Squelch Patents (Class 455/218)
  • Patent number: 11960341
    Abstract: Various techniques and circuit implementations for power reduction management in integrated circuits are disclosed. Different sets of power delivery trigger circuits may be coupled to the integrated circuit by wiring or serial communication interfaces. Power reduction responses may be implemented at faster rates utilizing the wired power delivery trigger circuits while slower power reduction response can be implemented utilizing serially connected power delivery trigger circuits. The threshold for power reduction response by wired power delivery trigger circuits may also be closer to a functional failure point of the integrated circuit in order to provide fast response to avoid failure of the integrated circuit.
    Type: Grant
    Filed: February 21, 2022
    Date of Patent: April 16, 2024
    Assignee: Apple Inc.
    Inventors: Jamie L. Langlinais, Inder M. Sodhi, Lior Zimet, Keith Cox
  • Patent number: 11874718
    Abstract: High-speed data communication devices, e.g., repeaters, interfacing between a host and a peripheral operate such that high-speed components except for a host-side squelch detector are set or maintained in a deactivated state during an idle period of a micro frame. In an example, a start of a micro frame is detected on a data bus during a first time period. In a second time period after the first time period, the high-speed communication device determines whether at least one data packet is contained in the micro frame. When it is determined during the second time period that no data packet is contained in the micro frame, active components, except a squelch detector, are controlled to be inactive during a third time period after the second time period.
    Type: Grant
    Filed: May 25, 2021
    Date of Patent: January 16, 2024
    Assignee: Texas Instruments Incorporated
    Inventors: Mustafa Ulvi Erdogan, Suzanne Mary Vining, Bharath Kumar Singareddy, Douglas Edward Wente
  • Patent number: 11233488
    Abstract: A squelch detection device is provided. The squelch detection device receives first and second input signals and first and second threshold voltages. The squelch detection device determines a first common mode of the first and second input signals and a second common mode of the first and second threshold voltages. The squelch detection device averages the first common mode with the second common mode to produce an average common mode and sets the first common mode of the first and second input signals to the average common mode. The squelch detection device sets the second common mode of the first and second threshold voltages to the average common mode and determines a state of a squelch signal, indicative of whether the first and second input signals are attributable to noise, based on the first and second input signals and the first and second threshold voltages.
    Type: Grant
    Filed: January 17, 2020
    Date of Patent: January 25, 2022
    Assignee: STMicroelectronics International N.V.
    Inventor: Prashant Singh
  • Patent number: 10664075
    Abstract: A method of controlling a watch-type mobile terminal including a bezel, the method includes executing a contact application stored in a memory; outputting a contact list on a display unit when the contact application is executed; sensing a touch input signal on the display unit, wherein the touch input signal is a drag touch input on the display unit in a first direction; scrolling the contact list to search for a specific contact regardless of the drag touch input's speed; sensing a rotation input on the bezel, wherein the rotation input is an input for rotating the bezel with a speed in a second direction, further the first direction is different from the second direction; and controlling a scroll pop-up for searching for the specific contact to be output on the contact list of the contact application if the speed of the rotation input is faster than a first predetermined speed.
    Type: Grant
    Filed: June 14, 2018
    Date of Patent: May 26, 2020
    Assignee: LG ELECTRONICS INC.
    Inventors: Yung Kim, Jonghwan Kim
  • Patent number: 9686657
    Abstract: A mobile radio has selectable transmit and receive channels, and is in a talkgroup that has a primary channel and multiple auxiliary channels. The mobile radio receives a broadcast-start command, and responsively selects its transmit channel to be the primary channel (if available) or an inactive auxiliary channel (if the primary channel is not available). The mobile radio receives user media via its user interface, and transmits that received user media on its selected transmit channel. The mobile radio scans for an auxiliary channel transitioning from inactive to active. Responsive to detecting such a transition, the mobile radio selects that auxiliary channel as its receive channel. The mobile radio mixes inbound media received on its selected receive channel with user media received via its user interface, and transmits the mixed media on its selected transmit channel.
    Type: Grant
    Filed: July 10, 2014
    Date of Patent: June 20, 2017
    Assignee: MOTOROLA SOLUTIONS, INC.
