According to one embodiment, a wireless communication apparatus includes receiver circuitry and transmitter circuitry. The receiver circuitry is configured to receive a first frame addressed to another apparatus, the first frame being transmitted by a first wireless communication apparatus, and estimate a difference between an oscillation frequency of an oscillator of the first wireless communication apparatus and an oscillation frequency of an oscillator of the wireless communication apparatus based on the first frame. The transmitter circuitry is configured to transmit a third frame at a frequency determined based on the difference during a period at least partially overlapping a period during which the first wireless communication apparatus transmits a second frame addressed to a second wireless communication apparatus.

According to one embodiment, a wireless communication apparatus includes receiver circuitry and transmitter circuitry. The receiver circuitry is configured to receive a first frame addressed to another apparatus, the first frame being transmitted by a first wireless communication apparatus, and estimate a difference between an oscillation frequency of an oscillator of the first wireless communication apparatus and an oscillation frequency of an oscillator of the wireless communication apparatus based on the first frame. The transmitter circuitry is configured to transmit a third frame at a frequency determined based on the difference during a period at least partially overlapping a period during which the first wireless communication apparatus transmits a second frame addressed to a second wireless communication apparatus.

Apparatus for use in a communications satellite can include a first mixer arranged to mix and down-convert a received signal in an input frequency range with a first local oscillator LO signal so that a signal within the received signal at a center frequency of a first frequency range is converted to an intermediate frequency IF, a bandpass filter having a passband with a center frequency at the IF arranged to filter the mixed signal such that the filter bandwidth defines the width of the first frequency range, and a second mixer arranged to mix the filtered IF signal with a second LO signal to up-convert the IF signal to an output frequency range. One of the first and second LO signals is a mixed LO signal obtained by mixing the other one with a third LO signal, and the output frequency range is different from the input frequency range.

Apparatus for use in a communications satellite can include a first mixer arranged to mix and down-convert a received signal in an input frequency range with a first local oscillator LO signal so that a signal within the received signal at a center frequency of a first frequency range is converted to an intermediate frequency IF, a bandpass filter having a passband with a center frequency at the IF arranged to filter the mixed signal such that the filter bandwidth defines the width of the first frequency range, and a second mixer arranged to mix the filtered IF signal with a second LO signal to up-convert the IF signal to an output frequency range. One of the first and second LO signals is a mixed LO signal obtained by mixing the other one with a third LO signal, and the output frequency range is different from the input frequency range.

The present disclosure relates to a system for exchanging signals between a device of a vehicle and an external apparatus outside the vehicle via at least one antenna of the vehicle, wherein high-frequency signals are exchanged between the at least one external apparatus and the at least one antenna of the vehicle via electromagnetic waves, wherein the at least one antenna is connected via at least one first path to a first end of a line of the vehicle, and the device is connected via at least one second path to a second end of the line of the vehicle, wherein the system has at least one frequency reduction module which is arranged along at least one of the paths, and wherein the at least one frequency reduction module is designed to adjust a value of a frequency of the high-frequency signals to a low value prior to transport along the line.

A method of mitigating interference in a wireless signal of interest (SOI) received on an active frequency channel due to a common template multi-channel jamming attack includes selecting at least one reference channel from among a plurality of monitored frequency channels in which correlated jamming patterns are present without the SOI. The method further includes generating a plurality of weights according to data obtained from the active and reference channels, and applying an adaptive digital filter to the active channel according to the generated weights. The monitored frequency channels can be centered about the active frequency channel. The selection of reference channels can be varied and optimized. The data from each reference channel can be used to create a single virtual antenna tap or a plurality thereof. Assignment of the active channel can be time-varied to match a hopping pattern of a frequency hopping SOI.

A method of mitigating interference in a wireless signal of interest (SOI) received on an active frequency channel due to a common template multi-channel jamming attack includes selecting at least one reference channel from among a plurality of monitored frequency channels in which correlated jamming patterns are present without the SOI. The method further includes generating a plurality of weights according to data obtained from the active and reference channels, and applying an adaptive digital filter to the active channel according to the generated weights. The monitored frequency channels can be centered about the active frequency channel. The selection of reference channels can be varied and optimized. The data from each reference channel can be used to create a single virtual antenna tap or a plurality thereof. Assignment of the active channel can be time-varied to match a hopping pattern of a frequency hopping SOI.

A low noise block down converter for receiving satellite broadcasting comprises an input terminal; a low noise amplifying unit including one or more low noise amplifiers configured to amplify a signal received from the input terminal, and a built-in cavity waveguide band pass filter configured to pass a frequency band being higher or lower than a frequency band of a predetermined terrestrial transmission signal among satellite broadcasting frequency bands of signals amplified by the one or more low noise amplifiers; and a mixer configured to convert the signal output from the low noise amplifying unit into an intermediate frequency signal by mixing the signal output from the low noise amplifying unit with a local oscillation signal.

A reconfigurable image suppressing receiver includes a front-end amplifier, a first multi-mode circuit, a second multi-mode circuit, a wideband combining transformer, and a controller. The front-end amplifier is configured to receive a radio frequency (RF) signal from an antenna and adjust a gain of the RF signal. The first multi-mode circuit is configured to mix a first instance of the RF signal with an in-phase local oscillator signal to generate an in-phase intermediate frequency (IF) signal. The second multi-mode circuit is configured to mix a second instance of the RF signal with a quadrature local oscillator signal to generate a quadrature IF signal. The wideband combining transformer is configured to combine the in-phase IF signal and the quadrature IF signal to generate a combined IF signal. The controller is configured to adjust one or more tunable parameters associated with the combined IF signal.

According to one embodiment, a wireless communication apparatus includes receiver circuitry and transmitter circuitry. The receiver circuitry is configured to receive a first frame addressed to another apparatus, the first frame being transmitted by a first wireless communication apparatus, and estimate a difference between an oscillation frequency of an oscillator of the first wireless communication apparatus and an oscillation frequency of an oscillator of the wireless communication apparatus based on the first frame. The transmitter circuitry is configured to transmit a third frame at a frequency determined based on the difference during a period at least partially overlapping a period during which the first wireless communication apparatus transmits a second frame addressed to a second wireless communication apparatus.