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).
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Patent number: 8649446Abstract: 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: GrantFiled: October 28, 2011Date of Patent: February 11, 2014Assignee: Texas Instruments IncorporatedInventors: Taejoon Kim, Timothy M. Schmidl, Tarkesh Pande, Anuj Batra, June Chul Roh
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Patent number: 8644428Abstract: 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: GrantFiled: October 28, 2011Date of Patent: February 4, 2014Assignee: Texas Instruments IncorporatedInventors: Taejoon Kim, Timothy M. Schmidl
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Publication number: 20130343366Abstract: 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: ApplicationFiled: June 13, 2013Publication date: December 26, 2013Inventors: Anuj Batra, Timothy M. Schmidl, Srinath Hosur, June C. Roh
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Patent number: 8605568Abstract: 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: GrantFiled: April 14, 2010Date of Patent: December 10, 2013Assignee: Texas Instruments IncorporatedInventors: Anuj Batra, Timothy M. Schmidl, Srinath Hosur, June Chul Roh
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Patent number: 8570946Abstract: 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: GrantFiled: November 18, 2010Date of Patent: October 29, 2013Assignee: Texas Instruments IncorporatedInventors: Timothy M. Schmidl, Eko N. Onggosanusi, Anand G. Dabak, Aris Papasakellariou, Jaiganesh Balakrishnan, Yan Hui
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Patent number: 8553730Abstract: 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: GrantFiled: August 25, 2010Date of Patent: October 8, 2013Assignee: Texas Instruments IncorporatedInventors: Timothy M. Schmidl, Anuj Batra, Srinath Hosur
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Patent number: 8503553Abstract: 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: GrantFiled: December 6, 2010Date of Patent: August 6, 2013Assignee: Texas Instruments IncorporatedInventors: Timothy M. Schmidl, Anuj Batra
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Patent number: 8488655Abstract: 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: GrantFiled: April 14, 2010Date of Patent: July 16, 2013Assignee: Texas Instruments IncorporatedInventors: Anuj Batra, Timothy M. Schmidl, Srinath Hosur, June Chul Roh
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Patent number: 8483327Abstract: 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: GrantFiled: March 20, 2009Date of Patent: July 9, 2013Assignee: Texas Instruments IncorporatedInventors: Timothy M. Schmidl, Ariel Zaltsman, Anand G. Dabak
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Patent number: 8472569Abstract: 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: GrantFiled: December 6, 2010Date of Patent: June 25, 2013Assignee: Texas Instruments IncorporatedInventors: June Chul Roh, Srinath Hosur, Timothy M. Schmidl
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Patent number: 8446934Abstract: 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: GrantFiled: August 31, 2010Date of Patent: May 21, 2013Assignee: Texas Instruments IncorporatedInventors: Timothy M. Schmidl, Anuj Batra, Srinath Hosur
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Patent number: 8437245Abstract: 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: GrantFiled: August 31, 2010Date of Patent: May 7, 2013Assignee: Texas Instruments IncorporatedInventors: Timothy M. Schmidl, Anuj Batra, Srinath Hosur
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Patent number: 8391228Abstract: 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: GrantFiled: April 14, 2010Date of Patent: March 5, 2013Assignee: Texas Instruments IncorporatedInventors: Anuj Batra, Timothy M. Schmidl, Srinath Hosur, June Chul Roh
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Patent number: 8290084Abstract: 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: GrantFiled: March 10, 2010Date of Patent: October 16, 2012Assignee: Texas Instruments IncorporatedInventors: Anand G. Dabak, Timothy M. Schmidl, Chaitali Sengupta
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Publication number: 20120195246Abstract: 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: ApplicationFiled: April 13, 2012Publication date: August 2, 2012Applicant: TEXAS INSTRUMENTS INCORPORATEDInventors: Aris Papasakellariou, Timothy M. Schmidl, Eko N. Onggosanusi, Anand Dabak
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Patent number: 8223867Abstract: 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: GrantFiled: February 5, 2001Date of Patent: July 17, 2012Assignee: Texas Instruments IncorporatedInventors: Timothy M. Schmidl, Anand G. Dabak, Mohammed Nafie
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Publication number: 20120163497Abstract: 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: ApplicationFiled: December 22, 2011Publication date: June 28, 2012Applicant: TEXAS INSTRUMENTS INCORPORATEDInventors: Taejoon KIM, Timothy M. Schmidl
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Publication number: 20120140858Abstract: 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: ApplicationFiled: December 6, 2010Publication date: June 7, 2012Applicant: TEXAS INSTRUMENTS INCORPORATEDInventors: June Chul ROH, Srinath HOSUR, Timothy M. SCHMIDL
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Patent number: 8175021Abstract: 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: GrantFiled: October 31, 2006Date of Patent: May 8, 2012Assignee: Texas Instruments IncorporatedInventors: Aris Papasakellariou, Timothy M Schmidl, Eko N. Onggosanusi, Anand Dabak
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Publication number: 20120106611Abstract: 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: ApplicationFiled: October 28, 2011Publication date: May 3, 2012Applicant: TEXAS INSTRUMENTS INCORPORATEDInventors: Taejoon KIM, Timothy M. SCHMIDL, Srinath HOSUR