Abstract: Systems and methods for controlling transmission of signals are described. A camera-side modem is configured to receive two signals from a video camera and to extract a received passband signal from a transmission line. A detector in the camera-side modem generates an alarm signal when disruption or loss of the received passband signal is identified. An enable signal is used to control transmission of at least one of the baseband video signal and the passband video signal. The passband signal may be identified by an estimate of mean square error in a quadrature amplitude demodulator, a measurement of reliability provided by a constellation detector, a measurement of reliability based on a sequence of frame synchronizations and/or an estimate of mean square error in an equalizer. The detector may monitor a gain factor in an automatic gain control module of the camera-side modern and/or a magnitude of the received passband signal.

Abstract: Systems and methods for controlling transmission of signals are described. A camera-side modem is configured to receive two signals from a video camera and to extract a received passband signal from a transmission line. A detector in the camera-side modem generates an enable signal when the received passband signal is identified. The enable signal is used to control transmission of at least one of the baseband video signal and the passband video signal. The passband signal may be identified by an estimate of mean square error in a quadrature amplitude demodulator, a measurement of reliability provided by a constellation detector, a measurement of reliability based on a sequence of frame synchronizations and/or an estimate of mean square error in an equalizer. The detector may monitor a gain factor in an automatic gain control module of the camera-side modem and/or a magnitude of the received passband signal.

Abstract: An equalizer and methods for equalizing a cable-borne signal are described. The cable-borne signal includes a digital signal and a baseband analog signal separated by frequency. Distortions are removed from the digital signal and an analog equalizer compensates for attenuations of the analog signal caused by the cable based on equalization settings of a digital equalizer. A baseband analog filter can be selected based on an estimate calculated by the digital equalizer of difference in attenuation at different frequencies.

Abstract: Systems and methods for controlling transmission of signals are described. A camera-side modem is configured to receive two signals from a video camera and to extract a received passband signal from a transmission line. A detector in the camera-side modem generates an alarm signal when disruption or loss of the received passband signal is identified. An enable signal is used to control transmission of at least one of the baseband video signal and the passband video signal. The passband signal may be identified by an estimate of mean square error in a quadrature amplitude demodulator, a measurement of reliability provided by a constellation detector, a measurement of reliability based on a sequence of frame synchronizations and/or an estimate of mean square error in an equalizer. The detector may monitor a gain factor in an automatic gain control module of the camera-side modern and/or a magnitude of the received passband signal.

Abstract: An equalizer and methods for equalizing a cable-borne signal are described. The cable-borne signal includes a digital signal and a baseband analog signal separated by frequency. Distortions are removed from the digital signal and an analog equalizer compensates for attenuations of the analog signal caused by the cable based on equalization settings of a digital equalizer. A baseband analog filter can be selected based on an estimate calculated by the digital equalizer of difference in attenuation at different frequencies.

Abstract: Systems and methods for controlling transmission of signals are described. A camera-side modem is configured to receive two signals from a video camera and to extract a received passband signal from a transmission line. A detector in the camera-side modem generates an enable signal when the received passband signal is identified. The enable signal is used to control transmission of at least one of the baseband video signal and the passband video signal. The passband signal may be identified by an estimate of mean square error in a quadrature amplitude demodulator, a measurement of reliability provided by a constellation detector, a measurement of reliability based on a sequence of frame synchronizations and/or an estimate of mean square error in an equalizer. The detector may monitor a gain factor in an automatic gain control module of the camera-side modem and/or a magnitude of the received passband signal.

Abstract: An engine diagnostic system is provided that enables a service technician to evaluate engine cylinder contribution to output power. The service technician couples one or more signal leads to the vehicle's battery, alternator, or accessory receptacle (e.g., cigarette lighter receptacle) to provide an alternator output signal to a signal analyzer. The signal analyzer processes the alternator output signal to generate an engine signature, which represents engine cylinder contribution to engine output power.

Abstract: An engine diagnostic system is provided that enables a service technician to evaluate engine cylinder contribution to output power. The service technician couples one or more signal leads to the vehicle's battery, alternator, or accessory receptacle (e.g., cigarette lighter receptacle) to provide an alternator output signal to a signal analyzer. The signal analyzer processes the alternator output signal to generate an engine signature, which represents engine cylinder contribution to engine output power.

Abstract: An engine diagnostic system is provided that enables a service technician to evaluate engine cylinder contribution to output power. The service technician couples one or more signal leads to the vehicle's battery, alternator, or accessory receptacle (e.g., cigarette lighter receptacle) to provide an alternator output signal to a signal analyzer. The signal analyzer processes the alternator output signal to generate an engine signature, which represents engine cylinder contribution to engine output power.

Abstract: An engine diagnostic system is provided that enables a service technician to evaluate engine cylinder contribution to output power. The service technician couples one or more signal leads to the vehicle's battery, alternator, or accessory receptacle (e.g., cigarette lighter receptacle) to provide an alternator output signal to a signal analyzer. The signal analyzer processes the alternator output signal to generate an engine signature, which represents engine cylinder contribution to engine output power.

Abstract: A television signal scrambling system scrambles by suppressing horizontal syncs and changing the phase of the video carrier during the horizontal intervals. Data is transmitted by using two different widths for the horizontal intervals. Framing code information is sent by means of long pulses of two different durations during the vertical blanking interval. Three filters are utilized for dynamic scrambling, with filters A and B defining one scrambling mode and A and C defining a second scrambling mode. Corresponding descrambling filters are included in subscriber terminals and the subscriber microprocessor controllers have information downloaded as to the filter pairs to be used for descrambling based upon the receipt of the first or second framing code and a mode definition. The mode definitions are in the form of encrypted data and are dynamically changed by downloading to the subscriber terminals.