By basing determination of a channel estimation scheme on the power delay profile and/or the time correlation of the channel, the channel estimation scheme is adapted to the particular environment of the transceiver by accounting for the delay spread of the channel and/or the speed of the transceiver.Type: ApplicationFiled: March 2, 2009Publication date: October 1, 2009Applicant: QUALCOMM INCORPORATEDInventors: Raghuraman Krishnamoorthi, Krishna Kiran Mukkavilli, Ashok Mantravadi
-
Publication number: 20090245154Abstract: In a multicasts wireless telecommunication system providing an aggregation of one or more independent data components as a flow, wherein the OIS is located at the latch point of the beginning of the superframe, and the OIS programming is latched at the superframe boundary, the improvement of deriving signal parameter information from Signaling Parameter Channel (SPC) symbols transmitted in a Forward Link only (FLO) network by deriving a time domain channel estimate by assuming each of the combinations for the signal parameter field in the scrambler seed and picking the signal parameter combination that yields the most energy in the time domain above a threshold value.Type: ApplicationFiled: December 12, 2008Publication date: October 1, 2009Applicant: QUALCOMM INCORPORATEDInventors: Krishna Kiran Mukkavilli, Ashok Mantravadi, Durk L. van Veen, Murali Ramaswamy Chari, Raghuraman Krishnamoorthi, Rajeev Krishnamurthi, Fuyun Ling
-
Publication number: 20090190525Abstract: A method for communicating transmitter identification in an interlace structure of a communication network system using positioning pilot channels (PPC), comprising: a) encoding pilot information on a first portion of a plurality of subcarriers in a positioning pilot channel symbol for an active transmitter; and b) encoding transmitter identification information on a second portion of a plurality of subcarriers of the symbol; wherein the first portion of the plurality of subcarriers comprises at least first and second interlaces and the second portion of the plurality of subcarriers comprises at least a third interlace; the pilot information is scrambled in the first interlace with a wide area identifier and scrambled in the at least second interlaces with the wide area identifier and a local area identifier; and wherein at least one of the interlace includes the transmitter identification information in the form of one or more transmitter location coordinates in a free interlace.Type: ApplicationFiled: July 1, 2008Publication date: July 30, 2009Applicant: QUALCOMM IncorporatedInventors: Krishna Kiran Mukkavilli, Ashok Mantravadi
-
Publication number: 20090129511Abstract: To allow a receiving entity to derive a longer channel estimate while limiting overhead, a transmitting entity transmits a pilot on different groups of subbands in different time intervals. N subbands in the system are arranged into M non-overlapping groups. Each group includes P=N/M subbands that are uniformly distributed across the N subbands. The transmitting entity transmits the pilot on a different subband group in each time interval, and selects all M subband groups in M time intervals based on a pilot staggering pattern. The receiving entity derives (1) an initial impulse response estimate with P channel taps based on the pilot received on one subband group and (2) two longer impulse response estimates with different lengths used for data detection and time tracking. Each longer impulse response estimate may be derived by filtering initial impulse response estimates for a sufficient number of subband groups using a time-domain filter.Type: ApplicationFiled: October 20, 2008Publication date: May 21, 2009Applicant: QUALCOMM IncorporatedInventors: Rajiv Vijayan, Ashok Mantravadi, Krishna Kiran Mukkavilli
-
Publication number: 20090080378Abstract: Methods and apparatus for RF channel switching in a multi-frequency network. In an aspect, a method includes identifying a local area operations infrastructure (LOI) in the multi-frequency network, generating a channel description message that associates at least one descrambling sequence identifier with each RF channel associated with the LOI, respectively, and distributing the CDM over the LOI. In another aspect, a method includes receiving a CDM that associates at least one descrambling sequence identifier with each RF channel available in a LOI, detecting an RF channel switch event that identifies a selected RF channel, determining a selected descrambling sequence identifier from the CDM based on the selected RF channel, switching to the selected RF channel wherein the selected descrambling sequence identifier identifies a selected descrambling sequence to descramble desired content carried on the selected RF channel, and acquiring the desired content on the selected RF channel.Type: ApplicationFiled: March 26, 2008Publication date: March 26, 2009Inventors: Binita Gupta, An Mei Chen, Linbo Li, Raghuraman Krishnamoorthi, Ashok Mantravadi