    Inventors: Kang-Kai Zhao, Da-Jun Chen, Yong Li, Yong Tian, Wu Yang
  • Patent number: 9081659
    Abstract: A controlling method for connector is provided, which includes: receiving a first signal stream under a condition that a squelch detector is turned-off; determining whether the first signal stream contains a burst signal under a first operating frequency; if the first signal stream contains the burst signal, turning on the squelch detector and determining by the squelch detector under a second operating frequency whether a second signal stream is a waking signal, wherein the second signal stream is received after receiving the first signal stream and the second operating frequency is greater than the first operating frequency. The controlling method further includes: if the second signal stream is the waking signal, changing an operating state of the connector to an active state. In this way, the power consumption of the connector is reduced.
    Type: Grant
    Filed: December 3, 2012
    Date of Patent: July 14, 2015
    Assignee: PHISON ELECTRONICS CORP.
    Inventors: Chih-Ming Chen, Wei-Yung Chen, Ming-Hui Tseng
  • Patent number: 8886146
    Abstract: An IR receiver having a decision logic circuit for activating or deactivating a squelch. Activation or deactivation of the squelch is effected in dependence on a mean value of the frequency, a variance of the receiver intermediate frequency, a mean value of the audio amplitude, a variance of the audio amplitude and/or a signal strength of the receiver intermediate circuit frequency.
    Type: Grant
    Filed: October 8, 2009
    Date of Patent: November 11, 2014
    Assignee: Sennheiser electronic GmbH & Co. KG
    Inventors: Joerg Andres, Dirk Reymann
  • Patent number: 8843093
    Abstract: Described is an apparatus comprising: a reference generator to provide a first reference and a second reference; a first input coupled to the first reference; a second input coupled to the second reference; and a comparator coupled to the first and second inputs, the comparator to receive a clock signal and to update an output signal according to a phase of the clock signal.
    Type: Grant
    Filed: December 20, 2012
    Date of Patent: September 23, 2014
    Assignee: Intel Corporation
    Inventors: Michael V. De Vita, Roan M. Nicholson, Shenggao Li
  • Patent number: 8824987
    Abstract: A squelch detector includes a first circuit, a second circuit, and a comparator. The first circuit is configured to receive a first pair of differential input signals and in response output a second pair of differential signals. The second pair of differential signals have higher voltages than the first pair of differential input signals. The second circuit is coupled to the first circuit and is configured to extract first and second voltage levels from the second pair of differential signals. The comparator is configured to output a squelch level signal based on a comparison of the first voltage level and a third voltage level. The third voltage level is based on the second voltage level and a reference voltage.
    Type: Grant
    Filed: July 27, 2011
    Date of Patent: September 2, 2014
    Assignee: Taiwan Semiconductor Manufacturing Co., Ltd.
    Inventor: Hao-Jie Zhan
  • Patent number: 8799417
    Abstract: The illustrative embodiments described herein provide a method, apparatus, and computer program product for customizing settings in a communication device for a user. In one illustrative embodiment, the process identifies a user profile to which a user belongs. The process identifies a set of custom communication device settings associated with the user profile. The process also sets a current set of communication device settings for a set of functions in a communication device to the set of custom communication device settings. In one embodiment, identifying the user profile to which the user belongs includes identifying the user profile to which the user belongs based on one or more characteristics of the user.
    Type: Grant
    Filed: April 24, 2008
    Date of Patent: August 5, 2014
    Assignee: CenturyLink Intellectual Property LLC
    Inventor: Catherine M. Pearce
  • Patent number: 8644780
    Abstract: The present invention provides a gain control circuit for an FM receiver that can reduce a reproduced audio output according to the magnitude of the noise component of an intended signal included in a received signal. The gain control circuit of the present invention is constituted by a noise level measurement circuit 26 and a preamplifier 25. The noise level measurement circuit 26 measures a noise level in an audio signal Sa1 output from an FM detector 4 and outputs a control signal Sc corresponding to the noise level. The preamplifier 25 reduces an output according a value of the control signal Sc. With the gain control circuit of the present invention, the volume of the speaker is reduced as the noise component in the audio signal Sa1 increases due to a decrease in received electric field strength, and therefore discomfort caused by unpleasant noise can be reduced.
    Type: Grant
    Filed: January 25, 2012
    Date of Patent: February 4, 2014
    Assignee: Icom Incorporated
    Inventor: Tadayoshi Tohoku
  • Patent number: 8542035
    Abstract: A squelch detection circuit for high-speed serial communication includes: an input level shifter configured to receive signals inputted through signal lines and shift the received signals to a predetermined potential level; a comparator configured to receive signals outputted from the input level shifter, and compares the received signals to determine whether data signals are noise or signal components; and a reset signal generator configured to receive the signals outputted from the input level shifter, convert the received signals into a single signal, and then generate a reset signal for an elastic buffer. The squelch detection circuit may detect a squelch state and provide a reset value for an elastic buffer in a USB 2.0 interface, and may reduce power consumption as much as possible in a suspend mode.
