Patents by Inventor Timothy M. Schmidl

Timothy M. Schmidl 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: 8649446
    Abstract: A system and method for classifying a channel with regard to delay spread in a wireless network applying orthogonal frequency division multiplexing. In one embodiment, a wireless receiver includes a channel classifier. The channel classifier is configured to compute a channel estimate corresponding to a channel traversed by a packet received by the wireless receiver. The channel classifier is also configured to partition the channel estimate into a plurality of windows. Each window corresponds to a range of time of the channel estimate. The channel classifier is further configured to assign a delay spread classification to the channel based on a distribution of energy across the windows.
    Type: Grant
    Filed: October 28, 2011
    Date of Patent: February 11, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Taejoon Kim, Timothy M. Schmidl, Tarkesh Pande, Anuj Batra, June Chul Roh
  • Patent number: 8644428
    Abstract: A system and method for channel interpolation in a wireless device. In one embodiment a wireless device includes a channel estimator. The channel estimator is configured to generate estimated channel coefficients for a wireless channel over which the wireless device receives a packet. The channel estimator includes an interpolation filter. The interpolation filter is configured to provide interpolated channel coefficients for a plurality of non-pilot sub-carriers. The interpolated channel coefficients are based on pilot sub-carriers of non-preamble symbols.
    Type: Grant
    Filed: October 28, 2011
    Date of Patent: February 4, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Taejoon Kim, Timothy M. Schmidl
  • Publication number: 20130343366
    Abstract: In at least some embodiments, a communication device includes a transceiver with a physical (PHY) layer. The PHY layer is configured for body area network (BAN) operations in a limited multipath environment based on a constant symbol rate for BAN packet transmissions and based on M-ary PSK, differential M-ary PSK or rotated differential M-ary PSK modulation. The PHY layer is configured to transmit and receive data in a frequency band selected from the group consisting of: 402-405 MHz, 420-450 MHz, 863-870 MHz, 902-928 MHz, 950-956 MHz, 2360-2400 MHz, and 2400-2483.5 MHz.
    Type: Application
    Filed: June 13, 2013
    Publication date: December 26, 2013
    Inventors: Anuj Batra, Timothy M. Schmidl, Srinath Hosur, June C. Roh
  • Patent number: 8605568
    Abstract: In at least some embodiments, a communication device includes a transceiver with a physical (PHY) layer. The PHY layer is configured for body area network (BAN) operations in a limited multipath environment using M-ary PSK, differential M-ary PSK or rotated differential M-ary PSK. Also, the PHY layer uses a constant symbol rate for BAN packet transmissions.
    Type: Grant
    Filed: April 14, 2010
    Date of Patent: December 10, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Anuj Batra, Timothy M. Schmidl, Srinath Hosur, June Chul Roh
  • Patent number: 8570946
    Abstract: System and method for signaling control information in a multi-carrier communications system to transmit data. A preferred embodiment comprises demodulating a first carrier that is used for transmitting a control channel transmission, determining a second carrier that is used for transmitting a data channel transmission based upon the demodulated control channel transmission, and demodulating the second carrier to obtain the data channel transmission. Additionally, designs for multi-carrier receivers are provided.
    Type: Grant
    Filed: November 18, 2010
    Date of Patent: October 29, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Timothy M. Schmidl, Eko N. Onggosanusi, Anand G. Dabak, Aris Papasakellariou, Jaiganesh Balakrishnan, Yan Hui
  • Patent number: 8553730
    Abstract: A method includes receiving a first plurality of symbols comprising complex portions. The method further includes applying conjugate symmetry to the first plurality of symbols, producing a second plurality of symbols comprising no complex portions. The method further includes transforming the second plurality of symbols using an inverse fast Fourier transform, producing a third plurality of symbols. The method further includes interpolating the third plurality of symbols, generating a short training field comprising at least one real portion of the third plurality of symbols, generating a long training field comprising at least one real portion of the third plurality of symbols, and transmitting the short training field and long training field in a WPAN.
    Type: Grant
    Filed: August 25, 2010
    Date of Patent: October 8, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Timothy M. Schmidl, Anuj Batra, Srinath Hosur
  • Patent number: 8503553
    Abstract: An integrated circuit includes logic configured to encode pilot signals in a first set of subcarriers of an orthogonal frequency division multiplexing (“OFDM”) symbol and in a second set of subcarriers of a consecutive OFDM symbol. The symbol and the consecutive symbol are in the same smart-utility-network packet.