-
Publication number: 20090028100Abstract: Methods and apparatus for transmitter identification in a wireless network are disclosed. In an example, a method is provided that encodes pilot information on a first portion of a number of subcarriers in a symbol within a pilot positioning channel for an active transmitter. The method further includes encoding transmitter identification information on a second dedicated portion of the number of subcarriers of the symbol. The method also encompasses including a transmitter allocation field that signals the number of succeeding symbols that will be used by the transmitter for transmitting any other information in an interference free manner. In another example, a method is provided that receives a symbol having a number of subcarriers from a transmitter. A channel estimate and an energy measurement of the symbol using a first portion of the subcarriers. A dedicated second portion of the number of subcarriers in the symbol are then decoded to determine the transmitter identification information.Type: ApplicationFiled: August 6, 2007Publication date: January 29, 2009Applicant: QUALCOMM INCORPORATEDInventors: Krishna Kiran Mukkavilli, Ashok Mantravadi, Raghuraman Krishnamoorthi, Murali Ramaswamy Chari
-
Publication number: 20090029709Abstract: Methods and apparatus for signaling parameter distribution for neighboring radio frequencies. A method includes identifying selected local operations infrastructures (LOIs) and one or more neighboring LOIs, generating a neighbor description message (NDM) that identifies the selected LOIs and their respective neighbors and specifies SP information for each RF channel associated with the selected LOIs and their respective neighbors, and distributing the NDM over each of the selected LOIs. An apparatus includes a message decoder configured to receive a NDM that identifies RF channels associated with selected LOIs and one or more neighboring LOIs, wherein each RF channel is associated with SP information, and processing logic configured to receive a request to obtain selected SP information associated with a selected RF channel, determine the selected SP information associated with the selected RF channel based on the NDM, and output the selected SP information.Type: ApplicationFiled: July 20, 2008Publication date: January 29, 2009Inventors: Binita GUPTA, Krishna Kiran MUKKAVILLI, Ashok MANTRAVADI, Raghuraman KRISHNAMOORTHI
-
Publication number: 20090029705Abstract: Methods and apparatus for service acquisition in a multi-frequency network. In an aspect, a method is provided for service acquisition in a multi-frequency network. The method includes detecting a service acquisition trigger event and identifying a selected RF channel from an acquisition RF list based on signal strength, wherein the acquisition RF list identifies RF channels in one or more local operations infrastructures (LOIs) of the multi-frequency network. The method also includes acquiring a wide system on the selected RF channel, removing the selected RF channel from the acquisition RF list if the wide system can not be acquired on the selected RF channel, and repeating said operations of identifying, acquiring and removing until the wide system is acquired on the selected RF channel or a system acquisition timeout occurs.Type: ApplicationFiled: June 18, 2008Publication date: January 29, 2009Inventors: Binita Gupta, Linbo Li, Raghuraman Krishnamoorthi, Ashok Mantravadi
-
Publication number: 20090031201Abstract: A receiver includes a decoder configured to decode at least a portion of a data stream comprising a data frame. The data frame includes a code block having a data block and a parity block. The receiver also includes a controller. The controller is configured to determine whether to disable at least a portion of the receiver during transmission of the parity block to the receiver when the data block contains at least one erasure.Type: ApplicationFiled: July 25, 2007Publication date: January 29, 2009Applicant: QUALCOMM INCORPORATEDInventors: Soumya Das, Ashok Mantravadi, Ravishanker Mudigonda
-
