Abstract: A cable assembly improves the signal integrity of high-speed differential data communicated from a host to a device by removing common-mode noise at the device end of the cable before it can enter the device. The cable includes a differential pair of conductors, a ground conductor, and a common-mode suppressor circuit with differential inputs and outputs. The common-mode suppressor circuit forwards differential signals from its inputs to its outputs, but reduces common-mode voltages. It returns common-mode currents to the host via the ground conductor. The common-mode suppressor circuit may include passive and/or active circuits, and may be implemented as an integrated circuit.

Abstract: Noise caused by and leaking from a transmit signal into a radio-frequency (RF) receive path signal is reduced by forwarding the transmit signal to a first filter or a digital processor and DAC, scaling the transmit signal and approximating the noise, subtracting first and second corrective signals from the RF receive path signal, down-converting a resulting corrected RF receive path signal, filtering the down-converted corrected signal in a second filter, up-converting the filtered corrected signal to create the first corrective signal, and up-converting the filter or DAC output signal to create the second corrective signal. The transmit signal may come from an output of an RF power amplifier, and may be down-converted prior to filtering in the first filter or processing in the digital processor. The second filter may be a series filter or a shunt filter. A radio includes the circuits to perform the above method.

Abstract: Noise caused by and leaking from a transmit signal into a radio-frequency (RF) receive path signal is reduced by forwarding the transmit signal to a first filter or a digital processor and DAC, scaling the transmit signal and approximating the noise, subtracting first and second corrective signals from the RF receive path signal, down-converting a resulting corrected RF receive path signal, filtering the down-converted corrected signal in a second filter, up-converting the filtered corrected signal to create the first corrective signal, and up-converting the filter or DAC output signal to create the second corrective signal. The transmit signal may come from an output of an RF power amplifier, and may be down-converted prior to filtering in the first filter or processing in the digital processor. The second filter may be a series filter or a shunt filter. A radio includes the circuits to perform the above method.

Abstract: A radio receiver processing path has a mixer with active interference/blocker cancellation to reduce the intensity of leaked and undesired signals by using a replica of the transmitted signal, emulating the phase and attenuation through the leakage path and subtracting the emulated signal within the mixer. Intermodulation distortions are predicted through the use of nonlinear modeling in the digital baseband between the baseband transmitter and baseband receiver and subsequently subtracted from the received signal. The nonlinear basis functions are combined to model the composite nonlinearity in the signal path based on digital baseband transmitted data. The modeled nonlinearity is subtracted from the received signal, and the result is observed and used to guide the nonlinear modeling parameters using self-contained control loops.

Abstract: A cable assembly improves the signal integrity of high-speed differential data communicated from a host to a device by removing common-mode noise at the device end of the cable before it can enter the device. The cable includes a differential pair of conductors, a ground conductor, and a common-mode suppressor circuit with differential inputs and outputs. The common-mode suppressor circuit forwards differential signals from its inputs to its outputs, but reduces common-mode voltages. It returns common-mode currents to the host via the ground conductor. The common-mode suppressor circuit may include passive and/or active circuits, and may be implemented as an integrated circuit.

Abstract: Digital data, including audio and video, may be communicated at increased data rates by utilizing non-data signal channels in cables to communicate additional data. For data transmission, a reformatter receives data in a first format adapted for communication over the data signal channels of a cable. The reformatter may convert the received data into a second format with one or more additional data signals. The reformatter then utilizes non-data signal channels of the cable to carry the additional data signals. An example non-data signal channel may include a clock signal channel, and the reformatter may fold a clock signal into one or more of the data signals to allow for clock recovery downstream. Data may also be split into two or more subsets and each subset encoded separately, for example with two or more data encoders such as legacy HDMI encoders.

