A communications system may include radio frequency (RF) circuitry, an antenna assembly, and an RF cable coupling the RF circuitry and the antenna assembly. The antenna assembly may include an antenna and RF impedance selection circuitry coupled thereto. The RF circuitry may be configured to communicate RF signals with the antenna via the RF cable, and communicate RF impedance selection signals to the RF impedance selection circuitry via the RF cable and using an alternating pulse width modulation scheme.

Embodiments of the present invention disclose systems and methods for providing an ATC Overlay data link. Through embodiments of the present invention, existing ATC (or other) modulated signals using existing standard frequencies may be utilized to transmit (e.g., from an aircraft transponder) additional information in a manner that does not render the transmitted signal unrecognizable by legacy ATC equipment. Legacy equipment will be able to demodulate and decode information that was encoded in the transmitted signal in accordance with preexisting standard modulation formats, and updated equipment can also extract the additional information that was overlaid on transmitted signals.

A handshaking process for time-reversal wireless communication is provided. A first device receives a handshake signal transmitted from a second device through multiple propagation paths, the handshake signal including a preamble and a training sequence, in which the training sequence includes a sequence of symbols known to the first and second devices. A synchronization index is determined based on the preamble, and the training sequence in the handshake signal is identified based on the synchronization index. A channel response signal is determined based on the received training sequence, and a signature waveform that is a time-reversed signal of the channel response signal is generated. A transmission signal is generated based on transmit data and the signature waveform, in which the transmit data are data configured to be transmitted to the second device.

The present invention provides a receiver including a sampling circuit, a data sampling point selection circuit and a determination circuit. The sampling circuit is configured to use a clock signal to sample an input signal to generate a sampled signal, wherein a frequency of the clock signal is greater than a frequency of the input signal. The data sampling point selection circuit is configured to filter start point data to generate a filtered start point data, and to generate a data sampling point by adding an offset to the filtered start point data, wherein the start point data corresponds to a time point that a sampled value of sampled signal starts to change. The determination circuit is configured to refer to a sampled value corresponding to the data sampling point in the sampled signal to determine a logical value of a digital output signal corresponding to the input signal.

A receiving device includes: a receiver that receives a signal including PPM symbols; a clock generator that generates a clock for sampling; an A/D converter that digital-converts the received signal; a reference position detector that detects a leading position of the PPM symbols based on data from the A/D converter; and a clock error detector that detects a clock error. The clock error detector includes: a pulse position detector that detects a pulse position in the PPM symbols based on data from the reference position detector and A/D converter; a position error calculator that calculates a deviation of the pulse position based on data from the reference position detector, A/D converter, and pulse position detector; and a clock error calculator that calculates the clock error based on data from the position error calculator. The receiving device varies a frequency of the clock based on data from the clock error calculator.

An electronic device having a housing structure that is configured to receive at least one glass cover is disclosed. The glass cover serves to cover a display assembly provided within the electronic device. The glass cover can be secured to the housing structure so as to facilitate providing a narrow border between an active display area and an outer edge of the housing structure. The enclosure for the electronic device can be thin yet be sufficiently strong to be suitable for use in electronic devices, such as portable electronic devices.

In some embodiments, an apparatus and a system, as well as a method and an article, may operate to transmit and receive data. Transmission may comprise transforming larger values of acquired data into smaller values of transformed data using a transform defined by a seed value selected to reduce digital pulse position modulation transmission time for the acquired data. Additional activities include digital pulse position modulating the transformed data and a checksum associated with the transformed data to provide a propagation signal, and transmitting the propagation signal into drilling fluid or a geological formation. Reception may comprise receiving the propagation signal, demodulating the propagation signal to extract the transformed data and the checksum, and transforming the transformed data into an estimate of the acquired data, using the transform defined by the seed value validated by the checksum. Additional apparatus, systems, and methods are described.

A fiber optic-based communications network includes: a power insertion device, connected to multiple fiber links from a data source, configured to provide power insertion to a hybrid fiber/power cable connected to at least one fiber link of the multiple fiber links; the hybrid fiber/power cable, connecting the power insertion device to a connection interface device, configured to transmit data and power from the power insertion device to the connection interface device; and the connection interface device, configured to provide an interface for connection to an end device via a power over Ethernet (PoE)-compatible connection and to provide optical to electrical media conversion for data transmitted from the power insertion device to an end device via the hybrid fiber/power cable and the PoE-compatible connection.

A power encoder includes a pulse width modulator for modulating a signal according to a set of thresholds to produce a pulse width modulated (PWM) signal and a switch mode power amplifier for amplifying the PWM signal by switching states of switching devices according to amplitudes of the PWM signal. At least one or combination of a distribution of values of the voltage thresholds in the set and a distribution of values of a current generated by different switching devices are non-uniform. The set of voltage thresholds includes at least two positive voltage thresholds.

Methods and apparatus are described for time domain signals. An apparatus includes an electrical circuit decoder coupled to a receiver.