Patents by Inventor Bernard Arambepola

Bernard Arambepola 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: 8396144
    Abstract: A method and system for OFDM symbol timing recovery is described. A symbol timing recovery module of an OFDM receiver is configured to determine an optimum trigger point for performing a discrete Fourier transform in a manner that minimizes inter-symbol interference.
    Type: Grant
    Filed: December 31, 2008
    Date of Patent: March 12, 2013
    Assignee: Intel Corporation
    Inventors: Bernard Arambepola, Parveen K. Shukla, Thushara Hewavithana
  • Patent number: 8392802
    Abstract: Methods and systems to identify a codeword associated with samples of a signal from spectral content of the samples, and to estimate a frequency offset from the spectral contents. The samples may correspond to a physical layer header of a data frame. Modulation may be removed from the samples in accordance with each of a plurality of modulation sequences, each sequence associated with a corresponding codeword. Power levels in spectral contents of the modulation-removed samples are examined to identify a peak power level indicative of a match between a modulation sequence and the samples. The corresponding codeword is identified as being associated with the header, and transmission parameters associated with the identified codeword are used to decode a corresponding frame. An estimated frequency offset may be determined from a frequency associated with the peak power level.
    Type: Grant
    Filed: December 23, 2009
    Date of Patent: March 5, 2013
    Assignee: Intel Corporation
    Inventors: Bernard Arambepola, Vinesh Bhunjun, Thushara Hewavithana, Parveen K. Shukla, Sahan Gamage
  • Publication number: 20130022097
    Abstract: According to various embodiments, devices and methods disclosed herein include performing, using a processor, a linear operation on a first plurality of channel frequency responses and a plurality of corresponding predictor coefficients to estimate a new channel frequency response. Each of the plurality of corresponding predictor coefficients may be updated based on an error value and a second plurality of channel frequency responses to obtain an updated predictor coefficient. The error value may be computed based on an estimated current channel frequency response and a predicted current channel frequency response. The new channel frequency response may be used to equalize a received modulated signal including a single-carrier modulated signal, e.g., a signal modulated using a vestigial sideband modulation scheme, or a quadrature amplitude modulation scheme.
    Type: Application
    Filed: July 18, 2011
    Publication date: January 24, 2013
    Inventors: Thushara HEWAVITHANA, Bernard ARAMBEPOLA, Sahan S. GAMAGE, Parveen K. SHUKLA
  • Patent number: 8351862
    Abstract: Device, system, and method of mitigating interference to digital television signals. For example, an apparatus includes a diversity-based digital television receiver having a filter controller and at least first and second channel paths, wherein the first channel path includes a first Global System for Mobile communication (GSM) reject filter, the second channel path includes a second GSM reject filter, the second channel path is parallel to the first channel path, and the filter controller is to selectively switch an operational state of the first GSM reject filter.
    Type: Grant
    Filed: January 1, 2008
    Date of Patent: January 8, 2013
    Assignee: Intel Corporation
    Inventors: Ernest T. Tsui, Nick Cowley, Bernard Arambepola
  • Patent number: 8340222
    Abstract: Methods and systems to resolve the cyclic time ambiguity of a scattered pilot based channel impulse response, including to determine a channel impulse response from a combination of scattered pilots and encoded parameters, such as L1-pre signaling within P2 symbols of a terrestrial digital video broadcast (DVD) in a single frequency network (SFN), and including to re-use a corresponding window time to track the channel impulse response in the absence of encoded parameters. Methods and systems disclosed herein may be implemented with respect to channel acquisition and tracking, including adjusting a Fast Fourier Transform trigger point to reduce inter-symbol interference.
    Type: Grant
    Filed: December 24, 2009
    Date of Patent: December 25, 2012
    Assignee: Intel Corporation
    Inventors: Bernard Arambepola, Thushara Hewavithana, Praveen K. Shukla
  • Patent number: 8340227
    Abstract: An embodiment of the present invention provides an apparatus, comprising a digital demodulator including an automatic gain control (AGC) circuit with a self-adapting target to provide optimum performance under all signal conditions.
    Type: Grant
    Filed: August 25, 2008
    Date of Patent: December 25, 2012
    Assignee: Intel Corporation
    Inventors: Parveen K Shukla, Bernard Arambepola, Thushara Hewavithana
  • Patent number: 8275057
    Abstract: Methods and systems to determine channel frequency responses corresponding to multi-carrier signals, such as OFDM signals, including to filter or mask noise from channel frequency response estimates in a time domain.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: September 25, 2012
    Assignee: Intel Corporation
    Inventors: Thushara Hewavithana, Bernard Arambepola, Parveen K. Shukla
  • Publication number: 20120212675
    Abstract: An embodiment of the present invention provides a method for digital television demodulation, comprising using adjacent-channel power dependent automatic gain control (AGC) for the digital television demodulation, wherein an AGC technique takes into account a total power as well as power of adjacent channels to control gain of a gain control amplifier.
