With Signal Conversion (e.g., Dial To Dtmf, Analog To Pcm) Patents (Class 379/339)
  • Patent number: 9369978
    Abstract: A mobile device receives a signal, from a base station, comprising a primary synchronization sequence (PSS) and a secondary synchronization sequence (SSS). The mobile device utilizes two different sampling rates to perform the PSS synchronization and the SSS detection individually. For example, the mobile device synchronizes to the received PSS at a first sampling rate such as 0.96 MHz, which is determined based on the PSS transmission rate and/or the length of the received PSS. The mobile device detects the received SSS at a second sampling rate such as 1.92 MHz, which equals to the sampling rate for an analog-to-digital conversion at the mobile device. The received PSS and associated symbol timing are detected through the PSS synchronization to support the SSS detection. The detected SSS is used to acquire cell-specific parameters such as cell ID. The acquired cell-specific parameters ensure proper communications between the mobile device and the base station.
    Type: Grant
    Filed: November 11, 2013
    Date of Patent: June 14, 2016
    Assignee: Broadcom Corporation
    Inventors: Francis Swarts, Mark Kent
  • Patent number: 8385363
    Abstract: A system for adapting an analog system to a packet network may include an electronic signal adapter in communication with the analog system and packet network. The electronic signal adapter may be configured to convert information received in data packets from the packet network into dual-tone multiple frequency (DTMF) signals and single tone analog signals and to communicate the DTMF and single tone analog signals to the analog system. The single tones may have a signal strength below approximately ?25 dBm. The electronic signal adapter may further be configured to receive and convert analog signals into digital data for communication in data packets over a packet network.
    Type: Grant
    Filed: May 15, 2007
    Date of Patent: February 26, 2013
    Assignee: CenturyLink Intellectual Property LLC
    Inventors: Amar N. Ray, John M. Heinz, Warren K. Okeson
  • Publication number: 20100274563
    Abstract: A method and mobile communication device for generating dual-tone multi-frequency (DTMF) commands on a mobile communication device having a touchscreen are provided. In accordance with one embodiment, there is provided a method for generating dual-tone multi-frequency (DTMF) commands on a mobile communication device having a touchscreen, comprising: detecting an automated attendant during a telephone call; activating speech recognition in respect of incoming voice data during the telephone call in response to detecting an automated attendant; translating spoken prompts in the incoming voice data into respective DTMF commands; displaying a menu having selectable menu options corresponding to the DTMF commands In a graphical user interface on the touchscreen; receiving input selecting one of the menu options; receiving input via the touchscreen activating a selected one of the menu options; and generating a DTMF command in accordance with the activated menu option.
    Type: Application
    Filed: April 24, 2009
    Publication date: October 28, 2010
    Applicant: RESEARCH IN MOTION LIMITED
    Inventors: Eric G. Malo, Lawrence Edward Kuhl
  • Patent number: 7697965
    Abstract: The present invention is to provide a mobile phone comprising a body and a housing. A hollow is formed within the housing and the body is slidably disposed in the hollow. The hollow has an opening in an end of the housing and the other end terminated at a closed end of the housing distal the opening. A display (e.g., LCD (liquid crystal display)) is disposed on a front surface of the housing. The body comprises a circuit board and an input device. The circuit board is installed within the body and comprises electronic circuits and devices for controlling the components of the mobile phone. The input device (e.g., alphanumeric keypad) is disposed on a front surface of the body for operating the mobile phone. The body is capable of being engaged with the housing and being slid towards outside of the hollow through the opening to expose the input device for a user to make a phone call.