Publication number: 20090028257Abstract: A method of acquiring a forward link only (FLO) network in a radio frequency (RF) in a wireless communication environment, includes selecting a RF from a first list; selecting a signal parameter (SP) from a second list; determining if a first parameter is found using the selected RF and SP; and, upon determination that the first parameter is found, enabling the use of the selected RF and SP to communicate in the FLO network. An apparatus for implementing the method is also disclosed.Type: ApplicationFiled: August 6, 2007Publication date: January 29, 2009Applicant: QUALCOMM INCORPORATEDInventors: Krishna Kiran Mukkavilli, Ashok Mantravadi, Raghuraman Krishnamoorthi, Murali Ramaswamy Chari, Tao Tian
-
Publication number: 20090028256Abstract: A new channel is added to FLO networks that carries embedded signaling parameter information. The design is such that regardless of the actual values of the signaling parameters conveyed, a receiver will be able to demodulate this new channel. Moreover, the addition of the new channel does not render a FLO network that has been so configured to not be backwards-compatible with existing devices.Type: ApplicationFiled: August 6, 2007Publication date: January 29, 2009Applicant: QUALCOMM INCORPORATEDInventors: Durk L. van Veen, Ashok Mantravadi, Raghuraman Krishnamoorthi, Murali Ramaswamy Chari, Krishna Kiran Mukkavilli, Fuyun Ling
-
Publication number: 20090016380Abstract: Methods and apparatus for RF channel switching in a multi-frequency network. In an aspect, a method includes identifying a multiplex set that comprises one or more content flows, wherein the multiplex set is one of a vertical multiplex (VM) set and a unified multiplex (UM) set, generating an overhead message that associates one or more RF carrier frequencies with the one or more content flows, and transmitting the overhead message over the multi-frequency network. An apparatus includes input logic configured to receive an overhead message that associates one or more content flows with one or more RF carrier frequencies, and processing logic configured to detect a channel switch event that identifies a selected content flow, determine a selected RF carrier frequency associated with the selected content flow based on the overhead message, and switch to the selected RF carrier frequency to receive the selected content flow.Type: ApplicationFiled: March 19, 2008Publication date: January 15, 2009Inventors: Binita Gupta, An Mei Chen, Devarshi Shah, Linbo Li, Raghuraman Krishnamoorthi, Ashok Mantravadi, Taoufik Tani
-
Patent number: 7457231Abstract: To allow a receiving entity to derive a longer channel estimate while limiting overhead, a transmitting entity transmits a pilot on different groups of subbands in different time intervals. N subbands in the system are arranged into M non-overlapping groups. Each group includes P=N/M subbands that are uniformly distributed across the N subbands. The transmitting entity transmits the pilot on a different subband group in each time interval, and selects all M subband groups in M time intervals based on a pilot staggering pattern. The receiving entity derives (1) an initial impulse response estimate with P channel taps based on the pilot received on one subband group and (2) two longer impulse response estimates with different lengths used for data detection and time tracking. Each longer impulse response estimate may be derived by filtering initial impulse response estimates for a sufficient number of subband groups using a time-domain filter.Type: GrantFiled: August 25, 2004Date of Patent: November 25, 2008Assignee: QUALCOMM IncorporatedInventors: Rajiv Vijayan, Ashok Mantravadi, Krishna Kiran Mukkavilli
-
Publication number: 20080261547Abstract: Methods and apparatus for RF channel selection in a multi-frequency network. A method includes identifying selected local operations infrastructures (LOIs) and their neighboring LOIs, generating a neighbor description message (NDM) that identifies the selected LOIs and their neighboring LOIs and associates a descrambling sequence identifier with each RF channel of the selected LOIs and their neighboring LOIs, and distributing the NDM over the selected LOIs. An apparatus includes a message decoder to receive an NDM that identifies RF channels of a first LOI and neighboring LOIs, and wherein each RF channel is associated with a descrambling sequence identifier, and processing logic to detect content acquisition failures, determine a list of RF channels and their associated LOIs that carry desired content, and select a selected RF channel that is associated with a selected LOI that carries the most additional content among the associated LOIs.Type: ApplicationFiled: March 19, 2008Publication date: October 23, 2008Inventors: Binita Gupta, Linbo Li, Raghuraman Krishnamoorthi, Ashok Mantravadi