Using A Training Sequence Patents (Class 370/292)
  • Patent number: 11736621
    Abstract: A method of quick set up of PSTN modem connection is proposed.
    Type: Grant
    Filed: March 12, 2021
    Date of Patent: August 22, 2023
    Inventor: Oleksandr Vasylyovych Tsaruk
  • Patent number: 11228465
    Abstract: A method of operation for an Ethernet transceiver is disclosed. The method includes entering a training sequence. The training sequence includes transferring uncoded two-level symbols to a link partner; exchanging updated precoder coefficients with the link partner; and directly following exchanging updated precoder coefficients, transferring multi-level symbols to the link partner. The multi-level symbols being encoded consistent with the exchanged updated precoder coefficients and having greater than two symbol levels.
    Type: Grant
    Filed: March 22, 2019
    Date of Patent: January 18, 2022
    Assignee: Marvell Asia Pte, Ltd.
    Inventors: Hossein Sedarat, Seid Alireza Razavi Majomard, Dragan Labalo, Ramin Farjadrad
  • Patent number: 10985800
    Abstract: Echo cancellation to alleviate timing varying channels may be provided. First, a feedback signal corresponding to one of a plurality of downstream paths and a combination upstream signal comprising a combination of upstream signals from a plurality of upstream paths may be received. Next, a plurality of echo corrected signals may be created using the feedback signal, the combination upstream signal, and a plurality of echo cancelation coefficients that each respectively correspond to each one of the plurality of echo corrected signals and that are different from each other. Then a one of the plurality of echo cancelation coefficients that corresponds to a one of the plurality of echo corrected signals that provides a best echo cancelation performance as compared to other ones of the plurality of echo corrected signals may be selected to use.
    Type: Grant
    Filed: February 17, 2020
    Date of Patent: April 20, 2021
    Assignee: CISCO TECHNOLOGY, INC.
    Inventors: John T. Chapman, Hang Jin, Tong Liu
  • Patent number: 10212759
    Abstract: A first field of a preamble of a physical layer (PHY) data unit is generated to include a first set of one or more information bits indicating a duration of the data unit and is formatted to conform to a first communication protocol such that the first field allows a receiver device conforming to a second communication protocol to determine the duration of the data unit. A second field of the preamble is generated to include a second set of one or more information bits indicating to a receiver device conforming to the first communication protocol that the data unit conforms to the first communication protocol. The second field is convolutionally coded using a tail biting technique, and the first field and the second field are modulated using a modulation scheme specified for a field corresponding to the first field and the second field, respectively, by the second communication protocol.
    Type: Grant
    Filed: August 8, 2016
    Date of Patent: February 19, 2019
    Assignee: Marvell World Trade Ltd.
    Inventor: Hongyuan Zhang
  • Patent number: 10027428
    Abstract: Provided is a method of calibrating a power for a multiple input and multiple output-orthogonal frequency division multiplexing transmitter having a plurality of antennas via a measurement equipment, the method including: receiving a cyclic delay diversity (CDD) signal simultaneously output from the transmitter to obtain a starting point of a frame of a corresponding signal; performing a fast Fourier transform on a sample proceeded from the starting point by an extent of a maximum CDD delay; calculating a channel coefficient; calculating a channel impulse response and a power of the channel impulse response; converting CDD delay values of each antenna into values in units of samples by using a sampling rate in the channel impulse response; mapping a peak point position of the channel impulse response to each antenna using CDD delay sample values; and simultaneously performing a power calibration of each antenna based on each peak point power.
    Type: Grant
    Filed: February 22, 2016
    Date of Patent: July 17, 2018
    Assignee: INNOWIRELESS CO., LTD.
    Inventors: Jin Soup Joung, Joo Hyeong Lee, Yong Hoon Lim, Byung Kwan Jang
  • Patent number: 9973368
    Abstract: A fine timing method is provided. The method comprises: calculating values of a first timing metric function based on cross-correlation between a received signal and M training sequences within a time period, to obtain a plurality of sets of X values spaced according to a certain pattern; calculating summations for the plurality of sets of X values, respectively; and determining the beginning of a data frame based on the calculated summations.
    Type: Grant
    Filed: August 12, 2013
    Date of Patent: May 15, 2018
    Assignee: Harman Internatioanl Industries, Incorporated
    Inventors: Wenjiang Pei, Jinguang Hao, Kai Wang, Zeng Yang
  • Patent number: 9860102
    Abstract: Disclosed is a method for transmitting signal in a communication system. A method for transmitting signal comprises generating a short training field (STF) comprising a cyclic prefix (CP) and an effective symbol period including four RP regions; generating a long training field (LTF) comprising a cyclic prefix (CP) and an effective symbol period including two RP regions; generating a frame comprising the STF and the LTF; and transmitting the frame. Thus, efficiency of the communication system may be enhanced by using the method.