    Type: Grant
    Filed: July 20, 2006
    Date of Patent: April 13, 2010
    Assignee: Inventec Appliances
    Inventor: Zheng Li
  • Publication number: 20080273688
    Abstract: The present invention PCM (phone computing machine) uses general purpose programmable device (101) as its core. Line-end interface (201), includes RJ11 jack (210), DAA (212) and CODEC (214), connects to telephone line. User-end interface (301), in one embodiment includes RJ11 jack (310), SLIC (312) and CODEC (314) connects to user apparatus/networks/systems. The functionality of PCM is defined when a portable data storage device with application software is plugged in the machine's external memory interface (401). PCM's great flexibility and low cost will open up new frontier in the telephone system. In addition, a general method similar as PCM can be applied to other cost-effective information processing applications between predetermined information sources. Examples are voice application in microphone system, audio/video processing in home entertain systems.
    Type: Application
    Filed: May 5, 2007
    Publication date: November 6, 2008
    Inventors: Wei Lu, Liping Chen
  • Patent number: 7286089
    Abstract: A portable device with a sliding variable built-in antenna is provided including a main body, a variable built-in antenna which is assembled at a predetermined location of the main body and configured to slide up/down with respect to the main body according to an antenna reception sensitivity, and an electrical connection device for signal transmission between the main body and the variable built-in antenna.
    Type: Grant
    Filed: July 5, 2005
    Date of Patent: October 23, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jae-Ho Lee, Do-Hwan Choi, Yeong-Moo Ryu, Hark-Sang Kim
  • Patent number: 7257220
    Abstract: A method for providing extended reach of a digital subscriber line signal includes receiving an incoming DSL signal, splitting the DSL signal into separate voice and data signals, demodulating the data signal, requantizing the demodulated data signal, modulating the requantized data signal, amplifying the modulated requantized data signal and the voice signal, combining the amplified voice and data signal into a combined signal, and transmitting the combined signal.
    Type: Grant
    Filed: December 29, 2000
    Date of Patent: August 14, 2007
    Assignee: Cisco Technology, Inc.
    Inventors: Robert A. Marshall, Michael H. Capon
  • Patent number: 7158633
    Abstract: Subscriber line interface circuitry includes an integrated circuit having sense inputs for a sensed tip signal and a sensed ring signal of a subscriber loop. The integrated circuit generates a subscriber loop linefeed driver control signal in response to the sensed signals. The linefeed driver does not reside with the integrated circuit. A method for monitoring power dissipation of the linefeed driver components includes the step of sampling at least one of the tip and ring signals to determine a line voltage and a line current of a selected linefeed driver component. Instantaneous power dissipation of the linefeed component is estimated and then filtered to generate an estimated junction temperature of the linefeed component. In one embodiment, the linefeed driver includes a tip fuse series-coupled to the tip line and a ring fuse series-coupled to the ring line.
    Type: Grant
    Filed: November 16, 1999
    Date of Patent: January 2, 2007
    Assignee: Silicon Laboratories, Inc.
    Inventor: Jerrell P. Hein
  • Patent number: 6829768
    Abstract: An information processing apparatus has an SDL execution unit described in a specification and description language (SDL), an external environment description unit described in a programming language other than the SDL, and an adapter having a pseudo internal signal generator and a queue manager. A task of an operation system is assigned to the external environment description unit, which is combined with the SDL execution unit through the adapter. The pseudo internal signal generator converts signals including messages, events, and parameters to be transferred between the SDL execution unit and the external environment description unit. The converted signals are transferred between the SDL execution unit and the external environment description unit through the queue manager. Also provided is an information processing method to materialize the information processing apparatus. These method and apparatus reduce the overhead of the operation system.
    Type: Grant
    Filed: September 29, 1998
    Date of Patent: December 7, 2004
    Assignee: Fujitsu Limited
    Inventors: Yumi Suzuki, Chizu Yoshioka, Fumiyasu Ige
  • Patent number: 6757276
    Abstract: Tones that are generated by a telephone or PC (such as DTMF tones) and subject to loss or noise during generation or during transmission along a medium are detected and replaced with substantially noise-free and distortionless digital signals. In one embodiment, the replacement of the tones is done in a modem embodied in an Internet telephony Gateway/Terminal, such as in a network access server coupling a time division multiplexed telephone line to a packet-switched network. The replacement of the tones may also be performed in any suitable device that provides an interface between a time division multiplexed transmission medium and a packet switched data network, such as in the modems of a cellular telephone network to Internet network access server.