Abstract: A communications channel may radiate energy undesirably, for example in the form of electromagnetic radiation, when a communication signal transmits over the communications channel. Processing the signal before and after transmission on the communications channel can reduce the level of radiated energy. Signal processing in advance of transmission over the communications channel can transform the communication signal into a waveform that has a reduced propensity to emit radiated energy during transmission over the communications channel. Exemplary signal transformations can involve applying either frequency-selective or broadband attenuation to the communication signal. Following transmission of the waveform over the communications channel, the original communication signal can be restored via reversing the signal transformation. The reverse transformation can comprise applying frequency-selective gain or broadband gain to the transmitted waveform.

Abstract: Systems and methods reduce electromagnetic interference from high speed data carried by wired interconnects with a radio receiver for at least one protected radio frequency band. A spectral encoder changes the encoding of the high speed data to modify its frequency spectrum and reduce its spectral in the protected frequency band. The wired interconnect carries the spectrally encoded data to its destination, where it is spectrally decoded back to its original form. Spectral encoding may include polynomial scrambling. The data may be encoded with different coding parameters in parallel and the best result selected for communication over the wired interconnect. The coding parameters may be changed depending on which radio receivers and/or protected frequency bands are in use at any given time.

Abstract: A circuit can compensate for intra pair skew or mode conversion in a channel by applying a second or corrective mode conversion effect that counters the channel's mode conversion. The circuit can process the common mode signal with a frequency dependent filter prior to injection back into the differential mode. The circuit can implement the reverse mode conversion with passive circuits using integrated resistors and metal oxide semiconductor (MOS) switches. In certain embodiments, such actions can proceed effectively without necessarily consuming active power.

Abstract: HDMI is a digital audio and video communications protocol commonly used in consumer electronics. HDMI is particularly synonymous with high fidelity audio and video. Even though HDMI is a digital communications protocol, the audio quality can be impaired by analog signal impairments and distortions even if there are no digital decoding errors. In particular, the very process by which the audio is converted from Digital (HDMI) to human audible “Analog Audio” can be prone to errors. This occurs when the Digital to Analog Converter (DAC) clock, which is derived from the HDMI TMDS clock or HDMI source, is “distorted” due to its jitter, resulting in erroneous sampling or outputting of vital audio samples, thereby reducing the audio quality of the experience. The present invention reduces the jitter on the TMDS clock, and hence the audio DAC clock, resulting in lower audio distortion.

Abstract: Systems and methods reduce electromagnetic interference from high speed data carried by wired interconnects with a radio receiver for at least one protected radio frequency band. A spectral encoder changes the encoding of the high speed data to modify its frequency spectrum and reduce its spectral in the protected frequency band. The wired interconnect carries the spectrally encoded data to its destination, where it is spectrally decoded back to its original form. Spectral encoding may include polynomial scrambling. The data may be encoded with different coding parameters in parallel and the best result selected for communication over the wired interconnect. The coding parameters may be changed depending on which radio receivers and/or protected frequency bands are in use at any given time.

Abstract: Digital data, including audio and video, may be communicated at increased data rates by utilizing non-data signal channels in cables to communicate additional data. For data transmission, a reformatter receives data in a first format adapted for communication over the data signal channels of a cable. The reformatter may convert the received data into a second format with one or more additional data signals. The reformatter then utilizes non-data signal channels of the cable to carry the additional data signals. An example non-data signal channel may include a clock signal channel, and the reformatter may fold a clock signal into one or more of the data signals to allow for clock recovery downstream. Data may also be split into two or more subsets and each subset encoded separately, for example with two or more data encoders such as legacy HDMI encoders.

Abstract: HDMI is a digital audio and video communications protocol commonly used in consumer electronics. HDMI is particularly synonymous with high fidelity audio and video. Even though HDMI is a digital communications protocol, the audio quality can be impaired by analog signal impairments and distortions even if there are no digital decoding errors. In particular, the very process by which the audio is converted from Digital (HDMI) to human audible “Analog Audio” can be prone to errors. This occurs when the Digital to Analog Converter (DAC) clock, which is derived from the HDMI TMDS clock or HDMI source, is “distorted” due to its jitter, resulting in erroneous sampling or outputting of vital audio samples, thereby reducing the audio quality of the experience. The present invention reduces the jitter on the TMDS clock, and hence the audio DAC clock, resulting in lower audio distortion.