    Type: Grant
    Filed: July 7, 2014
    Date of Patent: January 2, 2018
    Assignee: ELECTRONICS & TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Kap Seok Chang, Byung Jae Kwak, Moon Sik Lee
  • Patent number: 9553706
    Abstract: Reference signals may not uniformly span over time and/or frequency on a resource unit. For example, reference signals may non-uniformly occupy symbols of a subframe. Alternatively, reference signals normally transmitted over certain tones of a subframe may have to be punctured to avoid collisions with a PSS and/or SSS transmitted over the same tones. Consequently, a UE may only be able to use a subset of reference signal tones for performing channel estimation. Accordingly, a method, an apparatus, and a computer program product for wireless communication are provided for improving channel estimation under a non-uniform signal pattern. The apparatus indicates to a UE to utilize a subset of reference signals to derive a channel estimate for demodulating data in a specific subframe, and transmits a plurality of subframes, the plurality of subframes including the reference signals and the specific subframe, the specific subframe including a PSS and/or SSS.
    Type: Grant
    Filed: May 12, 2014
    Date of Patent: January 24, 2017
    Assignee: QUALCOMM Incorporated
    Inventors: Tao Luo, Michael Mao Wang, Wanshi Chen, Peter Gaal, Yongbin Wei, Aleksandar Damnjanovic, Hao Xu, Taesang Yoo
  • Patent number: 9270497
    Abstract: Systems and methods are disclosed herein to provide improved channel estimation in a wireless data communication system, including but not limited to Multiple Input Multiple Output (MIMO) communication systems. In accordance with one or more embodiments and aspects thereof, a channel estimation system is disclosed that utilizes data payload portions of received wireless packets to calculate estimates of the radio frequency (RF) channel traversed by these packets, and iteratively refines and improves these estimates by selectively utilizing successive received packets according to the application of certain metrics. Such a system may offer improved capabilities such as: more accurate signal reception, reduced bit error ratio, and better reception of short data packets.
    Type: Grant
    Filed: June 18, 2014
    Date of Patent: February 23, 2016
    Assignee: Ixia
    Inventors: David Jennings Wicker, Jr., Thomas Alexander
  • Patent number: 9231715
    Abstract: An In-phase/Quadrature phase (I/Q) mismatch compensation method of a transceiver is provided. The method includes establishing a first loopback path between a transmitter and a receiver, transmitting a training sequence from the transmitter to the receiver through the established first loopback path, acquiring, at the receiver, a first correlation result value by correlating the training sequence received through the established first loopback path, establishing a second loopback path between the transmitter and the receiver, transmitting the training sequence from the transmitter to the receiver through the established second loopback path, acquiring, at the receiver, a second correlation result value by correlating the training sequence received through the second loopback path, and estimating I/Q mismatch values of the transmitter and the receiver using the first and second correlation result values.
    Type: Grant
    Filed: January 5, 2015
    Date of Patent: January 5, 2016
    Assignee: Samsung Electronics Co., Ltd
    Inventors: Donghan Kim, Sungtae Choi, Jaehwa Kim, Yiju Roh, Sanghoon Lee
  • Patent number: 9128178
    Abstract: A correlation calculation process execution method utilizes a first mode and a second mode as a positioning mode that performs a correlation calculation process on a received signal of a positioning signal that is spread-modulated by a spreading code and a signal replica of the spreading code, the first mode being a mode in which correlation values are averaged in a first mode process period to output a correlation value, and the second mode being a mode in which correlation values are integrated in a second mode process period to output a correlation value, the method including repeating the first mode and the second mode while setting an intermediate time of the first mode process period to be the same as an integration reference time of the second mode process period, and variably setting a ratio of an ON/OFF period in at least one period of the first mode process period and the second mode process period.
    Type: Grant
    Filed: December 22, 2008
    Date of Patent: September 8, 2015
    Assignee: Seiko Epson Corporation
    Inventor: Naoki Gobara
  • Patent number: 9088329
    Abstract: Canceling narrowband interfering signals in a distributed antenna system is provided. In one aspect, a cancellation sub-system includes a decimator module, a filter, an interpolator module, and a combiner module coupled to the uplink path and a reference path in parallel with the uplink path. The reference path includes the decimator module, the filter, and the interpolator module. The decimator module decimates a reference signal sampled from an uplink signal traversing an uplink path of the remote antenna unit. Each of the uplink signal and the reference signal includes a narrowband interfering signal component. The filter generates a cancellation signal from the reference signal by attenuating the reference signal outside a frequency band that includes the interfering signal component. The interpolator module interpolates the cancellation signal to a sampling rate of the uplink signal. The combiner module can subtract the cancellation signal from the uplink signal.