    Type: Grant
    Filed: November 24, 1998
    Date of Patent: June 29, 2004
    Assignee: 3Com Corporation
    Inventors: Matthew Harper, Richard J. Dynarski, Timothy G. Mortsolf, Kenneth L. Peirce, Jr.
  • Patent number: 6694010
    Abstract: A fast-converging, computationally simple, method for recognizing a single frequency tone or a sinusoid in a signal without prior knowledge of the tone frequency. The method employs a second order or higher auto-regressive model and includes: (a) sampling the signal at a constant sampling rate, and, for each sample, recursively determining a finite number of correlation coefficients using a time-reversed, exponentially weighted, future sliding equivalent of the signal, wherein the correlation coefficients are determined using pre-existing values of the correlation coefficients determined in a previous iteration, a current sample of the signal and at least two consecutively previous samples of the signal; (b) periodically determining at least the second auto-regressive coefficient modeling the signal using the correlation coefficients; and (c) recognizing the presence of the tone based on the value of the second auto-regressive coefficient.
    Type: Grant
    Filed: April 27, 1999
    Date of Patent: February 17, 2004
    Assignee: Alcatel Canada Inc.
    Inventor: Eric Verreault
  • Patent number: 6671375
    Abstract: Disclosed is a telephone circuit in which two simultaneously available telephones are connected by use of a pair of twisted-paired cables. A PBX 1 and a digital multi-function telephone 2 are connected by a pair of twisted-paired cables, a digital signal channel of 2B+D is established bidirectionally between the PBX 1 and the digital multi-function telephone 2, and user information and a control signal are sent and received therebetween. The digital multi-function telephone 2 and an analog telephone 3 are connected by a pair of twisted-paired cables, and a signal is sent and received between the digital multi-function telephone 2 and an analog telephone 3 by an analog signal of a voice band and a DC/AC control signal. A B1-channel on a 2-wire digital line 4 is allocated for user information transmission of the digital multi-function telephone 2, and a B2-channel is allocated for user information transmission of the analog telephone 3.
    Type: Grant
    Filed: July 5, 2000
    Date of Patent: December 30, 2003
    Assignees: Hitachi, Ltd., Hitachi Communication Systems, Inc.
    Inventors: Takeshi Fukuju, Toshihiko Umeda, Yoshiro Hasegawa
  • Patent number: 6665350
    Abstract: A method and system for improved detection of analog signals, where the analog signals may be composed of one or more analog frequencies. In the method and system, an analog signal is received. A stream of data samples is created from the analog signal. Based on the stream of data samples, a confidence factor regarding the presence of the one or more analog signals is created. The confidence factor is created based upon a confidence factor calculated for each of the one or more analog frequency signals. The confidence factor calculated for each of the one or more analog frequency signals is calculated utilizing incremental energies associated with each of the one or more analog frequency signals.
    Type: Grant
    Filed: September 25, 1998
    Date of Patent: December 16, 2003
    Assignee: Legerity, Inc.
    Inventor: John G. Bartkowiak
  • Patent number: 6628638
    Abstract: A diversity receiving apparatus for use in an OFDM transmission radio communication/broadcasting system where OFDM signals are received by a plurality of antennas and input into a plurality of receivers. The OFDM received signals are further transformed into frequency spectra. Channel frequency responses are calculated by using OFDM received signal frequency spectra and a reference frequency spectrum generated in a reference spectrum generator. OFDM received signal frequency spectra distortions are compensated by using corresponding channel frequency responses. The transformed OFDM received signal frequency spectra are input into a selector unit as first input signals, while the distortion-compensated OFDM received signal frequency spectra are input into the selector unit as second input signals. The selector unit then selects a second input signal corresponding to a first input signal having maximum amplitude or maximum power.