    Type: Grant
    Filed: December 15, 2010
    Date of Patent: September 24, 2013
    Assignee: Postech Academy-Industry Foundation
    Inventors: Hong June Park, Seong Hwan Jeon
  • Patent number: 8538362
    Abstract: A squelch detection circuit and method involves a first comparator coupled to a complimentary input signal pair and having a first polarity output. A second comparator coupled to the complimentary input signal pair has a second polarity output. An offset associated with complimentary input signal pair establishes a positive squelch threshold and a negative squelch threshold. A calibration unit coupled to the first comparator and the second comparator generates a digital output including threshold settings and calibration settings to the first comparator and to the second comparator. The digital output can be associated with establishing the offset and with calibrating the positive squelch threshold and the negative squelch threshold.
    Type: Grant
    Filed: July 16, 2010
    Date of Patent: September 17, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Ankit Srivastava, Xiaohong Quan
  • Patent number: 8457215
    Abstract: A receiver suppresses noise simultaneously using a noise suppressor and an automatic gain controller (AGC). The receiver divides a received signal into an audio period and a non-audio period, analyzes whether the noise characteristic of the non-audio period corresponds to a non-static noise or a static noise, and if the noise characteristic corresponds to the static noise, analyzes whether the static noise is caused by a network or a transmitter side terminal. In accordance with the analyzed noise characteristic, the noise suppressor firstly suppresses the noise by determining the noise suppressing intensity, and sends a signal, from which the noise has been firstly suppressed, to the AGC. The AGC secondly suppresses the noise included in the signal. In this case, the threshold value of the AGC is controlled in real time in accordance with the noise characteristic.
    Type: Grant
    Filed: December 22, 2009
    Date of Patent: June 4, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Beak-Kwon Son, Sang-Ki Kang, Dong-Won Lee
  • Publication number: 20130029622
    Abstract: A squelch detector includes a first circuit, a second circuit, and a comparator. The first circuit is configured to receive a first pair of differential input signals and in response output a second pair of differential signals. The second pair of differential signals have higher voltages than the first pair of differential input signals. The second circuit is coupled to the first circuit and is configured to extract first and second voltage levels from the second pair of differential signals. The comparator is configured to output a squelch level signal based on a comparison of the first voltage level and a third voltage level. The third voltage level is based on the second voltage level and a reference voltage.
    Type: Application
    Filed: July 27, 2011
    Publication date: January 31, 2013
    Applicant: Taiwan Semiconductor Manufacturing Co., Ltd.
    Inventor: Hao-Jie ZHAN
  • Patent number: 8265578
    Abstract: In a radio receiving apparatus, an analog received signal is converted into a digital received signal. An unwanted wave in an adjacent channel band is rejected, that is adjacent to a passband for the digital received signal. The digital received signal with no unwanted wave is converted into a first demodulated signal. The first demodulated signal is converted into a second demodulated signal in analog form. A noise component is extracted from the first demodulated signal. The second demodulated signal is suppressed under squelch control when a squelch voltage that is a voltage of the noise component after rectification and smoothing becomes equal to or higher than a predetermined threshold level.
    Type: Grant
    Filed: December 21, 2010
    Date of Patent: September 11, 2012
    Assignee: Kabushiki Kaisha Kenwood
    Inventor: Takashi Takeuchi
  • Publication number: 20120015617
    Abstract: A squelch detection circuit and method involves a first comparator coupled to a complimentary input signal pair and having a first polarity output. A second comparator coupled to the complimentary input signal pair has a second polarity output. An offset associated with complimentary input signal pair establishes a positive squelch threshold and a negative squelch threshold. A calibration unit coupled to the first comparator and the second comparator generates a digital output including threshold settings and calibration settings to the first comparator and to the second comparator. The digital output can be associated with establishing the offset and with calibrating the positive squelch threshold and the negative squelch threshold.
    Type: Application
    Filed: July 16, 2010
    Publication date: January 19, 2012
    Applicant: QUALCOMM Incorporated
    Inventors: Ankit Srivastava, Xiaohong Quan
  • Patent number: 8081942
    Abstract: A constant modulus indicator (CMI) measure is calculated for a received signal having a constant modulus component C and a noise component N. The CMI measure indicates a ratio of an energy of C to an energy of N. A determination of whether to attenuate a derived signal is made based on the CMI measure, wherein the derived signal is generated from the received signal. The derived signal is attenuated based on the determination.
