An apparatus includes a plurality of signal processing stages configured to convert a digital baseband signal into an analog radio frequency signal for transmission. The signal processing stages are configured to be operatively coupled to a positive supply voltage and a negative supply voltage. At least one signal processing stage of the plurality of signal processing stages is configured to generate an analog voltage signal which comprises a voltage level that is outside of a voltage range defined by the positive supply voltage and the negative supply voltage.

A signal processing device includes: a processor; and a memory having instructions. When executed by the processor, the instructions cause the signal processing device to perform operations including: converting a first signal that is a time domain signal into a second signal that is a frequency domain signal in response to reception of the first signal, the first signal containing noise superimposed on a broadcast electric signal derived from a broadcast electromagnetic wave, the noise having peaks of amplitude at regular frequency intervals in the frequency domain; calculating a frequency interval between the peaks of the noise in the frequency domain based on a correlation of the second signal; determining a frequency shift amount in the frequency domain based on the frequency interval; and shifting a frequency of the second signal by the frequency shift amount to create a frequency-shifted signal.

It is an objective of the current disclosure to design a novel communications system capable of offering improvement in channel capacity compared to current communications systems. To this end, the disclosure teaches how to add new information to a select number of Degrees of Freedom (DOF), through three design steps. All three steps aim to design the system such that the minimum required average received Signal-to-Noise Ratio (SNR) is reduced for a given desired capacity and for a given specified mask. The first design step identifies the select number of DOF required for achieving the desired capacity. The second design step enhances the contribution of the selected DOF by matching them to the specified mask. This step aims to have the transmitted signal comply with the specified mask. The third design step randomizes the DOF using a pseudo-random phase. This step aims to reduce the required average received SNR.

In a receiver that demodulates a received signal, deterioration of signal quality is suppressed. A current output unit generates and outputs, from a voltage signal, a current signal including a predetermined offset current in a low-frequency component between a high-frequency component having a frequency higher than a predetermined frequency and the low-frequency component having a frequency lower than the predetermined frequency. A demodulation unit demodulates the high-frequency component. A filter circuit passes, in the current signal, the high-frequency component from a current output unit to the demodulation unit, and causes the low-frequency component to flow from the current output unit to a predetermined reference potential point.

An in-band full-duplex transceiver includes a self-interference mixer for up-converting an adjusted digital baseband signal into an up-converted self-interference cancellation signal. The adjusted digital baseband signal has a phase opposite to a phase for a leakage signal from a leakage path for the transceiver. Similarly, the adjusted digital baseband signal has a magnitude matching a magnitude for the leakage signal. Given this phasing and magnitude for the up-converted self-interference signal, it substantially cancels the leakage signal when added with a received signal contaminated by the leakage signal.

An aspect includes a filtering method including operating a first filter to filter a first input signal to generate a first output signal; operating a second filter to filter a second input signal to generate a second output signal; and selectively coupling at least a portion of the second filter with the first filter to filter a third input signal to generate a third output signal. Another aspect includes a filtering method including operating switching devices to configure a filter with a first set of pole(s); filtering a first input signal to generate a first output signal with the filter configured with the first set of pole(s); operating the switching devices to configure the filter with a second set of poles; and filtering a second input signal to generate a second output signal with the filter configured with the second set of poles.

In a receiver that demodulates a received signal, deterioration of signal quality is suppressed. A current output unit generates and outputs, from a voltage signal, a current signal including a predetermined offset current in a low-frequency component between a high-frequency component having a frequency higher than a predetermined frequency and the low-frequency component having a frequency lower than the predetermined frequency. A demodulation unit demodulates the high-frequency component. A filter circuit passes, in the current signal, the high-frequency component from a current output unit to the demodulation unit, and causes the low-frequency component to flow from the current output unit to a predetermined reference potential point.

The disclosure relates to technology for an apparatus having a current conveyer comprising a first stage having a first differential input, and a second stage having a second differential input. The first and second stages are configured to operate in a push-pull mode to provide an output signal at a current conveyer output between the first stage and the second stage. The apparatus has a first frequency mixer configured to generate a first mixer signal based on an input signal and an oscillator signal having a first frequency. The first frequency mixer is configured to provide the first mixer signal to the first differential input. The apparatus has a second frequency mixer configured to generate a second mixer signal based on the input signal and a second oscillator signal having the first frequency. The second frequency mixer is configured to provide the second mixer signal to the second differential input.

An IQ estimation module comprising a powerup state IQ estimator configured to generate powerup state IQ estimates based on a powerup calibration of the IQ estimation module, a steady state IQ estimator configured to generate steady state IQ estimates during a steady state operation of the IQ estimation module, and an IQ estimate extender configured to determine differences between the powerup state IQ estimates and steady state IQ estimates at their respective frequency bins and adjust the powerup state IQ estimates to improve the accuracy of IQ estimates.

A signal processing device includes: a processor; and a memory having instructions. When executed by the processor, the instructions cause the signal processing device to perform operations including: converting a first signal that is a time domain signal into a second signal that is a frequency domain signal in response to reception of the first signal, the first signal containing noise superimposed on a broadcast electric signal derived from a broadcast electromagnetic wave, the noise having peaks of amplitude at regular frequency intervals in the frequency domain; calculating a frequency interval between the peaks of the noise in the frequency domain based on a correlation of the second signal; determining a frequency shift amount in the frequency domain based on the frequency interval; and shifting a frequency of the second signal by the frequency shift amount to create a frequency-shifted signal.