Patents by Inventor Karthik Ramasubramanian
Karthik Ramasubramanian 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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Publication number: 20130016010Abstract: A GNSS receiver includes at least one buffer and at least one correlator block. The at least one buffer stores a plurality of samples corresponding to a received signal. The at least one correlator block includes a Doppler derotation block configured to perform Doppler derotation corresponding to at least one Doppler frequency on the plurality of samples, a register array configured to be loaded with the plurality of samples on Doppler derotation corresponding to a Doppler frequency of the at least one Doppler frequency, and a correlator engine configured to generate correlation results by correlating the plurality of samples in the register array with a plurality of code phases for at least one GNSS satellite. A presence of at least one GNSS satellite signal may be detected based on coherent accumulation and a non-coherent accumulation of the correlation results.Type: ApplicationFiled: July 13, 2011Publication date: January 17, 2013Applicant: Texas Instruments IncorporatedInventors: Jasbir Singh Nayyar, Jawaharlal Tangudu, Karthik Ramasubramanian
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Patent number: 8331898Abstract: An electronic circuit includes a receiver circuit (BSP) operable to perform coherent summations having a coherent summations time interval, and a power control circuit (2130) coupled to said receiver circuit (BSP) and operable to impress a power controlling duty cycle (TON, TOFF) on the receiver circuit (BSP) inside the coherent summations time interval. Other circuits, devices, systems, methods of operation and processes of manufacture are also disclosed.Type: GrantFiled: October 2, 2008Date of Patent: December 11, 2012Assignee: Texas Instruments IncorporatedInventors: Deric Wayne Waters, Karthik Ramasubramanian, Arun Raghupathy
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Publication number: 20110250931Abstract: A personal navigation device configured to determine heading readings continuously using data from a sensor in the personal navigation device. Heading readings are selected corresponding to a periodic event. A representative heading is determined from the selected heading readings. When a portion of the selected heading readings has a value within a range of the representative heading, a static heading indicator is asserted to indicate the personal navigation device is moving in a static heading. The static heading indicator may be used to smooth an estimated trajectory of the personal navigation device.Type: ApplicationFiled: April 1, 2011Publication date: October 13, 2011Inventors: Tarkesh Pande, Jaiganesh Balakrishnan, Deric Waters, Goutam Dutta, Jayawardan Janardhanan, Sthanunathan Ramakrishnan, Sandeep Rao, Karthik Ramasubramanian
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Publication number: 20110187596Abstract: An electronic circuit (2250) for a satellite receiver (100, 2200). The electronic circuit (2250) includes a correlator circuit (2310) operable to supply a data signal including ephemeris data and a subsequent satellite time datum, and a data processor (2370, 2380) operable to infer satellite time TS from as few as one of the ephemeris data prior to the satellite time datum. Other circuits, devices, receivers, systems, processes of operation and processes of manufacture are also disclosed.Type: ApplicationFiled: March 18, 2010Publication date: August 4, 2011Applicant: TEXAS INSTRUMENTS INCORPORATEDInventors: Sandeep Rao, Jawaharlal Tangudu, Karthik Ramasubramanian
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Publication number: 20110068979Abstract: In at least some embodiments, an electronic device includes a navigation system receiver and a receiver motion estimator coupled to the navigation system receiver. The receiver motion estimator determines and provides a receiver motion estimation to the navigation system receiver to reduce complexity of a satellite signal search operation performed by the navigation system receiver.Type: ApplicationFiled: September 24, 2010Publication date: March 24, 2011Applicant: TEXAS INSTRUMENTS INCORPORATEDInventors: Deric W. WATERS, Karthik RAMASUBRAMANIAN, Ravi BHAT
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Publication number: 20110026651Abstract: Automatic gain control in a receiver. A method for controlling operating range of an analog-to-digital converter (ADC) by an automatic gain control circuit includes estimating a peak-to-average ratio corresponding to an analog signal from digital samples of the analog signal. The method includes determining a peak value corresponding to the analog signal based on the peak-to-average ratio. Further, the method includes maintaining magnitude of the analog signal at an input of the ADC and gain of the receiver based on the peak value.Type: ApplicationFiled: February 2, 2010Publication date: February 3, 2011Applicant: Texas Instruments IncorporatedInventors: Bijoy BHUKANIA, Jawaharlal Tangudu, Karthik Ramasubramanian
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Patent number: 7826341Abstract: In at least some embodiments, a system may comprise one or more devices configurable to communicate according to a first protocol that implements a first data packet, and one or more devices configurable to communicate according to a second protocol that implements a second data packet having a predetermined quadrature component. The one or more devices configurable to communicate according to the second protocol associate detection of the predetermined quadrature component with a function that is not supported by the one or more devices that communicate according to the first protocol.Type: GrantFiled: August 24, 2007Date of Patent: November 2, 2010Assignee: Texas Instruments IncorporatedInventors: Arndt Joseph Mueller, Karthik Ramasubramanian
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Publication number: 20100171659Abstract: Embodiments of the invention provide a method for making information in the position engine (PE) available to the measurement engine (ME). With the right information the ME can reduce its power consumption, and improve its performance. Other circuits, devices, systems, methods of operation and processes of manufacture are also disclosed.Type: ApplicationFiled: February 25, 2010Publication date: July 8, 2010Applicant: TEXAS INSTRUMENTS INCORPORATEDInventors: Deric Wayne Waters, Sandeep Rao, Karthik Ramasubramanian