    Type: Grant
    Filed: May 14, 2008
    Date of Patent: December 20, 2011
    Assignee: Marvell International Ltd.
    Inventor: Chris Cheng-Chieh Lee
  • Patent number: 8040144
    Abstract: An interface circuit includes a reference voltage generation circuit to generate a reference voltage, a differential voltage signal generation circuit to convert send data input in sending data into a pair of differential voltage signals and output the pair of differential voltage signals based on the reference voltage generated by the reference voltage generation circuit, a receiver to convert a pair of differential voltage signals input in receiving data and output received data, and a receiver test circuit to perform a sensitivity test of the receiver, the receiver test circuit having a resistance circuit to generate a pair of differential voltage signals having a potential difference being necessary for the sensitivity test of the receiver.
    Type: Grant
    Filed: March 28, 2008
    Date of Patent: October 18, 2011
    Assignee: Renesas Electronics Corporation
    Inventor: Hiroyuki Aizawa
  • Patent number: 8026743
    Abstract: An envelope detecting circuit is provided. The envelope detecting circuit comprises a source degeneration circuit that amplifies an input differential signal, a differential gain stage that supplies a voltage proportional to the amplified signal, a potential hold circuit that holds the voltage supplied from the gain stage, a comparator circuit that compares the voltage held by the potential holding circuit with a reference potential to output a detect signal, and envelope level adjustment and selection unit that responds to the detect signal and outputs a control signal to the source degeneration circuit.
    Type: Grant
    Filed: December 14, 2010
    Date of Patent: September 27, 2011
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventor: Chiung-Ting Ou
  • Patent number: 7827126
    Abstract: Disclosed is a method for changing emotion of a software robot (sobot) in a sobot terminal. The sobot terminal includes a short-term memory unit and a long-term memory unit. When an emotional change occurs during the operation of the short-term memory unit, the sobot terminal stores a short-term reference emotion value of the corresponding emotion in the long-term reference memory. When the operation time of the long-term memory unit elapses, the sobot terminal resets the long-term reference emotion value using the short-term reference emotion values stored in the long-term memory unit. The sobot terminal can change the emotion of the sobot more naturally through the above process.
    Type: Grant
    Filed: September 5, 2007
    Date of Patent: November 2, 2010
    Assignee: Samsung Electronics Co., Ltd
    Inventors: Kang-Hee Lee, Kwang-Choon Kim
  • Patent number: 7805120
    Abstract: A noise blanker circuit and method of removing impulse noise from a signal and correcting the signal is provided. The circuit includes a detection stage, a pulse removal stage, and a pulse removal correction stage. The detection stage includes at least an input that emits an input signal along a first signal path and a second signal path. The first and second signal paths are in communication with a blank pulse generator. The pulse removal stage is in communication with the input and includes at least a sample and hold device that samples and holds the input signal based upon an output of the blank pulse generator. The pulse removal correction stage includes at least a pulse removal device in communication with the detection stage and the pulse removal stage and corrects the input received from the pulse removal stage based upon the output of the blank pulse generator.
    Type: Grant
    Filed: April 17, 2007
    Date of Patent: September 28, 2010
    Assignee: Delphi Technologies, Inc.
    Inventor: Daniel T. Altizer
  • Patent number: 7706851
    Abstract: Apparatus, and an associated method, for companding communication data. Companding is provided for a two-way radio communication station operable pursuant to a coded squelch scheme, such as an MURS or FRS radio. A baseband processor invokes compression operations upon originating communication data that is originated at the communication station. And, the processor invokes operation of expansion operations when the communication data comprises terminating data.
    Type: Grant
    Filed: July 21, 2005
    Date of Patent: April 27, 2010
    Assignee: Radioshack Corporation
    Inventors: Man Lung Lam, Man Tai Vincent Lam
  • Publication number: 20100081406
    Abstract: In one embodiment, the present invention includes power control logic for squelch detection circuitry to enable selective enabling of one or more squelch detection circuits of an interconnect interface in a low power mode. The logic may include a squelch mode control register to select a first mode or a second mode of power control, a second register coupled to the squelch mode control register to receive software settings to indicate which squelch detect circuit(s) to disable in a low power state of the interconnect, and a detector to dynamically detect a logical lane zero of the interconnect in the second mode. Other embodiments are described and claimed.