    Type: Grant
    Filed: December 6, 2010
    Date of Patent: August 6, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Timothy M. Schmidl, Anuj Batra
  • Patent number: 8488655
    Abstract: In at least some embodiments, a communication device includes a transceiver with a physical (PHY) layer. The PHY layer is configured for body area network (BAN) operations in a limited multipath environment based on a constant symbol rate for BAN packet transmissions and based on M-ary PSK, differential M-ary PSK or rotated differential M-ary PSK modulation. The PHY layer is configured to transmit and receive data in a frequency band selected from the group consisting of: 402-405 MHz, 420-450 MHz, 863-870 MHz, 902-928 MHz, 950-956 MHz, 2360-2400 MHz, and 2400-2483.5 MHz.
    Type: Grant
    Filed: April 14, 2010
    Date of Patent: July 16, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Anuj Batra, Timothy M. Schmidl, Srinath Hosur, June Chul Roh
  • Patent number: 8483327
    Abstract: A convolutionally encoded frame to be decoded includes a first portion of bits having additional error protection and another portion without additional error protection. The decoding of the frame involves reverse Viterbi decoding or Viterbi decoding on a reversed bit sequence followed by applying a serial list Viterbi algorithm to the first portion. The result is that the list of probable sequences have unique sets of bits in the first portion.
    Type: Grant
    Filed: March 20, 2009
    Date of Patent: July 9, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Timothy M. Schmidl, Ariel Zaltsman, Anand G. Dabak
  • Patent number: 8472569
    Abstract: Systems and methods for fine symbol timing estimation are disclosed herein. In one embodiment, a wireless receiver includes a differential detector, a correlator, a coarse symbol timing estimator, and a fine symbol timing estimator. The differential detector is configured to detect phase differences in a received preamble signal modulated using differential phase shift keying. The correlator is configured to correlate symbol values output by the differential detector against a reference sequence. The coarse symbol timing estimator is configured to generate a coarse symbol timing estimate, and to generate a coarse timing sample symbol index value corresponding to the coarse symbol timing estimate. The fine symbol timing estimator is configured to generate a fine symbol timing estimate that is more accurate than the coarse symbol timing estimate based on the coarse timing sample symbol index value and correlation samples at index values preceding and succeeding the coarse timing sample index value.
    Type: Grant
    Filed: December 6, 2010
    Date of Patent: June 25, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: June Chul Roh, Srinath Hosur, Timothy M. Schmidl
  • Patent number: 8446934
    Abstract: An integrated circuit includes logic configured to encode one or more first data symbols in one or more first sub-carriers as one or more second data symbols in one or more second sub-carriers of a smart-utility-network communication.
    Type: Grant
    Filed: August 31, 2010
    Date of Patent: May 21, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Timothy M. Schmidl, Anuj Batra, Srinath Hosur
  • Patent number: 8437245
    Abstract: A integrated circuit includes logic configured to support smart-utility-network communication using an integer number of data bits per symbol for 96, 48, 24, 12, and 4 data subcarriers across IFFT sizes of 128, 64, 32, 16, and 8.
    Type: Grant
    Filed: August 31, 2010
    Date of Patent: May 7, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Timothy M. Schmidl, Anuj Batra, Srinath Hosur
  • Patent number: 8391228
    Abstract: In at least some embodiments, a communication device includes a transceiver with a physical (PHY) layer. The PHY layer is configured for body area network (BAN) operations in a limited multipath environment based on a constant symbol rate for BAN packet transmissions and based on M-ary PSK, differential M-ary PSK or rotated differential M-ary PSK modulation. The PHY layer is configured to construct a physical-layer service data unit (PSDU) based on a concatenate block, an insert shortened bits block, a Bose, Ray-Chaudhuri, Hocquenghem (BCH) encoder, a remove shortened bits block, an add pad bits block, a spreader, a bit interleaver, a scrambler, and a symbol mapper.
    Type: Grant
    Filed: April 14, 2010
    Date of Patent: March 5, 2013
    Assignee: Texas Instruments Incorporated
    Inventors: Anuj Batra, Timothy M. Schmidl, Srinath Hosur, June Chul Roh
  • Patent number: 8290084
    Abstract: A circuit is designed with a matched filter circuit including a plurality of fingers (700, 702, 704) coupled to receive a data symbol. Each finger corresponds to a respective path of the data symbol. Each finger produces a respective output signal. A plurality of decoder circuits (706, 708, 710) receives the respective output signal from a respective finger of the plurality of fingers. Each decoder circuit produces a respective output signal. A joint detector circuit (1310) is coupled to receive each respective output signal from the plurality of decoder circuits. The joint detector circuit produces an output signal corresponding to a predetermined code.