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Publication number: 20100119020Abstract: An aspect of the present invention detects the presence of interference by examining an input signal received on an input path, and blanks the receiver if interference is detected. Information contained in the input signal may be recovered otherwise. In an embodiment, the duty cycle of a jamming signal is determined by examining the input signal, and a threshold strength having a positive correlation with the duty cycle is determined. If the strength of the jamming signal during the on-interval (start and end of the interference in each cycle) is greater than the threshold strength, then only the receiver is blanked. Otherwise, no blanking is performed, and only the gain of an amplifier in the path from the input path to a baseband processor is reduced. According to another aspect, one or more cycles of the interference is used to detect the start of interference and the receiver is blanked when interference is present.Type: ApplicationFiled: July 20, 2009Publication date: May 13, 2010Applicant: TEXAS INSTRUMENTS INCORPORATEDInventors: Bijoy Bhukania, Jawaharlal Tangudu, Karthik Ramasubramanian, Arun Raghupathy
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Patent number: 7710856Abstract: In at least some embodiments, a system may comprise one or more devices configurable to communicate according to a first protocol that implements a first data packet, and one or more devices configurable to communicate according to a second protocol that implements a second data packet having a predetermined quadrature component. The one or more devices configurable to communicate according to the second protocol associate detection of the predetermined quadrature component with a function that is not supported by the one or more devices that communicate according to the first protocol.Type: GrantFiled: February 13, 2004Date of Patent: May 4, 2010Assignee: Texas Instruments IncorporatedInventors: Arndt Joseph Mueller, Karthik Ramasubramanian
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Patent number: 7701839Abstract: A multi-rate interleaved frequency division multiple access (IFDMA) modulation scheme permits users to transmit at different data rates or to vary their data rates while providing frequency diversity and preserving low peak-to-average power ratios and orthogonality between user data rates. The modulation scheme allows user-specific data block and repetition sizes, as well as user-specific modulation codes. Code assignment rules are provided for maintaining orthogonality between the different user data rates. Block and phase ramp modulation codes can be used. Asynchronous transmissions by users are supported by ensuring that the length of the cyclic extension is sufficiently long to tolerate worst case relative signal arrival delays between users and the channel pulse response duration over the communication medium. The modulation scheme can be employed in wireless communication systems, such as cellular or paging systems.Type: GrantFiled: November 20, 2006Date of Patent: April 20, 2010Assignee: Motorola, Inc.Inventors: Vijay Nangia, Kevin Lynn Baum, Karthik Ramasubramanian
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Patent number: 7583764Abstract: The present invention provides a system for obviating interference effects in packet detection within a wireless communications network. A plurality of reference signals is provided—a first of which corresponds to desired packets, and the remainder of which correspond to undesired packets or interference. A plurality of cross-correlation constructs corresponds, respectively, to the plurality of reference signals. Each cross-correlation construct correlates an incoming signal to a plurality of repetitions of its respective reference signal. An analysis construct compares output from each cross-correlation construct with other cross-correlation construct outputs, and with a threshold value, to determine which incoming signal corresponds to desired packet data. Once this incoming signal is identified, packets from the signal may be reliably received.Type: GrantFiled: May 26, 2006Date of Patent: September 1, 2009Assignee: Texas Instruments IncorporatedInventors: Karthik Ramasubramanian, Sthanunathan Ramakrishnan
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Publication number: 20090168843Abstract: An electronic circuit includes a receiver circuit (BSP) operable to perform coherent summations having a coherent summations time interval, and a power control circuit (2130) coupled to said receiver circuit (BSP) and operable to impress a power controlling duty cycle (TON, TOFF) on the receiver circuit (BSP) inside the coherent summations time interval. Other circuits, devices, systems, methods of operation and processes of manufacture are also disclosed.Type: ApplicationFiled: October 2, 2008Publication date: July 2, 2009Applicant: TEXAS INSTRUMENTS INCORPORATEDInventors: Deric Wayne Waters, Karthik Ramasubramanian, Arun Raghupathy
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Publication number: 20070286067Abstract: In at least some embodiments, a system may comprise one or more devices configurable to communicate according to a first protocol that implements a first data packet, and one or more devices configurable to communicate according to a second protocol that implements a second data packet having a predetermined quadrature component. The one or more devices configurable to communicate according to the second protocol associate detection of the predetermined quadrature component with a function that is not supported by the one or more devices that communicate according to the first protocol.Type: ApplicationFiled: August 24, 2007Publication date: December 13, 2007Applicant: TEXAS INSTRUMENTS INCORPORATEDInventors: Arndt Mueller, Karthik Ramasubramanian