    Type: Application
    Filed: September 29, 2008
    Publication date: April 1, 2010
    Inventors: Sin Tan, Sivakumar Radhakrishnan, Bruce A. Tennant, Jasper Balraj, Altug Koker
  • Patent number: 7668529
    Abstract: An audio system may comprise a transceiver configured to receive, detect, and transmit audio signals on a first channel frequency and to receive and detect audio signals on at least one additional channel frequency. The at least one additional channel frequency may include a second channel frequency. The system may include a controller configured to output a first audio cue while outputting audio signals received from the at least one additional channel frequency, to output a second audio cue at a time when the controller begins outputting an audio signal received from the first channel frequency, and to output a third audio cue at a time when the controller begins outputting an audio signal received from the second channel frequency. The first, second, and third audio cues may be different from one another.
    Type: Grant
    Filed: August 4, 2005
    Date of Patent: February 23, 2010
    Assignee: Honeywell International Inc.
    Inventors: Timothy P. Gibson, Jeffrey K. Hunter
  • Patent number: 7668169
    Abstract: A method and apparatus for routing data in a device having a plurality of parts. A signal is received at a first port. A detection is made that the first port received the signal. information contained in the signal is selectively routed from the first port to a data recovery circuit.
    Type: Grant
    Filed: October 20, 2008
    Date of Patent: February 23, 2010
    Assignee: Synopsys, Inc.
    Inventor: Ravikumar Govindaraman
  • Patent number: 7653423
    Abstract: Embodiments of the present invention can be used to enhance signals in a peer-to-peer radio system, such as a two-way radio system. In one embodiment, the invention includes receiving a communications signal on a channel from a remote radio at a radio using a plurality of antenna elements, such as an antenna array. The received communications signal includes a squelch code. The radio detects the squelch code, and enhances the received communications signal using the squelch code.
    Type: Grant
    Filed: July 7, 2006
    Date of Patent: January 26, 2010
    Inventor: Lawrence Alder
  • Patent number: 7653367
    Abstract: A squelch detector that differentially detects a presence of a communication signal on a communication channel. The squelch detector being coupled to outputs of a differential offset bias amplifier to receive differential offset biased signals and generate a differential direct current signal.
    Type: Grant
    Filed: March 30, 2006
    Date of Patent: January 26, 2010
    Assignee: Intel Corporation
    Inventors: Hongjiang Song, Yueming He
  • Patent number: 7619964
    Abstract: Fast fading in cellular systems causes time variation of the Channel Impulse Response (CIR) resulting in significant performance degradation that is reduced by adding a pulse train to the transmitted data symbols and estimating the CIR by averaging the symbols as they vary from one OFDM symbol to another within the physical data frame (or packet).
    Type: Grant
    Filed: July 8, 2004
    Date of Patent: November 17, 2009
    Assignee: Nokia Corporation
    Inventors: Jae H Son, Jan C Olivier, Victor Stolpman, Tony Reid
  • Patent number: 7545309
    Abstract: A method is disclosed for transmitting low data rate symbols from a communications terminal to a burst radar transceiver. A plurality of bursts can be emitted from a burst radar transceiver, each burst having a burst interval and separated by an inter-burst interval. A symbol can be transmitted from the communications terminal to the burst radar transceiver. The symbol has a symbol period that is substantially longer than a radar transceiver burst period comprising the burst interval and the inter-burst interval. Symbol energy can be accumulated during inter-burst intervals at the burst radar transceiver over a plurality of burst periods for approximately the symbol period.
    Type: Grant
    Filed: November 3, 2006
    Date of Patent: June 9, 2009
    Assignee: L-3 Communications, Corp.
    Inventors: William K. McIntire, Larry S. Thomson, David H. Robbins, James J. Boesch
  • Patent number: 7489915
    Abstract: A squelch circuit and a communication apparatus used with the same that are able to generate a squelch signal even if a squelch period is short and an operation of a squelch detecting circuit is insufficient, the circuit having: a squelch detecting circuit detecting the existence of a signal on a communication line in response to a transmission signal or a received signal and generating a first squelch signal; and a squelch control circuit generating a squelch mask signal in response to the first squelch signal and a transmission control signal and generating a second squelch signal based on the squelch mask signal and the control signal. The first squelch signal is controlled by the transmission signal to generate the second squelch signal in which the lacked portion of the first squelch signal is temporally restructured.