    Type: Grant
    Filed: December 12, 2014
    Date of Patent: July 21, 2015
    Assignee: COMMSCOPE TECHNOLOGIES LLC
    Inventors: Christopher Goodman Ranson, Gregory Allan Maca, Thomas Kummetz
  • Patent number: 9026072
    Abstract: A receiver can extract digital data from wireless radio frequency signal. The digital data contains at least two sets of compressed digital audio data each associated with a different set of audio program. One set of compressed digital audio data is delivered in a first frequency band and the other set in a second frequency band. One of the sets is stored in a memory system and the remaining set is not stored in the memory system. A user can select one of the sets of compressed digital audio data for decompression and then conversion to analog audio signal.
    Type: Grant
    Filed: May 22, 2014
    Date of Patent: May 5, 2015
    Inventor: Hark C Chan
  • Patent number: 9008082
    Abstract: A method applied in a routing node, and a forwarding engine implemented in a routing node, are provided for handling data packets received at the routing node. A N-tuple comprising N elements is extracted from a first header of a data packet. A default meta-field is added to the N elements, providing a N+1-tuple. The N+1-tuple is used to make a first lookup of inspection rules. The default meta-field makes the inspection rules apply to the first header. The data packet is handled according to a result of the first lookup, wherein a possible outcome is a finding of a second header within the data packet. If a second header is found, a new meta-field value is set and a second lookup is made. The second lookup of the inspection rules is made according to N elements from the second header and the new value of the meta-field.
    Type: Grant
    Filed: December 7, 2009
    Date of Patent: April 14, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventor: Eric Dyke
  • Patent number: 9001713
    Abstract: A learning on a weight of an adaptive array antenna which becomes necessary for a space division multiple access is carried out while a backward compatibility with a conventional standard is maintained. When a TRQ frame and a training frame for the learning are exchanged, a spoof is applied on these frames to preferably avoid collisions with a surrounding station STA4 that follows a conventional standard. Also, after the weight of the adaptive array antenna is learnt, a STA0 multiplexes and transmits the plurality of data frames addressed to a plurality of users while a wireless resource on a spatial axis is shared by the plurality of users, so that a throughput for one-to-many, that is, for the plurality of users as a whole is improved.
    Type: Grant
    Filed: April 19, 2010
    Date of Patent: April 7, 2015
    Assignee: Sony Corporation
    Inventors: Yuichi Morioka, Hiroaki Takano, Kazuyuki Sakoda
  • Patent number: 8989247
    Abstract: Techniques, apparatus and systems for providing radio frequency wireless communications based on time reversal of the channel impulse response of an RF pulse in a transmission channel between an RF transmitter and an RF receiver to enhance reception and detection of an RF pulse at the RF receiver against various effects that can adversely affect and complicate the reception and detection of the RF pulse at the RF receiver.
    Type: Grant
    Filed: April 1, 2013
    Date of Patent: March 24, 2015
    Assignee: Ziva Corporation
    Inventors: David F. Smith, Anis Husain
  • Patent number: 8989063
    Abstract: A method of far-end crosstalk (FEXT) channel estimation in a digital subscriber line (DSL) system, wherein the DSL system comprises a first subscriber line and a second subscriber line, the method comprising allocating a plurality of time slots, wherein the plurality of time slots comprises a first period and a second period, wherein the first period precedes the second period, and wherein each of the first and second periods comprises at least one time slot, transmitting at least one training symbol in the first period onto the second subscriber line in a downstream direction while no transmission is made on the first subscriber line, receiving at least one feedback symbol in the second period from the first subscriber line in an upstream direction, and estimating a level of downstream FEXT from the second subscriber line into the first subscriber line based on the at least one feedback symbol.
    Type: Grant
    Filed: November 12, 2012
    Date of Patent: March 24, 2015
    Assignee: Futurewei Technologies, Inc.
    Inventors: Haixiang Liang, Yuchen Jia, Chin Ngek Hung
  • Patent number: 8982745
    Abstract: A method for improving the data rate of data for M/H receivers and for improving the quality of channel estimation in an ATSC-M/H transport data stream marks the transport data packets determined for the transmission of data for M/H receivers in N (e.g., 38) consecutively transmitted transport data packets in an ATSC-M/H-slot of the uncoded ATSC-M/H transport data stream originally determined for the transmission of data for stationary receivers. Coded data for M/H receivers are inserted in the marked transport data packets and introduce training sequences in segments of data fields of the coded ATSC-M/H transport data stream containing marked transport data packets.
    Type: Grant
    Filed: March 19, 2010
    Date of Patent: March 17, 2015
    Assignee: Rohde & Schwarz GmbH & Co. KG
    Inventors: Günther Zurek-Terhardt, Torsten Görig, Jens Rusch-Ihwe, Denis Hagemeier, Michael Simon
  • Patent number: 8892140
    Abstract: A method and apparatus for bi-direction training in D2D/cellular networks. An embodiment method includes sending training symbols to sense interference from the cellular UEs, calculating an interference subspace from the cellular UE to each of the D2D UEs, calculating an orthogonal projection matrix based on the interference subspace calculated, and iteratively updating receive filters through forward training and transmit beamformers through backward training after the orthogonal projection matrix is calculated to align the D2D UEs. In an embodiment, training symbols are sent to sense interference from the cellular UE.