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Publication number: 20070274205Abstract: The present invention provides a system for obviating interference effects in packet detection within a wireless communications network. A plurality of reference signals is provided—a first of which corresponds to desired packets, and the remainder of which correspond to undesired packets or interference. A plurality of cross-correlation constructs corresponds, respectively, to the plurality of reference signals. Each cross-correlation construct correlates an incoming signal to a plurality of repetitions of its respective reference signal. An analysis construct compares output from each cross-correlation construct with other cross-correlation construct outputs, and with a threshold value, to determine which incoming signal corresponds to desired packet data. Once this incoming signal is identified, packets from the signal may be reliably received.Type: ApplicationFiled: May 26, 2006Publication date: November 29, 2007Applicant: TEXAS INSTRUMENTS INCORPORATEDInventors: Karthik Ramasubramanian, Sthanunathan Ramakrishnan
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Publication number: 20070091866Abstract: A multi-rate interleaved frequency division multiple access (IFDMA) modulation scheme permits users to transmit at different data rates or to vary their data rates while providing frequency diversity and preserving low peak-to-average power ratios and orthogonality between user data rates. The modulation scheme allows user-specific data block and repetition sizes, as well as user-specific modulation codes. Code assignment rules are provided for maintaining orthogonality between the different user data rates. Block and phase ramp modulation codes can be used. Asynchronous transmissions by users are supported by ensuring that the length of the cyclic extension is sufficiently long to tolerate worst case relative signal arrival delays between users and the channel pulse response duration over the communication medium. The modulation scheme can be employed in wireless communication systems, such as cellular or paging systems.Type: ApplicationFiled: November 20, 2006Publication date: April 26, 2007Applicant: MOTOROLA, INC.Inventors: Vijay Nangia, Kevin Baum, Karthik Ramasubramanian
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Patent number: 7139237Abstract: A multi-rate interleaved frequency division multiple access (IFDMA) modulation scheme permits users to transmit at different data rates or to vary their data rates while providing frequency diversity and preserving low peak-to-average power ratios and orthogonality between users at different data rates. The modulation scheme allows user-specific data block and repetition sizes, as well as user-specific modulation codes. Code assignment rules are provided for maintaining orthogonality between users having different data rates. Block and phase ramp modulation codes can be used. Asynchronous transmissions by users are supported by ensuring that the length of the cyclic extension is sufficiently long to tolerate worst case relative signal arrival delays between users and the channel pulse response duration over the communication medium. The modulation scheme can be employed in wireless communication systems, such as cellular or paging systems.Type: GrantFiled: September 24, 2001Date of Patent: November 21, 2006Assignee: Motorola, Inc.Inventors: Vijay Nangia, Kevin Lynn Baum, Karthik Ramasubramanian
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Patent number: 7133474Abstract: A timing recovery scheme demarcates a complete range of inter-symbol interference free (ISI-free) sampling positions available in a cyclically extended symbol. The timing recovery scheme computes an ensemble correlation between the cyclic extension and the data part of symbols to estimate timing. The ensemble correlation function retains delay-spread and timing information by separately maintaining the correlation value for each sample position within the symbol duration and combines the correlation values for identical sample positions over an ensemble of symbols. In this manner, the scheme not only provides timing estimates, but can also provide estimates of the multipath delay-spread in a channel. The delay-spread estimates provide valuable information about the nature of the channel. A receiver can use this information, for example, to adjust the frequency-domain channel interpolation filter bandwidth in order to improve performance for the given channel condition.Type: GrantFiled: July 31, 2001Date of Patent: November 7, 2006Assignee: Motorola, Inc.Inventors: Karthik Ramasubramanian, Kevin Lynn Baum
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Publication number: 20050180310Abstract: In at least some embodiments, a system may comprise one or more devices configurable to communicate according to a first protocol that implements a first data packet, and one or more devices configurable to communicate according to a second protocol that implements a second data packet having a predetermined quadrature component. The one or more devices configurable to communicate according to the second protocol associate detection of the predetermined quadrature component with a function that is not supported by the one or more devices that communicate according to the first protocol.Type: ApplicationFiled: February 13, 2004Publication date: August 18, 2005Applicant: Texas Instruments IncorporatedInventors: Arndt Mueller, Karthik Ramasubramanian
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Publication number: 20030026360Abstract: A timing recovery scheme demarcates a complete range of inter-symbol interference free (ISI-free) sampling positions available in a cyclically extended symbol. The timing recovery scheme computes an ensemble correlation between the cyclic extension and the data part of symbols to estimate timing. The ensemble correlation function retains delay-spread and timing information by separately maintaining the correlation value for each sample position within the symbol duration and combines the correlation values for identical sample positions over an ensemble of symbols. In this manner, the scheme not only provides timing estimates, but can also provide estimates of the multipath delay-spread in a channel. The delay-spread estimates provide valuable information about the nature of the channel. A receiver can use this information, for example, to adjust the frequency-domain channel interpolation filter bandwidth in order to improve performance for the given channel condition.Type: ApplicationFiled: July 31, 2001Publication date: February 6, 2003Inventors: Karthik Ramasubramanian, Kevin Lynn Baum