Abstract: A radio receiver processing path has a mixer with active interference/blocker cancellation to reduce the intensity of leaked and undesired signals by using a replica of the transmitted signal, emulating the phase and attenuation through the leakage path and subtracting the emulated signal within the mixer. Intermodulation distortions are predicted through the use of nonlinear modeling in the digital baseband between the baseband transmitter and baseband receiver and subsequently subtracted from the received signal. The nonlinear basis functions are combined to model the composite nonlinearity in the signal path based on digital baseband transmitted data. The modeled nonlinearity is subtracted from the received signal, and the result is observed and used to guide the nonlinear modeling parameters using self-contained control loops.

Abstract: A circuit can compensate for intra pair skew or mode conversion in a channel by applying a second or corrective mode conversion effect that counters the channel's mode conversion. The circuit can process the common mode signal with a frequency dependent filter prior to injection back into the differential mode. The circuit can implement the reverse mode conversion with passive circuits using integrated resistors and metal oxide semiconductor (MOS) switches. In certain embodiments, such actions can proceed effectively without necessarily consuming active power.

Abstract: A circuit can compensate for intra pair skew or mode conversion in a channel by applying a second or corrective mode conversion effect that counters the channel's mode conversion. The circuit can process the common mode signal with a frequency dependent filter prior to injection back into the differential mode. The circuit can implement the reverse mode conversion with passive circuits using integrated resistors and metal oxide semiconductor (MOS) switches. In certain embodiments, such actions can proceed effectively without necessarily consuming active power.

Abstract: A circuit can process a sample of a signal to emulate, simulate, or model an effect on the signal. Thus, an emulation circuit can produce a representation of a real-world signal transformation by processing the signal according to one or more signal processing parameters that are characteristic of the real-world signal transformation. The emulation circuit can apply analog signal processing and/or mixed signal processing to the signal. The signal processing can comprise feeding the signal through two signal paths, each having a different delay, and creating a weighted sum of the outputs of the two signal paths. The signal processing can also (or alternatively) comprise routing the signal through a network of delay elements, wherein a bank of switching or routing elements determines the route and thus the resulting delay.

Abstract: A received RF signal is down-converted to a baseband or low-IF digitized signal in order to search for a pilot signal that indicates a presence of a DTV signal such as an ATSC DTV signal. The pilot signal characteristically resides in a fixed frequency range for all valid DTV signals and is extracted by processing the baseband or low-IF signal in multiple stages. The first stage reduces signal information to that pertaining to the frequency band covering all valid pilot frequencies, thereby reducing the sampling rate and computational complexity of subsequent operations. A second stage operates on this reduced rate signal to focus on a series of particular pilot frequencies for interrogation. For each such candidate frequency, the cyclostationarity of the signal is measured and tested for statistical significance relative to the background energy to yield an effective test that is invariant with respect to background noise level.

Abstract: Processing a signal comprising signal distortions with filters. The filters comprise a first filter configured to a first time scale to compensate for signal distortions within respective symbols of the signal and a second filter configured to a second time scale to compensate for signal distortions among symbols of the signal. A probability estimate is produced based on an output of at least one of the first and second filters. At least one of the first and second time scales is adjusted according to the probability estimate.

Abstract: A slicer can receive a communication signal having a level or amplitude that is between two discrete levels of a multilevel digital communication scheme. The slicer can compare the communication signal to a plurality of references such that multiple comparisons proceed essentially in parallel. A summation node can add the results of the comparisons to provide an output signal set to one of the discrete levels. The slicer can process the communication signal and provide the output signal on a symbol-by-symbol basis. A decision feedback equalizer (“DFE”) can comprise the slicer. A feedback circuit of the DFE can delay and scale the output signal and apply the delayed and scaled signal to the communication signal to reduce intersymbol interference (“ISI”).