    Type: Grant
    Filed: September 4, 2012
    Date of Patent: November 18, 2014
    Assignee: Futurewei Technologies, Inc.
    Inventors: Binnan Zhuang, Weimin Xiao, Philippe Sartori, George Calcev, Fei Teng
  • Patent number: 8824371
    Abstract: Systems and methods for communicating packets having a plurality of formats are described herein. In some aspects, a signal (SIG) field in the preamble of a packet may indicate whether an extension field, such as an extension SIG field or SIG-B field, is included in the packet. In another aspect, one or more detectors may be used to auto-detect packets formatted as one of at least two different formats based on a short training field (STF) of a received packet. In some aspects, along training field (LTF) in the preamble of a packet may indicate whether the payload is repetition coded.
    Type: Grant
    Filed: May 8, 2012
    Date of Patent: September 2, 2014
    Assignee: Qualcomm Incorporated
    Inventors: Sameer Vermani, Santosh P. Abraham, Mohammad Hossein Taghavi Nasrabadi, Vincent K. Jones, Hemanth Sampath
  • Patent number: 8826093
    Abstract: Conserving power for coded transmissions comprises ceasing to process parity packets once associated data packets are deemed correct or corrected. Once data packets are deemed correct or corrected, the receiving unit can shut off during the transmission of parity packets.
    Type: Grant
    Filed: January 18, 2006
    Date of Patent: September 2, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Gordon Kent Walker, Chinnappa K. Ganapathy, Dhinakar Radhakrishnan, Fuyun Ling, Rajiv Vijayan
  • Patent number: 8717863
    Abstract: An apparatus includes a transmitter configured to transmit data via a plurality of communication channels of a communication connection. The transmitter is further configured to transmit a same sequence for vector training on each of the communication channels. The sequences for at least two of the communication channels are shifted with respect to each other.
    Type: Grant
    Filed: October 27, 2010
    Date of Patent: May 6, 2014
    Assignee: Lantiq Deutschland GmbH
    Inventors: Heinrich Schenk, Axel Clausen, Vladimir Oksman
  • Patent number: 8582447
    Abstract: A transmission destination of a packet to be transmitted by a web server (11) and an application server (21) incorporated in the same machine (30) is set to a loopback device (50). When a packet is received from one of the servers (11 and 21), the loopback device (50) decides whether or not a combination of a source IP address, a source port number, and a destination port number in the packet is known. If the combination is known, the source IP address and a destination IP address of the received packet are exchanged, and the packet is transmitted to the other server. Further, the packet received from the one of the servers and the packet transmitted to the one of the servers are copied, and the copied packets are transmitted to a communication state visualizing machine (90).
    Type: Grant
    Filed: July 28, 2009
    Date of Patent: November 12, 2013
    Assignee: Fujitsu Limited
    Inventor: Ken Yokoyama
  • Patent number: 8559532
    Abstract: To assist with the detection of unfiltered device(s), a system observes how the received noise changes between two links as the transmit signal is changed. Harmful unfiltered nonlinear devices will generate significant noise that depends on the transmitted signals; therefore, this additional noise can be quantified to some extent by comparing the observed noise for two different transmit signals. The total noise can be determined from the SNR if the received signal is known. The received signal may be read directly in some non-standard systems, or it may be determined from the known transmit signal and channel attenuation, which is sometimes the case in standard-compliant links, but often with a relatively large error. To circumvent this problem, certain embodiments of this invention only consider the change in noise between two links with the same channel attenuation. This differential comparison makes it unnecessary to accurately know the channel attenuation.
    Type: Grant
    Filed: January 26, 2009
    Date of Patent: October 15, 2013
    Assignee: AWARE, Inc.
    Inventor: Christopher Cunningham
  • Patent number: 8509125
    Abstract: Systems, methods, and other embodiments associated with echo cancellation are described. According to one embodiment, a method uses two signals from a transmitter as input to a look-up table to generate a non-linear echo cancellation signal. The non-linear echo cancellation signal is applied to a receiving path to reduce non-linear echo distortion on the receiving path based at least in part on the current signal and the previous signal.
    Type: Grant
    Filed: October 13, 2010
    Date of Patent: August 13, 2013
    Assignee: Marvell International Ltd.