    Type: Application
    Filed: February 22, 2011
    Publication date: August 23, 2012
    Inventors: Parveen K. Shukla, Bernard Arambepola, Thushara Hewavithana, Sahan S. Gamage
  • Patent number: 8237870
    Abstract: Disclosed is a receiver system, capable of receiving RF signals on television channels of multiple bandwidths. The receiver system includes a tuner, an analog IF filter, an ADC, a mixer module, one or more digital filters, an AGC module and a controller. The tuner converts an RF signal into an IF signal using a mixer frequency. The analog IF filter filters out a fixed band signal from the IF signal. The ADC module converts the fixed band signal into a digital signal, which is filtered by digital filters. The output of the digital filters is converted to a base band signal and the power level of the base band signal is controlled by the AGC module. The controller selects a mixer frequency from a group of mixer frequencies based on a function of power of the output of the AGC module by applying each mixer frequency to the tuner.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: August 7, 2012
    Assignee: Intel Corporation
    Inventors: Parveen K Shukla, Bernard Arambepola, Thushara Hewavithana
  • Patent number: 8234556
    Abstract: Embodiments of a broadcast receiver and method for optimizing a scale factor in a log-likelihood ratio (LLR) mapper are generally described herein. In some embodiments, the broadcast receiver includes an LLR mapper to generate LLRs from demodulated data samples, a low-density parity-check (LDPC) decoder to generate decoded data from the LLRs, and an LLR optimizer to dynamically select a scale factor for the LLR mapper based on a number of iterations for convergence of the LDPC decoder. In some embodiments, the LLR optimizer iteratively revises the scale factor during receipt of broadcast signals until the number of iterations of the iterative decoder is either minimized for convergence or minimized for convergence failures.
    Type: Grant
    Filed: December 30, 2008
    Date of Patent: July 31, 2012
    Assignee: Intel Corporation
    Inventors: Sahan S. Gamage, Bernard Arambepola, Thushara Hewavithana, Parveen K. Shukla, Vinesh Bhunjun
  • Publication number: 20120155577
    Abstract: According to various embodiments, a method is disclosed that includes receiving an orthogonal frequency-division multiplexing (OFDM) modulated signal at a modulator; filtering the received modulated signal using a plurality of sets of filter coefficients with a linear predictor algorithm; and estimating a channel frequency response based on the filtering.
    Type: Application
    Filed: December 21, 2010
    Publication date: June 21, 2012
    Inventors: Parveen K. SHUKLA, Bernard Arambepola, Thushara Hewavithana, Sahan S. Gamage
  • Patent number: 8204156
    Abstract: Apparatuses, systems, and methods that employ conditional probabilities to calculate phase errors are disclosed. For a received signal, the embodiments may develop several phase error estimates relative to each point of a constellation, the number and location of points of the constellation depending on the modulation technique of the received signal. In addition to calculating the phase error estimates, the embodiments may also calculate weights, or probabilities, associated with each of the estimates. The embodiments may use the estimates and the weights to calculate a composite phase error estimate. The composite phase error estimate may be used to correct the received signal and eliminate or reduce the impact of the phase error.
    Type: Grant
    Filed: December 31, 2008
    Date of Patent: June 19, 2012
    Assignee: Intel Corporation
    Inventors: Thushara Hewavithana, Bernard Arambepola, Parveen K. Shukla, Sahan S. Gamage, Vinesh Bhunjun
  • Publication number: 20120134398
    Abstract: According to various embodiments, a method is disclosed that includes a method is disclosed that includes determining, by a receiver, a frequency offset in a signal comprising a set of orthogonal frequency division multiplexed (OFDM) symbols by determining a first difference in phase angles between a nth OFDM symbol and a nth+1 OFDM symbol on a common OFDM carrier and a first difference in phase angles between the nth+1 OFDM symbol and a nth+2 OFDM symbol on the common OFDM carrier and determining a second difference in phase angles between the first difference in phase angles between the nth OFDM symbol and the nth+1 OFDM system and the first difference in phase angles between the nth+1 OFDM symbol and the nth+2 OFDM symbol to identify the frequency offset, wherein n?{1, . . . , N}; and correcting, by the receiver, the signal using the determined frequency offset.
    Type: Application
    Filed: November 30, 2010
    Publication date: May 31, 2012
    Inventors: Sahan S. Gamage, Bernard Arambepola, Thushara Hewavithana, Parveen K. Shukla
  • Publication number: 20120051469
    Abstract: Methods and systems to compute likelihood measures of demodulated, complex-coordinate data points, to and dynamically scale the likelihood measures as a function of a channel statistic, and to decode the data points from the scaled likelihood measures. Likelihood measures may be computed relative to all points, or a subset of points of a reference constellation, such as a subset of one or more nearest constellation points. Likelihood measures may be scaled as a function of a channel frequency response variance amongst a plurality of carriers, such as carriers of an OFDM signal, and/or as a function of a channel impulse response variance.