    Type: Grant
    Filed: January 7, 1999
    Date of Patent: September 30, 2003
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazumi Sato, Minoru Namekata
  • Publication number: 20020191551
    Abstract: The invention concerns a method and a system for ensuring successful setup of calls in a telephone exchange system comprising a local exchange (LE), an access node (AN) and a concentrating V5 interface (V5) connecting the access node (AN) to the local exchange (LE). In the method, the concentrating interface (V5) is divided into two or more parts.
    Type: Application
    Filed: April 29, 2002
    Publication date: December 19, 2002
    Inventors: Vesa Heikkila, Tom Vernoou
  • Patent number: 6353621
    Abstract: The invention provides systems, including a methods and apparatus, for providing seamless telephone service across MSC's that support multiple or different protocols. In accordance with a preferred embodiment of the invention, the home mobile switching center, where the subscriber record is stored, is equipped to respond to a first inquiry signal from an originating mobile switching center by identifying itself to the originating mobile switching center. The incoming call may then be trunked to the home mobile switching center and forwarded to the visited mobile switching center according to the second protocol. According to another preferred embodiment, in response to the first inquiry signal, the home mobile switching center sends a second inquiry signal to the visited mobile switching center. The first inquiry signal represents a request for an identification number identifying, in the first protocol, the visited mobile switching center.
    Type: Grant
    Filed: September 15, 1998
    Date of Patent: March 5, 2002
    Assignee: Lucent Technologies, Inc.
    Inventors: Richard R. Boland, Patrick Joseph Boyle, John M. Gafrick, Mark A. McCormick, Leslie J. Williams
  • Patent number: 6185293
    Abstract: A signal matching apparatus for exchanging signals between a digital switching system and a two-wire long distance subscriber line signal switching system comprises a first PCM equipment for converting a 4-wire E1 signal of the digital switching system into a 4-wire analog signal, and for connecting a 4-wire analog signal of the long distance subscriber line signal switching system into a 4-wire digital signal transferred to the digital switching system, and a second PCM equipment for converting the 4-wire analog signal of the first PCM equipment into a 2-wire signal, and for converting the analog signal of the long distance subscriber line signal switching system into a 4-wire analog signal transferred to the first PCM equipment.
    Type: Grant
    Filed: March 16, 1998
    Date of Patent: February 6, 2001
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Hyun-Soo Je
  • Patent number: 6044147
    Abstract: An apparatus for improving signal quality in a communications link includes apparatus for regenerating only the speech-like characteristics of signals received over the communications link so that an estimate of the original speech signal can be retransmitted. The apparatus may include a vocal tract model coupled to a synthesizer.
    Type: Grant
    Filed: September 11, 1997
    Date of Patent: March 28, 2000
    Assignee: British Teledommunications public limited company
    Inventor: Michael Peter Hollier
  • Patent number: 5995557
    Abstract: To detect a dual tone pair signal in a telephone communication system, the signal is sampled at the Nyquist frequency. The sampled signal is filtered to determine the top three tone frequency power results. The input signal is then resampled at one-half of the Nyquist frequency. The resampled signal is filtered to determine signal power in the row and column frequency bands. The top three power results from tone filtering and aliasing row and column band pass filter power results are checked for lack of excess power to reject false digits.
    Type: Grant
    Filed: June 12, 1997
    Date of Patent: November 30, 1999
    Assignee: Nortel Networks Corporation
    Inventor: Balaji Srinivasan
  • Patent number: 5937059
    Abstract: A dual tone multi-frequency detector includes a pulse code modulation expanding unit for converting pulse code modulation data into linear data. A correlating unit constructed from a plurality of correlators correlates the linear data with a plurality of predetermined reference signals to generate a plurality of power values of a frequency band corresponding to dual tone multi-frequency signals. A total power detecting unit detects a total power value of the linear data. A low frequency maximum power detecting unit detects a maximum low frequency power value from the power values of a low frequency band generated by the correlating unit. A high frequency maximum power detecting unit detects a maximum high frequency power value from the power values of a high frequency band generated by the correlating unit.
