Telefonaktiebolaget Lm Ericsson (Publ)

Apple Inc.

Rockstar Bidco, LP

Russell Clifford Smiley

Charles Tremlett Nicholls

Mark William Wyville

Mark Wyville

Embodiments of a digital-to-analog conversion system that utilizes a specialized clock signal to reshape an analog impulse response of a digital-to-analog converter (DAC) are disclosed. Preferably, a shape of the specialized clock signal is such that Nyquist images resulting from digital-to-analog conversion are controlled in a desired manner. In one embodiment, the digital-to-analog conversion system includes a DAC that converts a digital input signal into an analog output signal. A specialized clock signal is applied to the analog output signal of the DAC such that an analog impulse response of the DAC is reshaped according to a shape of the specialized clock signal, thereby providing a modified analog output signal. The specialized clock signal reshapes the analog impulse response of the DAC such that Nyquist images resulting from digital-to-analog conversion are controlled in a desired manner.

Digital analog converter

The present disclosure relates to controlling a frequency band of operation of one or more base stations in a cellular communication network based on associated parameters of air interfaces of the one or more base stations. In one embodiment, a control element of the cellular communication network obtains parameters for an air interface of a base station. In addition, in some embodiments, the control element obtains one or more parameters for air interfaces of one or more additional base stations. Using the one or more parameters, the control element obtains a decision to switch a frequency band of operation of the base station from a first frequency band to a second frequency band. In response, the control element sends a command to the base station to switch the frequency band of operation of the base station from the first frequency band to the second frequency band.

Systems and methods for controlling a frequency band of operation of a base station

An amplifying circuit for use in, for example, broadband transceivers is described. A bias filter is connected between an amplifying transistor and a power supply to block a wide range of frequencies associated with amplified RF input signals from reaching the power supply, while permitting DC power to reach the transistor.

Broadband transistor bias network

A device is provided having a local oscillator (LO) configured to generate a first signal comprising at least one of timing information, frequency information, phase information and combinations thereof. The device also has a LO error corrector comprising an input, the input configured to receive a second signal comprising at least one of timing information, frequency information, phase information and combinations thereof. The second signal is used for disciplining the LO. The LO error corrector is capable of disciplining the LO using a source that is less accurate than a preferred second signal, if the preferred second signal is unavailable to discipline the LO.

System and method for reducing holdover duration

A device is provided having a local oscillator (LO) configured to generate a first signal having timing information, frequency information, phase information or combinations thereof. The device also includes a prioritizer comprising at least two inputs, each input configured to receive a respective second signal having timing information, frequency information, phase information or combinations thereof. The prioritizer is configured to determine an accuracy of at least one second signal of the at least two second signals in relation to a second signal assigned to be a most accurate of the at least two second signals. The prioritizer is also configured to order the at least two second signals from most accurate to least accurate. The LO is disciplined to correct an offset error of the LO relative to a most accurate second signal that is available to the device, based on the order of the at least two second signals.

System and method for selecting optimum local oscillator discipline source

Interference-reducing circuits include a feed-forward circuit for subtracting all or part of a desired transmitter-signal component from a signal coupled from the power amplifier's output path. The error signal from this feed-forward circuit contains a replica of distortion in the power amplifier output. A cancellation loop adjusts the phase and/or amplitude of this error signal and combines this adjusted error signal with an interference-carrying signal, removing some of the undesired distortion. A spread-spectrum pilot signal is used in one or both loops, to provide a reference signal that can be monitored by an adjustment circuit, which measures the magnitude and/or phase of a spread-spectrum signal that is injected into the interference-carrying signal and, based on that measurement, adjusts the amplitude, phase, and/or delay of the cancellation signal that is added to the interference-carrying signal. This yields a reduced-interference signal in which undesired distortion is reduced.

Spread-spectrum pilot signals in a communications transmitter

Disclosed herein is an electromagnetic wave circuit disruptor apparatus including: a biasable non-reciprocal device having terminals for receiving and transmitting the electromagnetic signals, a controllable biaser, a signal detector, and a controller connected to the signal detector and the controllable biaser to selectively reverse the bias of the controllable biaser. The energy level at the receiver terminal of the non-reciprocal device is monitored to detect a condition such as an inappropriate amount of power at a circuit, such as at a receiver circuit. When a failure mode is detected the bias of the controllable biaser is reversed, thus reversing the direction of the non-reciprocal device. Instead of flowing into the circuit, energy flows into a properly matched load on a provided terminal of the non-reciprocal device and is dissipated.

Electromagnetic wave circuit disruptor and method

Spread spectrum pilot signals in an electronic duplexer

A device is provided having a local oscillator (LO) configured to generate a first signal comprising at least one of: timing information; frequency information; phase information; and combinations thereof. The device also has a LO error corrector comprising an input, the input configured to receive a second signal comprising at least one of: timing information; frequency information; phase information and combinations thereof, wherein the second signal is used for disciplining the LO. The LO error corrector is configured to: if the second signal is unavailable to discipline the LO, discipline the LO using a source that is less accurate than the second signal. Upon the second signal becoming at least temporarily available, the LO corrector determines an offset error of the LO relative to the second signal. If the second signal becomes unavailable before the device uses the second signal to discipline the LO on an ongoing basis, the LO corrector corrects the offset error of the LO relative to the second signal based information obtained during the second signal's temporary availability and disciplines the LO using a source that is less accurate than the second signal until the second signal becomes at least temporarily available at a subsequent time.

Growing community of inventors

Richmond, CA, United States of America

Russell Clifford Smiley