    Inventor: Jagadish Venkataraman
  • Patent number: 8509126
    Abstract: Aspects of a method and system for utilization of an reserved and/or out of band channel for maintaining a network connection are provided. In this regard, information relating to training of one or more link partners communicatively coupled to an Ethernet link may be exchanged via a reserved and/or out of band channel on the Ethernet link. The reserved and/or out of band channel may be an auxiliary channel as specified by the IEEE802.1AN standard. The reserved and/or out of band channel may be utilized for scheduling training of one or more of the link partners, determining which of the link partners require training, synchronizing training of the link partners, training the link partners based on changes in environmental conditions. The training may comprise configuring an echo canceller a far-end crosstalk canceller, and/or a near-end crosstalk canceller.
    Type: Grant
    Filed: February 1, 2011
    Date of Patent: August 13, 2013
    Assignee: Broadcom Corporation
    Inventors: Wael William Diab, Scott Powell
  • Patent number: 8483108
    Abstract: Methods and apparatus for achieving adaptive de-emphasis on a data network. In one embodiment, the network comprises a high-speed serialized bus network, and the invention is adapted to correct for inter-symbol interference (ISI) associated with data transmissions between two nodes communicating over the network. In one variant, a first device transmits a plurality of symbols to a second device. If the second device detects that these symbols have unacceptably degraded during transmission, it generates an interrupt during a designated interval that is subsequently transmitted to the first device, and used to either attenuate the signal strength associated with data transmissions to the second device, or undertake one or more remedial measures. In another embodiment, sequential calibration of nodes is achieved by executing a process adapted to identify an optimal de-emphasis level associated with data transmissions.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: July 9, 2013
    Assignee: Apple Inc.
    Inventor: Colin Whitby-Strevens
  • Patent number: 8462193
    Abstract: A multimedia conferencing system includes a loud speaker system, one or more microphones for receiving a local audio signal and a remote audio signal, a state machine and an echo canceller that operates in conjunction with two reference signals to remove substantially all of a feedback signal component in the local audio signal that results from reinforcing and playing the local audio signal over the loud speaker system. The state machine operates to detect that only the local audio is active, and if so controls the operation of the echo canceller such that only the feedback component of the local audio signal is removed and the local audio signal is not suppressed.
    Type: Grant
    Filed: January 8, 2010
    Date of Patent: June 11, 2013
    Assignee: Polycom, Inc.
    Inventors: Kwan Truong, Peter Chu, Michael Pocino, John Allen
  • Patent number: 8411847
    Abstract: Disclosed methods and systems measure acoustic responses to training signals activated prior to communication sessions. Profiles related to the acoustic responses are saved and adapted during communication sessions. Training signals may have uniform frequency distributions over a frequency range and may be in response to user inputs, timeouts, or predetermined events. In the next excessive divergence is detected, an adapted profile may be substituted by an original, trained profile.
    Type: Grant
    Filed: June 10, 2008
    Date of Patent: April 2, 2013
    Assignee: Conexant Systems, Inc.
    Inventors: Bryan J. Burns, Yair Kerner, Eitan David
  • Patent number: 8400949
    Abstract: A UE in the idle or semi-idle state determines that a wirelessly received signal is scrambled by a scrambling code which is not within a locally stored list of scrambling codes received from its serving network node, and applies a rule to determine from the scrambling code whether to decode broadcast system information that is transmitted by an access node using the scrambling code. In one embodiment such a rule is that if the scrambling code is not within the list, do not decode the broadcast system information again if the scrambling code is locally stored from a previous instance of decoding the system information. Another rule embodiment is if the scrambling code is not within the list, do not attempt to decode the system information unless a measured signal strength for the wirelessly received signal is higher than a threshold, which may be absolute or dependent on strength of a signal received from the serving network node.
    Type: Grant
    Filed: January 7, 2011
    Date of Patent: March 19, 2013
    Assignee: Renesas Mobile Corporation
    Inventors: Christopher P. Callender, Brian A. Martin
  • Patent number: 8396206
    Abstract: Embodiments of a multi-channel audio communication device and methods for reducing echoes are generally described herein. Other embodiments may be described and claimed. In some embodiments, echo-reduction circuitry may insert training signals into digital audio signals at or below a noise floor and in a non-audible portion of the frequency spectrum based on a spectral mask. Training signals may be generated from spectrum estimates and training sequences. An adaptive filter may generate echo-cancellation signals using filter coefficients generated fawn the training sequences and return-path signals. The echo cancellation signals may remove echo signals from the return-path signals.
    Type: Grant
    Filed: February 15, 2007
    Date of Patent: March 12, 2013
    Assignee: Infineon Technologies AG
    Inventors: Simon Jäermyr, Mikael Hjelm
  • Patent number: 8391191
    Abstract: An echo cancellation device relies on the known characteristics of the sync frame to monitor, update in an off-line fashion and determine the accuracy of an echo canceller in, for example, a modem, such as an ADSL modem. Specifically, time domain samples are read from the transmit (Tx) and receive (Rx) paths of the modem. These samples are stored in memory. When the sync frame has received a predetermined number of the same Tx samples and Rx samples, the samples are stored. Running averages, over the sync frames, of the TX and RX samples are maintained. These averages are subtracted from a sync frame of samples, to allow LMS updating of the echo canceller taps, free of extraneous signals. Updating, i.e., tracking of changes in the echo channel, is done for the echo canceller in an off-line fashion. The coefficients for the in-line version are updated, while the off-line version is updated over several sync frames. Periodically, the performance of the off-line version is compared with the in-line version.