    Type: Grant
    Filed: March 10, 2010
    Date of Patent: October 16, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Anand G. Dabak, Timothy M. Schmidl, Chaitali Sengupta
  • Publication number: 20120195246
    Abstract: Embodiments of the invention provide methods for maximizing the bandwidth utilization in the uplink of a communication system supporting time division multiplexing between unicast and multicast/broadcast communication modes during transmission time intervals in the downlink of a communication system. This is accomplished by multiplexing at least unicast control signaling for UL scheduling assignments in TTIs supporting the multicast/broadcast communication mode. Moreover, multiplexing of unicast control signaling can also be accomplished by splitting a symbol of the multicast/broadcast TTI into two shorter symbols with the first of these two shorter symbols carrying at least unicast control signaling and the second of these shorter symbols carrying multicast/broadcast signaling.
    Type: Application
    Filed: April 13, 2012
    Publication date: August 2, 2012
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Aris Papasakellariou, Timothy M. Schmidl, Eko N. Onggosanusi, Anand Dabak
  • Patent number: 8223867
    Abstract: A data encoding algorithm can be used (120) to generate overhead bits from original data bits, and the original data bits and overhead bits can be transmitted in respectively separate transmissions (121, 123), if the overhead bits are needed. At the receiver, the original data bits can be determined (125) from the received overhead bits, or the received data bits and the received overhead bits can be combined and decoded together (126) to produce the original data bits.
    Type: Grant
    Filed: February 5, 2001
    Date of Patent: July 17, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Timothy M. Schmidl, Anand G. Dabak, Mohammed Nafie
  • Publication number: 20120163497
    Abstract: In at least some embodiments, a receiver includes channel estimation logic configured to a process a long training field symbol having a doubled cyclic prefix. The channel estimation logic is configured to vary an amount of the doubled cyclic prefix used for channel estimation. Further, in some embodiments, a wireless communication device includes logic to enable communications based on at least two long training field symbols having a doubled cyclic prefix as part of a synchronization header. Further, in some embodiments, a method includes receiving a long training field symbol having a synchronization header with a doubled cyclic prefix and varying an amount of the doubled cyclic prefix used for channel estimation.
    Type: Application
    Filed: December 22, 2011
    Publication date: June 28, 2012
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Taejoon KIM, Timothy M. Schmidl
  • Publication number: 20120140858
    Abstract: Systems and methods for fine symbol timing estimation are disclosed herein. In one embodiment, a wireless receiver includes a differential detector, a correlator, a coarse symbol timing estimator, and a fine symbol timing estimator. The differential detector is configured to detect phase differences in a received preamble signal modulated using differential phase shift keying. The correlator is configured to correlate symbol values output by the differential detector against a reference sequence. The coarse symbol timing estimator is configured to generate a coarse symbol timing estimate, and to generate a coarse timing sample symbol index value corresponding to the coarse symbol timing estimate. The fine symbol timing estimator is configured to generate a fine symbol timing estimate that is more accurate than the coarse symbol timing estimate based on the coarse timing sample symbol index value and correlation samples at index values preceding and succeeding the coarse timing sample index value.
    Type: Application
    Filed: December 6, 2010
    Publication date: June 7, 2012
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: June Chul ROH, Srinath HOSUR, Timothy M. SCHMIDL
  • Patent number: 8175021
    Abstract: Embodiments of the invention provide methods for maximizing the bandwidth utilization in the uplink of a communication system supporting time division multiplexing between unicast and multicast/broadcast communication modes during transmission time intervals in the downlink of a communication system. This is accomplished by multiplexing at least unicast control signaling for UL scheduling assignments in TTIs supporting the multicast/broadcast communication mode. Moreover, multiplexing of unicast control signaling can also be accomplished by splitting a symbol of the multicast/broadcast TTI into two shorter symbols with the first of these two shorter symbols carrying at least unicast control signaling and the second of these shorter symbols carrying multicast/broadcast signaling.
    Type: Grant
    Filed: October 31, 2006
    Date of Patent: May 8, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Aris Papasakellariou, Timothy M Schmidl, Eko N. Onggosanusi, Anand Dabak
  • Publication number: 20120106611
    Abstract: A phase-locking loop (PLL) for use with orthogonal frequency division multiplexed signals. In one embodiment, a wireless receiver includes a PLL is configured to reduce phase and frequency divergence between the wireless receiver and a transmitter of a packet received by the wireless receiver. The PLL includes a loop bandwidth controller. The loop bandwidth controller is configured to set a bandwidth of the PLL to a first value for reception of an initial symbol of the packet. The loop bandwidth controller is configured to reduce the bandwidth of the PLL over a number of symbols preceding an initial header of the packet.
    Type: Application
    Filed: October 28, 2011
    Publication date: May 3, 2012
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Taejoon KIM, Timothy M. SCHMIDL, Srinath HOSUR