    Type: Application
    Filed: August 25, 2010
    Publication date: March 1, 2012
    Inventors: Sahan S. Gamage, Bernard Arambepola, Thushara Hewavithana, Parveen K. Shukla, Vinesh Bhunjun
  • Publication number: 20120051471
    Abstract: Methods and systems to resolve cyclic ambiguity of a scattered-pilot based channel impulse response as a function of transmission parameter signalling (TPS), such as in a single frequency network, including to zero-pad a first orientation of the channel impulse response to an interval of an effective symbol duration of the multi-carrier signal, compute a channel frequency response from the zero-padded first orientation of the channel impulse response, and correlate components of the channel frequency response corresponding to frequencies of TPS carriers with raw channel frequency response data of obtained from the TPS carriers. Frequency response components of multiple zero-padded orientations of the channel impulse response may be correlated with the raw TPS carrier data to identify an optimum orientation of the channel impulse response. Frequency response components of subsequent zero-padded orientations may be iteratively computed from components of preceding orientations.
    Type: Application
    Filed: August 25, 2010
    Publication date: March 1, 2012
    Inventors: Thushara Hewavithana, Bernard Arambepola, Parveen K. Shukla, Sahan S. Gamage, Vinesh Bhunjun
  • Patent number: 8116404
    Abstract: The present disclosure provides a diversity receiver. The diversity receiver includes a plurality of tuners, a plurality of demodulators operatively coupled to the plurality of tuners and a controller operatively coupled to the plurality of demodulators and the plurality of tuners. Each tuner is capable of receiving a modulated signal from a path of a plurality of distinct paths. The controller determines information for each path and computes a ratio of signal strength to an additive noise for each path based on determined information. Further, the controller adjusts power of signal in each path based on comparison of computed ratio of signal strength to additive noise with a predetermined threshold. The diversity receiver also includes a MRC circuitry operatively coupled to the plurality of demodulators and configured to combine the signal of each path for obtaining a resultant combined signal having an improved ratio of signal strength to additive noise.
    Type: Grant
    Filed: October 10, 2007
    Date of Patent: February 14, 2012
    Assignee: Intel Corporation
    Inventors: Bernard Arambepola, Nick Cowley
  • Publication number: 20120014372
    Abstract: Embodiments of methods for receiving and processing multi-band signals in wideband and narrowband environments are described herein. Other embodiments may be described and claimed.
    Type: Application
    Filed: September 26, 2011
    Publication date: January 19, 2012
    Inventors: Bernard Arambepola, Tony Cole, Parveen Shukla, Thushara Hewavithana, Sahan Gamage
  • Patent number: 8085859
    Abstract: In one embodiment of the invention, a Fourier transform unit converts unsynchronized data received through multiple antennas to a frequency domain. Also, a spectrum estimation unit determines a power spectrum for the unsynchronized data. A notch filter removes data within a frequency band from additional unsynchronized data based on the power spectrum. A synchronization unit synchronizes the notch filtered data and a noise estimation unit determines a noise covariance matrix between the synchronized data received from multiple antennas. In addition, an equalization unit performs channel equalization on the synchronized data based on the noise covariance matrix.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: December 27, 2011
    Assignee: Intel Corporation
    Inventors: Yongfang Guo, Lei Shao, Ernest T. Tsui, Bernard Arambepola, Thushara Hewavithana, Xintian D. Lin
  • Patent number: 8059687
    Abstract: Embodiments of methods for receiving and processing multi-band signals in wideband and narrowband environments are described herein. Other embodiments may be described and claimed.
    Type: Grant
    Filed: December 16, 2008
    Date of Patent: November 15, 2011
    Assignee: Intel Corporation
    Inventors: Bernard Arambepola, Tony Cole, Parveen Shukla, Thushara Hewavithana, Sahan Gamage
  • Patent number: 8036319
    Abstract: A direct conversion receiver and a method for correcting phase imbalance including applying an input signal to an in-phase channel and a quadrature channel of the receiver. The input signal is processed by the receiver to obtain an in-phase zero intermediate frequency (IF) signal in the in-phase channel and a quadrature zero-IF signal in the quadrature channel. The in-phase zero-IF signal and the quadrature zero-IF signal are filtered to obtain a fixed band signal. A phase imbalance correction value is obtained for the fixed-band quadrature zero-IF signal as a function of the frequency of the fixed-band in-phase zero-IF signal and the fixed-band quadrature zero-IF signal. The in-phase zero-IF signal and the quadrature zero-IF signal are sampled and the phase imbalance correction value is applied using an interpolation to the sampled quadrature zero-IF signal or to the sampled in-phase zero-IF signal to correct the phase imbalance in the direct conversion receiver.
    Type: Grant
    Filed: November 1, 2007
    Date of Patent: October 11, 2011
    Assignee: Intel Corporation
    Inventors: Bernard Arambepola, Nick Cowley