Patents Assigned to CoreOptics, Inc.
  • Patent number: 7738602
    Abstract: The invention relates to a method for channel estimation. The method comprises digitizing an analog signal representing a sequence of symbols thereby associating one digital word out to the level of said analog signal at each sampling time. The most likely sequence of said symbols is detected. To this end branch metrics are provided. According to one embodiment, a symbol period comprises at least two sampling times. Moreover, the branch metrics are obtained from frequencies of digital words resulting from a digitizing and the symbols of the most likely sequence. According to another embodiment, a symbol period comprises at least one sampling time. Events are counted wherein each event is defined by a channel state and a current digital word. Each channel state is defined by a pattern of symbols relative to a current symbol determined at the time of a current digital word. A model distribution is fitted to event counts and a branch metrics is obtained from the fitted model distribution.
    Type: Grant
    Filed: July 1, 2004
    Date of Patent: June 15, 2010
    Assignee: CoreOptics, Inc.
    Inventors: Stefan Langenbach, Nebojsa Stojanovic
  • Publication number: 20090100314
    Abstract: This invention relates to a receiver circuit which comprises an equalizer (27) and an error decorrelator (25). The error decorrelator being configured for changing (501; 601, 602) the position of symbols. The invention further relates to a corresponding method. This invention finally relates to an interleaving or deinterleaving method which comprises selecting a first number of symbols (204; 302) within a stream of digital data (13; 28) thereby obtaining selected symbols. The method further comprises exchanging (601, 602) the position of at least half of said first number of symbols of said selected symbols with the position of other symbols from said selected symbols. The invention further relates to an interleaving or deinterleaving circuit.
    Type: Application
    Filed: October 25, 2007
    Publication date: April 16, 2009
    Applicant: COREOPTICS INC.
    Inventors: Markus Danninger, Paul Presslein, Theodor Kupfer
  • Patent number: 7319363
    Abstract: This invention relates to a method for controlling an amplification within a receiver. The gain of a variable gain amplifier which amplifies an input signal to obtain a gain-controlled signal is set. Said gain controlled signal is analog-to-digital converted. Thereby digital words are generated. Each digital word has a value out of a plurality of possible digital values. Digital words having a value within a first and a second subset of the possible digital values are counted in order to generate a first and a second counter value. The gain is set in accordance with the first and second counter values in a fashion that all counter values are as equal as possible. Furthermore, this invention is related to a circuit to be used within a receiver for adjusting the gain of a variable gain amplifier in order to ensure a proper analog-to-digital conversion.
    Type: Grant
    Filed: April 23, 2004
    Date of Patent: January 15, 2008
    Assignee: CoreOptics, Inc.
    Inventors: Stefan Langenbach, Nebojsa Stojanovic
  • Publication number: 20070109053
    Abstract: This invention relates to a method for controlling an amplification within a receiver. The gain of a variable gain amplifier which amplifies an input signal to obtain a gain-controlled signal is set. Said gain controlled signal is analog-to-digital converted. Thereby digital words are generated. Each digital word has a value out of a plurality of possible digital values. Digital words having a value within a first and a second subset of the possible digital values are counted in order to generate a first and a second counter value. The gain is set in accordance with the first and second counter values in a fashion that all counter values are as equal as possible. Furthermore, this invention is related to a circuit to be used within a receiver for adjusting the gain of a variable gain amplifier in order to ensure a proper analog-to-digital conversion.
    Type: Application
    Filed: April 23, 2004
    Publication date: May 17, 2007
    Applicant: CoreOptics Inc.
    Inventors: Stefan Langenbach, Nebojsa Stojanovic
  • Patent number: 7149270
    Abstract: A clock recovery circuit for use with a high-speed data signal having a low signal to noise ratio is disclosed. The circuit includes a first phase locked loop circuit operating in a fast acquisition mode for acquiring the clock from a data signal, a second phase locked loop circuit for operating in a normal mode to recover the clock signal in the digital data signal once the first phase locked loop circuit has acquired the clock from the data signal, and a switch circuit responsive to switch control signals for switching between the first phase locked loop circuit and the second phase locked loop circuit after the first phase locked loop circuit has acquired the digital data signal.
    Type: Grant
    Filed: May 3, 2002
    Date of Patent: December 12, 2006
    Assignee: CoreOptics, Inc.
    Inventors: Claus Dorschky, Theodor Kupfer
  • Patent number: 7095817
    Abstract: A high-speed digital interface circuit for use with an N bit digital data signal is disclosed. The circuit comprises a source device that initially receives the N bit digital data signal, and a sink device that receives the N bit digital data signal from the source device. The N bit digital data signal has a skew when received by the sink device. A skew detection circuit in the sink device detects the skew in the N bit digital data signal and generates a skew detection signal. A line supplies the skew detection signal to the source device. A compensation circuit in the source device receives the skew detection signal and compensates for the skew in the N bit digital data signal.
    Type: Grant
    Filed: May 3, 2002
    Date of Patent: August 22, 2006
    Assignee: CoreOptics, Inc.
    Inventors: Claus Dorschky, Theodor Kupfer, Paul Presslein
  • Patent number: 6930628
    Abstract: A circuit for generating a digital data signal from an analog input data signal is disclosed. The circuit comprises a master-slave flip-flop with a clock input for receiving the analog input data signal, an amplitude detecting circuit for detecting the amplitude of the analog input data signal and generating an amplitude detection signal in response thereto, and a phase shifting circuit responsive to the amplitude detection signal for supplying a phase shifted signal to the clock input of the master-slave flip-flop. The circuit may further include a clock recovery circuit for generating a recovered clock signal from a clock signal contained in the analog input data signal. The recovered clock signal may be supplied to the amplitude detecting circuit, or a feedback loop may supply the phase shifted clock signal to the amplitude detecting circuit.
    Type: Grant
    Filed: May 3, 2002
    Date of Patent: August 16, 2005
    Assignee: CoreOptics, Inc.
    Inventors: Mario Reinhold, Eduard Rose, Frank Kunz