A high-frequency front end module includes a primary antenna terminal and a secondary antenna terminal, a first multiplexer and a second multiplexer, a switch circuit, and a first amplifier and a second amplifier. The first multiplexer has a first transmission filter and a first reception filter. The second multiplexer has a second transmission filter and a second reception filter. The switch circuit exclusively switches connection between the primary antenna terminal and the first multiplexer and connection between the primary antenna terminal and the second multiplexer, and exclusively switches connection between the secondary antenna terminal and the first multiplexer and connection between the secondary antenna terminal and the second multiplexer.

A receiving circuit includes: a first receiving terminal for receiving a RF signal; a second receiving terminal for receiving an external oscillating signal generated by an external oscillator; a low-noise amplifier coupled with the first receiving terminal and the second receiving terminal and utilized for generating an output signal; a first switch element positioned between the second receiving terminal and the low-noise amplifier; an in-phase signal processing circuit for generating an in-phase detection signal based on the output signal; an quadrature signal processing circuit for generating an quadrature detection signal based on the output signal; and a calibration circuit for controlling the first switch element and capable of performing an I/Q mismatch calibration operation according to the in-phase detection signal and the quadrature detection signal when the first switch element is turned on.

In some embodiments, a method for mitigating interference in a channel having multiple users includes: transmitting, by a transmitter, a signal of interest (SOI) to a sequential interference cancellation (SIC) receiver at a transmit power; determining a packet drop rate as seen by the receiver; and decreasing the transmit power in response to determining the packet drop rate exceeds a predetermined maximum packet drop rate. The transmitter's coding rate and/or modulation level may also be lowered based on the decrease in transmit power.

A noise reduction device includes: a combiner to shift a phase of one of a first signal propagating through a first propagation path and a second signal propagating through a second propagation path by a predetermined angle and combine the phase-shifted one signal of the first signal and the second signal with the other signal of the first signal and the second signal; and a phase difference absorption circuit having a phase shift characteristic that reduces a difference between a phase difference between two signals each having a lower limit frequency of a band of the broadcast wave and passing through the first propagation path and the second propagation path and a phase difference between two signals each having an upper limit frequency of the band of the broadcast wave and passing through the first propagation path and the second propagation path.

A cascadable AGC amplifier in a signal distribution system includes a low noise cascadable amplifier having a through path and a cascadable output. The cascadable amplifier is also configured to provide AGC over a predetermined input power range. The cascadable AGC amplifier can be configured to provide gain or attenuation. When the cascadable AGC amplifier is implemented in a signal distribution system, typically as part of a signal distribution device, an input signal can be gain controlled and supplied to multiple signal paths without distortion due to degradation of signal to noise ratio or distortion due to higher order amplifier products. The distributed signal is not significantly degraded by distortion regardless of the number of cascadable AGC amplifiers connected in series or the position of the cascadable AGC amplifier in the signal distribution system.

In an embodiment, a cross-polarization interference compensation module is included in a receiver of a wireless communication system. The module includes first and second input lines configured to receive respective first and second down-converted digital polarized signals based on receipt of a wireless transmission. The module further includes first and second output lines electrically coupled to at least one modem. The module further includes a first complex finite impulse response (FIR) filter configured to receive the second down-converted digital polarized signal and generate a correction factor that cancels cross-polarization components in the first down-converted digital polarized signal. The module further includes a first filter coefficient engine in communication with the first complex FIR filter and configured to adapt the first complex FIR filter over time based on the first and second down-converted digital polarized signals.

A variable filter circuit includes a serial arm connected between ports (P1-P2), a parallel arm having a resonator connected in series between ports (P1-P3), and another parallel arm having another resonator connected in series between ports (P2-P3). The serial arm includes a capacitor connected between the ports (P1-P2), and the parallel arms include variable capacitances connected in series to the resonators.

A multichannel transmission system which includes a calibration functionality that allows precise calibration of the frequency conversion chains and of the multiport amplifier of the system to be performed without interruption of service. The proposed calibration makes it possible to correct the defects over the entire frequency band of the system.

The present invention relates to a wireless communication system. A method for cancelling interference and receiving a signal by a user equipment in a wireless communication system, the method performed by the user equipment comprising: receiving assistance information for cancelling an interference signal transmitted from an interfering base station; cancelling the interference signal based on the assistance information; and receiving a desired signal from a serving base station, wherein the user equipment assumes a part of the assistance information for cancelling the interference signal as a limited value and then receives the interference signal.

A frequency-agnostic wireless radio-frequency front end includes a primary antenna that receives a desired receive signal and interference signals and transmits a desired transmit signal. A diversity antenna receives an internal interference signal and an external interference signal, and a desired receive signal. A receive front end has a first port electrically connected to the diversity antenna and a second port electrically connected to a transmit signal reference source and includes a cancelling circuit that removes the internal interference signal and the external interference signal and provides the desired receive signal to a third port. A transmit-and-receive front end generates the desired transmit signal and includes a connector that passes the desired transmit signal while simultaneously passing the desired receive signal and interference signals to a third port while at least partially blocking the desired transmit signal from propagating to the third port.