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.

The present invention relates to a radar device and a frequency interference cancellation method thereof, and arranges a configuration comprising: an antenna unit for transmitting a radar transmission signal to a periphery and receiving a signal reflected from a target; an RF unit for generating the transmission signal, converting frequencies of a transmission signal and a reception signal, and amplifying a reception signal; a signal processing unit for generating a control signal to generate the transmission signal and cancelling frequency interference from a reception signal of the RF unit; and a control unit for generating radar detection information by using an output signal of the signal processing unit, and tracking information by accumulating the radar detection information. The present invention enables real time changing of a hopping pattern according to a radar frequency interference environment, thereby achieving operation of the hopping pattern adaptively optimized to the frequency interference environment.

A communication system provides reliable wideband communications with reduced power consumption in a user equipment (UE) receiver. A UE may include receiver circuitry to receive a radio frequency (RF) signal from a wireless network and output an analog baseband signal. The RF signal includes M copies of a duplicated signal in a frequency domain. The analog baseband signal includes the M copies of the duplicated signal uniformly offset from one another in the frequency domain by a bandwidth F and including a gap between adjacent copies. The UE further includes an anti-aliasing analog filter an analog to digital converter (ADC). The ADC samples an output of the anti-aliasing analog filter at a sampling frequency selected to obtain a digital baseband signal comprising a combined digital copy of the M copies of the duplicated signal folded over each other.

A wireless signal processing circuit includes plural phase switchers, plural variable amplifiers and plural mixers. The plural phase switchers are provided on each of plural paths along which all in-phase signal and a quadrature signal are distributed. The plural phase switchers rotate the phases of the signals by signal phase rotation amounts according to a transmission direction of a transmission signal. The plural variable amplifiers alter amplitudes of input signals or output signals of the corresponding phase switchers in accordance with the transmission direction of the transmission signal. The plural mixers up-convert frequencies of the signals processed by the corresponding phase switchers and variable amplifiers.

One embodiment is directed to a universal digital card (UDC) for use in a node of a distributed antenna system (DAS). The UDC is configured to convert data between an external interface format used to communicate on an external communication link and a fronthaul interface format natively used in the DAS. The UDC is configured to be selectively used either as: a donor card to communicatively couple the node to one or more base station entities via the external digital interface or a distribution card to communicatively couple the node to one or more non-DAS nodes, hubs, switches, or remote radio heads or one or more other DAS nodes access points. Other embodiments are disclosed.

A communication management resource implements an iterative process to derive settings for digital precoder W, analog precoder A, and decode function D with a bandwidth-limited fronthaul link between the application of digital precoder W and the application of analog precoder A. The iterative process includes: for a first instance of digital precoder W and decode function D, optimize an instance of the analog precoder A; and based on the optimized instance of the analog precoder A, optimize a second instance of the digital precoder W and the decode function D. In one implementation, for each iteration of multiple iterations, the communication management resource: i) optimizes an instance of the analog precoder A based on an instance of the digital precoder W and the decode function D, and ii) optimizes an instance of the digital precoder W and the decode function D based on the instance of the analog precoder A.

According to one embodiment, a compact broadband radio frequency (RF) frontend circuit includes a number of single-channel transceivers, a number of analog to digital converters (ADCs), where each of the ADCs is coupled to one of the single-channel transceivers, a number of digital to analog converters (DACs), where each of the DACs is coupled to one of the single-channel transceivers, and a digital signal processing (DSP) unit coupled to the ADCs and the DACs. The DSP unit is configured to generate a first set of digital data streams simultaneously and each of the first set of digital data streams is converted by a respective one of the DACs into an analog data stream to be transmitted to a remote device by a respective one of the single-channel transceiver.

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.

A communication circuit may include a first pair of digital-to-analog converters (DACs) coupled to an input of a first mixer and configured to generate first baseband signals. The communication circuit may further include a second pair of DACs coupled to an input of a second mixer and configured to generate second baseband signals. The second baseband signals may be shifted in phase relative to the first baseband signals.

A communication circuit may include a first pair of digital-to-analog converters (DACs) coupled to an input of a first mixer and configured to generate first baseband signals. The communication circuit may further include a second pair of DACs coupled to an input of a second mixer and configured to generate second baseband signals. The second baseband signals may be shifted in phase relative to the first baseband signals.