    Type: Grant
    Filed: November 19, 1996
    Date of Patent: August 10, 1999
    Assignee: SamSung Electronics Co., Ltd.
    Inventors: Nam-Sun Kim, Young-Ky Kim, Yoon-Seok Kang, Ho-Young Park
  • Patent number: 5878131
    Abstract: Acoustic dialers are widely used to dial telephone numbers by generating a pair of DTMF tones for each key being depressed. Non-linearities in telephone systems, acoustic dialer loudspeakers, and telephone microphones may cause interfering tones to be produced due to mixing of generated DTMF tones. These interfering tones are especially problematic when they are near the frequencies of the DTMF tones and have similar amplitudes. When these interfering tones are received by a receiver decoder, the decoder may be unable to distinguish the interfering tones from the DTMF tones, and consequently the decoder may reject the DTMF tones received. The present invention prevents these types of rejections by generating a supplemental tone in addition to the normal DTMF tones. This supplemental tone attenuates the interfering tones so that receiver decoders can distinguish the interfering tones from the DTMF tones.
    Type: Grant
    Filed: November 18, 1996
    Date of Patent: March 2, 1999
    Assignee: AT&T Corp
    Inventor: Robert Albert Boie
  • Patent number: 5793862
    Abstract: An information signal detection device and an information signal detection method are disclosed with which it is possible to transmit information by means of a DTMF signal using a channel that is prone to distortion, such as a high-efficiency channel. The information signal detection device comprises a filter bank component and a logic component. The filter bank component receives via a channel an information signal in which are superposed sine waves of two different frequencies selected from a specific number of frequencies sent by the sender, and generates binary information patterns showing in binary information whether the signal components of the various frequencies of this information signal are present. The logic component recognizes the end of the signal region when the binary information pattern generated in the binary information pattern generation step is containing no binary information showing that a signal component is present continuously for a specific period of time.
    Type: Grant
    Filed: March 21, 1996
    Date of Patent: August 11, 1998
    Assignee: Fujitsu Limited
    Inventors: Teruyuki Sato, Toshiaki Nobumoto, Hideaki Kurihara, Mitsuru Takahashi
  • Patent number: 5754635
    Abstract: An apparatus for receiving multi-channel caller identification data in a switching system with a path forming portion for forming a path to receive the caller identification data in response to an incoming ring signal from a plurality of central office lines; a multiplexer for selecting one of a plurality of channel signals containing the call identification data and received from the path forming portion; a decoder for sampling an analog signal of a corresponding channel selected by the multiplexer at a predetermined sampling frequency, to thereby convert the analog signal containing the call identification data into a PCM signal; a time switch for switching and outputting the converted PCM signal converted in the decoder and containing the call identification data to a corresponding channel; a demodulator for receiving the PCM signal output through the time switch to thereby demodulate the caller identification data; and a controller establishing a path for the caller identification data in response to the
    Type: Grant
    Filed: June 24, 1996
    Date of Patent: May 19, 1998
    Assignee: SanSung Electronics Co., Ltd.
    Inventor: Hong-Han Kim
  • Patent number: 5715309
    Abstract: A conversion system using a lookup table of adjustment values for converting non-linear, logarithmic pcm codes between attenuated and unattenuated formats. A computer accesses attenuated pcm codes from a compression device, such as that found in the transmit portion of a digital speakerphone, and retrieves an adjustment value from the lookup table using the measured pcm code and a gain code. The gain code corresponds to a gain setting asserted by the computer to a gain device in the transmit portion of the speakerphone. The lookup table is preferably implemented in hardware, such as a ROM, RAM, PLA or similar type device, or is implemented in software or firmware executed by the computer. The retrieved adjustment value is added to the attenuated pcm code to determine the corresponding unattenuated pcm code.