    Type: Grant
    Filed: May 20, 2010
    Date of Patent: March 5, 2013
    Assignee: TQ Delta, LLC
    Inventors: Igor Tkachov, Stuart Sandberg
  • Patent number: 8223959
    Abstract: A system includes microphone devices, echo cancellation mechanism, and speaker devices. Each echo cancellation mechanism corresponds to one of the microphone devices. Each speaker device corresponds to a sound source signal. Each sound source signal is spatially distributed to all the speaker devices, and each echo cancellation mechanism receives as a reference signal a combination of all the sound source signals.
    Type: Grant
    Filed: July 31, 2007
    Date of Patent: July 17, 2012
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Scott Grasley, David R Ingalls, Otto Gygax
  • Patent number: 8213597
    Abstract: Embodiments of an audio communication device and methods for reducing echoes are generally described herein. Other embodiments may be described and claimed. In some embodiments, echo-reduction circuitry may insert a training signal into digital audio signals at or below a noise floor and in a non-audible portion of the frequency spectrum based on a spectral mask. The training signal may be generated from a spectrum estimate and a training sequence. An adaptive filter may generate an echo-cancellation signal using filter coefficients generated from the training sequence and return-path signals. The echo-cancellation signal may remove echo signals from the return-path signals.
    Type: Grant
    Filed: February 15, 2007
    Date of Patent: July 3, 2012
    Assignee: Infineon Technologies AG
    Inventor: Mikael Hjelm
  • Patent number: 8208623
    Abstract: In an echo processing method and device which can detect an accurate echo section without effects of a far end signal, an echo delay, and a reduction of an echo cancellation amount, a signal of a specified frequency band is generated in conformity with a near end signal, and the signal of the specified frequency band is added to the near end signal to form a transmitting signal. Receiving signals are separated into the signal of the specified frequency band and a signal of a band other than the specified frequency band. An echo section is detected based on the signal of the specified frequency band separated. An echo component in the signal of the band other than the specified frequency band is removed and a level of the echo component is detected based on the near end signal in the echo section.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: June 26, 2012
    Assignee: Fujitsu Limited
    Inventors: Takeshi Otani, Masanao Suzuki, Yasuji Ota
  • Patent number: 8189650
    Abstract: A startup protocol is provided for use in a communications system having a communications line with a master transceiver at a first end and a slave transceiver at a second end, each transceiver having a noise reduction system, a timing recovery system and at least one equalizer all converging at startup of the system. The operation of the startup protocol is partitioned into stages. The first stage includes the step of converging the equalizer and the timing recovery system of the slave while converging the noise reduction system of the master. Upon completion of the first stage the protocol enters a second stage which includes the step of converging the equalizer and the timing recovery system of the master, converging the noise reduction system of the slave, freezing the timing recovery system of the slave, and resetting the noise reduction system of the master.
    Type: Grant
    Filed: October 29, 2002
    Date of Patent: May 29, 2012
    Assignee: Broadcom Corporation
    Inventor: Oscar E. Agazzi
  • Patent number: 8135058
    Abstract: An adaptive known signal canceller comprising of a known signal canceller filter responsive to a known signal including a known portion of a transmitted signal, the known signal canceller filter operative to generate a filtered known signal, and a subtractor unit responsive to an input signal and operative to generate an output signal, the subtractor unit configured to subtract the filtered known signal from the input signal to generate an output signal, such that the known portion of the transmitted signal is substantially removed from the input signal. The adaptive known signal canceller further comprising of a known signal canceller update unit, responsive to a desired signal and an output signal and operative to continually adjust the coefficients of the known signal canceller filter based on the difference between the output signal and the desired signal, so that the filter coefficients substantially reflect the impulse response of a channel.
    Type: Grant
    Filed: October 10, 2008
    Date of Patent: March 13, 2012
    Assignee: CSR Technology Inc.
    Inventors: Jordan Christopher Cookman, Ping Dong, Tao Yu
  • Patent number: 8121654
    Abstract: A method and apparatus for removing an echo signal in a signal transmission/reception apparatus of a communication system is provided. A signal transmission/reception apparatus estimates an input channel response using a training sequence, generates a first signal by removing the input channel response from a first reception signal, detects an echo channel impulse response using the first signal, detects an echo signal removing coefficient using the echo channel impulse response, generates a second signal in which an echo signal is removed by applying the echo signal removing coefficient to a second reception signal, and removes the second signal from a third signal, wherein the first signal is received prior to receiving the second signal and the second signal is received prior to receiving the third signal.
