Patents by Inventor Murali Ramaswamy Chari
Murali Ramaswamy Chari 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).
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Patent number: 7733968Abstract: Systems and methodologies are described that facilitate monitoring transmitter performance in a wireless communication environment. A signal analyzer can be used to sample the output of a transmitter and the sampled signal can be propagated to a processor. The processor can generate frequency domain channel estimates for the subcarriers. If the transmitted modulation symbols are unknown, the processor can determine the modulation symbols and use the determined modulation symbols to calculate the channel estimates. The channel estimates can be averaged and used to generate various metrics to evaluate the transmitter performance.Type: GrantFiled: February 22, 2006Date of Patent: June 8, 2010Assignee: QUALCOMM IncorporatedInventors: Fuyun Ling, Durk L. Van Veen, Murali Ramaswamy Chari, Thomas Sun
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Patent number: 7725799Abstract: A wireless communication apparatus in a hierarchically coded modulation system can use error control mechanisms generated during decoding of base layer information to predict a probability of successful demodulation of enhancement layer information. Performance in the demodulation of the base layer correlates to performance in the demodulation of the enhancement layer. The receiver can determine whether to attempt demodulation of temporally correlated enhancement layer data based in part on the predicted probability of success. If the receiver determines not to demodulate the enhancement layer, the receiver can power down the enhancement layer demodulator, or otherwise minimize the power expended in the enhancement layer demodulator.Type: GrantFiled: March 31, 2005Date of Patent: May 25, 2010Assignee: QUALCOMM IncorporatedInventors: Gordon Kent Walker, Rajiv Vijayan, Seong Taek Chung, Murali Ramaswamy Chari, Fuyun Ling
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Patent number: 7720027Abstract: Systems and methods are provided for processing forward link only (FLO) signals. A device receives a FLO signal, processes a TDM pilot comprising a TDM Pilot 1, a TDM Pilot 2, a WIC, a LIC, a Transition Pilot Channel, and a Positioning Pilot, from the FLO signal, processes an overhead information symbol (OIS) comprising a wide-area OIS and a local-area OIS, from the FLO signal, processes an FDM pilot comprising a wide-area FDM pilot and a local-area FDM pilot, from the FLO signal; and processes data comprising wide-area data and local-area data, from the FLO signal.Type: GrantFiled: July 27, 2006Date of Patent: May 18, 2010Assignee: QUALCOMM IncorporatedInventors: Fuyun Ling, Murali Ramaswamy Chari, Rajiv Vijayan, Ashok Mantravadi, Alok Kumar Gupta, Krishna Kiran Mukkavilli, Michael Mao Wang, Bojan Vrcelj, Bruce Collins
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Patent number: 7720185Abstract: The disclosure is directed to a receiver. The receiver includes an interference canceller configured to filter digital samples produced from a modulated signal transmitted over a wireless channel, and a digital variable gain amplifier (DVGA) configured to amplify the filtered digital samples.Type: GrantFiled: November 6, 2006Date of Patent: May 18, 2010Assignee: QUALCOMM IncorporatedInventors: Bojan Vrcelj, Ashok Mantravadi, Fuyun Ling, Linbo Li, Raghuraman Krishnamoorthi, Murali Ramaswamy Chari, Vinay Murthy
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Patent number: 7706328Abstract: Methods and apparatus for position location in a wireless network. In an aspect, a method is provided that includes determining whether a symbol to be transmitted is an active symbol, wherein the symbol comprises a plurality of subcarriers, and encoding identification information on a first portion of subcarriers if it is determined that the symbol is the active symbol. The method also includes encoding idle information on a second portion of subcarriers if it is determined that the symbol in not the active symbol. In an aspect, an apparatus includes detector logic configured to decode a plurality of symbols to determine identification information that identifies a plurality of transmitters, and to determine a plurality of channel estimate associated with the plurality of transmitters. The apparatus also includes position determination logic configured to calculate a device position based on the plurality of transmitters and the plurality of channel estimates.Type: GrantFiled: September 6, 2006Date of Patent: April 27, 2010Assignee: QUALCOMM IncorporatedInventors: Krishna Kiran Mukkavilli, Fuyun Ling, Gordon Kent Walker, Murali Ramaswamy Chari