    Type: Grant
    Filed: March 3, 1995
    Date of Patent: February 3, 1998
    Assignee: Advanced Micro Devices, Inc.
    Inventor: John G. Bartkowiak
  • Patent number: 5557670
    Abstract: A channel interface unit for interconnecting a two-wire transmission path which transmits analog signals and a digital signal transmission path. The channel interface unit includes a digital interface unit coupled with the digital signal transmission path and producing digital signals based on digital signals received from the digital signal transmission path, a converter for converting the digital signals to analog signals, a filter for removing noise, produced by the converter, from the analog signals, a driver, coupled with the two-wire transmission path, for amplifying the filtered analog signals, and a power supply for providing regulated voltage to the driver The channel interface unit also includes a device for decreasing effective capacitance by modifying the output impedance of the driver.
    Type: Grant
    Filed: October 12, 1993
    Date of Patent: September 17, 1996
    Assignee: Antec Corporation
    Inventors: Steven B. Perry, James P. Hogan
  • Patent number: 5557669
    Abstract: A channel interface unit for interconnecting a two-wire transmission path which transmits analog signals and a digital signal transmission path. The channel interface unit includes a digital interface unit coupled with the digital signal transmission path and producing digital signals based on digital signals received from the digital signal transmission path, a converter for converting the digital signals to analog signals, a filter for removing noise, produced by the converter, from the analog signals, a driver, coupled with the two-wire transmission path, for amplifying the filtered analog signals, and a power supply for providing regulated voltage to the driver.
    Type: Grant
    Filed: October 12, 1993
    Date of Patent: September 17, 1996
    Assignee: ANTEC Corporation
    Inventors: Steven B. Perry, James P. Hogan
  • Patent number: 5500896
    Abstract: A code converter for processing switching information signals, which comprises a protection circuit for limiting a current flowing in a telephone exchange wire. The protection circuit includes an evaluation circuit, which causes a switch arranged in series with the telephone exchange wire to open if the current, or a signal derived from the current, exceeds a threshold value. In an embodiment of the invention the current is also limited if the current assumes intolerably high values only for a brief period of time and no opening of the switch is effected.
    Type: Grant
    Filed: July 19, 1994
    Date of Patent: March 19, 1996
    Assignee: U. S. Philips Corporation
    Inventors: Wilfried Hache, Jost Kawczyk
  • Patent number: 5467395
    Abstract: When there is an incoming call to a digital line and the digital line is to be connected to a digital terminal, a CPU connects the line and the terminal directly. When the digital line is to be connected to an analog individual line telephone or the like, the line and the terminal are connected via a level controller. The level controller shifts, to an appropriate level, the level of a voice signal represented by data received from the digital line, and the analog individual line telephone or the like connected to the extension receives the voice signal shifted to the appropriate level.
    Type: Grant
    Filed: April 22, 1992
    Date of Patent: November 14, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventor: Michihiro Izumi
  • Patent number: 5448635
    Abstract: A network adapter and wiring scheme makes use of existing plain old telephone service (POTS) wiring to provide support between analog devices within the subscriber premise and an Integrated Digital Service Network (ISDN). Moreover, the network adapter and wiring scheme provides further support between digital devices within the premise and the ISDN while concurrently supporting analog devices.