    Type: Grant
    Filed: November 26, 2008
    Date of Patent: February 21, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hwa-Sun You, Jae-Bum Kim, Hee-Won Kang, Jung-Woo Ku
  • Patent number: 8059750
    Abstract: A method and apparatus for generating a TSC in a communication system are provided, in which a pair of sequences A and B having auto-correlation and cross-correlation properties are generated and the TSC is generated by inserting guard sequences Z each having z zero symbols in the most significant bits of the sequences A and B.
    Type: Grant
    Filed: February 8, 2008
    Date of Patent: November 15, 2011
    Assignee: Samsung Electronics Co., Ltd
    Inventors: Yan Xin, Jong-Soo Choi
  • Patent number: 8041844
    Abstract: A computer system that detects for a PCI Express compliant endpoint device is described. Specifically, the computer system clocks transmit and receive circuits at a first frequency and initiates a training sequence. If the endpoint device successfully trains at the first frequency, the endpoint device is PCI Express compliant. Otherwise, the computer system initiates another training sequence at a second frequency.
    Type: Grant
    Filed: December 29, 2004
    Date of Patent: October 18, 2011
    Assignee: Intel Corporation
    Inventors: Mikal C. Hunsaker, Karthi Vadivelu, Andrew W. Martwick
  • Patent number: 7933196
    Abstract: An apparatus for channel interference cancellation includes a first interference-cancellation module and a first cancellation-signal generating circuit. The first interference-cancellation module comprises a first processing circuit including a grouping circuit and a first transforming circuit. The grouping circuit divides received data into a plurality of groups of first sub-data. The first transforming circuit sequentially transforms the groups of first sub-data from a first domain to a second domain to generate a plurality of groups of first transformed sub-data. The first cancellation-signal generating circuit comprises a delay unit, a first processing unit and a second processing unit. The delay unit sequentially delays the groups of first transformed sub-data to generate a plurality of groups of delayed sub-data. The first and the second processing unit output a first and a second processed signal according to the groups of first transformed sub-data and the groups of delayed sub-data respectively.
    Type: Grant
    Filed: October 13, 2008
    Date of Patent: April 26, 2011
    Assignee: Realtek Semiconductor Corp.
    Inventors: Liang-Wei Huang, Chih-Yung Shih, Shieh-Hsing Kuo
  • Patent number: 7920599
    Abstract: Methods and systems for synchronizing wireless transmission of data packets is provided. Signals having a data packet frame format including a preamble (with a pattern of symbol sequences) and data are received, and patterns of symbol sequences are correlated. A first metric can be calculated that is a ratio of an average of the correlation values and an average of a power of the signals. A second metric can be calculated that defines an average of a power of noise in the signals. The methods include determining an approximate division of the preamble and data in the data packet of each signal based on the first and second metrics. The methods further include determining a cross-correlation between versions of a transmitted signal to produce a number of peaks equal to a number of transmit antennas, generating a third metric based on combinations of cross-correlations, and identifying a position of a maximum peak within the third metric as a fine timing offset amount.
    Type: Grant
    Filed: March 18, 2010
    Date of Patent: April 5, 2011
    Assignees: Anna University, KBC Research Foundation
    Inventors: Srikanth Subramanian, Sathish Viswanathan
  • Patent number: 7864661
    Abstract: The present invention is directed to a time-switched preamble generator and method of generating a time-switched preamble for use with a multiple-input, multiple-output (MIMO) transmitter employing first and second transmit antennas. In one embodiment, the time-switched preamble generator includes an initial preamble formatter configured to provide a first preamble to the first transmit antenna and a second preamble to the second transmit antenna during an initial time interval. The time-switched preamble generator also includes a subsequent preamble formatter coupled to the initial preamble formatter and configured to provide the second preamble to the first transmit antenna and the first preamble to the second transmit antenna during a subsequent time interval.
    Type: Grant
    Filed: January 12, 2004
    Date of Patent: January 4, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Srinath Hosur, Srikanth Gummadi, Anuj Batra, David P. Magee
  • Patent number: 7830976
    Abstract: Estimation of channel characteristics and interference level in a time-varying multi-carrier multi-user systems is carried out concurrently. To perform the estimation, a multitude of data symbols and dedicated pilot symbols are transmitted over the channel. Next, an initial estimate value is selected for the interference level. The initial estimate value for the interference level is used together with the received pilot symbols to provide a first estimate of the channel. The first estimate of the channel is used to determine a new updated value for the interference level, which in turn, is used to update the value of the first estimate of the channel iteratively. The iterations continue until the iteratively updated values of the interference level and channel satisfy predefined limits. The data symbols and the final updated value of the channel are subsequently used to provide a second estimate for the channel.