    Type: Grant
    Filed: December 1, 2005
    Date of Patent: February 10, 2009
    Assignee: Sony Corporation
    Inventors: Tadaoki Yamamoto, Akira Matsuura, Koji Takayama
  • Publication number: 20080233912
    Abstract: A power reduction proposal for a receiver circuit that adheres to a plurality of defined states and masking logic to mask the output of the squelch receiver. Furthermore, the proposal utilizes and counters to count the various timeout conditions. Consequently, the squelch receiver consumes less power and can be either powered down or periodically enabled to allow for polling.
    Type: Application
    Filed: March 23, 2007
    Publication date: September 25, 2008
    Inventors: Mikal Hunsaker, Karthi R. Vadivelu
  • Publication number: 20080182536
    Abstract: Methods of controlling threshold voltages of a transmission envelope detector are provided. The methods include comparing a voltage of an input signal initially input with a threshold voltage of the transmission envelope detector and increasing the threshold voltage when the voltage of the input signal is higher than the threshold voltage after serial communication is started.
    Type: Application
    Filed: January 30, 2008
    Publication date: July 31, 2008
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Young Min KU, Ho Joong CHOI
  • Patent number: 7395042
    Abstract: Embodiments of the present invention can be used to enhance signals in a peer-to-peer radio system, such as a two-way radio system. In one embodiment, the invention includes receiving a communications signal on a channel from a remote radio at a radio using a plurality of antenna elements, such as an antenna array. The received communications signal includes a squelch code. The radio detects the squelch code, and enhances the received communications signal using the squelch code.
    Type: Grant
    Filed: August 31, 2006
    Date of Patent: July 1, 2008
    Assignee: Durham Logistics, LLC
    Inventor: Lawrence Alder
  • Patent number: 7359688
    Abstract: Disclosed are an apparatus and a method capable of expressing use state of a portable terminal by using a character image. The apparatus includes an emotion value memory for storing emotion variance values allocated to events occurring in the portable terminal in order to express an emotion of the portable terminal, a character memory for storing character images which express emotion states of the portable terminal, a controller for confirming an event variance value corresponding to an event when the event occurs in the portable terminal, changing an emotion value of the portable terminal by using the event variance value, confirming an emotion state corresponding to the emotion value, and selecting a character image corresponding to the confirmed emotional state from the character memory; and a display unit for displaying the selected character image as the emotional state of the portable terminal.
    Type: Grant
    Filed: April 22, 2005
    Date of Patent: April 15, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jeong-Wook Seo, Hwan Kim, Jae-Ho Kim, Wei-Jin Park
  • Publication number: 20080002793
    Abstract: A system and method are provided for auto-squelching digital communications. The method receives digital information from a source node. If the receive channel is corrupted, an alarm condition is detected that is associated with the received digital information. The method transmits an alarm-condition signal to a destination node, and in response to transmitting the alarm-condition signal, maintains a valid link to the destination node. For example, detecting the alarm condition may include: comparing a frequency associated with the recovered clock signal, with a reference frequency; and, detecting a variance between the recovered clock signal frequency and the reference frequency. Alternately, loss of signal, loss of lock, out of band, and run length alarm conditions may be detected. The alarm-condition signal that is transmitted may be a serial data stream of information such as all “0”s data, all “1”s data, or alternating “0”s and “1”s data for example.
    Type: Application
    Filed: June 29, 2006
    Publication date: January 3, 2008
    Inventors: Timothy Eric Giorgetta, Madjid A. Hamidi
  • Patent number: 7295631
    Abstract: A stereo demultiplexer is proposed which can be calculation power efficiently implemented in a DSP. Modern digital FM receivers exploit the information content in the in quadrature component of the modulated difference signal for a noise reduction. The proposed stereo demultiplexer derives the in phase component and the in quadrature component of the difference signal with a minimized number of sinus and cosinus calculations by first downconverting the modulated difference signal to a not synchronized complex baseband signal on basis of a fixed frequency, thereafter a complex sampling rate decimation unit sampling rate decimates the not synchronized complex baseband signal with a factor N and a second complex mixer synchronizes and coherent demodulates the sampling rate decimated not synchronized baseband signal on basis of a first complex carrier signal derived on basis of the pilot carrier signal and the fixed frequency.