    Type: Grant
    Filed: June 30, 1993
    Date of Patent: September 5, 1995
    Assignee: International Business Machines Corporation
    Inventors: Robert E. Biehl, Charles C. Hallock, Joe F. Jones, Jr., Robert E. Landa, Baiju D. Mandalia, Charles H. Sederholm
  • Patent number: 5386470
    Abstract: A multiport repeater for a local area network installation has (in addition to its conventional functions) means for storing access rules for the items of equipment connected to it. It reads a portion of each frame, which may be all or part of the destination address segment and/or of the source address segment and/or of the control segment of each incoming data frame, or it could be a frame or protocol identifier incorporated in opening bytes of the data segment. It compares the data that it reads with the stored access rules to determine whether the frame is permitted or not. If not, the repeater modifies the frame which it is in the course of re-transmitting, for example by overwriting it with meaningless digits or by encrypting it. It may also report the source address, destination address and reason for deciding to modify the frame to the network controller.
    Type: Grant
    Filed: August 24, 1993
    Date of Patent: January 31, 1995
    Assignee: 3Com Ireland
    Inventors: Steven H. Carter, Terence D. Lockyer, Christopher J. Gahan
  • Patent number: 5323460
    Abstract: An enhanced subscriber line interface circuit for a digital switching system which includes a line configuration and protection circuit connection tot he subscriber line and to a thick-film hybrid module. The thick-film hybrid module comprises a high voltage interface circuit and a PCM conversion circuit. The high voltage interface circuit provides power to the subscriber line, converts received analog voice signals transmitted from the subscriber instrument into differential voltage voice signals and detects the subscriber lines status. The PCM conversion circuit is connected to the high voltage interface circuit and is disposed to convert received differential voice signals into PCM digital signals.
    Type: Grant
    Filed: January 7, 1992
    Date of Patent: June 21, 1994
    Assignee: AG Communication Systems Corporation
    Inventors: Michael Warner, Lalit O. Patel, Absar Naseer
  • Patent number: 5305377
    Abstract: An interface for translating signals from a ISDN terminal to an analog telephone terminal including apparatus for separating ISDN signals into control and data signals, apparatus for utilizing the control signals to generate tone signals for transfer to a telephone line, apparatus for translating the digital control signals into signals controlling the transfer of data from digital to analog form, apparatus for translating digital signals in ISDN format into analog signals under control of the apparatus for translating the digital control signals into signals controlling the transfer of data from digital to analog form, apparatus for translating control signals in analog tone format to digital signals for controlling the transfer of signals to an ISDN terminal, apparatus for using the control signals for controlling the transfer of data from analog to digital form, and apparatus for translating analog signals into digital signals in ISDN format under control of the digital signals for controlling the transfer
    Type: Grant
    Filed: March 29, 1991
    Date of Patent: April 19, 1994
    Assignee: Sun Microsystems, Inc.
    Inventors: Paul D'Arcy, Robert Sloan, David Evans
  • Patent number: 5289538
    Abstract: A circuit arrangement converts signals and information between analog junction lines and digital terminal devices in communications exchanges. A decentralized control device is provided in order to process and pass on switching criteria and codes received and sent to the respective analog junction line, inside and outside the audio frequency band, the circuit arrangement including a plurality of line interfaces, each coupled directly to a respective one of the decentralized control devices, for the switching criteria and codes to be exchanged outside of the audio frequency. At least one digital signal processor is provided for processing the codes to be exchanged within the audio frequency band, the digital signal processor being looped in via a hybrid connection and converter in a speech path which cooperates with the control device.
    Type: Grant
    Filed: March 14, 1991
    Date of Patent: February 22, 1994
    Assignee: Telenorma GmbH
    Inventors: Walter Lauer, Udo Petri, Gerd Ponitz
  • Patent number: 5177781
    Abstract: A method and device for recognizing a signature of dialing pulse present in a communication signal isolate from the latter signal the signature. The so isolated signature is correlated with a statistic model obtained from a large number of dialing pulse signatures to determine whether the isolated signature corresponds to a dialing pulse. During this correlation, a first complex function representative of the isolated signature is calculated and correlated with a second complex function representative of the statistic model. The result of the correlation is normalized and whether the isolated signature is a signature of dialing pulse is decided in function of this normalization. The method and device can be used to convert into a tone frequency signal a series of dialing pulse signatures present in the communication signal and corresponding to a dialed digit.