    Type: Grant
    Filed: July 15, 2005
    Date of Patent: November 9, 2010
    Assignee: QUALCOMM Incorporated
    Inventors: Alexei Gorokhov, Avneesh Agrawal, Dhananjay Ashok Gore, Arvind Vijay Keerthi
  • Patent number: 7742386
    Abstract: A method and apparatus for reducing crosstalk in a multi-channel communication system is disclosed. In one embodiment, outgoing signals in a multi-channel environment are manipulated into a transform domain, such as the frequency domain. Thereafter, the signals may be combined and modified based on a weighting variable to create a cancellation signal. Combined processing greatly reduces system complexity and increases processing speed. After processing in the transform domain, the cancellation signal undergoes further processing to return the cancellation signal into the time domain. The cancellation signal may then be combined with received signals to cancel crosstalk or echo. A method and apparatus for crosstalk cancellation in the analog domain and digital domain is also disclosed.
    Type: Grant
    Filed: October 13, 2005
    Date of Patent: June 22, 2010
    Assignee: Solarflare Communications, Inc.
    Inventors: William W. Jones, George A. Zimmerman
  • Patent number: 7733770
    Abstract: A source node receives related frames of data to be transmitted from the source node to a destination node and places the frames in a queue. The queue is associated with a communication path over which the related frames are to be transmitted to the destination node. An interface that couples the source node to the communication path receives an indication directed to the source node of traffic congestion in the communication path. In response, the source node controls the rate at which the related frames of data are transferred from the queue to a transmit buffer accessible to the interface, in order to relieve the traffic congestion in the communication path.
    Type: Grant
    Filed: April 25, 2005
    Date of Patent: June 8, 2010
    Assignee: Intel Corporation
    Inventors: Gary McAlpine, Tanmay Gupta, Manoj Wadekar
  • Patent number: 7697602
    Abstract: A training sequence is pre-filtered in a radiocommunication system having an emitter in the form of an antenna device with several antenna systems, thereby making it possible to transmit the training sequences through a pre-filter to said antenna systems side for reradiation by the emitter. Estimation enabling to form the properties of radio transmission channels described by spatial correlations is formed. The prefilter is dimensioned according to the correlations, thereby minimizing the error value of an algorithm used for estimation the channel on a reception side.
    Type: Grant
    Filed: July 8, 2004
    Date of Patent: April 13, 2010
    Assignee: Nokia Siemens Networks GmbH & Co. KG
    Inventors: Thomas Frey, Mario Kiessling, Markus Reinhardt, Ingo Viering
  • Patent number: 7627348
    Abstract: A point to multipoint device for use in a wireless network operates a sequence of variable duration communication channels, allocatable to telecommunications units. A training sequence indication and a repetition rate indication are stored indicating a training sequence and repetition rate for the training sequence in the sequence of communication channels associated with the point to multipoint device. An interface receives a synchronization signal issued to all point to multipoint devices in the wireless network, and uses it to determine a time for a first occurrence of the training sequence to occur. Communication channel control logic causes control data to be transmitted to the telecommunications units identifying the sequence of channels, the training sequence indication and the repetition rate. Beamforming logic determines beamforming weights used to produce a reception beam at an antenna array.
    Type: Grant
    Filed: November 28, 2006
    Date of Patent: December 1, 2009
    Assignee: Airspan Networks, Inc.
    Inventors: Martin Lysejko, Andrew Logothetis
  • Patent number: 7526571
    Abstract: IPv6 traffic may be carried through an MPLS IPv4 network without the use of IPv6-over-IPv4 tunneling. This provides great savings in overhead, signaling, and state information storage and also allows for routing through the MPLS IPv4 network to adjust in response to changes in network state. In one embodiment, an edge node of an MPLS IPv4 network resolves a destination IPv6 network of a received IPv6 packet to an MPLS label switched path. The resolution exploits received inter-domain routing information. This information identifies the IPv4 address of an egress node that is usable as a gateway to the destination network. Within the inter-domain routing information, the IPv4 address may be encoded in IPv6 format.
    Type: Grant
    Filed: June 11, 2007
    Date of Patent: April 28, 2009
    Assignee: Cisco Technology, Inc.
    Inventors: Daniel C. Tappan, Eric C. Rosen, Ole Troan, Parag Jain, Eric Levy-Abegnoli, Luc Revardel, Francois Le Faucheur
  • Patent number: 7508812
    Abstract: A method of automatically keeping sockets open for always-on applications in a GPRS context is provided. Information is maintained by each wireless device identifying each APN (access point name)-port pair associated with a PDP (packet data protocol) context used by an always-on application. Upon the PDP context becoming available after having become unavailable, a socket is registered for each port-APN pair associated with the PDP context.
    Type: Grant
    Filed: January 28, 2005
    Date of Patent: March 24, 2009
    Assignee: Research In Motion Limited
    Inventors: Craig Stout, Robbie J. Maurice