A system for canceling signal interference (SI) includes a transceiver configured to concurrently transmit signals and receive signals within a single frequency band, which causes signal interference between the transmitted and received signals. The SI canceller is configured to use a set of cancellation coefficients to generate a cancellation signal to mitigate the SI. The system is configured to iteratively change the cancellation coefficients by a step factor to produce tuned cancellation coefficients. The step factor is determined by a cancellation error gradient and one or more of: a tunable coefficient step aggressiveness factor; and a time-based forgetting factor; and cause the SI canceller to cancel the SI using the tuned cancellation coefficients.

A circuit includes a radio frequency (RF) channel including an input node and an output node and being configured to receive an RF oscillator signal at the input node and to provide an RF output signal at the output node; a mixer configured to mix an RF reference signal and an RF test signal representative of the RF output signal to generate a mixer output signal; an analog-to-digital converter configured to sample the mixer output signal in order to provide a sequence of sampled values; and a control circuit configured to provide a sequence of phase offsets by phase-shifting at least one of the RF test signal and the RF reference signal using one or more phase shifters, calculate a spectral value from the sequence of sampled values; and calculate estimated phase information indicating a phase of the RF output signal based on the spectral value.

Disclosed is a method for updating a list of radio stations that can be received by a receiver system including at least two radio receivers, the method including: ⋅determining a list of radio stations that can be received at a given instant, ⋅measuring the quality of a current radio signal, corresponding to a frequency selected and listened to, ⋅determining the ageing of the list of receivable radio stations, ⋅comparing the quality with a configurable threshold that can be upgraded at least as a function of the ageing of the list, ⋅if the quality exceeds the configurable threshold, deactivating the phase diversity filtering function and evaluating the change in the quality of the received signals and, ⋅as a function of the evaluation:—automatically updating, or—keeping unchanged the list of receivable radio stations.

A circuit is described herein. In accordance with one embodiment the circuit includes two or more RF channels, wherein each channel includes an input node, a phase shifter and an output node. Each channel is configured to receive an RF oscillator signal at the input node and to provide an RF output signal at the output node. The circuit further includes an RF combiner circuit that is coupled with the outputs of the RF channels and configured to generate a combined signal representing a combination of the RF output signals, and a monitor circuit that includes a mixer and is configured to receive and down-convert the combined signal using an RF reference signal. Thus a mixer output signal is generated that depends on the phases of the RF output signals.

An apparatus for calibrating a multi-antenna system includes an unmanned aerial vehicle (UAV). The UAV includes one or more millimeter-wave (mm-wave) single channel radios that can transmit and receive a mm-wave signal to or from a multi-antenna system under test; at least one directional antenna connected to the one or more radios; sensors that determine a position of the UAV; an omni-directional mobile or Wi-Fi transceiver that communicates with an operator; and a digital microprocessor unit connected to the one or more mm-wave single channel radios, the sensors, and the omni-directional mobile or Wi-Fi transceiver. The digital microprocessor unit can control motion of the UAV and analyze signals received from the one or more min-wave single channel radios and the at least one directional antenna using position information received from the sensors.

Example signal processing methods and apparatus are described. The signal processing apparatus includes a first power amplifier, a second power amplifier, a first filter, a second filter, and a combiner. The first filter filters a second signal obtained by the first power amplifier to obtain a first sub-signal belonging to a first frequency band and a second sub-signal belonging to a second frequency band. The second filter filters a fourth signal obtained by the second power amplifier to obtain n sub-signals including at least a third sub-signal belonging to a third frequency band. The combiner combines the first sub-signal and i sub-signals in the n sub-signals based on a preset condition to obtain a first combined signal. The communication module sends the first combined signal by using a first port, and sends the second sub-signal by using a second port.

A method of mitigating interference in a received wireless signal by adaptive digital filtering efficiently deploys computational resources by using at least one of a DDC, weight generator, and scrubber to perform calculations necessary to generate a plurality of output streams. Embodiments transition a weight generator and scrubber between receiver frequencies according to a known frequency hopping pattern of an FHSS transmission. Other embodiments dedicate scrubbers to receiver frequencies while transitioning a weigh generator between the frequencies to generate sets of weights that can be persistently used by the scrubbers. Embodiments generate sets of weights according to one received multipath signal copy, and then apply the generated weights to filter additional multipath copes received at the same frequency. Various embodiments dedicate a DDC to each receive frequency to form a bank of down-converted outputs, from among which each weigh generator can select primary and reference inputs.

A radio frequency (RF) filter includes a signal conditioning circuit and a bandstop filter. The signal conditioning circuit receives a broadband RF signal that includes both a jamming signal at a jamming frequency and a signal of interest and generates a plurality of clock signals. Each of the plurality of clock signals has a substantially same frequency as the jamming frequency, but a different phase shift. The bandstop filter receives the RF signal and the plurality of clock signals. The bandstop filter attenuates signals within a bandstop centered at the frequency of the plurality of clock signals. A self-tuning N-path filter is provided.

An electronic device may be provided with wireless circuitry. The wireless circuitry may include one or more antennas. The antennas may include phased antenna arrays each of which includes multiple antenna elements. Phased antenna arrays may be mounted along edges of a housing for the electronic device, behind a dielectric window such as a dielectric logo window in the housing, in alignment with dielectric housing portions at corners of the housing, or elsewhere in the electronic device. A phased antenna array may include arrays of patch antenna elements on dielectric layers separated by a ground layer. A baseband processor may distribute wireless signals to the phased antenna arrays at intermediate frequencies over intermediate frequency signal paths. Transceiver circuits at the phased antenna arrays may include upconverters and downconverters coupled to the intermediate frequency signal paths.

A wireless access point serves dynamic direction-of-arrival reception. An access point radio wirelessly receives a wireless signal that transports time-domain data. Access point circuitry determines uplink utilization for the access point radio. The circuitry transforms the time-domain data into frequency-domain data. The circuitry filters the frequency-domain data for one direction-of-arrival responsive to the uplink utilization. The circuitry synthesizes the time-domain data from the filtered frequency-domain data. The radio wirelessly receives another wireless signal that transports additional time-domain data. The circuitry determines a higher uplink utilization for the access point radio. The circuitry transforms the additional time-domain data into additional frequency-domain data. The circuitry filters the additional frequency-domain data for multiple directions-of-arrival responsive to the higher uplink utilization. The circuitry synthesizes the additional time-domain data from the filtered additional frequency-domain data.