    Type: Grant
    Filed: May 10, 2002
    Date of Patent: November 13, 2007
    Assignee: Sony Deutschland GmbH
    Inventor: Jens Wildhagen
  • Patent number: 7218903
    Abstract: The present invention provides a squelch detecting circuit capable of high-speed transfer while using a reduced number of high-speed operating operational amplifiers to reduce power consumption and the cost of parts. Input differential signals inputted to a differential amplification circuit are amplified and the amplified signal is outputted to a gain proportion circuit. The gain proportion circuit supplies a potential holding circuit with a potential proportional to the amplified signal. The potential holding circuit holds the potential supplied from the gain proportion circuit. A comparator circuit compares the potential held by the potential holding circuit with a reference potential to decide whether it is a squelch state or a non-squelch state and outputs the result as a detect signal.
    Type: Grant
    Filed: September 8, 2004
    Date of Patent: May 15, 2007
    Assignee: Renesas Technology Corp.
    Inventors: Danichi Komatsu, Shintaro Mori
  • Patent number: 7180933
    Abstract: A squelch circuit for operating at high speed and at high frequencies includes a squelch input unit, a low swing pre-amplifier and a sampling and decision circuit. The squelch input unit pre-processes the positive and negative signals of an input signal to generate four pre-processed signals that are paired and sent to the low swing pre-amplifier. The outputs of the low-swing pre-amplifier are then over-sampled by the sampling and decision circuit. Multi-phase clocks are used to control the over-sampling in the sampling and decision circuit. A logic circuit then determines if the state of the input signal based on multiple samples.
    Type: Grant
    Filed: December 20, 2002
    Date of Patent: February 20, 2007
    Assignee: Silicon Integrated Systems Corporation
    Inventors: Ching-Lin Wu, Hsien-Feng Liu, Hung-Chih Liu
  • Patent number: 7149498
    Abstract: A circuit arrangement for detecting a usable frequency channel includes first and second devices for performing frequency conversion. The first and second frequency conversion devices have respective local oscillator inputs to which respective local oscillator signals are applied. The local oscillator signals are at a common frequency and have a phase difference of precisely 90°. A complex polyphase filter has first and second filter inputs connected to respective outputs of the first and second frequency conversion devices. A detection arrangement is connected to outputs of the complex polyphase filter in order to detect a signal level. A further arrangement can vary the phase angle of a signal output from at least one of the frequency conversion devices.
    Type: Grant
    Filed: April 22, 2004
    Date of Patent: December 12, 2006
    Assignee: Infineon Technologies AG
    Inventor: Giuseppe Li Puma
  • Patent number: 7120408
    Abstract: An electrical circuit detects a “squelch,” or “out-of-band,” state of a differential signal pair having a positive (“p”) signal line and a negative (“n”) signal line. In one embodiment of the invention, a first and a second comparator each have positive inputs driven by the positive and negative signal lines, respectively. The negative inputs of the comparators are driven by the outputs of separate digital-to-analog converters (DACs) which are set to a lower squelch threshold voltage. The outputs of the comparators then drive the inputs of a logical AND gate, the output of which indicates the current squelch state of the differential signal pair.
    Type: Grant
    Filed: July 31, 2003
    Date of Patent: October 10, 2006
    Assignee: Agilent Technologies, Inc.
    Inventor: Glenn Wood
  • Patent number: 7096051
    Abstract: Embodiments of the present invention can be used to enhance signals in a peer-to-peer radio system, such as a two-way radio system. In one embodiment, the invention includes receiving a communications signal on a channel from a remote radio at a radio using a plurality of antenna elements, such as an antenna array. The received communications signal includes a squelch code. The radio detects the squelch code, and enhances the received communications signal using the squelch code.
    Type: Grant
    Filed: September 27, 2002
    Date of Patent: August 22, 2006
    Inventor: Lawrence Alder
  • Patent number: 7043223
    Abstract: A high sensitivity of a Super-Regenerative Radio Frequency Receiver and its method is provided in the embodiment of the present invention. By using a common-mode feedback circuit and by replacing the rectifier with a feedback integral-rectifier, the rectifier, the low-pass filter, and the slicer will not be saturated during operation so that the output of the slicer is correctly generated, and the sensitivity of the Super-Regenerative Radio Frequency Receiver is greatly improved as a result.
    Type: Grant
    Filed: July 31, 2003
    Date of Patent: May 9, 2006
    Assignee: Winbond Electronics Corp.
    Inventors: Yi Lu, Yung-Chow Peng
  • Patent number: 6859645
    Abstract: Disclosed is a transmission envelope detector referred to a squelch detection circuit for effectively detecting an element of transmission data in a high speed serial data transmission system. The squelch detection circuit of the invention includes a differential input level shifter, a first reference voltage generator, an amplifier, a second reference voltage generator, and a comparator. The squelch detection circuit can detect whether the transmission data is a noise or signal element even at a cross point of the transmission data, resulting in achieving stable data transmission.