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Patent number: 7693231Abstract: The claimed subject matter relates to estimating noise variance associated with a transmitter. For example, the noise variance can be estimated in connection with determining performance parameters associated with a transmitter. Determining noise variance can include the acts of estimating phase alteration of a received signal through utilization of a least squares-based phase estimation algorithm. Determining noise variance can also include the act of determining an unbiased estimation of noise variance as a function of the estimated phase alteration.Type: GrantFiled: June 14, 2006Date of Patent: April 6, 2010Assignee: QUALCOMM IncorporatedInventors: Fuyun Ling, Thomas Sun, Raghuraman Krisnamoorthi, Durk L. van Veen, Murali Ramaswamy Chari
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Publication number: 20100046675Abstract: A media access control (MAC) layer controller can manage base layer data and enhancement layer data in a layered modulation system. The MAC layer controller can process both base layer data and enhancement layer data and map the encoded symbols to a layered modulation constellation when both are present. If data for one of the layers terminates, then the MAC layer controller can generate and supply predetermined stuffing data to the layer lacking additional data. The MAC layer controller can send a control signal to the physical layer hardware to cause the hardware to map the layered signals having the stuffing data to a modified signal constellation. The MAC controller can also generate an overhead message that indicates the occurrence of the stuffing data. The receiver can receive the overhead message and can use the information to configure the receiver for the layered modulation constellation or the modified signal constellation.Type: ApplicationFiled: October 28, 2009Publication date: February 25, 2010Applicant: QUALCOMM IncorporatedInventors: Bruce Collins, Rajeev Krishnamurthi, Murali Ramaswamy Chari, Shusheel Gautam, Rajiv Vijayan, Seong Taek Chung
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Publication number: 20090316835Abstract: A wireless communication apparatus in a hierarchically coded modulation system can use error control mechanisms generated during decoding of base layer information to predict a probability of successful demodulation of enhancement layer information. Performance in the demodulation of the base layer correlates to performance in the demodulation of the enhancement layer. The receiver can determine whether to attempt demodulation of temporally correlated enhancement layer data based in part on the predicted probability of success. If the receiver determines not to demodulate the enhancement layer, the receiver can power down the enhancement layer demodulator, or otherwise minimize the power expended in the enhancement layer demodulator.Type: ApplicationFiled: May 17, 2009Publication date: December 24, 2009Applicant: QUALCOMM IncorporatedInventors: Gordon Kent Walker, Rajiv Vijayan, Seong Taek Chung, Murali Ramaswamy Chari, Fuyun Ling
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Patent number: 7630451Abstract: A media access control (MAC) layer controller can manage base layer data and enhancement layer data in a layered modulation system. The MAC layer controller can process both base layer data and enhancement layer data and map the encoded symbols to a layered modulation constellation when both are present. If data for one of the layers terminates, then the MAC layer controller can generate and supply predetermined stuffing data to the layer lacking additional data. The MAC layer controller can send a control signal to the physical layer hardware to cause the hardware to map the layered signals having the stuffing data to a modified signal constellation. The MAC controller can also generate an overhead message that indicates the occurrence of the stuffing data. The receiver can receive the overhead message and can use the information to configure the receiver for the layered modulation constellation or the modified signal constellation.Type: GrantFiled: January 11, 2006Date of Patent: December 8, 2009Assignee: QUALCOMM IncorporatedInventors: Bruce Collins, Rajeev Krishnamurthi, Murali Ramaswamy Chari, Shusheel Gautam, Rajiv Vijayan, Seong Taek Chung
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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
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Patent number: 7613256Abstract: A multimedia distribution system is disclosed. The distribution system includes a transmitter unit that distributes content from a content provider to one or more wireless subscriber units. The transmitter unit includes a decoder configured to determine whether a plurality of incoming packets include one or more erasures, a transmitter configured to transmit the packets to a receiving unit, and an error detection code generator configured to generate an error detection code for each of the packets transmitted to the receiver unit, the error detection code being modified for each of the erased packets so that the receiver unit will be able to identify the erased packets.Type: GrantFiled: April 4, 2006Date of Patent: November 3, 2009Assignee: QUALCOMM IncorporatedInventors: Durk L. van Veen, Jai N. Subrahmanyam, Jinxia Bai, Murali Ramaswamy Chari
