Abstract: Self-leveling inspection system methods and devices for use in inspecting buried pipes or other cavities are disclosed. The system includes a camera head with an image sensor, an orientation sensor, and a signal processing module including a processing programmed to receive an image from the image sensor, and an orientation signal from the orientation sensor, generate a second image based at least in part on information provided from the orientation sensor, and store the second image in a non-transitory memory.

Abstract: Self-leveling inspection system methods and devices for use in inspecting buried pipes or other cavities are disclosed. The system includes a camera head with an image sensor, an orientation sensor, and a signal processing module including a processing programmed to receive an image from the image sensor, and an orientation signal from the orientation sensor, generate a second image based at least in part on information provided from the orientation sensor, and store the second image in a non-transitory memory.

Abstract: Methods and apparatus for wired communications are disclosed. A method for transmitting a data stream through a wired communications channel includes encoding the data stream to produce a first baseband modulating signal I(t) and a second baseband modulating signal Q(t) whose amplitudes together represent a time series of complex symbols (I, Q) each selected from a two-dimensional (2-D) constellation of symbols distributed on the phase plane about the origin such that at least one of the baseband modulating signals has a substantially non-zero mean amplitude, modulating the baseband signals I(t) and Q(t) to produce a modulated signal, wherein the I(t) and Q(t) components of the modulated signals are generally fixed in quadrature, and providing the modulated signal to a wired communications channel.

Abstract: Quadrature Amplitude Modulation (QAM) apparatus and systems for use in providing images or video via a wired connection in a video inspection system are disclosed.

Abstract: Self-leveling inspection system methods and devices for use in inspecting buried pipes or other cavities are disclosed. A camera head may include an image sensor, an orientation sensing module, and an image processing module with programming to adjust an image or video provided from the image sensor, based at least in part on information provided from the orientation sensor.

Abstract: Quadrature Amplitude Modulation (QAM) methods, apparatus, and systems are disclosed.

Abstract: Self-leveling inspection system methods and devices for use in inspecting buried pipes or other cavities are disclosed. A camera head may include an image sensor, an orientation sensing module, and an image processing module with programming to adjust an image or video provided from the image sensor, based at least in part on information provided from the orientation sensor.

Abstract: Methods and apparatus for wired communications are disclosed. A method for transmitting a data stream through a wired communications channel includes encoding the data stream to produce a first baseband modulating signal I(t) and a second baseband modulating signal Q(t) whose amplitudes together represent a time series of complex symbols (I, Q) each selected from a two-dimensional (2-D) constellation of symbols distributed on the phase plane about the origin such that at least one of the baseband modulating signals has a substantially non-zero mean amplitude, modulating the baseband signals I(t) and Q(t) to produce a modulated signal, wherein the I(t) and Q(t) components of the modulated signals are generally fixed in quadrature, and providing the modulated signal to a wired communications channel.

Abstract: Self-leveling inspection systems for use in inspecting buried pipes or other cavities are disclosed. A camera head may include an image sensor, an orientation sensing module, and an image processing module configured to adjust an image or video provided from the image sensor, based at least in part on information provided from the orientation sensor, in the camera head.

Abstract: Methods and apparatus for wired communications are disclosed. A method for transmitting a data stream through a wired communications channel includes encoding the data stream to produce a first baseband modulating signal I(t) and a second baseband modulating signal Q(t) whose amplitudes together represent a time series of complex symbols (I, Q) each selected from a two-dimensional (2-D) constellation of symbols distributed on the phase plane about the origin such that at least one of the baseband modulating signals has a substantially non-zero mean amplitude, modulating the baseband signals I(t) and Q(t) to produce a modulated signal, wherein the I(t) and Q(t) components of the modulated signals are generally fixed in quadrature, and providing the modulated signal to a wired communications channel.

Abstract: Quadrature Amplitude Modulation (QAM) methods, apparatus, and systems including a QAM transmit modulator to generate an output signal using a two-dimensional (2-D) QAM symbol constellation is disclosed.

Abstract: A Quadrature Amplitude Modulation (QAM) method and apparatus including a QAM transmit modulator with at least one unbalanced mixer, which creates an asymmetric two-dimensional (2-D) QAM symbol constellation. The asymmetrical symbol constellation provides baseband symbol clock signal leakage sufficient to facilitate quick and simple baseband symbol clock recovery and signal channel compensation at the QAM receiver without significantly degrading the system bit-error rate (BER). While slightly degrading static BER, overall system performance is improved when considering baseband symbol clock recovery and received signal compensation for an imperfect signal channel. This allows QAM to be deployed in systems where QAM is otherwise prohibitively expensive and improves overall system performance for any existing QAM system application without additional bandwidth, cost or complexity.

Abstract: A Quadrature Amplitude Modulation (QAM) method and apparatus including a QAM transmit modulator with at least one unbalanced mixer, which creates an asymmetric two-dimensional (2-D) QAM symbol constellation. The asymmetrical symbol constellation provides baseband symbol clock signal leakage sufficient to facilitate quick and simple baseband symbol clock recovery and signal channel compensation at the QAM receiver without significantly degrading the system bit-error rate (BER). While slightly degrading static BER, overall system performance is improved when considering baseband symbol clock recovery and received signal compensation for an imperfect signal channel. This allows QAM to be deployed in systems where QAM is otherwise prohibitively expensive and improves overall system performance for any existing QAM system application without additional bandwidth, cost or complexity.