    Type: Grant
    Filed: September 21, 1990
    Date of Patent: January 5, 1993
    Assignee: Teleliaison
    Inventors: Michel Ponton, Yves Lemieux, Normand Girard, Marc Gareau
  • Patent number: 5163050
    Abstract: In a digital messaging system (10), an apparatus (37) and method for determining whether a DTMF (Dual Tone Multi Frequency) digit is present on an input signal (11,12). A heuristics engine (37) performs a series of tests on the input signal (11,12) using a set of parameters that are stored in a RAM (38). There is one parameter for each of a set of input signal (11,12) characteristics and for each of a set of operating modes of the digital messaging system (10). All of the parameters are configurable. The configurability allows for the use of non-standard telephone equipment (13,14) and minimizes deleterious effects such as talkoff. The tests are from the set of sets comprising an absolute magnitude test, a frequency deviation test, a twist test, an echo test, a consistency test, and a temporal test.
    Type: Grant
    Filed: January 23, 1991
    Date of Patent: November 10, 1992
    Assignee: Digital Sound Corporation
    Inventor: Mark R. Cromack
  • Patent number: 4852160
    Abstract: A channel unit interface circuit for interconnecting a two-wire, bidirectional signal transmitting means and a four-wire signal transmitting means in a communication system includes a tip terminal line driver, a ring terminal line driver, a voice sense amplifier, a balance network, A/D signal processing circuit, D/A signal processing circuit, filter network, a voice codec/PCM filter, a channel logic circuit, and a DC-to-DC converter. The channel unit interface circuit is suitable for use with substantially all of the different alarm-signalling techniques utilized by the various alarm companies for connecting their equipment to a channel bank coupled to the four-wire means. The interface circuit simulates a transmission line or cable over carrier in the frequency range of DC to 3.5 KHz with an amplitude variation between +110 to -200 VDC.
    Type: Grant
    Filed: March 3, 1987
    Date of Patent: July 25, 1989
    Inventors: Frederick J. Kiko, George Kummer
  • Patent number: 4652703
    Abstract: A digital voice communication apparatus having improved echo suppression includes a transmission gain detection circuit for detecting a near talker signal and a receiver gain detection circuit for detecting a far talker signal. An echo detecting circuit detects which of the near talker and far talker signals has a lesser value and suppresses the gain of the one detected to have the lesser value. A far talker suppressing circuit detects whether the most recent peak gain in this near talker signal is greater than a threshold and is greater than the gain of the far talker signal. If this condition exists the far talker signal is suppressed. A near talker signal suppressing circuit detects whether the most recent gain of the far talker signal is greater than a threshold and is greater than the gain of the near talker signal. If so, the gain of the near talker signal is suppressed.
    Type: Grant
    Filed: March 1, 1983
    Date of Patent: March 24, 1987
    Assignee: Racal Data Communications Inc.
    Inventors: Chun C. Lu, William J. Miller, Jack E. Stephenson, Jay P. Jayapalan
  • Patent number: 4633225
    Abstract: A circuit for generating a desired two terminal impedance at the two terminals by coupling analog signals appearing at the two terminals into an analog to digital converter, supplying the output therefrom to a digital processing circuit, leading the outputs therefrom to a digital analog converter, and connecting the output therefrom to the two terminals to form a feedback loop. The digital processing circuit processes using a desired transfer function. An analog processing circuit is provided which receives the analog signals appearing at said two terminals as input, and which passes the component of the signal having frequencies higher than the frequencies processed in the digital processing circuit.
    Type: Grant
    Filed: March 12, 1984
    Date of Patent: December 30, 1986
    Assignee: Nippon Telegraph and Telephone Public Corp.
    Inventors: Toshio Hayashi, Youichi Maeda