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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
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Patent number: 7583584Abstract: A system and method for time diversity uses interleaving. To simplify the operation at both transmitters and receivers, a formula can be used to determine the mapping from slot to interlace at a given OFDM symbol time.Type: GrantFiled: July 29, 2005Date of Patent: September 1, 2009Assignee: QUALCOMM IncorporatedInventors: Michael Mao Wang, Fuyun Ling, Murali Ramaswamy Chari, Rajiv Vijayan
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Publication number: 20090190675Abstract: In an OFDM system, a transmitter broadcasts a first TDM pilot on a first set of subbands followed by a second TDM pilot on a second set of subbands in each frame. The subbands in each set are selected from among N total subbands such that (1) an OFDM symbol for the first TDM pilot contains at least S1 identical pilot-1 sequences of length L1 and (2) an OFDM symbol for the second TDM pilot contains at least S2 identical pilot-2 sequences of length L2, where L2>L1, S1·L1=N, and S2·L2=N. The transmitter may also broadcast an FDM pilot. A receiver processes the first TDM pilot to obtain frame timing (e.g., by performing correlation between different pilot-1 sequences) and further processes the second TDM pilot to obtain symbol timing (e.g., by detecting for the start of a channel impulse response estimate derived from the second TDM pilot).Type: ApplicationFiled: October 31, 2007Publication date: July 30, 2009Applicant: QUALCOMM INCORPORATEDInventors: Fuyun Ling, Alok Kumar Gupta, Raghuraman Krishnamoorthi, Ramaswamy Murali, Murali Ramaswamy Chari, Rajiv Vijayan, Bojan Vrcelj
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Publication number: 20090161776Abstract: A system and method for frequency diversity uses interleaving in a wireless communication system utilizing orthogonal frequency division multiplexing (OFDM) with various FFT sizes. Subcarriers of one or more interlaces are interleaved in a bit reversal fashion and the one or more interlaces are interleaved.Type: ApplicationFiled: July 24, 2008Publication date: June 25, 2009Applicant: Qualcomm IncorporatedInventors: Michael Mao Wang, Fuyung Ling, Murali Ramaswamy Chari, Rajiv Vijayan
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Publication number: 20090117917Abstract: Methods and apparatus for position location in a wireless network. In an aspect, a method is provided that includes determining whether a symbol to be transmitted is an active symbol, wherein the symbol comprises a plurality of subcarriers, and encoding identification information on a first portion of subcarriers if it is determined that the symbol is the active symbol. The method also includes encoding idle information on a second portion of subcarriers if it is determined that the symbol in not the active symbol. In an aspect, an apparatus includes detector logic configured to decode a plurality of symbols to determine identification information that identifies a plurality of transmitters, and to determine a plurality of channel estimate associated with the plurality of transmitters. The apparatus also includes position determination logic configured to calculate a device position based on the plurality of transmitters and the plurality of channel estimates.Type: ApplicationFiled: December 18, 2008Publication date: May 7, 2009Applicant: QUALCOMM IncorporatedInventors: Krishna Kiran Mukkavilli, Fuyun Ling, Gordon Kent Walker, Murali Ramaswamy Chari
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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
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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
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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
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Publication number: 20080317142Abstract: A system and method for frequency diversity uses interleaving in a wireless communication system utilizing orthogonal frequency division multiplexing (OFDM) with various FFT sizes. Subcarriers of one or more interlaces are interleaved in a bit reversal fashion and the one or more interlaces are interleaved in the bit reversal fashion.Type: ApplicationFiled: October 30, 2007Publication date: December 25, 2008Applicant: QUALCOMM INCORPORATEDInventors: Michael Mao Wang, Fuyun Ling, Murali Ramaswamy Chari, Rajiv Vijayan