    Type: Grant
    Filed: September 21, 2001
    Date of Patent: February 22, 2005
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jae-Suk Yu
  • Publication number: 20040176062
    Abstract: A method for detecting a tone signal having a predetermined tone frequency includes receiving an analog communication signal, using a sampling frequency to convert the analog communication signal into a digital communication signal, selecting a plurality of signal sectors corresponding to a predetermined frequency range of the digital communication signal where the predetermined tone frequency agrees with the predetermined frequency range, and using the number of samples of each signal sector to determine whether the analog communication signal contains the tone signal.
    Type: Application
    Filed: March 7, 2003
    Publication date: September 9, 2004
    Inventor: Chau-Kai Hsieh
  • Patent number: 6775527
    Abstract: A squelch circuit with an adjustable reference level, having an input level comparator with a first, a second, a third and a fourth current input terminal, a first and a second input terminal, and an output terminal. A first current source is coupled between the first current input terminal and an operation voltage. A second current source is coupled between the second current input terminal and the operation voltage. A third current source is coupled between the third current input terminal and a ground terminal. A fourth current source is coupled between the fourth current input terminal and the ground terminal. A bias generator is coupled to the first, second, third and fourth current sources to generate current control signals thereto according to a reference current and control bits, such that the first, second, third and fourth current sources generate the same current, which adjusts the reference level.
    Type: Grant
    Filed: January 14, 2002
    Date of Patent: August 10, 2004
    Assignee: Faraday Technology Corp.
    Inventors: Chien-Hsiung Lee, Kun-Chih Chang
  • Patent number: 6774700
    Abstract: An electrical circuit generates both a differential data signal and a “squelch,” or “out-of-band,” state over a differential signal pair by employing common-mode logic (CML) technology. In one embodiment of the invention, a CML buffer having true and complementary (inverted) data outputs drive the differential data signal onto the positive (‘p’) and negative (‘n’) signal lines of the differential pair. To implement the squelch state, the true and complementary outputs of a two-input CML multiplexer are coupled with the corresponding outputs of the buffer. The data inputs of the multiplexer are driven by the data input signal driving the buffer, as well as the logical inversion of the data input signal. A squelch state signal then drives an input selector of the multiplexer to impress the squelch state over the differential signal pair when active.
    Type: Grant
    Filed: August 29, 2003
    Date of Patent: August 10, 2004
    Assignee: Agilent Technologies, Inc.
    Inventor: Glenn Wood
  • Patent number: 6775526
    Abstract: A modulated input signal is filtered to reduce noise. The state of the input signal controls the state of a switch. Depending upon its state, the switch connects one of two circuits to a gate. The gate receives the input signal and it passes or blocks the signal depending upon the state of the signal received from the switched circuits. When it is passing the input signal, the output of the gate is equivalent to the input signal. When it is blocking the input signal, the output of the gate is set to a default state. The default state is independent of the input signal. One of the switched circuits gradually modifies the signal provided by the gate to allow the input signal to pass through. The other switched circuit gradually modifies the signal provided to the gate to block the input signal.
    Type: Grant
    Filed: December 1, 2000
    Date of Patent: August 10, 2004
    Assignee: Microchip Technology Incorporated
    Inventors: Pieter Schieke, Steven Dawson
  • Patent number: 6671503
    Abstract: There is provided an improved receiver unit for wireless microphone system. The receiver unit accomplishes desirable mute control in accordance with state transmitting conditions of electric wave from a wireless microphone.
    Type: Grant
    Filed: June 1, 2000
    Date of Patent: December 30, 2003
    Assignee: Kabushiki Kaisha Audio-Technica
    Inventor: Shigeyuki Niwamoto
  • Patent number: 6671504
    Abstract: A radio carrier signal is detected (20) after being converted to digital form and is filtered (22). A noise estimator (24) generates a noise estimate signal by estimating the noise in the detected signal due to atmospheric conditions and the noise due to the gain in noise figure properties of the circuitry. The output of the noise estimator is used to calculate a threshold signal (50) and another detection operation (52) determines whether the power of a signal derived from the detected signal exceeds the threshold. If the threshold is exceeded, the detected signal is passed through a signal conditioner, such as a switch (54) to an output path (56).
    Type: Grant
    Filed: September 29, 2000
    Date of Patent: December 30, 2003
    Assignee: Northrop Grumman Corporation
    Inventor: Michael H. Myers